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Sample records for reorientation task paradigms

  1. Using Perceptrons to Explore the Reorientation Task

    Science.gov (United States)

    Dawson, Michael R. W.; Kelly, Debbie M.; Spetch, Marcia L.; Dupuis, Brian

    2010-01-01

    The reorientation task is a paradigm that has been used extensively to study the types of information used by humans and animals to navigate in their environment. In this task, subjects are reinforced for going to a particular location in an arena that is typically rectangular in shape. The subject then has to find that location again after being…

  2. Age-related differences during a gaze reorientation task while standing or walking on a treadmill.

    Science.gov (United States)

    Cinelli, Michael; Patla, Aftab; Stuart, Bethany

    2008-02-01

    Falls among adults over the age of 65 years have become a growing concern. Two factors related to high incidence of falls in this group of adults are decreased head stability and impaired balance. Older adults' level of control of head stability or balance is unknown when they must reorient their gaze. In the current study, ten older adults (69 +/- 3.27 years) performed a gaze reorienting task while standing or walking on a treadmill. The task was the same as that used on young adults by Cinelli et al. (2007). The results show that older adults use a different strategy than young adults when reorienting gaze. Shoulder and hip rotations occurred synchronously when standing and were more variable when walking on a treadmill. As well, there was a larger difference between the onset of eye movements and body segment movement in the older adults. These differences can be accounted for by decreases in physiological subsystems. The visual presence of a visual target helped the older adults stabilize their heads-in-space by incorporating information from more than one sensory system.

  3. Spinning in the Scanner: Neural Correlates of Virtual Reorientation

    Science.gov (United States)

    Sutton, Jennifer E.; Joanisse, Marc F.; Newcombe, Nora S.

    2010-01-01

    Recent studies have used spatial reorientation task paradigms to identify underlying cognitive mechanisms of navigation in children, adults, and a range of animal species. Despite broad interest in this task across disciplines, little is known about the brain bases of reorientation. We used functional magnetic resonance imaging to examine neural…

  4. Spinning in the Scanner: Neural Correlates of Virtual Reorientation

    Science.gov (United States)

    Sutton, Jennifer E.; Joanisse, Marc F.; Newcombe, Nora S.

    2010-01-01

    Recent studies have used spatial reorientation task paradigms to identify underlying cognitive mechanisms of navigation in children, adults, and a range of animal species. Despite broad interest in this task across disciplines, little is known about the brain bases of reorientation. We used functional magnetic resonance imaging to examine neural…

  5. rTMS of medial parieto-occipital cortex interferes with attentional reorienting during attention and reaching tasks.

    Science.gov (United States)

    Ciavarro, Marco; Ambrosini, Ettore; Tosoni, Annalisa; Committeri, Giorgia; Fattori, Patrizia; Galletti, Claudio

    2013-09-01

    Unexpected changes in the location of a target for an upcoming action require both attentional reorienting and motor planning update. In both macaque and human brain, the medial posterior parietal cortex is involved in both phenomena but its causal role is still unclear. Here we used on-line rTMS over the putative human V6A (pV6A), a reach-related region in the dorsal part of the anterior bank of the parieto-occipital sulcus, during an attention and a reaching task requiring covert shifts of attention and planning of reaching movements toward cued targets in space. We found that rTMS increased RTs to invalidly cued but not to validly cued targets during both the attention and reaching task. Furthermore, we found that rTMS induced a deviation of reaching endpoints toward visual fixation and that this deviation was larger for invalidly cued targets. The results suggest that reorienting signals are used by human pV6A area to rapidly update the current motor plan or the ongoing action when a behaviorally relevant object unexpectedly occurs in an unattended location. The current findings suggest a direct involvement of the action-related dorso-medial visual stream in attentional reorienting and a more specific role of pV6A area in the dynamic, on-line control of reaching actions.

  6. Assessing the Cost of Task Switching with a Three-Task Paradigm

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    Remington, Roger W.; Ruthruff, Eric; Johnston, James C.; Connors, Mary M. (Technical Monitor)

    1998-01-01

    To study task switching when subjects need not inhibit inappropriate responses, we examine tasks with non-overlapping stimulus sets (e.g. color patches and uncolored letters). A new three-task paradigm permits the dissociation of several otherwise confounded variables. We find that performance declines monotonically with increasing time since last performance of a task. Adjusting for the effects of this factor permits a fresh assessment of the relationship between task expectancy and recency (Ruthruff, Remington & Johnston, 1996).

  7. A dual-task paradigm for behavioral and neurobiological studies in nonhuman primates.

    Science.gov (United States)

    Watanabe, Kei; Funahashi, Shintaro

    2015-05-15

    The dual-task paradigm is a procedure in which subjects are asked to perform two behavioral tasks concurrently, each of which involves a distinct goal with a unique stimulus-response association. Due to the heavy demand on subject's cognitive abilities, human studies using this paradigm have provided detailed insights regarding how the components of cognitive systems are functionally organized and implemented. Although dual-task paradigms are widely used in human studies, they are seldom used in nonhuman animal studies. We propose a novel dual-task paradigm for monkeys that requires the simultaneous performance of two cognitively demanding component tasks, each of which uses an independent effector for behavioral responses (hand and eyes). We provide a detailed description of an optimal training protocol for this paradigm, which has been lacking in the existing literature. An analysis of behavioral performance showed that the proposed dual-task paradigm (1) was quickly learned by monkeys (less than 40 sessions) with step-by-step training protocols, (2) produced specific behavioral effects, known as dual-task interference in human studies, and (3) achieved rigid and independent control of the effectors for behavioral responses throughout the trial. The proposed dual-task paradigm has a scalable task structure, in that each of the two component tasks can be easily replaced by other tasks, while preserving the overall structure of the paradigm. This paradigm should be useful for investigating executive control that underlies dual-task performance at both the behavioral and neuronal levels. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Sequential modulation of cue use in the task switching paradigm

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    Mike eWendt

    2012-08-01

    Full Text Available In task switching studies, pre-cuing of the upcoming task improves performance, indicating preparatory activation of the upcoming task set and/or inhibition of the previous task set. To further investigate cue-based task preparation, the authors presented both valid and invalid task cues in a task switching experiment involving three tasks. Consistent with previous findings, a validity effect in terms of higher reaction times on invalidly compared to validly cued tasks was obtained. However, this validity effect was reduced following invalidly cued trials, suggesting dynamic adjustment in terms of decreased cue-based preparation after being misled. Performance was particularly impaired when the current task was the one that was invalidly cued on the preceding trial. This finding may reflect either particular reluctance to prepare or persisting inhibition of the erroneously prepared task set from the pre-trial.

  9. Sequential Modulation of Cue Use in the Task Switching Paradigm

    Science.gov (United States)

    Wendt, Mike; Luna-Rodriguez, Aquiles; Reisenauer, Renate; Jacobsen, Thomas; Dreisbach, Gesine

    2012-01-01

    In task switching studies, pre-cuing of the upcoming task improves performance, indicating preparatory activation of the upcoming task-set, and/or inhibition of the previous task-set. To further investigate cue-based task preparation, the authors presented both valid and invalid task cues in a task switching experiment involving three tasks. Consistent with previous findings, a validity effect in terms of higher reaction times on invalidly compared to validly cued tasks was obtained. However, this validity effect was reduced following invalidly cued trials, suggesting dynamic adjustment in terms of decreased cue-based preparation after being misled. Performance was particularly impaired when the current task was the one that was invalidly cued on the preceding trial. This finding may reflect either particular reluctance to prepare or persisting inhibition of the erroneously prepared task-set from the pre-trial. PMID:22908004

  10. Behavioral Assessment of Listening Effort Using a Dual-Task Paradigm

    Science.gov (United States)

    Besser, Jana; Lemke, Ulrike

    2017-01-01

    Published investigations (n = 29) in which a dual-task experimental paradigm was employed to measure listening effort during speech understanding in younger and older adults were reviewed. A summary of the main findings reported in the articles is provided with respect to the participants’ age-group and hearing status. Effects of different signal characteristics, such as the test modality, on dual-task outcomes are evaluated, and associations with cognitive abilities and self-report measures of listening effort are described. Then, several procedural issues associated with the use of dual-task experiment paradigms are discussed. Finally, some issues that warrant future research are addressed. The review revealed large variability in the dual-task experimental paradigms that have been used to measure the listening effort expended during speech understanding. The differences in experimental procedures used across studies make it difficult to draw firm conclusions concerning the optimal choice of dual-task paradigm or the sensitivity of specific paradigms to different types of experimental manipulations. In general, the analysis confirmed that dual-task paradigms have been used successfully to measure differences in effort under different experimental conditions, in both younger and older adults. Several research questions that warrant further investigation in order to better understand and characterize the intricacies of dual-task paradigms were identified. PMID:28091178

  11. Effects of caffeine on anticipatory control processes : Evidence from a cued task-switch paradigm

    NARCIS (Netherlands)

    Tieges, Zoe; Snel, Jan; Kok, Albert; Plat, Niels; Ridderinkhof, Richard

    2007-01-01

    Effects of caffeine on task switching were studied using ERPs in a cued task-switch paradigm. The need for advance preparation was manipulated by varying the number of task-set aspects that required switching. In a double-blind, within-subjects experiment, caffeine reduced shift costs compared to pl

  12. Task switching and response correspondence in the psychological refractory period paradigm

    Science.gov (United States)

    Lien, Mei-Ching; Schweickert, Richard; Proctor, Robert W.

    2003-01-01

    Three experiments examined the effects of task switching and response correspondence in a psychological refractory period paradigm. A letter task (vowel-consonant) and a digit task (odd-even) were combined to form 4 possible dual-task pairs in each trial: letter-letter, letter-digit, digit-digit, and digit-letter. Foreknowledge of task transition (repeat or switch) and task identity (letter or digit) was varied across experiments: no foreknowledge in Experiment 1, partial foreknowledge (task transition only) in Experiment 2, and full foreknowledge in Experiment 3. For all experiments, the switch cost for Task 2 was additive with stimulus onset asynchrony, and the response-correspondence effect for Task 2 was numerically smaller in the switch condition than in the repeat condition. These outcomes suggest that reconfiguration for Task 2 takes place after the central processing of Task 1 and that the crosstalk correspondence effect is due to response activation by way of stimulus-response associations.

  13. Building Task-Oriented Applications: An Introduction to the Legion Programming Paradigm

    Science.gov (United States)

    2015-02-01

    parallel programming design and development in a task-oriented fashion and, as of this writing, is the only one to address this paradigm dynamically... fashion , providing a set of tasks to execute on defined logical regions in the code.5,6,10 These tasks are structured in a hierarchy and will bind...particular the extension of this work to include the Fast Multipole Method (FMM) of the n-body problem is an interesting direction. FMM is currently

  14. Measuring listening effort: driving simulator versus simple dual-task paradigm.

    Science.gov (United States)

    Wu, Yu-Hsiang; Aksan, Nazan; Rizzo, Matthew; Stangl, Elizabeth; Zhang, Xuyang; Bentler, Ruth

    2014-01-01

    The dual-task paradigm has been widely used to measure listening effort. The primary objectives of the study were to (1) investigate the effect of hearing aid amplification and a hearing aid directional technology on listening effort measured by a complicated, more real world dual-task paradigm and (2) compare the results obtained with this paradigm to a simpler laboratory-style dual-task paradigm. The listening effort of adults with hearing impairment was measured using two dual-task paradigms, wherein participants performed a speech recognition task simultaneously with either a driving task in a simulator or a visual reaction-time task in a sound-treated booth. The speech materials and road noises for the speech recognition task were recorded in a van traveling on the highway in three hearing aid conditions: unaided, aided with omnidirectional processing (OMNI), and aided with directional processing (DIR). The change in the driving task or the visual reaction-time task performance across the conditions quantified the change in listening effort. Compared to the driving-only condition, driving performance declined significantly with the addition of the speech recognition task. Although the speech recognition score was higher in the OMNI and DIR conditions than in the unaided condition, driving performance was similar across these three conditions, suggesting that listening effort was not affected by amplification and directional processing. Results from the simple dual-task paradigm showed a similar trend: hearing aid technologies improved speech recognition performance, but did not affect performance in the visual reaction-time task (i.e., reduce listening effort). The correlation between listening effort measured using the driving paradigm and the visual reaction-time task paradigm was significant. The finding showing that our older (56 to 85 years old) participants' better speech recognition performance did not result in reduced listening effort was not

  15. Specifying social cognitive processes with a social dual-task paradigm

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    Roman eLiepelt

    2012-04-01

    Full Text Available Automatic imitation tasks measuring motor priming effects showed that we directly map observed actions of other agents onto our own motor repertoire (direct matching. A recent joint-action study using a social dual-task paradigm provided evidence for task monitoring. In the present study, we aimed to test a if automatic imitation is disturbed during joint action and b if task monitoring is content or time dependent. We used a social dual task that was made of an automatic imitation task (Person 1: Task 1 and a two-choice number task (Person 2: Task 2. Each participant performed one of the two tasks, which were given with a variable stimulus onset asynchrony (SOA, in an individual and a joint condition. We found a regular motor priming effect in individual and joint conditions. Under joint conditions, we replicated the previous finding of an increase of reaction times for Person 2 with decreasing SOA. The latter effect was not related to the specific responses performed by both persons. Further, we did not find evidence for a representation of the other’s specific S-R mappings. Our findings suggest that a automatic imitation is not disturbed during joint action and b task monitoring is time dependent.

  16. Building a clinically relevant cognitive task: case study of the AX paradigm.

    Science.gov (United States)

    MacDonald, Angus W

    2008-07-01

    Tasks developed for basic cognitive neuroscience are often ill suited for experimental psychopathology. The development of the expectancy variant of AX continuous performance task to test theories about context processing in schizophrenia is used as an illustration of how this has been done in one research program. Four design principles are recommended: tasks should (1) have a foundation in existing literature and therefore stay as close as possible to an existing task; (2) be simple, which is frequently accomplished by paring down a task to evaluate the function of interest; (3) probe a mechanism of interest, with conditions that selectively manipulate this mechanism; and (4) have the potential to distinguish a specific deficit on the mechanism of interest from a generalized impairment. Data from a number of studies support several aspects of context-processing theory; however unpredicted results have also been reported. The development of the expectancy AX paradigm continues, and future developments that may enhance its usefulness are also described.

  17. Reorienting Hypnosis Education.

    Science.gov (United States)

    Alter, David S; Sugarman, Laurence Irwin

    2017-01-01

    The legacy model of professional clinical hypnosis training presents a restrictive frame increasingly incompatible with our evolving understanding of psychobiology, health, and care. Emerging science recognizes human experience not as disease and diagnosis, but as manifestations of individual, uniquely-endowed, adaptively self-regulating systems. Hypnosis is a particularly well-suited discipline for effecting beneficial change in this paradigm. Training in clinical hypnosis must progress from the current linearly-structured, diagnosis-based, reductionist model toward a more responsive, naturalistic, and client-centered curriculum in order to remain relevant and accessible to clinicians beginning to integrate it into their practices. To that end, this article extends Hope and Sugarman's (2015) thesis of hypnosis as a skill set for systemic perturbation and reorientation to consider what those skills may be, the principles on which they are based, and how they may be taught. Parsing a clinical vignette reveals how incorporation of novelty and uncertainty results in less restrictive and more naturalistic hypnotic encounters that, in response to client-generated cues, elicit psychophysiological plasticity. This disruptive hypnosis education and training framework extends the utility and benefit of applied clinical hypnosis.

  18. Bypassing the central bottleneck after single-task practice in the psychological refractory period paradigm: evidence for task automatization and greedy resource recruitment.

    Science.gov (United States)

    Maquestiaux, François; Laguë-Beauvais, Maude; Ruthruff, Eric; Bherer, Louis

    2008-10-01

    In this research, the controversial issue of whether the central bottleneck can be bypassed through task automatization was investigated. To examine this issue, participants received six single-task practice sessions with an auditory-vocal task (low vs. high pitch). We then assessed dual-task performance using the analytically tractable psychological refractory period (PRP) paradigm, in which the highly practiced auditory-vocal task was presented as Task 2, along with an unpracticed visual-manual Task 1. The results provide evidence of bottleneck bypass for virtually all the participants (17 out of 20). Several converging tests suggest that the bottleneck reemerged, however, in a follow-up experiment with tasks presented in the opposite order (auditory-vocal Task 1 and visual-manual Task 2). One possible explanation is that tasks greedily recruit central resources when available, even though they can operate without central resources when unavailable.

  19. Comparison of Functional Connectivity Estimated from Concatenated Task-State Data from Block-Design Paradigm with That of Continuous Task

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    Zhu, Yang; Cheng, Lin; He, Naying; Yang, Yang; Ling, Huawei; Tong, Shanbao

    2017-01-01

    Functional connectivity (FC) analysis with data collected as continuous tasks and activation analysis using data from block-design paradigms are two main methods to investigate the task-induced brain activation. If the concatenated data of task blocks extracted from the block-design paradigm could provide equivalent FC information to that derived from continuous task data, it would shorten the data collection time and simplify experimental procedures, and the already collected data of block-design paradigms could be reanalyzed from the perspective of FC. Despite being used in many studies, such a hypothesis of equivalence has not yet been tested from multiple perspectives. In this study, we collected fMRI blood-oxygen-level-dependent signals from 24 healthy subjects during a continuous task session as well as in block-design task sessions. We compared concatenated task blocks and continuous task data in terms of region of interest- (ROI-) based FC, seed-based FC, and brain network topology during a short motor task. According to our results, the concatenated data was not significantly different from the continuous data in multiple aspects, indicating the potential of using concatenated data to estimate task-state FC in short motor tasks. However, even under appropriate experimental conditions, the interpretation of FC results based on concatenated data should be cautious and take the influence due to inherent information loss during concatenation into account. PMID:28191030

  20. Effects of Aging and Tai Chi on a Finger-Pointing Task with a Choice Paradigm

    Directory of Open Access Journals (Sweden)

    William W. N. Tsang

    2013-01-01

    Full Text Available Background. This cross-sectional study examined the effect of aging on performing finger-pointing tasks involving choices and whether experienced older Tai Chi practitioners perform better than healthy older controls in such tasks. Methods. Thirty students and 30 healthy older controls were compared with 31 Tai Chi practitioners. All the subjects performed a rapid index finger-pointing task. The visual signal appeared randomly under 3 conditions: (1 to touch a black ball as quickly and as accurately as possible, (2 not to touch a white ball, (3 to touch only the white ball when a black and a white ball appeared simultaneously. Reaction time (RT of anterior deltoid electromyogram, movement time (MT from electromyogram onset to touching of the target, end-point accuracy from the center of the target, and the number of wrong movements were recorded. Results. Young students displayed significantly faster RT and MT, achieving significantly greater end-point accuracy and fewer wrong movements than older controls. Older Tai Chi practitioners had significantly faster MT than older controls. Conclusion. Finger-pointing tasks with a choice paradigm became slower and less accurate with age. Positive findings suggest that Tai Chi may slow down the aging effect on eye-hand coordination tasks involving choices that require more cognitive progressing.

  1. Behavior generation strategy of artificial behavioral system by self-learning paradigm for autonomous robot tasks

    Science.gov (United States)

    Dağlarli, Evren; Temeltaş, Hakan

    2008-04-01

    In this study, behavior generation and self-learning paradigms are investigated for the real-time applications of multi-goal mobile robot tasks. The method is capable to generate new behaviors and it combines them in order to achieve multi goal tasks. The proposed method is composed from three layers: Behavior Generating Module, Coordination Level and Emotion -Motivation Level. Last two levels use Hidden Markov models to manage dynamical structure of behaviors. The kinematics and dynamic model of the mobile robot with non-holonomic constraints are considered in the behavior based control architecture. The proposed method is tested on a four-wheel driven and four-wheel steered mobile robot with constraints in simulation environment and results are obtained successfully.

  2. Navigation as a source of geometric knowledge: Young children’s use of length, angle, distance, and direction in a reorientation task

    Science.gov (United States)

    Lee, Sang Ah; Sovrano, Valeria A.; Spelke, Elizabeth S.

    2012-01-01

    Geometry is one of the highest achievements of our species, but its foundations are obscure. Consistent with longstanding suggestions that geometrical knowledge is rooted in processes guiding navigation, the present study examines potential sources of geometrical knowledge in the navigation processes by which young children establish their sense of orientation. Past research reveals that children reorient both by the shape of the surface layout and the shapes of distinctive landmarks, but it fails to clarify what shape properties children use. The present study explores two-year-old children's sensitivity to angle, length, distance and direction by testing disoriented children’s search in a variety of fragmented rhombic and rectangular environments. Children reoriented themselves in accord with surface distances and directions, but they failed to use surface lengths or corner angles either for directional reorientation or as local landmarks. Thus, navigating children navigate by some but not all of the abstract properties captured by formal Euclidean geometry. While navigation systems may contribute to children's developing geometric understanding, they likely are not the sole source of abstract geometric intuitions. PMID:22257573

  3. Diversity of the P3 in the task-switching paradigm.

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    Gajewski, Patrick D; Falkenstein, Michael

    2011-09-09

    Electrophysiological studies investigating task switching usually reveal results of the parietal P3. In this study we investigated the frontal and parietal P3 after cues, targets and responses in a combined go/no-go task switch paradigm. We confirm behavioral findings showing reduction of switch costs after no-go trials. This was accompanied by a number of P3 findings: first, the cue-locked parietal P3 was increased after a switch relative to a repetition, regardless whether a go or no-go was previously required but the frontal counterpart was less positive after inhibited responses. Secondly, in the target-locked ERPs task-set switching decreased the P3 at parietal sites, while persisting inhibition from no-go in n-1 was associated with an attenuation of the frontal P3 relative to go in n-1. No impact of task set on the frontal P3 and response mode in n-1 on the parietal P3 was found, suggesting functional dissociation between task set switch and response mode in n-1. Thirdly, exactly the same pattern was observed in the response locked frontal and parietal P3. Fourthly, the task switch related parietal P3 attenuation after targets was also observed in current no-go trials, indicating task and response selection without response execution. No task switch effect on the frontal "no-go P3" was found. In sum, these results suggest that the cue-locked long-lasting P3 reflects task-set updating, whereas the post-target frontal P3 is associated with persisting response inhibition and parietal P3 is related to an after-effect of task-set activation in terms of response selection as it appears both in the target- as well as response-locked ERPs. Furthermore, the post-target parietal P3 effects are most likely due to N2 effects as a more pronounced N2 in switch trials the smaller the P3. A fronto-parietal network for an adaptive control of response requirements and task sets is proposed.

  4. Reorienting with terrain slope and landmarks.

    Science.gov (United States)

    Nardi, Daniele; Newcombe, Nora S; Shipley, Thomas F

    2013-02-01

    Orientation (or reorientation) is the first step in navigation, because establishing a spatial frame of reference is essential for a sense of location and heading direction. Recent research on nonhuman animals has revealed that the vertical component of an environment provides an important source of spatial information, in both terrestrial and aquatic settings. Nonetheless, humans show large individual and sex differences in the ability to use terrain slope for reorientation. To understand why some participants--mainly women--exhibit a difficulty with slope, we tested reorientation in a richer environment than had been used previously, including both a tilted floor and a set of distinct objects that could be used as landmarks. This environment allowed for the use of two different strategies for solving the task, one based on directional cues (slope gradient) and one based on positional cues (landmarks). Overall, rather than using both cues, participants tended to focus on just one. Although men and women did not differ significantly in their encoding of or reliance on the two strategies, men showed greater confidence in solving the reorientation task. These facts suggest that one possible cause of the female difficulty with slope might be a generally lower spatial confidence during reorientation.

  5. Gazing toward humans: a study on water rescue dogs using the impossible task paradigm.

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    D'Aniello, Biagio; Scandurra, Anna; Prato-Previde, Emanuela; Valsecchi, Paola

    2015-01-01

    Various studies have assessed the role of life experiences, including learning opportunities, living conditions and the quality of dog-human relationships, in the use of human cues and problem-solving ability. The current study investigates how and to what extent training affects the behaviour of dogs and the communication of dogs with humans by comparing dogs trained for a water rescue service and untrained pet dogs in the impossible task paradigm. Twenty-three certified water rescue dogs (the water rescue group) and 17 dogs with no training experience (the untrained group) were tested using a modified version of the impossible task described by Marshall-Pescini et al. in 2009. The results demonstrated that the water rescue dogs directed their first gaze significantly more often towards the owner and spent more time gazing toward two people compared to the untrained pet dogs. There was no difference between the dogs of the two groups as far as in the amount of time spent gazing at the owner or the stranger; neither in the interaction with the apparatus attempting to obtain food. The specific training regime, aimed at promoting cooperation during the performance of water rescue, could account for the longer gazing behaviour shown toward people by the water rescue dogs and the priority of gazing toward the owner.

  6. Towards Unifying OpenMP Under the Task-Parallel Paradigm Implementation and Performance of the taskloop Construct

    DEFF Research Database (Denmark)

    Podobas, Artur; Karlsson, Sven

    2016-01-01

    OpenMP 4.5 introduced a task-parallel version of the classical thread-parallel for-loop construct: the taskloop construct. With this new construct, programmers are given the opportunity to choose between the two parallel paradigms to parallelize their for loops. However, it is unclear where...

  7. When Stroop helps Piaget: An inter-task positive priming paradigm in 9-year-old children.

    Science.gov (United States)

    Linzarini, A; Houdé, O; Borst, G

    2015-11-01

    To determine whether inhibitory control is domain general or domain specific in school children, we asked 40 9-year-old children to perform an inter-task priming paradigm in which they responded to Stroop items on the primes and to Piaget number conservation items on the probes. The children were more efficient in the inhibition of a misleading "length-equals-number" heuristic in the number conservation task if they had successfully inhibited a previous prepotent reading response in the Stroop task. This study provides evidence that the inhibitory control ability of school children generalizes to distinct cognitive domains, that is, verbal for the Stroop task and logico-mathematical for Piaget's number conservation task.

  8. Testing the Automatization Deficit Hypothesis of Dyslexia via a Dual-Task Paradigm.

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    Yap, Regina L.; van der Leij, Aryan

    1994-01-01

    Fourteen Dutch children with dyslexia were compared with controls on automatic processing under a dual task (motor balance task and auditory choice task) model. Results indicated the dyslexic group was more impaired in the dual task condition than in the single task condition, compared with controls. Findings support the automatization deficit…

  9. Developing paradigms of data fusion for sensor-actuator networks that perform engineering tasks.

    OpenAIRE

    Iyengar, SS; Sastry, S.; Balakrishnan, N.

    2003-01-01

    In this article we provided a new foundation for data fusion based on two concepts: a conceptual framework and the goal-seeking paradigm. The conceptual framework emphasizes the dominant structures in the system. The goal-seeking paradigm is a mechanism for representing system evolution that explicitly manages uncertainty. The goal-seeking formulation for data fusion helps to distinguish between subjective decisions that resolve uncertainty by involving humans and objective decisions that can...

  10. Monitoring supports performance in a dual-task paradigm involving a risky decision-making task and a working memory task

    Directory of Open Access Journals (Sweden)

    Bettina eGathmann

    2015-02-01

    Full Text Available Performing two cognitively demanding tasks at the same time is known to decrease performance. The current study investigates the underlying executive functions of a dual-tasking situation involving the simultaneous performance of decision making under explicit risk and a working memory task. It is suggested that making a decision and performing a working memory task at the same time should particularly require monitoring - an executive control process supervising behavior and the state of processing on two tasks. To test the role of a supervisory/monitoring function in such a dual-tasking situation we investigated 122 participants with the Game of Dice Task plus 2-back task (GDT plus 2-back task. This dual task requires participants to make decisions under risk and to perform a 2-back working memory task at the same time. Furthermore, a task measuring a set of several executive functions gathered in the term concept formation (Modified Card Sorting Test, MCST and the newly developed Balanced Switching Task (BST, measuring monitoring in particular, were used. The results demonstrate that concept formation and monitoring are involved in the simultaneous performance of decision making under risk and a working memory task. In particular, the mediation analysis revealed that BST performance partially mediates the influence of MCST performance on the GDT plus 2-back task. These findings suggest that monitoring is one important subfunction for superior performance in a dual-tasking situation including decision making under risk and a working memory task.

  11. The perturbation paradigm modulates error-based learning in a highly automated task: outcomes in swallowing kinematics.

    Science.gov (United States)

    Anderson, C; Macrae, P; Taylor-Kamara, I; Serel, S; Vose, A; Humbert, I A

    2015-08-15

    Traditional motor learning studies focus on highly goal-oriented, volitional tasks that often do not readily generalize to real-world movements. The goal of this study was to investigate how different perturbation paradigms alter error-based learning outcomes in a highly automated task. Swallowing was perturbed with neck surface electrical stimulation that opposes hyo-laryngeal elevation in 25 healthy adults (30 swallows: 10 preperturbation, 10 perturbation, and 10 postperturbation). The four study conditions were gradual-masked, gradual-unmasked, abrupt-masked, and abrupt-unmasked. Gradual perturbations increasingly intensified overtime, while abrupt perturbations were sustained at the same high intensity. The masked conditions reduced cues about the presence/absence of the perturbation (pre- and postperturbation periods had low stimulation), but unmasked conditions did not (pre- and postperturbation periods had no stimulation). Only hyo-laryngeal range of motion measures had significant outcomes; no timing measure demonstrated learning. Systematic-error reduction occurred only during the abrupt-masked and abrupt-unmasked perturbations. Only the abrupt-masked perturbation caused aftereffects. In this highly automated task, gradual perturbations did not induce learning similarly to findings of some volitional, goal-oriented adaptation task studies. Furthermore, our subtle and brief adjustment of the stimulation paradigm (masked vs. unmasked) determined whether aftereffects were present. This suggests that, in the unmasked group, sensory predictions of a motor plan were quickly and efficiently modified to disengage error-based learning behaviors. Copyright © 2015 the American Physiological Society.

  12. Electrocortical sources related to whole-body surface translations during a single- and dual-task paradigm

    Directory of Open Access Journals (Sweden)

    Mark D Bogost

    2016-10-01

    Full Text Available Appropriate reactive motor responses are essential in maintaining upright balance. However, little is known regarding the potential location of cortical sources that are related to the onset of a perturbation during single- and dual-task paradigms. The purpose of this study was to estimate the location of cortical sources in response to a whole-body surface translation and whether diverted attention decreases the N1 event-related potential (ERP amplitude related to a postural perturbation. This study utilized high-resolution electroencephalography in conjunction with measure projection analysis from ERPs time-locked to backwards surface translation onsets to determine which cortical sources were related to whole-body postural perturbations. Subjects (n = 15 either reacted to whole-body surface translations with (dual task or without (single task performing a visual working memory task. For the single task, four domains were identified that were mainly localized within the frontal and parietal lobes and included sources from the prefrontal, premotor, primary and supplementary motor, somatosensory, and anterior cingulate cortex. Five domains were estimated for the dual task and also included sources within the frontal and parietal lobes, but the sources also shifted to other locations that included areas within the temporal and occipital lobes. Additionally, mean absolute N1 ERP amplitudes representing the activity from similar locations in both tasks were greater for the single than dual task. The present localization results highlight the importance of frontal, parietal and anterior cingulate cortical areas in reactive postural control and suggest a re-allocation or shift of cortical sources related to reactive balance control in the presence of a secondary task. Thus, this study provides novel insight into the underlying neurophysiology and contribution of cortical sources in relation to the neural control of reactive balance.

  13. Electrocortical Sources Related to Whole-Body Surface Translations during a Single- and Dual-Task Paradigm

    Science.gov (United States)

    Bogost, Mark D.; Burgos, Pablo I.; Little, C. Elaine; Woollacott, Marjorie H.; Dalton, Brian H.

    2016-01-01

    Appropriate reactive motor responses are essential in maintaining upright balance. However, little is known regarding the potential location of cortical sources that are related to the onset of a perturbation during single- and dual-task paradigms. The purpose of this study was to estimate the location of cortical sources in response to a whole-body surface translation and whether diverted attention decreases the N1 event-related potential (ERP) amplitude related to a postural perturbation. This study utilized high-resolution electroencephalography in conjunction with measure projection analysis from ERPs time-locked to backwards surface translation onsets to determine which cortical sources were related to whole-body postural perturbations. Subjects (n = 15) either reacted to whole-body surface translations with (dual task) or without (single task) performing a visual working memory task. For the single task, four domains were identified that were mainly localized within the frontal and parietal lobes and included sources from the prefrontal, premotor, primary and supplementary motor, somatosensory and anterior cingulate cortex. Five domains were estimated for the dual task and also included sources within the frontal and parietal lobes, but the sources also shifted to other locations that included areas within the temporal and occipital lobes. Additionally, mean absolute N1 ERP amplitudes representing the activity from similar locations in both tasks were greater for the single than dual task. The present localization results highlight the importance of frontal, parietal and anterior cingulate cortical areas in reactive postural control and suggest a re-allocation or shift of cortical sources related to reactive balance control in the presence of a secondary task. Thus, this study provides novel insight into the underlying neurophysiology and contribution of cortical sources in relation to the neural control of reactive balance.

  14. Interaction between semantic and phonological processes in stuttering Evidence from the dual-task paradigm

    Institute of Scientific and Technical Information of China (English)

    Luping Song; Danling Peng; Ning Ning

    2010-01-01

    Stuttering is a common neurological deficit and its underlying cognitive mechanisms are a matter of debate,with evidence suggesting abnormal modulation between speech encoding and other cognitive components.Previous studies have mainly used single task experiments to investigate the disturbance of language production.It is unclear whether there is abnormal interaction between the three language tasks(orthographic,phonological and semantic judgment)in stuttering patients.This study used dual tasks and manipulated the stimulus onset asynchrony(SOA)between tasks 1and 2 and the nature of the second task,including orthographic,phonological,and semantic judgments.The results showed that the performance records of orthographic judgment,phonological judgment,and semantic judgment were significantly reduced between the patient and control groups with short SOA(P 0.05).These results indicated that the interaction mechanism between semantic processing and phonological encoding might be an underlying cause for stuttering.

  15. Spatial re-orienting of visual attention along the horizontal or the vertical axis.

    Science.gov (United States)

    Macaluso, E; Patria, F

    2007-06-01

    Neuroimaging data indicate functional segregation between voluntary and stimulus-driven control of spatial attention in dorsal and ventral fronto-parietal regions, respectively. While recent evidences demonstrated location-specific attentional effects in dorsal regions, little is known about any location or direction selectivity within the ventral network. Here, we used a spatial cueing paradigm to investigate stimulus-driven spatial re-orienting along different axes (horizontal or vertical). We found that re-orienting of attention activated the ventral attentional network, irrespective of axis-orientation. Statistical comparisons between homologous regions in the two hemispheres revealed significant main effects of attention re-orienting (common activation for the two hemispheres), irrespective of leftward or rightward re-orienting along the horizontal axis, or re-orienting along the vertical axis. We conclude that in healthy volunteers, a bilateral ventral network controls spatial covert re-orienting, and that this system is multidirectional.

  16. The influence of task paradigm on motor imagery ability in children with Developmental Coordination Disorder.

    Science.gov (United States)

    Ferguson, G D; Wilson, P H; Smits-Engelsman, B C M

    2015-12-01

    Children with Developmental Coordination Disorder (DCD) have difficulty imagining movements such that they conform to the customary temporal constraints of real performance. We examined whether this ability is influenced by the choice of task used to elicit motor imagery (MI). Performance of typically developing (TD) (n=30) and children with DCD (n=30) was compared on two tasks: the Visually Guided Pointing Task (VGPT) and the Computerized Virtual Radial Fitts Task (C-VRFT). Since the VGPT places higher demands on executive functions like working memory but requires less spatial planning, we reasoned that the C-VRFT would provide a purer measure of motor imagery (or simulation). Based on our earlier work, we predicted that imagery deficits in DCD would more likely manifest on the C-VRFT. Results showed high correlations between tasks in terms of executed and imagined movement time suggest that both tasks measure MI ability. However, group differences were more pronounced in the imagined condition of the radial Fitts' task. Taken together, the more spatially complex C-VRFT appears to be a more sensitive measure of motor imagery, better discriminating between DCD and TD. Implications for theory and practice are discussed.

  17. Paap and Noel revisited: individual differences in independent word recognition tasks in relation to the dual-task paradigm.

    Science.gov (United States)

    Hayes, Maureen; Masterson, Jackie

    2002-07-01

    Paap and Noel (1991) found that participants' pronunciation latencies were faster for low-frequency irregular words when named under a concurrent high digit memory load than when named under a low load. The effects reported by Paap and Noel haveproved difficult to replicate in subsequent studies. The present research suggests that individual differences in word recognition skill relate to who will or will not show these effects. In two experiments, participants were allocated to skill groups on the basis of latency in tasks tapping lexical and sub-lexical reading processes. In both studies, only one group (the "intermediate skilled"), showed evidence of such effects. A combined analysis of the data from Experiments 1 and 2 was carried out. This confirmed and extended the analyses of the individual experiments. The results are discussed in relation to contemporary models of word recognition.

  18. Alternatives to switch-cost scoring in the task-switching paradigm: their reliability and increased validity.

    Science.gov (United States)

    Hughes, Meredith M; Linck, Jared A; Bowles, Anita R; Koeth, Joel T; Bunting, Michael F

    2014-09-01

    In the task-switching paradigm, the latency switch-cost score-the difference in mean reaction time between switch and nonswitch trials-is the traditional measure of task-switching ability. However, this score does not reflect accuracy, where switch costs may also emerge. In two experiments that varied in response deadlines (unlimited vs. limited time), we evaluated the measurement properties of two traditional switch-cost scoring methods (the latency switch-cost score and the accuracy switch-cost score) and three alternatives (a rate residual score, a bin score, and an inverse efficiency score). Scores from the rate residual, bin score, and inverse efficiency methods had comparable reliability for latency switch-cost scores without response deadlines but were more reliable than latency switch-cost scores when higher error rates were induced with a response deadline. All three alternative scoring methods appropriately accounted for differences in accuracy switch costs when higher error rates were induced, whereas pure latency switch-cost scores did not. Critically, only the rate residual and bin score methods were more valid indicators of task-switching ability; they demonstrated stronger relationships with performance on an independent measure of executive functioning (the antisaccade analogue task), and they allowed the detection of larger effect sizes when examining within-task congruency effects. All of the three alternative scoring methods provide researchers with a better measure of task-switching ability than do traditional scoring methods, because they each simultaneously account for latency and accuracy costs. Overall, the three alternative scoring methods were all superior to the traditional latency switch-cost scoring method, but the strongest methods were the rate residual and bin score methods.

  19. The part task of the part-spacing paradigm is not a pure measurement of part-based information of faces.

    Directory of Open Access Journals (Sweden)

    Qi Zhu

    Full Text Available BACKGROUND: Faces are arguably one of the most important object categories encountered by human observers, yet they present one of the most difficult challenges to both the human and artificial visual systems. A variety of experimental paradigms have been developed to study how faces are represented and recognized, among which is the part-spacing paradigm. This paradigm is presumed to characterize the processing of both the featural and configural information of faces, and it has become increasingly popular for testing hypotheses on face specificity and in the diagnosis of face perception in cognitive disorders. METHODOLOGY/PRINCIPAL FINDINGS: In two experiments we questioned the validity of the part task of this paradigm by showing that, in this task, measuring pure information about face parts is confounded by the effect of face configuration on the perception of those parts. First, we eliminated or reduced contributions from face configuration by either rearranging face parts into a non-face configuration or by removing the low spatial frequencies of face images. We found that face parts were no longer sensitive to inversion, suggesting that the previously reported inversion effect observed in the part task was due in fact to the presence of face configuration. Second, self-reported prosopagnosic patients who were selectively impaired in the holistic processing of faces failed to detect part changes when face configurations were presented. When face configurations were scrambled, however, their performance was as good as that of normal controls. CONCLUSIONS/SIGNIFICANCE: In sum, consistent evidence from testing both normal and prosopagnosic subjects suggests the part task of the part-spacing paradigm is not an appropriate task for either measuring how face parts alone are processed or for providing a valid contrast to the spacing task. Therefore, conclusions from previous studies using the part-spacing paradigm may need re-evaluation with

  20. Congruity Effects between Materials and Processing Tasks in the Survival Processing Paradigm

    Science.gov (United States)

    Butler, Andrew C.; Kang, Sean H. K.; Roediger, Henry L., III

    2009-01-01

    Nairne, Thompson, and Pandeirada (2007) reported a series of experiments in which processing unrelated words in terms of their relevance to a grasslands survival scenario led to better retention relative to other semantic processing tasks. The impetus for their study was the premise that human memory systems evolved under the selection pressures…

  1. Production of False Memories in Collaborative Memory Tasks Using the DRM Paradigm

    Science.gov (United States)

    Saraiva, Magda; Albuquerque, Pedro B.; Arantes, Joana

    2017-01-01

    Studies on collaborative memory have revealed an interesting phenomenon called collaborative inhibition (CI) (i.e., nominal groups recall more information than collaborative groups). However, the results of studies on false memories in collaborative memory tasks are controversial. This study aimed to understand the production of false memories in…

  2. Cell reorientation under cyclic stretching

    CERN Document Server

    Livne, Ariel; Geiger, Benjamin

    2014-01-01

    Mechanical cues from the extracellular microenvironment play a central role in regulating the structure, function and fate of living cells. Nevertheless, the precise nature of the mechanisms and processes underlying this crucial cellular mechanosensitivity remains a fundamental open problem. Here we provide a novel framework for addressing cellular sensitivity and response to external forces by experimentally and theoretically studying one of its most striking manifestations -- cell reorientation to a uniform angle in response to cyclic stretching of the underlying substrate. We first show that existing approaches are incompatible with our extensive measurements of cell reorientation. We then propose a fundamentally new theory that shows that dissipative relaxation of the cell's passively-stored, two-dimensional, elastic energy to its minimum actively drives the reorientation process. Our theory is in excellent quantitative agreement with the complete temporal reorientation dynamics of individual cells, measu...

  3. How do children complete a seated combined cognitive and motor multi-tasking paradigm?

    Science.gov (United States)

    Hinton, Dorelle C; Vallis, Lori Ann

    2015-06-01

    Healthy children (n=12, age 7years) and young adults (n=11, age 21years) were asked to perform a bimanual balance and reaching protocol in a seated posture. Subjects balanced a ball on a Frisbee on the non-dominant palm of the hand while reaching with the dominant hand to pick up a toy off the ground. During half of the trials, an auditory Stroop task was administered simultaneous to onset of the participants' reach. All children (CH) and adults (AD) successfully completed both motor and cognitive tasks when combined: the ball and Frisbee were not dropped and cognitive accuracy rate for both groups was 77%. Angular range of motion (ROM) measures indicated that the trunk, upper arm (UA) and forearm (FA) segments were moving as articulated individual segments in both adults and children (ROM for trunk≠UA≠FA; pcontrol were evident: greater variability existed between trials and between subjects for segmental ROM in CH compared to AD (pcontrol is still developing in this age group. Results indicate children aged 7years can successfully perform a simultaneous upper body motor and cognitive task in a seated posture, however motor performance control is not yet at the same level as adults.

  4. Cognitive malingering assessed using event-related potential P300 evoked by the old-new task in the oddball paradigm

    Institute of Scientific and Technical Information of China (English)

    Jianping Zhang; Zhenhe Zhou

    2011-01-01

    The P300, an endogenous subcomponent of the event-related potential, is thought to reflect cognitive processes. The event-related potential evoked by the old-new memory recognition task in the oddball paradigm is suitable for examining the neural processes involved in malingered neurocognitive deficits. Forty-four undergraduates were randomly assigned to a simulated malingering group and a truth-telling group. Another 22 patients with head injuries were enrolled as a control group. All participants completed the old-new memory recognition task in the oddball paradigm. The mean P300 amplitude of the simulated malingering group was significantly reduced compared with the truth-telling group (P < 0.01), but was increased compared with the control group (P < 0.01). These results revealed that the P300, evoked by the old-new memory recognition task of the oddball paradigm, may be a helpful indicator for determining cognitive malingering.

  5. A Paradigm to Assess Implicit Attitudes towards God: The Positive/Negative God Associations Task.

    Science.gov (United States)

    Pirutinsky, Steven; Carp, Sean; Rosmarin, David H

    2017-02-01

    Psychological research on the relationship between spirituality/religion and mental health has grown considerably over the past several decades and now constitutes a sizable body of scholarship. Among dimensions of S/R, positive beliefs about God have been significantly related to better mental health outcomes, and conversely negative beliefs about God are generally associated with more distress. However, prior research on this topic has relied heavily upon self-report Likert-type scales, which are vulnerable to self-report biases and measure only explicit cognitive processes. In this study, we developed and validated an implicit social cognition task, the Positive/Negative God Go/No-go Association Task (PNG-GNAT), for use in psychological research on spirituality and religion (S/R). Preliminary evidence in a large sample (N = 381) suggests that the PNG-GNAT demonstrates internal consistency, test-retest and split-half reliability, and concurrent evidence of validity. Further, our results suggest that PNG-GNAT scores represent different underlying dimensions of S/R than explicit self-report measures, and incrementally predict mental health above and beyond self-report assessment. The PNG-GNAT appears to be an effective tool for measuring implicit positive/negative beliefs about God.

  6. ERPs dissociate proactive and reactive control: evidence from a task-switching paradigm with informative and uninformative cues.

    Science.gov (United States)

    Czernochowski, Daniela

    2015-03-01

    According to the dual mechanism of control (DMC) framework, cognitive control can be recruited proactively to prevent response conflict when advance preparation is feasible or is up-regulated to overcome response conflict after it is detected. This study aimed at empirically dissociating proactive and reactive control processes proposed by the DMC and identifying corresponding event-related potential (ERP) correlates. Behavioral and electrophysiological indices of cognitive control were measured during a task-switch paradigm with or without informative advance cues, in which proactive control was feasible or not. Proactive control was associated with a (right-) frontal sustained ERP modulation during the cue-target interval. In line with the successful recruitment of proactive control, informative, as compared with uninformative, cue conditions were associated with reduced behavioral and ERP correlates of conflict. ERP correlates of conflict were evident both during conflict detection upon target presentation (N(inc)) and during conflict resolution-in particular, following uninformative cues. Reactive control assumed to support conflict resolution was associated with a (left-) frontal transient preresponse ERP modulation for uninformative, but not informative, cue conditions. Together, these data suggest that complementary proactive and reactive control processes operate in concert to flexibly support goal-directed behavior in response to variable task-demands, by either preventing or resolving response conflicts, as they are detected or anticipated.

  7. Optimal Reorientation Of Spacecraft Orbit

    Directory of Open Access Journals (Sweden)

    Chelnokov Yuriy Nikolaevich

    2014-06-01

    Full Text Available The problem of optimal reorientation of the spacecraft orbit is considered. For solving the problem we used quaternion equations of motion written in rotating coordinate system. The use of quaternion variables makes this consideration more efficient. The problem of optimal control is solved on the basis of the maximum principle. An example of numerical solution of the problem is given.

  8. Reorientation from Altered States: Please, More Carefully.

    Science.gov (United States)

    Heikkinen, Charles A.

    1989-01-01

    Claims counselors too often appear to forget to reorient clients from altered states of consciousness used in counseling and that failure to reorient can result in unnecessary discomfort for clients. Provides suggestions for when and how to reorient to avoid unwanted, lingering aftereffects. (Author/ABL)

  9. Working memory updating occurs independently of the need to maintain task-context: accounting for triggering updating in the AX-CPT paradigm.

    Science.gov (United States)

    Kessler, Yoav; Baruchin, Liad J; Bouhsira-Sabag, Anat

    2017-01-01

    Theoretical models suggest that maintenance and updating are two functional states of working memory (WM), which are controlled by a gate between perceptual information and WM representations. Opening the gate enables updating WM with input, while closing it enables keeping the maintained information shielded from interference. However, it is still unclear when gate opening takes place, and what is the external signal that triggers it. A version of the AX-CPT paradigm was used to examine a recent proposal in the literature, suggesting that updating is triggered whenever the maintenance of the context is necessary for task performance (context-dependent tasks). In four experiments using this paradigm, we show that (1) a task-switching cost takes place in both context-dependent and context-independent trials; (2) task-switching is additive to the dependency effect, and (3) unlike switching cost, the dependency effect is not affected by preparation and, therefore, does not reflect context-updating. We suggest that WM updating is likely to be triggered by a simple mechanism that occurs in each trial of the task regardless of whether maintaining the context is needed or not. The implications for WM updating and its relationship to task-switching are discussed.

  10. Executive function deficits in team sport athletes with a history of concussion revealed by a visual-auditory dual task paradigm.

    Science.gov (United States)

    Tapper, Anthony; Gonzalez, Dave; Roy, Eric; Niechwiej-Szwedo, Ewa

    2017-02-01

    The purpose of this study was to examine executive functions in team sport athletes with and without a history of concussion. Executive functions comprise many cognitive processes including, working memory, attention and multi-tasking. Past research has shown that concussions cause difficulties in vestibular-visual and vestibular-auditory dual-tasking, however, visual-auditory tasks have been examined rarely. Twenty-nine intercollegiate varsity ice hockey athletes (age = 19.13, SD = 1.56; 15 females) performed an experimental dual-task paradigm that required simultaneously processing visual and auditory information. A brief interview, event description and self-report questionnaires were used to assign participants to each group (concussion, no-concussion). Eighteen athletes had a history of concussion and 11 had no concussion history. The two tests involved visuospatial working memory (i.e., Corsi block test) and auditory tone discrimination. Participants completed both tasks individually, then simultaneously. Two outcome variables were measured, Corsi block memory span and auditory tone discrimination accuracy. No differences were shown when each task was performed alone; however, athletes with a history of concussion had a significantly worse performance on the tone discrimination task in the dual-task condition. In conclusion, long-term deficits in executive functions were associated with a prior history of concussion when cognitive resources were stressed. Evaluations of executive functions and divided attention appear to be helpful in discriminating participants with and without a history concussion.

  11. The New Modus Operandi: Techno Tasking--Recognizing Students' Ability to Use Multiple Technologies Simultaneously Presents a New Paradigm

    Science.gov (United States)

    Simon, Alan E.

    2005-01-01

    The ability of students to multi-task with technology carries major ramifications for classroom instruction and decision making. Multi-tasking with technology has created a new way to process and use information. Techno tasking occurs when an individual uses two or more technologies at the same time. This is distinguished from multi-tasking where…

  12. Genomic Signals of Reoriented ORFs

    Directory of Open Access Journals (Sweden)

    Paul Dan Cristea

    2004-01-01

    Full Text Available Complex representation of nucleotides is used to convert DNA sequences into complex digital genomic signals. The analysis of the cumulated phase and unwrapped phase of DNA genomic signals reveals large-scale features of eukaryote and prokaryote chromosomes that result from statistical regularities of base and base-pair distributions along DNA strands. By reorienting the chromosome coding regions, a “hidden” linear variation of the cumulated phase has been revealed, along with the conspicuous almost linear variation of the unwrapped phase. A model of chromosome longitudinal structure is inferred on these bases.

  13. A Molecular Jump Mechanism of Water Reorientation

    National Research Council Canada - National Science Library

    Damien Laage; James T. Hynes

    2006-01-01

    .... This water reorientation mechanism involves large-amplitude angular jumps, rather than the commonly accepted sequence of small diffusive steps, and therefore calls for reinterpretation of many...

  14. Effects of state anxiety on performance using a task-switching paradigm: an investigation of attentional control theory.

    Science.gov (United States)

    Derakshan, Nazanin; Smyth, Sinéad; Eysenck, Michael W

    2009-12-01

    Low- and high-anxious participants performed arithmetical tasks under task-switching or nontask-switching conditions. These tasks were low or high in complexity. The task on each trial was either explicitly cued or not cued. We assumed that demands on attentional control would be greater in the task-switching condition than in the nontask-switching condition, and would be greater with high-complexity tasks than with low-complexity ones. We also assumed that demands on attentional control would be greater when cues were absent rather than present. According to attentional control theory (Eysenck, Derakshan, Santos, & Calvo, 2007), anxiety impairs attentional control processes required to shift attention optimally within and between tasks. We predicted that there would be greater negative effects of high state anxiety in the task-switching condition than in the nontask-switching condition. Our theoretical predictions were supported, suggesting that state anxiety reduces attentional control.

  15. The effect of pain on task switching: pain reduces accuracy and increases reaction times across multiple switching paradigms.

    Science.gov (United States)

    Attridge, Nina; Keogh, Edmund; Eccleston, Christopher

    2016-10-01

    Pain disrupts attention, which may have negative consequences for daily life for people with acute or chronic pain. It has been suggested that switching between tasks may leave us particularly susceptible to pain-related attentional disruption, because we need to disengage our attention from one task before shifting it onto another. Switching tasks typically elicit lower accuracies and/or longer reaction times when participants switch to a new task compared with repeating the same task, and pain may exacerbate this effect. We present 3 studies to test this hypothesis. In study 1, participants completed 2 versions of an alternating runs switching task under pain-free and thermal pain-induction conditions. Pain did not affect performance on either task. In studies 2 and 3, we examined 7 versions of the switching task using large general population samples, experiencing a variety of naturally occurring pain conditions, recruited and tested on the internet. On all tasks, participants with pain had longer reaction times on both switch and repeat trials compared with participants without pain, but pain did not increase switch costs. In studies 2 and 3, we also investigated the effects of type of pain, duration of pain, and analgesics on task performance. We conclude that pain has a small dampening effect on performance overall on switching tasks. This suggests that pain interrupts attention even when participants are engaged in a trial, not only when attention has been disengaged for shifting to a new task set.

  16. Environmental Geometry Aligns the Hippocampal Map during Spatial Reorientation.

    Science.gov (United States)

    Keinath, Alex T; Julian, Joshua B; Epstein, Russell A; Muzzio, Isabel A

    2017-02-06

    When a navigator's internal sense of direction is disrupted, she must rely on external cues to regain her bearings, a process termed spatial reorientation. Extensive research has demonstrated that the geometric shape of the environment exerts powerful control over reorientation behavior, but the neural and cognitive mechanisms underlying this phenomenon are not well understood. Whereas some theories claim that geometry controls behavior through an allocentric mechanism potentially tied to the hippocampus, others postulate that disoriented navigators reach their goals by using an egocentric view-matching strategy. To resolve this debate, we characterized hippocampal representations during reorientation. We first recorded from CA1 cells as disoriented mice foraged in chambers of various shapes. We found that the alignment of the recovered hippocampal map was determined by the geometry of the chamber, but not by nongeometric cues, even when these cues could be used to disambiguate geometric ambiguities. We then recorded hippocampal activity as disoriented mice performed a classical goal-directed spatial memory task in a rectangular chamber. Again, we found that the recovered hippocampal map aligned solely to the chamber geometry. Critically, we also found a strong correspondence between the hippocampal map alignment and the animal's behavior, making it possible to predict the search location of the animal from neural responses on a trial-by-trial basis. Together, these results demonstrate that spatial reorientation involves the alignment of the hippocampal map to local geometry. We hypothesize that geometry may be an especially salient cue for reorientation because it is an inherently stable aspect of the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. INIST: databases reorientation; INIST: reorientation des bases de donnees

    Energy Technology Data Exchange (ETDEWEB)

    Bidet, J.C.

    1995-08-01

    INIST is a CNRS (Centre National de la Recherche Scientifique) laboratory devoted to the treatment of scientific and technical informations and to the management of these informations compiled in a database. Reorientation of the database content has been proposed in 1994 to increase the transfer of research towards enterprises and services, to develop more automatized accesses to the informations, and to create a quality assurance plan. The catalog of publications comprises 5800 periodical titles (1300 for fundamental research and 4500 for applied research). A science and technology multi-thematic database will be created in 1995 for the retrieval of applied and technical informations. ``Grey literature`` (reports, thesis, proceedings..) and human and social sciences data will be added to the base by the use of informations selected in the existing GRISELI and Francis databases. Strong modifications are also planned in the thematic cover of Earth sciences and will considerably reduce the geological information content. (J.S.). 1 tab.

  18. A novel eye-tracking method to assess attention allocation in individuals with and without aphasia using a dual-task paradigm.

    Science.gov (United States)

    Heuer, Sabine; Hallowell, Brooke

    2015-01-01

    Numerous authors report that people with aphasia have greater difficulty allocating attention than people without neurological disorders. Studying how attention deficits contribute to language deficits is important. However, existing methods for indexing attention allocation in people with aphasia pose serious methodological challenges. Eye-tracking methods have great potential to address such challenges. We developed and assessed the validity of a new dual-task method incorporating eye tracking to assess attention allocation. Twenty-six adults with aphasia and 33 control participants completed auditory sentence comprehension and visual search tasks. To test whether the new method validly indexes well-documented patterns in attention allocation, demands were manipulated by varying task complexity in single- and dual-task conditions. Differences in attention allocation were indexed via eye-tracking measures. For all participants significant increases in attention allocation demands were observed from single- to dual-task conditions and from simple to complex stimuli. Individuals with aphasia had greater difficulty allocating attention with greater task demands. Relationships between eye-tracking indices of comprehension during single and dual tasks and standardized testing were examined. Results support the validity of the novel eye-tracking method for assessing attention allocation in people with and without aphasia. Clinical and research implications are discussed. Readers will be able to: (1) summarize the nature of dual-task paradigms, (2) identify shortcomings of existing dual-task measures of attention allocation for application to people with aphasia, (3) describe how eye-tracking measures may be recorded and analyzed to reflect differences in attention allocation across conditions, and (4) summarize potential clinical applications for eye-tracking measures of attention allocation. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. The reorientation of spatial planning systems and policies

    DEFF Research Database (Denmark)

    Galland, Daniel; Enemark, Stig

    2012-01-01

    spatial planning has become reoriented. This is performed through an empirical analysis regarding the transformation of spatial planning in relation with the evolving conception of planning policies at different scales, the changing role of planning in conceiving and handling growth and development......Danish spatial planning has been increasingly subjected to profound reorientations over the past two decades. The comprehensive frame wherein planning policies and practices operated across different levels of administration has become significantly altered. This has been particularly evident after...... radical shifts in terms of the scope of planning policies, the implementation of land-use tasks as well as the performance of the institutional arrangements operating within and beyond the planning system. Based on an in-depth analysis concerned with these changes, the paper endeavours into discussing how...

  20. Optimizing and Interpreting Insular Functional Connectivity Maps Obtained During Acute Experimental Pain: The Effects of Global Signal and Task Paradigm Regression.

    Science.gov (United States)

    Ibinson, James W; Vogt, Keith M; Taylor, Kevin B; Dua, Shiv B; Becker, Christopher J; Loggia, Marco; Wasan, Ajay D

    2015-12-01

    The insula is uniquely located between the temporal and parietal cortices, making it anatomically well-positioned to act as an integrating center between the sensory and affective domains for the processing of painful stimulation. This can be studied through resting-state functional connectivity (fcMRI) imaging; however, the lack of a clear methodology for the analysis of fcMRI complicates the interpretation of these data during acute pain. Detected connectivity changes may reflect actual alterations in low-frequency synchronous neuronal activity related to pain, may be due to changes in global cerebral blood flow or the superimposed task-induced neuronal activity. The primary goal of this study was to investigate the effects of global signal regression (GSR) and task paradigm regression (TPR) on the changes in functional connectivity of the left (contralateral) insula in healthy subjects at rest and during acute painful electric nerve stimulation of the right hand. The use of GSR reduced the size and statistical significance of connectivity clusters and created negative correlation coefficients for some connectivity clusters. TPR with cyclic stimulation gave task versus rest connectivity differences similar to those with a constant task, suggesting that analysis which includes TPR is more accurately reflective of low-frequency neuronal activity. Both GSR and TPR have been inconsistently applied to fcMRI analysis. Based on these results, investigators need to consider the impact GSR and TPR have on connectivity during task performance when attempting to synthesize the literature.

  1. Methylphenidate and brain activity in a reward/conflict paradigm: role of the insula in task performance.

    Science.gov (United States)

    Ivanov, Iliyan; Liu, Xun; Clerkin, Suzanne; Schulz, Kurt; Fan, Jin; Friston, Karl; London, Edythe D; Schwartz, Jeffrey; Newcorn, Jeffrey H

    2014-06-01

    Psychostimulants, such as methylphenidate, are thought to improve information processing in motivation-reward and attention-activation networks by enhancing the effects of more relevant signals and suppressing those of less relevant ones; however the nature of such reciprocal influences remains poorly understood. To explore this question, we tested the effect of methylphenidate on performance and associated brain activity in the Anticipation, Conflict, Reward (ACR) task. Sixteen healthy adult volunteers, ages 21-45, were scanned twice using functional magnetic resonance imaging (fMRI) as they performed the ACR task under placebo and methylphenidate conditions. A three-way repeated measures analysis of variance, with cue (reward vs. non-reward), target (congruent vs. incongruent) and medication condition (methylphenidate vs. placebo) as the factors, was used to analyze behaviors on the task. Blood oxygen level dependent (BOLD) signals, reflecting task-related neural activity, were evaluated using linear contrasts. Participants exhibited significantly greater accuracy in the methylphenidate condition than the placebo condition. Compared with placebo, the methylphenidate condition also was associated with lesser task-related activity in components of attention-activation systems irrespective of the reward cue, and less task-related activity in components of the reward-motivation system, particularly the insula, during reward trials irrespective of target difficulty. These results suggest that methylphenidate enhances task performance by improving efficiency of information processing in both reward-motivation and in attention-activation systems.

  2. Contingency learning is not affected by conflict experience: Evidence from a task conflict-free, item-specific Stroop paradigm.

    Science.gov (United States)

    Levin, Yulia; Tzelgov, Joseph

    2016-02-01

    A contingency learning account of the item-specific proportion congruent effect has been described as an associative stimulus-response learning process that has nothing to do with controlling the Stroop conflict. As supportive evidence, contingency learning has been demonstrated with response conflict-free stimuli, such as neutral words. However, what gives rise to response conflict and to Stroop interference in general is task conflict. The present study investigated whether task conflict can constitute a trigger or, alternatively, a booster to the contingency learning process. This was done by employing a "task conflict-free" condition (i.e., geometric shapes) and comparing it with a "task conflict" condition (i.e., neutral words). The results showed a significant contingency learning effect in both conditions, refuting the possibility that contingency learning is triggered by the presence of a task conflict. Contingency learning was also not enhanced by the task conflict experience, indicating its complete insensitivity to Stroop conflict(s). Thus, the results showed no evidence that performance optimization as a result of contingency learning is greater under conflict, implying that contingency learning is not recruited to assist the control system to overcome conflict.

  3. Comparison of Classifiers and Statistical Analysis for EEG Signals Used in Brain Computer Interface Motor Task Paradigm

    Directory of Open Access Journals (Sweden)

    Oana Diana Eva

    2015-01-01

    Full Text Available Using the EEG Motor Movement/Imagery database there is proposed an off-line analysis for a brain computer interface (BCI paradigm. The purpose of the quantitative research is to compare classifiers in order to determinate which of them has highest rates of classification. The power spectral density method is used to evaluated the (desynchronizations that appear on Mu rhythm. The features extracted from EEG signals are classified using linear discriminant classifier (LDA, quadratic classifier (QDA and classifier based on Mahalanobis distance (MD. The differences between LDA, QDA and MD are small, but the superiority of QDA was sustained by analysis of variance (ANOVA.

  4. Stimulus-driven reorienting in the ventral frontoparietal attention network: the role of emotion

    Directory of Open Access Journals (Sweden)

    David Witt Frank

    2012-05-01

    Full Text Available Activity in the human temporoparietal junction and inferior frontal gyrus is hypothesized to underlie stimulus-driven, or bottom-up attention reorienting. Demanding tasks require focused attention, and as task difficulty increases, activity suppression in the ventral network correlates positively with task performance, an effect thought to reflect the gating of irrelevant cues. However, activation in these structures is elicited by a range of stimulus features and task demands that vary across multiple characteristics, complicating the interpretation of the functional role of this pathway. Consideration of several current studies suggests that, in addition to task difficulty, the motivational relevance or emotional intensity of distractor stimuli may supersede ongoing task priority, and evoke ventral network activation. Support for this possibility is offered from a review of recent reports, and the import of this perspective for models of attention reorienting are discussed.

  5. Ontogenetic effects on gazing behaviour: a case study of kennel dogs (Labrador Retrievers) in the impossible task paradigm.

    Science.gov (United States)

    D'Aniello, Biagio; Scandurra, Anna

    2016-05-01

    Life experiences and living conditions can influence the problem-solving strategies and the communicative abilities of dogs with humans. The goals of this study were to determine any behavioural differences between Labrador Retrievers living in a kennel and those living in a house as pets and to assess whether kennel dogs show preferences in social behaviours for their caretaker relative to a stranger when they are faced with an unsolvable task. Nine Labrador Retrievers living in a kennel from birth and ten Labrador Retrievers living in a family as pets were tested. The experimental procedure consisted of three "solvable" tasks in which the dogs could easily retrieve food from a container followed by an "unsolvable" task in which the container was hermetically locked. Dogs of both groups spent the same amount of time interacting with the experimental apparatus. Kennel dogs gazed towards people for less time and with higher latency than pet dogs; however, there were no significant preferences in gazing towards the stranger versus the caretaker in both groups. These findings demonstrated that kennel dogs are less prone to use human-directed gazing behaviour when they are faced with an unsolvable problem, taking the humans into account to solve a task less than do the pet dogs.

  6. Junction Plasmon-Induced Molecular Reorientation

    Energy Technology Data Exchange (ETDEWEB)

    El-Khoury, Patrick Z.; Hu, Dehong; Hess, Wayne P.

    2013-10-17

    Time and frequency dependent intensity variations in sequences of Raman spectra recorded at plasmonic junctions can be assigned to molecular reorientation. This is revealed through Raman trajectories recorded at a nanojunction formed between a silver AFM tip and a corrugated silver surface coated with biphenyl-4,4’-dithiol. Molecular motion is not observed when the tip is retracted and only surface enhancement is operative. In effect, junction plasmon induced molecular reorientation is tracked.

  7. Simultaneous recording of EEG and fNIRS during visuo-spatial and facial expression processing in a dual task paradigm.

    Science.gov (United States)

    Herrmann, Martin J; Neueder, Dorothea; Troeller, Anna K; Schulz, Stefan M

    2016-11-01

    Emotional processing is probably the most crucial tool for orienting oneself in our everyday social life and has been considered to be highly automatic for a long time. Dual task (DT) research shows that information competing for working memory resources impairs the identification of emotional facial expressions. Effects of cognitive load in DT paradigms have been confirmed in numerous neuroimaging studies. However, interference occurring during a DT comprised of decoding emotional facial expressions and a visuo-spatial working memory task has yet to be visualized. To investigate the DT interference effect on brain areas associated not only with working memory, but also emotional and visuo-spatial processing, we recorded brain activation within the prefrontal cortex and parietal-occipital sensory areas using functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) simultaneously. Our study consisted of N = 36 participants (27 female) performing the following tasks: a) Corsi blocks, b) identification of emotional facial expressions or c) DT comprising of tasks a) and b). We predicted higher activation of the prefrontal cortex during DT and corresponding reduced P100 and P300 amplitudes. As expected, fNIRS measurements revealed significantly higher neuronal activation within the prefrontal cortex in the DT condition. When comparing DT to the single tasks, the P100 amplitude was reduced, but the P300 amplitude did not show the expected reduction. Our findings underline that at least some aspects of emotional processing are not entirely automatic, but depend on prefrontal control and are therefore affected by cognitive load, in particular visuo-spatial working memory resources.

  8. A new twist on old ideas: how sitting reorients crawlers.

    Science.gov (United States)

    Soska, Kasey C; Robinson, Scott R; Adolph, Karen E

    2015-03-01

    Traditionally, crawling and sitting are considered distinct motor behaviors with different postures and functions. Ten- to 12-month-old infants were observed in the laboratory or in their homes while being coaxed to crawl continuously over long, straight walkways (Study 1; N = 20) and during spontaneous crawling during free play (Study 2; N = 20). In every context, infants stopped crawling to sit 3-6 times per minute. Transitions from crawling to sitting frequently turned infants' bodies away from the direction of heading; subsequent transitions back to crawling were offset by as much as 180° from the original direction of heading. Apparently, body reorientations result from the biomechanics of transitioning between crawling and sitting. Findings indicate that sustained, linear crawling is likely an epiphenomenon of how gait is studied in standard paradigms. Postural transitions between crawling and sitting are ubiquitous and can represent a functional unit of action. These transitions and the accompanying body reorientations likely have cascading effects for infants' exploration, visual perception, and spatial cognition.

  9. On the Interpretation of Response Time vs Onset Asynchrony Functions: Application to Dual-Task and Precue-Utilization Paradigms.

    Science.gov (United States)

    Schwarz, Wolfgang; Ischebeck, Anja

    2001-06-01

    The central bottleneck model of dual-task performance (H. Pashler and J. C. Johnston, 1998, Quarterly Journal of Experimental Psychology, 46A, 51-82) and the serial processing model of precue utilization (R. Gottsdanker, 1992, Acta Psychologica, 79, 21-43) are based on a common formal structure: They both represent response time as RT(tau)=max(X-tau, Y)+Z, where X, Y, Z denote the duration of certain processing stages specified by the models and tau denotes the onset asynchrony (SOA) between two stimuli. We consider this model within a stochastic framework in which the stage durations are random variables following an arbitrary joint distribution and derive properties of the function relating E[RT(tau)] to SOA. We present a distribution-free result which relates the slope of this function to the distribution of the random durations of the assumed processing stages. Our results allow for a direct, model-based interpretation of data from related experiments; specifically, they show how the slope of the SOA-function depends on experimental factors which selectively influence individual processing stages. We explain the implications of our results for models of dual-task performance and precue utilization and illustrate their application to data obtained by M. C. Smith (1969, Acta Psychologica, 30, 220-231) and R. Gottsdanker (1992, loc. cit.) Copyright 2001 Academic Press.

  10. Illusionary delusions. Willingness to exercise self-control can mask effects of glucose on self-control performance in experimental paradigms that use identical self-control tasks.

    Science.gov (United States)

    Chatzisarantis, Nikos L D; Hagger, Martin S

    2015-01-01

    The purpose of the present article is to highlight limitations of Lange and Eggert's methodology of using identical self-control tasks in testing effects of glucose on depletion of self-control resources and self-control performance. We suggest that when participants engage in two identical self-control tasks, cognitions developed during initial act of self-control may mask the effects of glucose on self-control performance by undermining willingness to exert effort during the second act of self-control. As a consequence, glucose may increase ability to exercise self-control but participants may not want to capitalize on this "ability advantage" because they are unwilling to exercise self-control. The present article concludes that researchers who test the glucose hypothesis in the context of a depletion paradigm should employ dissimilar acts of self-control and ensure that depleted participants are sufficiently motivated to exercise self-control. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  11. The reorientation of spatial planning in Denmark

    DEFF Research Database (Denmark)

    Galland, Daniel

    2011-01-01

    has been reoriented at national, regional and urban/local levels over time. The fundamental objective of the project is hence to explore and examine the history and evolution of Danish spatial planning through three embedded case studies from inception until most recent transformations. Respectively......, these studies embrace the reorientations of Danish national spatial planning; regional spatial planning in North Jutland; and urban planning and waterfront redevelopment in the city of Aalborg. In attaining its aim, the dissertation is guided by the general premise that the reorientations of spatial planning...... planning practices at different administrative levels. As a whole, the outcome of this dissertation confirms that there is an increasing policy and institutional mismatch between national, regional and urban/local planning practices. It further suggests that the lack of spatial reflexion embedded...

  12. "A Change of Paradigm" in Developing Land Forces Officers' Professional Skills in Accordance with Hybrid Warfare Task-Requirements

    Directory of Open Access Journals (Sweden)

    Alexandru Rizescu

    2016-06-01

    Full Text Available In future conflicts, not only traditional or asymmetric actions will be used, but also a combination of the two in order to solve the disputes involving national and international actors, materialized today in different manifestation forms called hybrid war. The hybrid threats tell about the evolution of the contemporary and future threats, about the necessity of a national effort concerted towards providing an immediate effective response to these threats. From a different perspective, the diversity and the complexity of the issues raised by the hybrid threats prove that it is necessary to go beyond the technical or sequential nowadays answers. It results first that it is required to develop an appropriate security strategy which will make possible the efficient action against hybrid risks and threats, in an effective, operational and unitary manner. Therefore, the present article aims at sequentially highlighting the aspects supporting the need to correlate the coordinates of the national security strategy to the planning, conduct and quality assessment of the process of training officers from the “change of paradigm” perspective, in order to acquire the professional skills conforming to the task-requirements specific to the hybrid war. Nothing more natural, more necessary and at the same time more current in this perspective than modernizing the military continuous education system in accordance with the strategic norm of competence.

  13. Reorienting the future role of the religión: humanize humanity. The role of the religión in society of the future will be purely spiritual

    Directory of Open Access Journals (Sweden)

    José María Vigil

    2015-04-01

    Full Text Available The post-Religional paradigm enables emerge in many people, questions about the future of religiosity and religions. The author confronts himself with this concern and tries to control, in a concrete way, the possibilities of a future for religions. In order, and as a starting point, the current process of secularization and the new and growing social phenomenon of 'no religion', this article analyzes the profound changes that are occurring in this time of transition. Then makes a proposal for extension and conversion of the old anthropological concept of spirituality to redirect it towards human depth. In presenting these profound changes, this new concept of spirituality seeks to understand the dimensions and functions that religions are no longer able to keep in post agrarian society what is to come, contributing with ideas and suggestions to deploy creativity with the central task from which religions should reorient and focus, that is, the task of humanizing humanity.

  14. An Objective Screening Method for Major Depressive Disorder Using Logistic Regression Analysis of Heart Rate Variability Data Obtained in a Mental Task Paradigm

    Directory of Open Access Journals (Sweden)

    Guanghao Sun

    2016-11-01

    Full Text Available Background and Objectives: Heart rate variability (HRV has been intensively studied as a promising biological marker of major depressive disorder (MDD. Our previous study confirmed that autonomic activity and reactivity in depression revealed by HRV during rest and mental task (MT conditions can be used as diagnostic measures and in clinical evaluation. In this study, logistic regression analysis (LRA was utilized for the classification and prediction of MDD based on HRV data obtained in an MT paradigm.Methods: Power spectral analysis of HRV on R-R intervals before, during, and after an MT (random number generation was performed in 44 drug-naïve patients with MDD and 47 healthy control subjects at Department of Psychiatry in Shizuoka Saiseikai General Hospital. Logit scores of LRA determined by HRV indices and heart rates discriminated patients with MDD from healthy subjects. The high frequency (HF component of HRV and the ratio of the low frequency (LF component to the HF component (LF/HF correspond to parasympathetic and sympathovagal balance, respectively.Results: The LRA achieved a sensitivity and specificity of 80.0% and 79.0%, respectively, at an optimum cutoff logit score (0.28. Misclassifications occurred only when the logit score was close to the cutoff score. Logit scores also correlated significantly with subjective self-rating depression scale scores (p < 0.05.Conclusion: HRV indices recorded during a mental task may be an objective tool for screening patients with MDD in psychiatric practice. The proposed method appears promising for not only objective and rapid MDD screening, but also evaluation of its severity.

  15. Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

    NARCIS (Netherlands)

    Lisfi, A.; Williams, C.M.; Nguyen, L.T.; Lodder, J.C.; Coleman, A.; Corcoran, H.; Johnson, A.; Chang, P.; Kumar, A.; Morgan, W.

    2007-01-01

    Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition

  16. Reorientation of magnetic anisotropy in epitaxial cobalt ferrite thin films

    NARCIS (Netherlands)

    Lisfi, A.; Williams, C.M.; Nguyen, L.T.; Lodder, J.C.; Coleman, A.; Corcoran, H.; Johnson, A.; Chang, P.; Abhishek Kumar, A.K.; Kumar, A.; Morgan, W.

    2007-01-01

    Spin reorientation has been observed in CoFe2O4 thin single crystalline films epitaxially grown on (100) MgO substrate upon varying the film thickness. The critical thickness for such a spin-reorientation transition was estimated to be 300 nm. The reorientation is driven by a structural transition

  17. The reorientation of spatial planning systems and policies

    DEFF Research Database (Denmark)

    Galland, Daniel; Enemark, Stig

    2012-01-01

    Danish spatial planning has been increasingly subjected to profound reorientations over the past two decades. The comprehensive frame wherein planning policies and practices operated across different levels of administration has become significantly altered. This has been particularly evident after...... the implementation of a structural reform that changed the political and administrative structure in the country. Most importantly, the reform abolished the county level, which caused that planning policies, functions and responsibilities were re-scaled to municipal and national levels. This situation brought about...... radical shifts in terms of the scope of planning policies, the implementation of land-use tasks as well as the performance of the institutional arrangements operating within and beyond the planning system. Based on an in-depth analysis concerned with these changes, the paper endeavours into discussing how...

  18. Steering Demands Diminish the Early-P3, Late-P3 and RON Components of the Event-Related Potential of Task-Irrelevant Environmental Sounds.

    Science.gov (United States)

    Scheer, Menja; Bülthoff, Heinrich H; Chuang, Lewis L

    2016-01-01

    The current study investigates the demands that steering places on mental resources. Instead of a conventional dual-task paradigm, participants of this study were only required to perform a steering task while task-irrelevant auditory distractor probes (environmental sounds and beep tones) were intermittently presented. The event-related potentials (ERPs), which were generated by these probes, were analyzed for their sensitivity to the steering task's demands. The steering task required participants to counteract unpredictable roll disturbances and difficulty was manipulated either by adjusting the bandwidth of the roll disturbance or by varying the complexity of the control dynamics. A mass univariate analysis revealed that steering selectively diminishes the amplitudes of early P3, late P3, and the re-orientation negativity (RON) to task-irrelevant environmental sounds but not to beep tones. Our findings are in line with a three-stage distraction model, which interprets these ERPs to reflect the post-sensory detection of the task-irrelevant stimulus, engagement, and re-orientation back to the steering task. This interpretation is consistent with our manipulations for steering difficulty. More participants showed diminished amplitudes for these ERPs in the "hard" steering condition relative to the "easy" condition. To sum up, the current work identifies the spatiotemporal ERP components of task-irrelevant auditory probes that are sensitive to steering demands on mental resources. This provides a non-intrusive method for evaluating mental workload in novel steering environments.

  19. Fundamental experiments on hydride reorientation in zircaloy

    Science.gov (United States)

    Colas, Kimberly B.

    In the current study, an in-situ X-ray diffraction technique using synchrotron radiation was used to follow directly the kinetics of hydride dissolution and precipitation during thermomechanical cycles. This technique was combined with conventional microscopy (optical, SEM and TEM) to gain an overall understanding of the process of hydride reorientation. Thus this part of the study emphasized the time-dependent nature of the process, studying large volume of hydrides in the material. In addition, a micro-diffraction technique was also used to study the spatial distribution of hydrides near stress concentrations. This part of the study emphasized the spatial variation of hydride characteristics such as strain and morphology. Hydrided samples in the shape of tensile dog-bones were used in the time-dependent part of the study. Compact tension specimens were used during the spatial dependence part of the study. The hydride elastic strains from peak shift and size and strain broadening were studied as a function of time for precipitating hydrides. The hydrides precipitate in a very compressed state of stress, as measured by the shift in lattice spacing. As precipitation proceeds the average shift decreases, indicating average stress is reduced, likely due to plastic deformation and morphology changes. When nucleation ends the hydrides follow the zirconium matrix thermal contraction. When stress is applied below the threshold stress for reorientation, hydrides first nucleate in a very compressed state similar to that of unstressed hydrides. After reducing the average strain similarly to unstressed hydrides, the average hydride strain reaches a constant value during cool-down to room temperature. This could be due to a greater ease of deforming the matrix due to the applied far-field strain which would compensate for the strains due to thermal contraction. Finally when hydrides reorient, the average hydride strains become tensile during the first precipitation regime and

  20. The reorientation of spatial planning in Denmark

    DEFF Research Database (Denmark)

    Galland, Daniel

    2011-01-01

    have been increasingly overridden by growth-oriented and competitiveness logics. More recently, the effects of a structural reform that changed the geographies of inter-governmental arrangements within the country have significantly transformed the orientation, scope, structure and performance...... has been reoriented at national, regional and urban/local levels over time. The fundamental objective of the project is hence to explore and examine the history and evolution of Danish spatial planning through three embedded case studies from inception until most recent transformations. Respectively...

  1. Reorientation of Defect Dipoles in Ferroelectric Ceramics

    Institute of Scientific and Technical Information of China (English)

    LI Bao-Shan; LI Guo-Rong; ZHAO Su-Chuan; ZHU Zhi-Gang; DING Ai-Li

    2005-01-01

    @@ We investigate the frequency, temperature, tetragonality and quenched temperature dependences of the hysteresis loops in Pb[(Zr0.52 Ti0.48)0.95 (Mn1/3Nb2/3)0.05]O3 (PMnN-PZT) ceramics. It has been demonstrated that the polarization-field hysteresis curves show "pinched" shapes when tested at room temperature, higher frequency or using the large-tetragonality specimen. While normal square-like loops are observed at 200 ℃ and 0.01 Hz or using the small-tetragonality one. Meanwhile, close relations between the P-E loops and the applied frequency,temperature or tetragonality reveal that there exists a typical relaxation time corresponding to the reorientation of the defect dipoles. It can be seen further from the quenched temperature dependences of the loops that the reorientation of the defect dipoles may influence the pinching. Compared to the intrinsic depinning procedure induced by changes of the distribution of defect dipoles, we provide new evidence for extrinsic depinning mechanism of the defect dipoles in the ferroelectric ceramics.

  2. Involvement of the head and trunk during gaze reorientation during standing and treadmill walking.

    Science.gov (United States)

    Cinelli, Michael; Patla, Aftab; Stuart, Bethany

    2007-07-01

    As individuals stand or walk in an environment their gaze may be reoriented from one location to another in response to auditory or visual stimuli. In order to reorient gaze, the eyes and/or the head and trunk must rotate. However, what determines the exact degree of rotation of each segment while standing or walking is not fully understood. In the current study we show that when participants were asked to reorient their gaze towards light cues positioned at eccentric locations of up to 90 degrees while standing or walking on a treadmill their eyes and head mainly facilitated the action. Rotations of the head-in-space were similar for both tasks, but the rotation of the shoulders- and hips-in-space were lower for the treadmill walking condition. It is argued that this difference in the level of head-on-trunk rotation during the two tasks is controlled by the vestibular feedback loop. The regulation of this feedback loop is performed by the cerebellum in response to the level of threat to postural stability.

  3. Language Tasks and Mobile Technologies: A Paradigm Shift in Designing Task-Based CALL for Young Language Learners / Activités langagières et technologies mobiles : un changement de paradigme dans la conception des tâches en apprentissage des langues

    Directory of Open Access Journals (Sweden)

    Martine Pellerin

    2014-05-01

    Full Text Available This article examines how the use of mobile technologies (iPods and tablets in language classrooms contributes to redesigning task-based approaches for young language learners. The article is based on a collaborative action research (CAR project in Early French Immersion classrooms in the province of Alberta, Canada. The data collection included digital ethnographic observation in the classrooms, students’ artifacts, and interviews with teachers and students. The findings outlined how the use of mobile technologies such as iPods and tablets contributes to redesigning language tasks and activities by helping young learners to create their own learning environment and meaningful language tasks, as well as self-assess and regulate their language learning process. The research also provides evidence of how the use of mobile technologies contributes to redesigning task-based approaches for young language learners that reflect learning principles based on emergent learning theories as well as Vygotskian sociocultural theories in second language acquisition (SLA. Activités langagières et technologies mobiles : un changement de paradigme dans la conception des tâches en apprentissage des langues assisté par ordinateur pour jeunes apprenants Cet article étudie la façon dont l'utilisation des technologies mobiles (iPods et tablettes dans les classes de langue contribue à la refonte des approches basées sur des tâches pour les jeunes apprenants. L'article se fonde sur un projet de collaboration recherche-action (CRA dans les classes initiales d'immersion en français dans la province de l'Alberta, au Canada. La collecte de données comprenait l'observation ethnographique numérique dans les salles de classe, les artefacts des élèves, et des entrevues avec les enseignants et les étudiants. Les résultats ont montré comment l'utilisation des technologies mobiles telles que les iPods et tablettes contribue à la refonte des tâches et des

  4. Does Working Memory Enhance or Interfere with Speech Fluency in Adults Who Do and Do Not Stutter? Evidence from a Dual-Task Paradigm

    Science.gov (United States)

    Eichorn, Naomi; Marton, Klara; Schwartz, Richard G.; Melara, Robert D.; Pirutinsky, Steven

    2016-01-01

    Purpose: The present study examined whether engaging working memory in a secondary task benefits speech fluency. Effects of dual-task conditions on speech fluency, rate, and errors were examined with respect to predictions derived from three related theoretical accounts of disfluencies. Method: Nineteen adults who stutter and twenty adults who do…

  5. Resting-state functional connectivity of ventral parietal regions associated with attention reorienting and episodic recollection

    Directory of Open Access Journals (Sweden)

    Sander M Daselaar

    2013-02-01

    Full Text Available In functional neuroimaging studies, ventral parietal cortex (VPC is recruited by very different cognitive tasks. Explaining the contributions VPC to these tasks has become a topic of intense study and lively debate. Perception studies frequently find VPC activations during tasks involving attention-reorienting, and memory studies frequently find them during tasks involving episodic recollection. According to the Attention to Memory (AtoM model, both phenomena can be explained by the same VPC function: bottom-up attention. Yet, a recent functional MRI (fMRI meta-analysis suggested that attention-reorienting activations are more frequent in anterior VPC, whereas recollection activations are more frequent in posterior VPC. Also, there is evidence that anterior and posterior VPC regions have different functional connectivity patterns. To investigate these issues, we conducted a resting-state functional connectivity analysis using as seeds the center-of-mass of attention-reorienting and recollection activations in the meta-analysis, which were located in the supramarginal gyrus (SMG, around the temporo-parietal junction—TPJ and in the angular gyrus (AG, respectively. The SMG seed showed stronger connectivity with ventrolateral prefrontal cortex (VLPFC and occipito-temporal cortex, whereas the AG seed showed stronger connectivity with the hippocampus and default network regions. To investigate whether these connectivity differences were graded or sharp, VLPFC and hippocampal connectivity was measured in VPC regions traversing through the SMG and AG seeds. The results showed a graded pattern: VLPFC connectivity gradually decreases from SMG to AG, whereas hippocampal connectivity gradually increases from SMG to AG. Importantly, both gradients showed an abrupt break when extended beyond VPC borders. This finding suggests that functional differences between SMG and AG are more subtle than previously thought. These connectivity differences can be

  6. A new biomarker to examine the role of hippocampal function in the development of spatial reorientation in children: a review.

    Science.gov (United States)

    Vieites, Vanessa; Nazareth, Alina; Reeb-Sutherland, Bethany C; Pruden, Shannon M

    2015-01-01

    Spatial navigation is an adaptive skill that involves determining the route to a particular goal or location, and then traveling that path. A major component of spatial navigation is spatial reorientation, or the ability to reestablish a sense of direction after being disoriented. The hippocampus is known to be critical for navigating, and has more recently been implicated in reorienting in adults, but relatively little is known about the development of the hippocampus in relation to these large-scale spatial abilities in children. It has been established that, compared to school-aged children, preschool children tend to perform poorly on certain spatial reorientation tasks, suggesting that their hippocampi may not be mature enough to process the demands of such a task. Currently, common techniques used to examine underlying brain activity, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), are not suitable for examining hippocampal development in young children. In the present paper, we argue instead for the use of eyeblink conditioning (EBC), a relatively under-utilized, inexpensive, and safe method that is easy to implement in developing populations. In addition, EBC has a well defined neural circuitry, which includes the hippocampus, making it an ideal tool to indirectly measure hippocampal functioning in young children. In this review, we will evaluate the literature on EBC and its relation to hippocampal development, and discuss the possibility of using EBC as an objective measure of associative learning in relation to large-scale spatial skills. We support the use of EBC as a way to indirectly access hippocampal function in typical and atypical populations in order to characterize the neural substrates associated with the development of spatial reorientation abilities in early childhood. As such, EBC is a potential, simple biomarker for success in tasks that require the hippocampus, including spatial reorientation.

  7. A New Biomarker to Examine the Role of Hippocampal Function in the Development of Spatial Reorientation in Children: A Review

    Directory of Open Access Journals (Sweden)

    Vanessa eVieites

    2015-04-01

    Full Text Available Spatial navigation is an adaptive skill that involves determining the route to a particular goal or location, and then travelling that path. A major component of spatial navigation is spatial reorientation, or the ability to reestablish a sense of direction after being disoriented. The hippocampus is known to be critical for navigating, and has more recently been implicated in reorienting in adults, but relatively little is known about the development of the hippocampus in relation to these large-scale spatial abilities in children. It has been established that, compared to school-aged children, preschool children tend to perform poorly on certain spatial reorientation tasks, suggesting that their hippocampi may not be mature enough to process the demands of such a task. Currently, common techniques used to examine underlying brain activity, such as electroencephalography (EEG and functional magnetic resonance imaging (fMRI, are not suitable for examining hippocampal development in young children. In the present paper, we argue for the use of eyeblink conditioning (EBC, a relatively under-utilized, inexpensive, and safe method that is easy to implement in developing populations. In addition, EBC has a well defined neural circuitry, which includes the hippocampus, making it an ideal tool to indirectly measure hippocampal functioning in young children. In this review, we will evaluate the literature on EBC and its relation to hippocampal development, and discuss the possibility of using EBC as an objective measure of associative learning in relation to large-scale spatial skills. We support the use of EBC as a way to indirectly access hippocampal function in typical and atypical populations in order to characterize the neural substrates associated with the development of spatial reorientation abilities in early childhood. Thus, we advocate for EBC as a simple biomarker for success in various tasks that require the hippocampus, including spatial

  8. Task-switching cost and repetition priming: two overlooked confounds in the first-set procedure of the Sternberg paradigm and how they affect memory set-size effects.

    Science.gov (United States)

    Jou, Jerwen

    2014-10-01

    Subjects performed Sternberg-type memory recognition tasks (Sternberg paradigm) in four experiments. Category-instance names were used as learning and testing materials. Sternberg's original experiments demonstrated a linear relation between reaction time (RT) and memory-set size (MSS). A few later studies found no relation, and other studies found a nonlinear relation (logarithmic) between the two variables. These deviations were used as evidence undermining Sternberg's serial scan theory. This study identified two confounding variables in the fixed-set procedure of the paradigm (where multiple probes are presented at test for a learned memory set) that could generate a MSS RT function that was either flat or logarithmic rather than linearly increasing. These two confounding variables were task-switching cost and repetition priming. The former factor worked against smaller memory sets and in favour of larger sets whereas the latter factor worked in the opposite way. Results demonstrated that a null or a logarithmic RT-to-MSS relation could be the artefact of the combined effects of these two variables. The Sternberg paradigm has been used widely in memory research, and a thorough understanding of the subtle methodological pitfalls is crucial. It is suggested that a varied-set procedure (where only one probe is presented at test for a learned memory set) is a more contamination-free procedure for measuring the MSS effects, and that if a fixed-set procedure is used, it is worthwhile examining the RT function of the very first trials across the MSSs, which are presumably relatively free of contamination by the subsequent trials.

  9. PIE techniques for hydride reorientation test at NDC

    Energy Technology Data Exchange (ETDEWEB)

    Tsuda, Tomohiro; Shinohara, Yasunari; Yamaguchi, Yoichiro [Nuclear Development Corporation, Ibaraki (Japan)

    2008-11-15

    Dry storage of spent fuels in the interim storage facility is being planned in Japan. However, the gradual deterioration of the mechanical property of fuel cladding due to internal pressure and temperature during the storage term is known. Therefore, the integrity of stored fuel rods should be confirmed before the start of dry storage. For the last several years, NDC had a lot of experiences on the hydride reorientation test. The specimen preparation techniques on the hydride reorientation test and the mechanical testing techniques after the hydride reorientation are shown in this paper.

  10. Effects of nicotine on electroencephalographic (EEG) and behavioural measures of visual working memory in non-smokers during a dual-task paradigm.

    Science.gov (United States)

    Fisher, Derek J; Knobelsdorf, Amy; Jaworska, Natalia; Daniels, Richelle; Knott, Verner J

    2013-01-01

    Research in smokers has shown that nicotine may have the ability to improve certain aspects of cognitive performance, including working memory and attention, processes which implicate frontal and frontal-parietal brain networks. There is limited research on the cognitive effects of nicotine and their associated neural underpinnings in non-smokers. This study examined the effects of acute nicotine on a working memory task alone or combined with a visual detection task (single- and dual-task conditions) using electroencephalographic (EEG) recordings and behavioural performance measures. Twenty non-smokers (13 females; 7 males) received nicotine gum (6 mg) in a double-blind, randomized, placebo-controlled, repeated measures design. Spectral EEG, together with response speed and accuracy measures, were obtained while participants completed a series of N-Back tasks under single- and dual-task conditions. Nicotine failed to exert any significant effects on performance measures, however, EEG changes were observed, primarily in frontal recordings, which varied with memory load, task condition and hemisphere. These findings, discussed in relation to previous studies in smokers, support the notion that nicotine may modulate central executive systems and contribute to smoking behaviour.

  11. Spatial reorientation decline in aging: the combination of geometry and landmarks.

    Science.gov (United States)

    Caffò, Alessandro O; Lopez, Antonella; Spano, Giuseppina; Serino, Silvia; Cipresso, Pietro; Stasolla, Fabrizio; Savino, Michelina; Lancioni, Giulio E; Riva, Giuseppe; Bosco, Andrea

    2017-07-20

    The study is focused on the assessment of reorientation skills in a sample of community-dwelling elderly people, manipulating landmarks and geometric (layout) information. A neuropsychological assessment was administered to 286 elderly participants, divided into six groups (healthy controls, HC; four subgroups of participants with mild cognitive impairment, MCI; participants with probable dementia, Prob_D) and tested with the Virtual Reorientation Test (VReoT). VReoT manipulated different spatial cues: geometry and landmarks (proximal and distal). Compared with HC, participants with MCI and Prob_D showed to be impaired in tasks involving geometry, landmarks and a combination of them. Both single and multiple domain impairment in MCI had an impact on reorientation performance. Moreover, VReoT was marginally able to discriminate between amnesic and non-amnesic MCI. The occurrence of getting lost events seemed to be associated to learning of geometric information. The associative strength between landmark and target plays an important role in affecting spatial orientation performance of cognitively impaired participants. Geometry significantly supports landmark information and becomes helpful with the increase of cognitive impairment which is linked to a decrement in landmark encoding. VReoT seems to represent a reliable evaluation supplement for spatial orientation deficits in prodromal stages of dementia.

  12. "Task" as Research Construct

    Science.gov (United States)

    Seedhouse, Paul

    2005-01-01

    The article examines "task" as research construct as predominantly conceived in terms of task-as-workplan in the task-based learning/second language acquisition literature. It is suggested that "task" has weak construct validity and ontology in an overwhelmingly quantitative paradigm because the construct has a "split personality."…

  13. Reorientation of the early lunar pole

    Science.gov (United States)

    Takahashi, Futoshi; Tsunakawa, Hideo; Shimizu, Hisayoshi; Shibuya, Hidetoshi; Matsushima, Masaki

    2014-06-01

    Palaeomagnetic measurements suggest that an active core dynamo operated on the Moon from 4.2 to 3.56 billion years ago. Since the Apollo era, many magnetic anomalies have been observed on the Moon. The magnetization of the lunar crust in some of these regions could preserve the signature of an early dipolar magnetic field generated by a core dynamo. Thus, the magnetic anomalies may yield information about the position of the palaeomagnetic pole during the time that the dynamo operated. Here we present a comprehensive survey of magnetic anomalies on the lunar surface using magnetometer data obtained by the Lunar Prospector and Kaguya lunar orbiters. We extract magnetization vectors from 24 magnetic anomalies using an iterative inversion method and derive the palaeomagnetic poles. We find that the north poles, as well as the antipodal south poles, cluster in two distinct locations: one near the present rotation axis and the other at mid-latitude. The clustering is consistent with a dipole-dominated magnetic field generated in the lunar core by a dynamo that was reversing, much like that of Earth. Furthermore, the two pole clusters imply that the Moon experienced a polar wander event during its ancient history due to the reorientation of the Moon with respect to its spin axis by 45°-60°.

  14. Altruism and Re-Orientation as Core for the Development of Africa

    Directory of Open Access Journals (Sweden)

    Simeon Omale

    2014-11-01

    Full Text Available Jan Knippers Black in his book, Development in Theory and Practice: Paradigm and Paradoxes had identified theories ranging from Liberal international School; modernization school; cultural weakness; Interdependence School as reasons for the unparalleled development of the world. While often these are used along the like of cultural imperialism and the un-even trade opportunities as reasons for Africa’s developmental quagmire, it is the opinion of this paper that Africa’s underdevelopment are largely products of our actions and non-actions. It is in this light that we seek to argue for the development of the spirit of Altruism and a reorientation of the national consciousness via investment in the Early Child Education adopting participatory learning and communication approach as necessary panacea for Africa’s development. By instilling in the young minds the expediency of a more altruistic modus vivendi, the culture of egoistic corruption could be overturned.

  15. Measuring the Cognitive Resources Consumed per Second for Real-time Lie-Production and Recollection: a Dual-tasking Paradigm

    Directory of Open Access Journals (Sweden)

    Chao eHu

    2015-05-01

    Full Text Available This research report presents a novel method of dual-tasking lie-detection. Novel software Follow Me was invented for a concurrent eye-hand coordination task during truth-telling/lying. Undergraduate participants were instructed to tell truths on questions about undergraduate school whereas they were instructed to tell lies on interview questions about graduate school, pretending they were graduate students. Throughout the experiment, they operated the Follow Me software: moving the mouse pointer to follow a randomly-moving dot on a computer screen. The distance between the mouse pointer tip and the dot center was measured by the software every 50 milliseconds. Frequency of distance fluctuation was analyzed as the index of cognitive effort consumed per second (i.e., degree of cognitive effort. The results revealed that the dominant frequency of distance fluctuation was significantly lower during encoding than during retrieving responses; and lower during lying than truth-telling. Thus, dominant frequency of distance fluctuation may be an effective index of cognitive effort. Moreover, both encoding and retrieving bald-faced lies were more cognitively effortful than truth-telling. This novel definition and measurement of degree of cognitive effort may contribute to the research field of deception as well as to many other fields in social cognition.

  16. Spatial reorientation in rats (Rattus norvegicus): Use of geometric and featural information as a function of arena size and feature location

    NARCIS (Netherlands)

    Maes, J.H.R.; Fontanari, L.; Regolin, L.

    2009-01-01

    Rats were used in a spatial reorientation task to assess their ability to use geometric and non-geometric, featural, information. Experimental conditions differed in the size of the arena (small, medium, or large) and whether the food-baited corner was near or far from a visual feature. The main mea

  17. Planar reorientation maneuvers of space multibody systems using internal controls

    Science.gov (United States)

    Reyhanoglu, Mahmut; Mcclamroch, N. H.

    1992-01-01

    In this paper a reorientation maneuvering strategy for an interconnection of planar rigid bodies in space is developed. It is assumed that there are no exogeneous torques, and torques generated by joint motors are used as means of control so that the total angular momentum of the multibody system is a constant, assumed to be zero in this paper. The maneuver strategy uses the nonintegrability of the expression for the angular momentum. We demonstrate that large-angle maneuvers can be designed to achieve an arbitrary reorientation of the multibody system with respect to an inertial frame. The theoretical background for carrying out the required maneuvers is briefly summarized. Specifications and computer simulations of a specific reorientation maneuver, and the corresponding control strategies, are described.

  18. Resting-state functional connectivity of ventral parietal regions associated with attention reorienting and episodic recollection

    Science.gov (United States)

    Daselaar, S. M.; Huijbers, W.; Eklund, K.; Moscovitch, M.; Cabeza, R.

    2013-01-01

    In functional neuroimaging studies, ventral parietal cortex (VPC) is recruited by very different cognitive tasks. Explaining the contributions of VPC to these tasks has become a topic of intense study and lively debate. Perception studies frequently find VPC activations during tasks involving attention-reorienting, and memory studies frequently find them during tasks involving episodic recollection. According to the Attention to Memory (AtoM) model, both phenomena can be explained by the same VPC function: bottom-up attention. Yet, a recent functional MRI (fMRI) meta-analysis suggested that attention-reorienting activations are more frequent in anterior VPC, whereas recollection activations are more frequent in posterior VPC. Also, there is evidence that anterior and posterior VPC regions have different functional connectivity patterns. To investigate these issues, we conducted a resting-state functional connectivity analysis using as seeds the center-of-mass of attention-reorienting and recollection activations in the meta-analysis, which were located in the supramarginal gyrus (SMG, around the temporo-parietal junction—TPJ) and in the angular gyrus (AG), respectively. The SMG seed showed stronger connectivity with ventrolateral prefrontal cortex (VLPFC) and occipito-temporal cortex, whereas the AG seed showed stronger connectivity with the hippocampus and default network regions. To investigate whether these connectivity differences were graded or sharp, VLPFC and hippocampal connectivity was measured in VPC regions traversing through the SMG and AG seeds. The results showed a graded pattern: VLPFC connectivity gradually decreases from SMG to AG, whereas hippocampal connectivity gradually increases from SMG to AG. Importantly, both gradients showed an abrupt break when extended beyond VPC borders. This finding suggests that functional differences between SMG and AG are more subtle than previously thought. These connectivity differences can be explained by

  19. The World Is Not Flat: Can People Reorient Using Slope?

    Science.gov (United States)

    Nardi, Daniele; Newcombe, Nora S.; Shipley, Thomas F.

    2011-01-01

    Studies of spatial representation generally focus on flat environments and visual input. However, the world is not flat, and slopes are part of most natural environments. In a series of 4 experiments, we examined whether humans can use a slope as a source of allocentric, directional information for reorientation. A target was hidden in a corner of…

  20. Why water reorientation slows without iceberg formation around hydrophobic solutes.

    Science.gov (United States)

    Laage, Damien; Stirnemann, Guillaume; Hynes, James T

    2009-02-26

    The dynamics of water molecules next to hydrophobic solutes is investigated, specifically addressing the recent controversy raised by the first time-resolved observations, which concluded that some water molecules are immobilized by hydrophobic groups, in strong contrast to previous NMR conclusions. Through molecular dynamics simulations and an analytic jump reorientation model, we identify the water reorientation mechanism next to a hydrophobic solute and provide evidence that no water molecules are immobilized by hydrophobic solutes. Their moderate rotational slowdown compared to bulk water (e.g., by a factor of less than 2 at low solute concentration) is mainly due to slower hydrogen-bond exchange. The slowdown is quantitatively described by a solute excluded volume effect at the transition state for the key hydrogen-bond exchange in the reorientation mechanism. We show that this picture is consistent with both ultrafast anisotropy and NMR experimental results and that the transition state excluded volume theory yields quantitative predictions of the rotational slowdown for diverse hydrophobic solutes of varying size over a wide concentration range. We also explain why hydrophobic groups slow water reorientation less than do some hydrophilic groups.

  1. Reorientation of magnetic anisotropy in obliquely sputtered metallic thin films

    NARCIS (Netherlands)

    Lisfi, A.; Lodder, J.C.; Wormeester, H.; Poelsema, B.

    2002-01-01

    Reorientation in the magnetic anisotropy as a function of film thickness has been observed in Co-Ni and Co thin films, obliquely sputtered on a polyethylene terephthalate substrate at a large incidence angle (70°). This effect is a consequence of the low magnetocrystalline anisotropy of the films (f

  2. Stategic reorientation of industrial R&D towards commercial objectives.

    NARCIS (Netherlands)

    Brook, Jacques W.; de Bruijn, E.J.; McDonough III, Edward F.; Kaynak, E.; Harcar, T.D.

    2007-01-01

    In an effort to leverage R&D knowledge asset and to create more value from industrial R&D in today’s increasing liberalized and globalising business environments, some corporations adopt a strategic reorientation of their industrial R&D organisation towards commercial objectives. This study suggests

  3. ORNL Interim Progress Report on Hydride Reorientation CIRFT Tests

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yan, Yong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-28

    A systematic study of H. B. Robinson (HBR) high burnup spent nuclear fuel (SNF) vibration integrity was performed in Phase I project under simulated transportation environments, using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) hot cell testing technology developed at Oak Ridge National Laboratory in 2013–14. The data analysis on the as-irradiated HBR SNF rods demonstrated that the load amplitude is the dominant factor that controls the fatigue life of bending rods. However, previous studies have shown that the hydrogen content and hydride morphology has an important effect on zirconium alloy mechanical properties. To address the effect of radial hydrides in SNF rods, in Phase II a test procedure was developed to simulate the effects of elevated temperatures, pressures, and stresses during transfer-drying operations. Pressurized and sealed fuel segments were heated to the target temperature for a preset hold time and slow-cooled at a controlled rate. The procedure was applied to both non-irradiated/prehydrided and high-burnup Zircaloy-4 fueled cladding segments using the Nuclear Regulatory Commission-recommended 400°C maximum temperature limit at various cooling rates. Before testing high-burnup cladding, four out-of-cell tests were conducted to optimize the hydride reorientation (R) test condition with pre-hydride Zircaloy-4 cladding, which has the same geometry as the high burnup fuel samples. Test HR-HBR#1 was conducted at the maximum hoop stress of 145 MPa, at a 400°C maximum temperature and a 5°C/h cooling rate. On the other hand, thermal cycling was performed for tests HR-HBR#2, HR-HBR#3, and HR-HBR#4 to generate more radial hydrides. It is clear that thermal cycling increases the ratio of the radial hydride to circumferential hydrides. The internal pressure also has a significant effect on the radial hydride morphology. This report describes a procedure and experimental results of the four out-of-cell hydride reorientation tests of

  4. Reorienting programme budgeting and marginal analysis (PBMA towards disinvestment

    Directory of Open Access Journals (Sweden)

    Mortimer Duncan

    2010-10-01

    Full Text Available Abstract Background Remarkable progress has been made over the past 40 years in developing rational, evidence-based mechanisms for the allocation of health resources. Much of this progress has centred on mechanisms for commissioning new medical devices and pharmaceuticals. The attention of fund-managers and policy-makers is only now turning towards development of mechanisms for decommissioning, disinvesting or redeploying resources from currently funded interventions. While Programme Budgeting and Marginal Analysis would seem well-suited to this purpose, past applications include both successes and failures in achieving disinvestment and resource release. Discussion Drawing on recent successes/failures in achieving disinvestment and resource release via PBMA, this paper identifies four barriers/enablers to disinvestment via PBMA: (i specification of the budget constraint, (ii scope of the programme budget, (iii composition and role of the advisory group, and (iv incentives for/against contributing to a 'shift list' of options for disinvestment and resource release. A number of modifications to the PBMA process are then proposed with the aim of reorienting PBMA towards disinvestment. Summary The reoriented model is differentiated by four features: (i hard budget constraint with budgetary pressure; (ii programme budgets with broad scope but specific investment proposals linked to disinvestment proposals with similar input requirements; (iii advisory/working groups that include equal representation of sectional interests plus additional members with responsibility for advocating in favour of disinvestment, (iv 'shift lists' populated and developed prior to 'wish lists' and investment proposals linked to disinvestment proposals within a relatively narrow budget area. While the argument and evidence presented here suggest that the reoriented model will facilitate disinvestment and resource release, this remains an empirical question. Likewise

  5. Rocket propellant reorientation and fluid management used in space commercialization

    Science.gov (United States)

    Hung, R. J.; Lee, C. C.; Shyu, K. L.

    1990-01-01

    In a spacecraft design, the requirements of settled propellant are different for tank pressurization, engine restart, venting, or propellant transfer. The requirement to settle or to position liquid fuel over the outlet end of the spacecraft propellant tank prior main engine restart possess a microgravity fluid behavior problem. In this paper, the dynamical behavior of liquid propellant, fluid reorientation, and propellant resettling have been carried out.

  6. A model of cytoskeletal reorientation in response to substrate stretching

    Directory of Open Access Journals (Sweden)

    Lazopoulos K.A.

    2008-01-01

    Full Text Available Living adherent cells change their orientation in response to substrate stretching such that their cytoskeletal components reorganize in a new direction. To study this phenomenon, we model the cytoskeleton as a planar system of elastic cables and struts both pinned at their endpoints to a flat flexible substrate. Tensed (pre-strained cables represent acting stress fibers, whereas compression-bearing struts represent microtubules. We assume that in response to uniaxial substrate stretching the model reorients and deforms into a new configuration that minimizes its total potential energy. Using the Maxwell's global stability criterion, we find global minima configurations during static extension and compression of the substrate. Based on these results, we predict reorientation during cyclic stretching of the substrate. We find that in response to cyclic stretching cells either reorient transversely to the direction of stretching, or exhibit multiple configurations symmetrically distributed relative to the direction of stretching. These predictions are consistent with experimental data on living cells from the literature.

  7. Combined effects of attention and motivation on visual task performance: transient and sustained motivational effects

    Directory of Open Access Journals (Sweden)

    Jan B Engelmann

    2009-03-01

    Full Text Available We investigated how the brain integrates motivational and attentional signals by using a neuroimaging paradigm that provided separate estimates for transient cue- and target-related signals, in addition to sustained block-related responses. Participants performed a Posner-type task in which an endogenous cue predicted target location on 70% of trials, while motivation was manipulated by varying magnitude and valence of a cash incentive linked to task performance. Our findings revealed increased detection performance (d’ as a function of incentive value. In parallel, brain signals revealed that increases in absolute incentive magnitude led to cue- and target-specific response modulations that were independent of sustained state effects across visual cortex, fronto-parietal regions, and subcortical regions. Interestingly, state-like effects of incentive were observed in several of these brain regions, too, suggesting that both transient and sustained fMRI signals may contribute to task performance. For both cue and block periods, the effects of administering incentives were correlated with individual trait measures of reward sensitivity. Taken together, our findings support the notion that motivation improves behavioral performance in a demanding attention task by enhancing evoked responses across a distributed set of anatomical sites, many of which have been previously implicated in attentional processing. However, the effect of motivation was not simply additive as the impact of absolute incentive was greater during invalid than valid trials in several brain regions, possibly because motivation had a larger effect on reorienting than orienting attentional mechanisms at these sites.

  8. Modularity beyond Perception: Evidence from the PRP Paradigm

    Science.gov (United States)

    Magen, Hagit; Cohen, Asher

    2010-01-01

    The Dimension Action (DA) model asserts that the visual system is modular, and that each task involves multiple-response mechanisms rather than a unitary-response selection mechanism. The model has been supported by evidence from single-task interference paradigms. We use the psychological refractory period paradigm and show that dual-task…

  9. Involuntary Capture and Voluntary Reorienting of Attention Decline in Middle-Aged and Old Participants

    Science.gov (United States)

    Correa-Jaraba, Kenia S.; Cid-Fernández, Susana; Lindín, Mónica; Díaz, Fernando

    2016-01-01

    The main aim of this study was to examine the effects of aging on event-related brain potentials (ERPs) associated with the automatic detection of unattended infrequent deviant and novel auditory stimuli (Mismatch Negativity, MMN) and with the orienting to these stimuli (P3a component), as well as the effects on ERPs associated with reorienting to relevant visual stimuli (Reorienting Negativity, RON). Participants were divided into three age groups: (1) Young: 21–29 years old; (2) Middle-aged: 51–64 years old; and (3) Old: 65–84 years old. They performed an auditory-visual distraction-attention task in which they were asked to attend to visual stimuli (Go, NoGo) and to ignore auditory stimuli (S: standard, D: deviant, N: novel). Reaction times (RTs) to Go visual stimuli were longer in old and middle-aged than in young participants. In addition, in all three age groups, longer RTs were found when Go visual stimuli were preceded by novel relative to deviant and standard auditory stimuli, indicating a distraction effect provoked by novel stimuli. ERP components were identified in the Novel minus Standard (N-S) and Deviant minus Standard (D-S) difference waveforms. In the N-S condition, MMN latency was significantly longer in middle-aged and old participants than in young participants, indicating a slowing of automatic detection of changes. The following results were observed in both difference waveforms: (1) the P3a component comprised two consecutive phases in all three age groups—an early-P3a (e-P3a) that may reflect the orienting response toward the irrelevant stimulation and a late-P3a (l-P3a) that may be a correlate of subsequent evaluation of the infrequent unexpected novel or deviant stimuli; (2) the e-P3a, l-P3a, and RON latencies were significantly longer in the Middle-aged and Old groups than in the Young group, indicating delay in the orienting response to and the subsequent evaluation of unattended auditory stimuli, and in the reorienting of

  10. Young children reorient by computing layout geometry, not by matching images of the environment.

    Science.gov (United States)

    Lee, Sang Ah; Spelke, Elizabeth S

    2011-02-01

    Disoriented animals from ants to humans reorient in accord with the shape of the surrounding surface layout: a behavioral pattern long taken as evidence for sensitivity to layout geometry. Recent computational models suggest, however, that the reorientation process may not depend on geometrical analyses but instead on the matching of brightness contours in 2D images of the environment. Here we test this suggestion by investigating young children's reorientation in enclosed environments. Children reoriented by extremely subtle geometric properties of the 3D layout: bumps and ridges that protruded only slightly off the floor, producing edges with low contrast. Moreover, children failed to reorient by prominent brightness contours in continuous layouts with no distinctive 3D structure. The findings provide evidence that geometric layout representations support children's reorientation.

  11. Didaktiske paradigmer og refleksion

    DEFF Research Database (Denmark)

    Christensen, Torben Spanget

    2014-01-01

    this article. A possible utilitarian didactical paradigm, already indicated by Krogh as a historical paradigm prominent in our time, is also discussed. It is suggested that reflection could be seen as a normative response to the utilitarian paradigm, and not as a paradigm in its own right. It is concluded...... that reflection must be understood as an overarching cultural phenomenon and a very important qualification of all Nielsen’s paradigms, and also a possible utilitarian paradigm, because it has the potential to add dynamic elements to the more or less static didactic paradigms. Thus the semiotic analysis may...

  12. Monitoring source in an unconscious plagiarism paradigm.

    Science.gov (United States)

    Landau, J D; Marsh, R L

    1997-06-01

    Current laboratory paradigms used to assess unconscious plagiarism consist of three tasks. First, participants generate solutions to a puzzle task with a partner (initial generation task); second, they recall their individual contribution (recall-own task); and third, they attempt to create new solutions that were not offered previously (generate-new task). An analysis of these tasks indicated that they differ in terms of the source monitoring they require. The two generative tasks require less differentiated information (e.g., familiarity) and relatively lax decision criteria. The recall-own task, however, demands more differentiated information and more extended decision criteria. In two experiments, factors known to influence source monitoring were manipulated. Consistent with the analysis, no effects were associated with the generative tasks. Recall-own plagiarisms increased when self- and other-generated solutions were difficult to distinguish (Experiment 1) and decreased when the two sources were easier to distinguish (Experiment 2).

  13. Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto.

    Science.gov (United States)

    Nimmo, F; Hamilton, D P; McKinnon, W B; Schenk, P M; Binzel, R P; Bierson, C J; Beyer, R A; Moore, J M; Stern, S A; Weaver, H A; Olkin, C B; Young, L A; Smith, K E

    2016-12-01

    The deep nitrogen-covered basin on Pluto, informally named Sputnik Planitia, is located very close to the longitude of Pluto's tidal axis and may be an impact feature, by analogy with other large basins in the Solar System. Reorientation of Sputnik Planitia arising from tidal and rotational torques can explain the basin's present-day location, but requires the feature to be a positive gravity anomaly, despite its negative topography. Here we argue that if Sputnik Planitia did indeed form as a result of an impact and if Pluto possesses a subsurface ocean, the required positive gravity anomaly would naturally result because of shell thinning and ocean uplift, followed by later modest nitrogen deposition. Without a subsurface ocean, a positive gravity anomaly requires an implausibly thick nitrogen layer (exceeding 40 kilometres). To prolong the lifetime of such a subsurface ocean to the present day and to maintain ocean uplift, a rigid, conductive water-ice shell is required. Because nitrogen deposition is latitude-dependent, nitrogen loading and reorientation may have exhibited complex feedbacks.

  14. Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto

    Science.gov (United States)

    Nimmo, F.; Hamilton, D. P.; McKinnon, W. B.; Schenk, P. M.; Binzel, R. P.; Bierson, C. J.; Beyer, R. A.; Moore, J. M.; Stern, S. A.; Weaver, H. A.; Olkin, C. B.; Young, L. A.; Smith, K. E.; Moore, J. M.; McKinnon, W. B.; Spencer, J. R.; Beyer, R.; Binzel, R. P.; Buie, M.; Buratti, B.; Cheng, A.; Cruikshank, D.; Ore, C. Dalle; Earle, A.; Gladstone, R.; Grundy, W.; Howard, A. D.; Lauer, T.; Linscott, I.; Nimmo, F.; Parker, J.; Porter, S.; Reitsema, H.; Reuter, D.; Roberts, J. H.; Robbins, S.; Schenk, P. M.; Showalter, M.; Singer, K.; Strobel, D.; Summers, M.; Tyler, L.; White, O. L.; Umurhan, O. M.; Banks, M.; Barnouin, O.; Bray, V.; Carcich, B.; Chaikin, A.; Chavez, C.; Conrad, C.; Hamilton, D. P.; Howett, C.; Hofgartner, J.; Kammer, J.; Lisse, C.; Marcotte, A.; Parker, A.; Retherford, K.; Saina, M.; Runyon, K.; Schindhelm, E.; Stansberry, J.; Steffl, A.; Stryk, T.; Throop, H.; Tsang, C.; Verbiscer, A.; Winters, H.; Zangari, A.; Stern, S. A.; Weaver, H. A.; Olkin, C. B.; Young, L. A.; Smith, K. E.

    2016-12-01

    The deep nitrogen-covered basin on Pluto, informally named Sputnik Planitia, is located very close to the longitude of Pluto’s tidal axis and may be an impact feature, by analogy with other large basins in the Solar System. Reorientation of Sputnik Planitia arising from tidal and rotational torques can explain the basin’s present-day location, but requires the feature to be a positive gravity anomaly, despite its negative topography. Here we argue that if Sputnik Planitia did indeed form as a result of an impact and if Pluto possesses a subsurface ocean, the required positive gravity anomaly would naturally result because of shell thinning and ocean uplift, followed by later modest nitrogen deposition. Without a subsurface ocean, a positive gravity anomaly requires an implausibly thick nitrogen layer (exceeding 40 kilometres). To prolong the lifetime of such a subsurface ocean to the present day and to maintain ocean uplift, a rigid, conductive water-ice shell is required. Because nitrogen deposition is latitude-dependent, nitrogen loading and reorientation may have exhibited complex feedbacks.

  15. Surface instabilities and reorientation induced by vibration in microgravity conditions

    Science.gov (United States)

    Porter, Jeff; Laverón-Simavilla, Ana; Tinao Perez-Miravete, Ignacio; Fernandez Fraile, Jose Javier; Ezquerro Navarro, Jose Miguel

    2012-07-01

    The behavior of vibrated fluids and, in particular, the surface or interfacial instabilities that commonly arise in these systems have been the subject of continued experimental and theoretical attention since Faraday's seminal experiments in 1831. Both orientation and frequency are critical in determining the response of the fluid to excitation. Low frequencies are associated with sloshing while higher frequencies may generate Faraday waves or cross-waves, depending on whether the axis of vibration is perpendicular or parallel to the interface. In addition, high frequency vibrations are known to produce large scale reorientation of the fluid (vibroequilibria), an effect that becomes especially pronounced in the absence of gravity. We describe the results of investigations conducted at the ESA affiliated Spanish User Support and Operations Centre (E-USOC) on the effect of vibrations on fluid interfaces, particularly the interaction between Faraday waves, which arise in vertically vibrated systems, cross-waves, which are found in horizontally forced systems, and large scale reorientation (vibroequilibria). Ongoing ground experiments utilizing a dual-axis shaker configuration are described, including the effect on pattern formation of varying the two independent forcing frequencies, amplitudes, and phases. Theoretical results, based on the analysis of reduced models, and on numerical simulations, are then described and compared to experiment. Finally, the interest of a corresponding microgravity experiment is discussed and implications for fluid management strategies considered.

  16. The cognitive paradigm ontology: design and application.

    Science.gov (United States)

    Turner, Jessica A; Laird, Angela R

    2012-01-01

    We present the basic structure of the Cognitive Paradigm Ontology (CogPO) for human behavioral experiments. While the experimental psychology and cognitive neuroscience literature may refer to certain behavioral tasks by name (e.g., the Stroop paradigm or the Sternberg paradigm) or by function (a working memory task, a visual attention task), these paradigms can vary tremendously in the stimuli that are presented to the subject, the response expected from the subject, and the instructions given to the subject. Drawing from the taxonomy developed and used by the BrainMap project ( www.brainmap.org ) for almost two decades to describe key components of published functional imaging results, we have developed an ontology capable of representing certain characteristics of the cognitive paradigms used in the fMRI and PET literature. The Cognitive Paradigm Ontology is being developed to be compliant with the Basic Formal Ontology (BFO), and to harmonize where possible with larger ontologies such as RadLex, NeuroLex, or the Ontology of Biomedical Investigations (OBI). The key components of CogPO include the representation of experimental conditions focused on the stimuli presented, the instructions given, and the responses requested. The use of alternate and even competitive terminologies can often impede scientific discoveries. Categorization of paradigms according to stimulus, response, and instruction has been shown to allow advanced data retrieval techniques by searching for similarities and contrasts across multiple paradigm levels. The goal of CogPO is to develop, evaluate, and distribute a domain ontology of cognitive paradigms for application and use in the functional neuroimaging community.

  17. On the reorientation of non-spherical prey particles in a feeding current

    DEFF Research Database (Denmark)

    Visser, Andre; Jonsson, P.R.

    2000-01-01

    Potentially, non-spherical prey can be re-oriented in a flow field and impact on the predator's feeding structures in a non- random manner. Herein, we quantify a process whereby this passive reorientation occurs, and present a model that predicts the orientation of a spheroidal prey as a function...

  18. A Bilingual Advantage in Task Switching

    Science.gov (United States)

    Prior, Anat; MacWhinney, Brian

    2010-01-01

    This study investigated the possibility that lifelong bilingualism may lead to enhanced efficiency in the ability to shift between mental sets. We compared the performance of monolingual and fluent bilingual college students in a task-switching paradigm. Bilinguals incurred reduced switching costs in the task-switching paradigm when compared with…

  19. Thin film magnetoelectric composites near spin reorientation transition

    Energy Technology Data Exchange (ETDEWEB)

    Tiercelin, N. [Joint European Laboratory LEMAC: IEMN CNRS 8520-Ecole Centrale de Lille, Villeneuve d' Ascq 59652 (France)], E-mail: Nicolas.Tiercelin@iemn.univ-lille1.fr; Preobrazhensky, V. [Joint European Laboratory LEMAC: IEMN CNRS 8520-Ecole Centrale de Lille, Villeneuve d' Ascq 59652 (France); Joint European Laboratory LEMAC: WRC-GPI-RAS 117454, Vernadsky prosp. 78, Moscow (Russian Federation); Mortet, V. [Institute for Materials Research (IMO), Hasselt University, IMEC vzw, Division IMOMEC, B-3590 Diepenbeek (Belgium); Talbi, A. [Joint European Laboratory LEMAC: IEMN CNRS 8520-Ecole Centrale de Lille, Villeneuve d' Ascq 59652 (France); Soltani, A. [IEMN CNRS 8520, Bd Poincare, Villeneuve d' Ascq 59651 (France); Haenen, K. [Institute for Materials Research (IMO), Hasselt University, IMEC vzw, Division IMOMEC, B-3590 Diepenbeek (Belgium); Pernod, P. [Joint European Laboratory LEMAC: IEMN CNRS 8520-Ecole Centrale de Lille, Villeneuve d' Ascq 59652 (France)

    2009-06-15

    We report the use of a magnetic instability of the spin reorientation transition type to enhance the magnetoelectric sensitivity in magnetostrictive-piezoelectric structures. We present the theoretical study of a clamped beam resonant actuator composed of a piezoelectric element on a passive substrate actuated by a magnetostrictive nanostructured layer. The experiments were made on a polished 150 {mu}m thick 18x3 mm{sup 2} lead zirconate titanate (PZT) plate glued to a 50 {mu}m thick silicon plate and coated with a giant magnetostrictive nanostructured Nx(TbCo{sub 25nm}/FeCo{sub 5nm}) layer. A second set of experiments was done with magnetostrictive layer deposited on PZT plate. Finally, a film/film structure using magnetostrictive and aluminium nitride films on silicon substrate was realized, and showed ME amplitudes reaching 30 V Oe{sup -1} cm{sup -1}. Results agree with analytical theory.

  20. Understanding the reorientations and roles of spatial planning

    DEFF Research Database (Denmark)

    Galland, Daniel

    2012-01-01

    Spatial planning commonly adopts a diversity of functions and logics in contributing to handle growth and development. Being influenced by an array of contextual driving forces that result in specific institutional practices and policy agendas, spatial planning seems to be constantly reoriented...... by analytical concepts drawn from planning theory, state spatial theory and discourse analysis. Based on an in-depth study, the article then attempts to qualify, illustrate and synthesise the diverse roles that spatial planning has taken in Denmark throughout that time frame. The article concludes that spatial...... in terms of its purposes and reasoning. This article sets out to explore the diverse orientations and roles that spatial planning has assumed in Denmark over a 50-year period. In doing so, the article examines the evolution of national planning policy by means of a multi-disciplinary framework comprised...

  1. Tidal reorientation and the fracturing of Jupiter's moon Europa

    Science.gov (United States)

    Mcewen, A. S.

    1986-01-01

    The lineaments on Europa are discussed in terms of the orientation of the lineaments relative to the tensile stress trajectories due to tidal distortions and to nonsynchronous rotation. The cracks are noticeable by their darker albedo compared to the presumed water ice surrounding them. The stress trajectories for tidal distortion of a thin elastic shell are superimposed on Mercator projection maps of the lineaments. It is shown that the lineaments are mainly oriented at high angles to the tensile stress trajectories that would be expected for regularly occurring nonsynchronous rotation, i.e., extensional fractures would appear. The reorientation motions which would cause the fractures are estimated. It is suggested that the fractures occur episodically to release stresses built up on the tensile surface of the crust during the continuous nonsynchronous rotation of Europa.

  2. Reorienting MHD colliding flows: a shock physics mechanism for generating filaments normal to magnetic fields

    Science.gov (United States)

    Fogerty, Erica; Carroll-Nellenback, Jonathan; Frank, Adam; Heitsch, Fabian; Pon, Andy

    2017-09-01

    We present numerical simulations of reorienting oblique shocks that form in the collision layer between magnetized colliding flows. Reorientation aligns post-shock filaments normal to the background magnetic field. We find that reorientation begins with pressure gradients between the collision region and the ambient medium. This drives a lateral expansion of post-shock gas, which reorients the growing filament from the outside-in (i.e. from the flow/ambient boundary, towards the colliding flows axis). The final structures of our simulations resemble polarization observations of filaments in Taurus and Serpens South, as well as the integral-shaped filament in Orion A. Given the ubiquity of colliding flows in the interstellar medium, shock reorientation may be relevant to the formation of filaments normal to magnetic fields.

  3. Reorienting MHD Colliding Flows: A Shock Physics Mechanism for Generating Filaments Normal to Magnetic Fields

    CERN Document Server

    Fogerty, Erica L; Frank, Adam; Heitsch, Fabian; Pon, Andy

    2016-01-01

    We present numerical simulations of reorienting oblique shocks that form in the collision layer between magnetized colliding flows. Reorientation aligns parsec-scale post-shock filaments normal to the background magnetic field. We find that reorientation begins with pressure gradients between the collision region and the ambient medium. This drives a lateral expansion of post-shock gas, which reorients the growing filament from the outside-in (i.e. from the flow-ambient boundary, toward the colliding flows axis). The final structures of our simulations resemble polarization observations of filaments in Taurus and Serpens South, as well as the integral-shaped filament in Orion A. Given the ubiquity of colliding flows in the interstellar medium, shock reorientation may be relevant to the formation of filaments normal to magnetic fields.

  4. Paradigms of polyamory.

    Science.gov (United States)

    Zambrano, M

    1999-01-01

    SUMMARY The paradigm theory of Thomas Kuhn is used as a framework to discuss alternative ways of intimacy. The author discusses the implications of structuring actual lesbian relationships by a paradigm of monogamy among Latin-American women. The author proposes that creating alternative paradigms of multiple relationships would be useful for many lesbians as models for alternative life patterns.

  5. Positioning Theory in Paradigms

    Institute of Scientific and Technical Information of China (English)

    FU Xiao-qiu

    2015-01-01

    This article discusses the importance of theory and paradigm to a researcher. It starts from introducing and analyzing the definition of the two terms, by using the theories in the field of intercultural communication as examples. To a good researcher, he needs not only clarifying the paradigm his research is positioned, but also integrating the theories in his paradigm.

  6. Does constraining field of view prevent extraction of geometric cues for humans during virtual-environment reorientation?

    Science.gov (United States)

    Sturz, Bradley R; Kilday, Zachary A; Bodily, Kent D

    2013-10-01

    Environment size has been shown to influence the reliance on local and global geometric cues during reorientation. Unless changes in environment size are produced by manipulating length and width proportionally, changes in environment size are confounded by the amount of the environment that is visible from a single vantage point. Yet, the influence of the amount of the environment that is visible from any single vantage point on the use of local and global geometric cues remains unknown. We manipulated the amount of an environment that was visually available to participants by manipulating field of view (FOV) in a virtual environment orientation task. Two groups of participants were trained in a trapezoid-shaped enclosure to find a location that was uniquely specified by both local and global geometric cues. One group (FOV 50°) had visually less of the environment available to them from any one perspective compared to another group (FOV 100°). Following training, we presented both groups with a control test along with three novel-shaped environments. Testing assessed the use of global geometry in isolation, in alignment with local geometry, or in conflict with local geometry. Results (confirmed by a follow-up experiment) indicated that constraining FOV prevented extraction of geometric properties and relationships of space and resulted in an inability to use either global or local geometric cues for reorientation.

  7. Reorienting in virtual 3D environments: do adult humans use principal axes, medial axes or local geometry?

    Directory of Open Access Journals (Sweden)

    Althea H Ambosta

    Full Text Available Studies have shown that animals, including humans, use the geometric properties of environments to orient. It has been proposed that orientation is accomplished primarily by encoding the principal axes (i.e., global geometry of an environment. However, recent research has shown that animals use local information such as wall length and corner angles as well as local shape parameters (i.e., medial axes to orient. The goal of the current study was to determine whether adult humans reorient according to global geometry based on principal axes or whether reliance is on local geometry such as wall length and sense information or medial axes. Using a virtual environment task, participants were trained to select a response box located at one of two geometrically identical corners within a featureless rectangular-shaped environment. Participants were subsequently tested in a transformed L-shaped environment that allowed for a dissociation of strategies based on principal axes, medial axes and local geometry. Results showed that participants relied primarily on a medial axes strategy to reorient in the L-shaped test environment. Importantly, the search behaviour of participants could not be explained by a principal axes-based strategy.

  8. Dynamics of the central bottleneck: dual-task and task uncertainty.

    Directory of Open Access Journals (Sweden)

    Mariano Sigman

    2006-07-01

    Full Text Available Why is the human brain fundamentally limited when attempting to execute two tasks at the same time or in close succession? Two classical paradigms, psychological refractory period (PRP and task switching, have independently approached this issue, making significant advances in our understanding of the architecture of cognition. Yet, there is an apparent contradiction between the conclusions derived from these two paradigms. The PRP paradigm, on the one hand, suggests that the simultaneous execution of two tasks is limited solely by a passive structural bottleneck in which the tasks are executed on a first-come, first-served basis. The task-switching paradigm, on the other hand, argues that switching back and forth between task configurations must be actively controlled by a central executive system (the system controlling voluntary, planned, and flexible action. Here we have explicitly designed an experiment mixing the essential ingredients of both paradigms: task uncertainty and task simultaneity. In addition to a central bottleneck, we obtain evidence for active processes of task setting (planning of the appropriate sequence of actions and task disengaging (suppression of the plan set for the first task in order to proceed with the next one. Our results clarify the chronometric relations between these central components of dual-task processing, and in particular whether they operate serially or in parallel. On this basis, we propose a hierarchical model of cognitive architecture that provides a synthesis of task-switching and PRP paradigms.

  9. The effect of stress state on zirconium hydride reorientation

    Science.gov (United States)

    Cinbiz, Mahmut Nedim

    Prior to storage in a dry-cask facility, spent nuclear fuel must undergo a vacuum drying cycle during which the spent fuel rods are heated up to elevated temperatures of ≤ 400°C to remove moisture the canisters within the cask. As temperature increases during heating, some of the hydride particles within the cladding dissolve while the internal gas pressure in fuel rods increases generating multi-axial hoop and axial stresses in the closed-end thin-walled cladding tubes. As cool-down starts, the hydrogen in solid solution precipitates as hydride platelets, and if the multiaxial stresses are sufficiently large, the precipitating hydrides reorient from their initial circumferential orientation to radial orientation. Radial hydrides can severely embrittle the spent nuclear fuel cladding at low temperature in response to hoop stress loading. Because the cladding can experience a range of stress states during the thermo-mechanical treatment induced during vacuum drying, this study has investigated the effect of stress state on the process of hydride reorientation during controlled thermo-mechanical treatments utilizing the combination of in situ X-ray diffraction and novel mechanical testing analyzed by the combination of metallography and finite element analysis. The study used cold worked and stress relieved Zircaloy-4 sheet containing approx. 180 wt. ppm hydrogen as its material basis. The failure behavior of this material containing radial hydrides was also studied over a range of temperatures. Finally, samples from reactor-irradiated cladding tubes were examined by X-ray diffraction using synchrotron radiation. To reveal the stress state effect on hydride reorientation, the critical threshold stress to reorient hydrides was determined by designing novel mechanical test samples which produce a range of stress states from uniaxial to "near-equibiaxial" tension when a load is applied. The threshold stress was determined after thermo-mechanical treatments by

  10. Understanding paradigms used for nursing research.

    Science.gov (United States)

    Weaver, Kathryn; Olson, Joanne K

    2006-02-01

    The aims of this paper are to add clarity to the discussion about paradigms for nursing research and to consider integrative strategies for the development of nursing knowledge. Paradigms are sets of beliefs and practices, shared by communities of researchers, which regulate inquiry within disciplines. The various paradigms are characterized by ontological, epistemological and methodological differences in their approaches to conceptualizing and conducting research, and in their contribution towards disciplinary knowledge construction. Researchers may consider these differences so vast that one paradigm is incommensurable with another. Alternatively, researchers may ignore these differences and either unknowingly combine paradigms inappropriately or neglect to conduct needed research. To accomplish the task of developing nursing knowledge for use in practice, there is a need for a critical, integrated understanding of the paradigms used for nursing inquiry. We describe the evolution and influence of positivist, postpositivist, interpretive and critical theory research paradigms. Using integrative review, we compare and contrast the paradigms in terms of their philosophical underpinnings and scientific contribution. A pragmatic approach to theory development through synthesis of cumulative knowledge relevant to nursing practice is suggested. This requires that inquiry start with assessment of existing knowledge from disparate studies to identify key substantive content and gaps. Knowledge development in under-researched areas could be accomplished through integrative strategies that preserve theoretical integrity and strengthen research approaches associated with various philosophical perspectives. These strategies may include parallel studies within the same substantive domain using different paradigms; theoretical triangulation to combine findings from paradigmatically diverse studies; integrative reviews; and mixed method studies. Nurse scholars are urged to

  11. Control and Interference in Task Switching--A Review

    Science.gov (United States)

    Kiesel, Andrea; Steinhauser, Marco; Wendt, Mike; Falkenstein, Michael; Jost, Kerstin; Philipp, Andrea M.; Koch, Iring

    2010-01-01

    The task-switching paradigm offers enormous possibilities to study cognitive control as well as task interference. The current review provides an overview of recent research on both topics. First, we review different experimental approaches to task switching, such as comparing mixed-task blocks with single-task blocks, predictable task-switching…

  12. Time course and auxin sensitivity of cortical microtubule reorientation in maize roots

    Science.gov (United States)

    Blancaflor, E. B.; Hasenstein, K. H.

    1995-01-01

    The kinetics of MT [microtubule] reorientation in primary roots of Zea mays cv. Merit, were examined 15, 30, 45, and 60 min after horizontal positioning. Confocal microscopy of longitudinal tissue sections showed no change in MT orientation 15 and 30 min after horizontal placement. However, after 45 and 60 min, MTs of the outer 4-5 cortical cell layers along the lower side were reoriented. In order to test whether MT reorientation during graviresponse is caused by an auxin gradient, we examined the organization of MTs in roots that were incubated for 1 h in solutions containing 10(-9) to 10(-6) M IAA. IAA treatment at 10(-8) M or less showed no major or consistent changes but 10(-7) M IAA resulted in MT reorientation in the cortex. The auxin effect does not appear to be acid-induced since benzoic acid (10(-5) M) did not cause MT reorientation. The region closest to the maturation zone was most sensitive to IAA. The data indicate that early stages of gravity induced curvature occur in the absence of MT reorientation but sustained curvature leads to reoriented MTs in the outer cortex. Growth inhibition along the lower side of graviresponding roots appears to result from asymmetric distribution of auxin following gravistimulation.

  13. Paradigms and pragmatism: approaches to medical statistics.

    Science.gov (United States)

    Healy, M J

    2000-01-01

    Until recently, the dominant philosophy of science was that due to Karl Popper, with its doctrine that the proper task of science was the formulation of hypotheses followed by attempts at refuting them. In spite of the close analogy with significance testing, these ideas do not fit well with the practice of medical statistics. The same can be said of the later philosophy of Thomas Kuhn, who maintains that science proceeds by way of revolutionary upheavals separated by periods of relatively pedestrian research which are governed by what Kuhn refers to as paradigms. Through there have been paradigm shifts in the history of statistics, a degree of continuity can also be discerned. A current paradigm shift is embodied in the spread of Bayesian ideas. It may be that a future paradigm will emphasise the pragmatic approach to statistics that is associated with the name of Daniel Schwartz.

  14. Spin reorientation transition in Co/Au multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Quispe-Marcatoma, J., E-mail: jquispem@unmsm.edu.pe [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180 (Brazil); Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, P.O. Box 14-0149, Lima 14, Perú (Peru); Tarazona, H. [Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, P.O. Box 14-0149, Lima 14, Perú (Peru); Pandey, B. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180 (Brazil); Department of Applied Science, Symbiosis Institute of Technology, SIU, Lavale, Pune 412 115, India. (India); Sousa, M.A. de [Instituto de Física, Universidade Federal de Goiás, Goiânia 74001-970 (Brazil); Carvalho, M. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180 (Brazil); Landauro, C.V. [Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, P.O. Box 14-0149, Lima 14, Perú (Peru); Pelegrini, F. [Instituto de Física, Universidade Federal de Goiás, Goiânia 74001-970 (Brazil); Baggio Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro 22290-180 (Brazil)

    2014-10-01

    We report a study about the spin reorientation transition (SRT) from perpendicular easy axis to in-plane easy axis of magnetization in Co/Au multilayers. A series of multilayers of Si/Au(100 Å)/{[Co(t_C_o)/Au(20 Å)]_2_0}/Au(50 Å) family were studied, with Co layer thickness varying between 6 Å to 30 Å. The thickness of the Au layer was chosen large enough in order to minimize the interlayer exchange coupling between Co layers. In such thick Au-layer samples the magnetic properties are mainly the result of competition between interlayer magnetostatic coupling due to stray field, perpendicular magnetic anisotropy and shape anisotropy. The effective anisotropy constant K{sub eff} and the second order anisotropy K{sub 2} were deduced from the fit of the resonant magnetic field obtained from out of plane dependence Ferromagnetic Resonance (FMR) experiments. To study the SRT, we have plotted the phase diagram between K{sub eff} and K{sub 2}. The results show that SRT occurs through the metastable region with K{sub 2} ≤ −½ K{sub eff}, (K{sub eff} > 0). It is interesting to note that FMR shows the coexistence of two modes with different anisotropy for small Co thickness, while for thick Co layers the modes have the same anisotropy. Moreover, in thick Co layer samples, volume and surface spin wave resonance (SWR) modes were also excited by the microwave field, around the perpendicular FMR geometry, giving a clear evidence of a magnetic coupling between the Co layers. - Highlights: • Co/Au multilayers with varying Co layer thickness are prepared by DC-magnetron sputtering. • The spin reorientation transition (SRT) and flipping of magnetic moment are studied. • Effective anisotropy constant (K) and 2nd order anisotropy constant (K{sub 2}) are calculated. • K Vs K{sub 2} plot showed that SRT occurs through the metastable region with K{sub 2} ≤ −½ K, (K > 0). • Ferromagnetic Resonance spectra showed the coexistence of two resonance modes.

  15. Public Administration Education in Europe: Continuity or Reorientation?

    Science.gov (United States)

    Hajnal, Gyorgy

    2015-01-01

    The article explores the changing patterns of disciplinary orientation in European public administration (PA) education. The study builds on an earlier research, which defined three distinct clusters of countries, based on their specific PA education tradition. It asks whether countries' movement away from the Legalist paradigm has continued since…

  16. Temperature-driven spin reorientation transition of magnetron sputtered nickel thin film

    Institute of Scientific and Technical Information of China (English)

    Song Xiao-Hui; Zhang Dian-Lin

    2008-01-01

    The temperature-driven spin reorientation transition of magnetron sputtered Ni/Si(111)systems has been studied.The relationship between ac initial susceptibility and temperature of nickel films with different thicknesses shows that the magnetization orientation changes from in-plane to out-of-plane with the increase of temperature.The temperature dependence of magnetoelastic,magneto-crystalline,and magnetostatic anisotropies determines the direction of the reorientation transition.The temperature-driven spin reorientation transition is supported by Hall coefficient measurements which show that its temperature dependence is similar to that of susceptibility.

  17. Stress-induced martensite variant reorientation in magnetic shape memory Ni Mn Ga single crystal studied by neutron diffraction

    Science.gov (United States)

    Molnar, P.; Sittner, P.; Lukas, P.; Hannula, S.-P.; Heczko, O.

    2008-06-01

    Stress-induced martensite variant reorientation in magnetic shape memory Ni-Mn-Ga single crystal was studied in situ by the neutron diffraction technique. Principles of determination of individual tetragonal martensitic variants in shape memory alloys are explained. Using neutron diffraction we show that the macroscopic strain originates solely from the martensite structure reorientation or variant redistribution. Neutron diffraction also reveals that the reorientation of martensite is not fully completed even at a stress value of 25 MPa, which is about 20 times larger than the mean stress needed for reorientation. Only one twinning system is active during the reorientation process.

  18. Separating limits on preparation versus online processing in multitasking paradigms: Evidence for resource models.

    Science.gov (United States)

    Mittelstädt, Victor; Miller, Jeff

    2017-01-01

    We conducted 2 multitasking experiments to examine the finding that first-task reaction times (RTs) are slower in the psychological refractory period (PRP) paradigm than in the prioritized processing (PP) paradigm. To see whether this difference between the 2 paradigms could be explained entirely by differences in first-task preparation, which would be consistent with the standard response selection bottleneck (RSB) model for multitasking interference, we compared the size of this difference for trials in which a second-task stimulus actually occurred against the size of the difference for trials without any second-task stimulus. The slowing of first-task RTs in the PRP paradigm relative to the PP paradigm was larger when the second-task stimulus appeared than when it did not, indicating that the difference cannot be explained entirely by between-paradigm differences in first-task preparation. Instead, the results suggest that the slowing of first-task RTs in the PRP paradigm relative to the PP paradigm is partly because of differences between paradigms in the online reallocation of processing capacity to tasks. Thus, the present results provide new evidence supporting resource models over the RSB model. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  19. Structure-induced spin reorientation in magnetic nanostructures

    Science.gov (United States)

    Neumann, Alexander; Frauen, Axel; Vollmers, Julian; Meyer, Andreas; Oepen, Hans Peter

    2016-09-01

    We report on structuring-induced changes of the magnetic anisotropy of cylindrical nanostructures which are carved out of thin Pt/Co/Pt films. The magnetic properties of films and structures with a diameter of about 34 nm were investigated via magneto-optic Kerr effect. The magnetic anisotropy is determined for both films and nanostructures for varying Co thicknesses (0.5-7 nm). In general, the nanostructures exhibit larger perpendicular anisotropy than the films. On thickness increase of the Co layer two spin reorientation transitions at about 2.2 and 5 nm are found. At 2.2 nm the nanostructures exhibit the transition from perpendicular to in-plane orientation of magnetization while at 5 nm the reversed transition is found. The variation of the magnetic anisotropy of the Co nanostructures is not solely caused by the change of shape anisotropy. The net change, corrected for the shape, reveals a reduction of strain in the thinnest Co layers while the increase of the anisotropy of the nanostructures at higher Co thicknesses is caused by a transformation of the Co lattice from fcc to hcp.

  20. Resolving coiled shapes reveals new reorientation behaviors in C. elegans

    Science.gov (United States)

    Broekmans, Onno D; Rodgers, Jarlath B; Ryu, William S; Stephens, Greg J

    2016-01-01

    We exploit the reduced space of C. elegans postures to develop a novel tracking algorithm which captures both simple shapes and also self-occluding coils, an important, yet unexplored, component of 2D worm behavior. We apply our algorithm to show that visually complex, coiled sequences are a superposition of two simpler patterns: the body wave dynamics and a head-curvature pulse. We demonstrate the precise Ω-turn dynamics of an escape response and uncover a surprising new dichotomy in spontaneous, large-amplitude coils; deep reorientations occur not only through classical Ω-shaped postures but also through larger postural excitations which we label here as δ-turns. We find that omega and delta turns occur independently, suggesting a distinct triggering mechanism, and are the serpentine analog of a random left-right step. Finally, we show that omega and delta turns occur with approximately equal rates and adapt to food-free conditions on a similar timescale, a simple strategy to avoid navigational bias. DOI: http://dx.doi.org/10.7554/eLife.17227.001 PMID:27644113

  1. Water reorientation in the hydration shells of hydrophilic and hydrophobic solutes

    Institute of Scientific and Technical Information of China (English)

    LAAGE; Damien; STIRNEMANN; Guillaume; HYNES; James; T.

    2010-01-01

    We discuss some key aspects of our recent theoretical work on water reorientation dynamics,which is important in a wide range of phenomena,including aqueous phase chemical reactions,protein folding,and drug binding to proteins and DNA. It is shown that,contrary to the standard conception that these dynamics are diffusional,the reorientation of a water molecule occurs by sudden,large amplitude angular jumps. The mechanism involves the exchange of one hydrogen bond for another by the reorienting water,and the process can be fruitfully viewed as a chemical reaction. The results for reorientation times,which can be well described analytically,are discussed in the context of the molecular level interpretation of recent ultrafast infrared spectroscopic results,focusing on the concepts of structure making/breaking and solvent ’icebergs’.

  2. Spin reorientation transition process in single crystal NdFeO3

    Science.gov (United States)

    Song, Gaibei; Jiang, Junjie; Kang, Baojuan; Zhang, Jincang; Cheng, Zhenxiang; Ma, Guohong; Cao, Shixun

    2015-06-01

    The spin reorientation transition in single crystal NdFeO3 is studied using AC magnetic susceptibility, hysteresis loops, and polarized terahertz (THz) time domain spectroscopy measurements. Different frequency dependence behaviors of AC susceptibility reflect that the dynamic response of magnetization inside the spin reorientation region differs from the phase outside the transition region. The magnetization hysteresis loops at different temperatures reveal that domains formed during the spin reorientation process, which coincides with the abrupt increase of AC magnetic susceptibility during the transition. In addition, temperature dependent THz wave excitation of quasi-antiferromagnetic mode indicates the process of spin reorientation as a continuous rotation of Fe3+ spins rather than a mixed phase of Γ4 and Γ2.

  3. Switching of bacterial adhesion to a glycosylated surface by reversible reorientation of the carbohydrate ligand

    DEFF Research Database (Denmark)

    Weber, Theresa; Chrasekaran, Vijayan; Stamer, Insa

    2014-01-01

    The surface recognition in many biological systems is guided by the interaction of carbohydrate-specific proteins (lectins) with carbohydrate epitopes (ligands) located within the unordered glycoconjugate layer (glycocalyx) of cells. Thus, for recognition, the respective ligand has to reorient...

  4. The Investment Paradigm

    Science.gov (United States)

    Perna, Mark C.

    2005-01-01

    Is marketing an expense or an investment? Most accountants will claim that marketing is an expense, and clearly that seems true when cutting the checks to fund these efforts. When it is done properly, marketing is the best investment. A key principle to Smart Marketing is the Investment Paradigm. The Investment Paradigm is understanding that every…

  5. Of Paradigms and Power

    DEFF Research Database (Denmark)

    Carstensen, Martin B.; Matthijs, Matthias

    game in town. In effect, while Hall’s approach can account for inter-paradigm change with reference to exogenous shocks, it does not allow for significant ideational change to occur intra-paradigm. In order to remedy this, we suggest that the concept of ideational power be placed more centrally...

  6. Low temperature spin reorientation in dysprosium iron garnet

    Energy Technology Data Exchange (ETDEWEB)

    Lahoubi, M; Younsi, W; Soltani, M L [Department of Physics, Badji-Mokhtar University, BP-12 Annaba, 23000 (Algeria); Voiron, J; Schmitt, D, E-mail: mlahoubi@gmail.co [Louis Neel Laboratory, CNRS-UJF, BP-166, 38042 Grenoble Cedex 9 (France)

    2009-03-01

    The spin reorientation (SR) phase transition in dysprosium iron garnet (Dy{sub 3}Fe{sub 5}O{sub 12} or DyIG) have been studied by specific heat C{sub p}(T) and high field magnetisation measurements M{sub T}(H) and M{sub H}(T) on single crystals at low temperature. A first order SR is observed with a sharp jump at T{sub SR} = 14.5+-0.5 K in the C{sub p}(T) curve which corresponds to a spontaneous change from the high temperature (HT) easy direction (111) to an (uuw) angular low temperature (LT) phases. Above T{sub SR}, the magnetic structure is described by the irreducible representation (IR) A{sub 2g} of the rhombohedral space group R 3 c. Below T{sub SR}, the magnetic structure changes in the monoclinic the space group C2/c with the IR A{sub g}. When the field H is kept aligned along the hard symmetry directions (100) and (110), we obtain respectively the variation of the angular positions theta(T) and theta'(T) from the total spontaneous magnetisation down to 1.5 K (theta = 39.23 deg. and theta' = 30.14 deg.) and the results are in good agreement with the previous observations in low fields. When the sample is allowed to rotate freely on itself, the critical field H{sub c}(T) between the HT(111) and the LT(uuw) angular phases permits us to precise the transition line up to 15 T and 40 K between the so called canted field induced (FI) and the associated collinear magnetic phases. The experimental magnetic phase diagram (MPD) is precisely determined in the (H{sub c}-T) plane and the domains of the existence and the stability of the two magnetic phases are specified.

  7. Subliminal Reorientation and Repositioning in Immersive Virtual Environments using Saccadic Suppression.

    Science.gov (United States)

    Bolte, Benjamin; Lappe, Markus

    2015-04-01

    Virtual reality strives to provide a user with an experience of a simulated world that feels as natural as the real world. Yet, to induce this feeling, sometimes it becomes necessary for technical reasons to deviate from a one-to-one correspondence between the real and the virtual world, and to reorient or reposition the user's viewpoint. Ideally, users should not notice the change of the viewpoint to avoid breaks in perceptual continuity. Saccades, the fast eye movements that we make in order to switch gaze from one object to another, produce a visual discontinuity on the retina, but this is not perceived because the visual system suppresses perception during saccades. As a consequence, our perception fails to detect rotations of the visual scene during saccades. We investigated whether saccadic suppression of image displacement (SSID) can be used in an immersive virtual environment (VE) to unconsciously rotate and translate the observer's viewpoint. To do this, the scene changes have to be precisely time-locked to the saccade onset. We used electrooculography (EOG) for eye movement tracking and assessed the performance of two modified eye movement classification algorithms for the challenging task of online saccade detection that is fast enough for SSID. We investigated the sensitivity of participants to translations (forward/backward) and rotations (in the transverse plane) during trans-saccadic scene changes. We found that participants were unable to detect approximately ±0.5m translations along the line of gaze and ±5° rotations in the transverse plane during saccades with an amplitude of 15°. If the user stands still, our approach exploiting SSID thus provides the means to unconsciously change the user's virtual position and/or orientation. For future research and applications, exploiting SSID has the potential to improve existing redirected walking and change blindness techniques for unlimited navigation through arbitrarily-sized VEs by real walking.

  8. Parallel Programming Paradigms

    Science.gov (United States)

    1987-07-01

    GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4, TITL.: td Subtitle) S. TYPE OF REPORT & PERIOD COVERED Parallel Programming Paradigms...studied. 0A ITI is Jt, t’i- StCUI-eASSIICATION OFvrHIS PAGFrm".n Def. £ntered, Parallel Programming Paradigms Philip Arne Nelson Department of Computer...8416878 and by the Office of Naval Research Contracts No. N00014-86-K-0264 and No. N00014-85- K-0328. 8 ?~~ O .G 1 49 II Parallel Programming Paradigms

  9. The fictionalist paradigm.

    Science.gov (United States)

    Paley, John

    2011-01-01

    The fictionalist paradigm is introduced, and differentiated from other paradigms, using the Lincoln & Guba template. Following an initial overview, the axioms of fictionalism are delineated by reference to standard metaphysical categories: the nature of reality, the relationship between knower and known, the possibility of generalization, the possibility of causal linkages, and the role of values in inquiry. Although a paradigm's 'basic beliefs' are arbitrary and can be assumed for any reason, in this paper the fictionalist axioms are supported with philosophical considerations, and the key differences between fictionalism, positivism, and constructivism are briefly explained. Paradigm characteristics are then derived, focusing particularly on the methodological consequences. Towards the end of the paper, various objections and misunderstandings are discussed. © 2010 Blackwell Publishing Ltd.

  10. How can health remain central post-2015 in a sustainable development paradigm?

    Science.gov (United States)

    Hill, Peter S; Buse, Kent; Brolan, Claire E; Ooms, Gorik

    2014-04-03

    In two years, the uncompleted tasks of the Millennium Development Goals will be merged with the agenda articulated in the 2012 United Nations Conference on Sustainable Development. This process will seek to integrate economic development (including the elimination of extreme poverty), social inclusion, environmental sustainability, and good governance into a combined sustainable development agenda. The first phase of consultation for the post-2015 Sustainable Development Goals reached completion in the May 2013 report to the Secretary-General of the High-Level Panel of Eminent Persons on the Post-2015 Development Agenda. Health did well out of the Millennium Development Goal (MDG) process, but the global context and framing of the new agenda is substantially different, and health advocates cannot automatically assume the same prominence. This paper argues that to remain central to continuing negotiations and the future implementation, four strategic shifts are urgently required. Advocates need to reframe health from the poverty reduction focus of the MDGs to embrace the social sustainability paradigm that underpins the new goals. Second, health advocates need to speak--and listen--to the whole sustainable development agenda, and assert health in every theme and every relevant policy, something that is not yet happening in current thematic debates. Third, we need to construct goals that will be truly "universal", that will engage every nation--a significant re-orientation from the focus on low-income countries of the MDGs. And finally, health advocates need to overtly explore what global governance structures will be needed to finance and implement these universal Sustainable Development Goals.

  11. Understanding the land management paradigm

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    structures by identifying an ideal and historically neutral LAS model for: servicing the needs of governments, business and the public; utilising the latest technologies; servicing rights, responsibilities, restrictions and risks in relation to land; and delivering much broader information about sustainable......Land management is the process by which the resources of land are put into good effect. Land management encompasses all activities associated with the management of land and natural resources that are required to achieve sustainable development. Land Administration Systems (LAS) are institutional...... frameworks complicated by the tasks they must perform, by national cultural, political and judicial settings, and by technology. This paper facilitates an overall understanding of the land management paradigm. This paper assists sharing LAS among countries with diverse legal systems and institutional...

  12. Understanding the land management paradigm

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    Land management is the process by which the resources of land are put into good effect. Land management encompasses all activities associated with the management of land and natural resources that are required to achieve sustainable development. Land Administration Systems (LAS) are institutional...... frameworks complicated by the tasks they must perform, by national cultural, political and judicial settings, and by technology. This paper facilitates an overall understanding of the land management paradigm. This paper assists sharing LAS among countries with diverse legal systems and institutional...... structures by identifying an ideal and historically neutral LAS model for: servicing the needs of governments, business and the public; utilising the latest technologies; servicing rights, responsibilities, restrictions and risks in relation to land; and delivering much broader information about sustainable...

  13. Reorientation phenomena in imidazolium methyl sulfonate as probed by advanced solid-state NMR.

    Science.gov (United States)

    Goward, Gillian R; Saalwächter, Kay; Fischbach, Ingrid; Spiess, Hans Wolfgang

    2003-01-01

    Evidence for reorientation of imidazolium rings in imidazolium methylsulfonate is demonstrated using solid-state NMR. This material is a model system for exciting new proton-conducting materials based on imidazole. Two advanced NMR methods, including 1H-13C and 1H-15N recoupled polarization transfer with dipolar sideband pattern analysis and analysis of the coalescence of 13C lineshapes are used to characterize the ring reorientation. The process is found to occur at temperatures well below the melting point of the salt, between 240 and 380 K, and is described by a single activation energy, of 38+/-5 kJ/mol. This material is considered as a model system for quantifying the ring reorientation process, which is often proposed to be the rate-limiting step in proton transport in imidazole-based proton conducting materials.

  14. Influence of Rayleigh-Taylor Instability on Liquid Propellant Reorientation in a Low-Gravity Environment

    Institute of Scientific and Technical Information of China (English)

    LI Zhang-Guo; LIU Qiu-Sheng; LIU Rong; HU Wei; DENG Xin-Yu

    2009-01-01

    A computational simulation is conducted to investigate the influence of Rayleigh-Taylor instability on liquid propellant reorientation flow dynamics for the tank of CZ-3A launch vehicle series fuel tanks in a low-gravity environment. The volume-of-fluid (VOF) method is used to simulate the free surface flow of gas-liquid. The process of the liquid propellant reorientation started from initially fiat and curved interfaces are numerically studied. These two different initial conditions of the gas-liquid interface result in two modes of liquid flow. It is found that the Rayleigh-Taylor instability can be reduced evidently at the initial gas-liquid interface with a high curve during the process of liquid reorientation in a low-gravity environment.

  15. Femtosecond study of the effects of ions on the reorientation dynamics of water

    CERN Document Server

    van der Post, Sietse T; Bakker, Huib J

    2013-01-01

    We study the effects of ions on the reorientation dynamics of liquid water with polarization-resolved femtosecond mid-infared spectroscopy. We probe the anisotropy of the excitation of the O-D stretch vibration of HDO molecules in solutions of NaCl, NaI and tetra-alkylammonium bromide salts in 8 percent HDO:H2O. We find that the reorientation O-D groups of HDO molecules hydrating the Cl- and I- anions occurs on two different time scales with time constants of 2pm0.3 ps and 9pm2 ps. The fast component is due to a wobbling motion of the O-D group that keeps the hydrogen bond with the halogenic anion intact. For solutions of tetra-alkylammonium bromide salts we observe a very strong slowing down of the reorientation of water that is associated with the hydration of the hydrophobic alkyl groups of the tetra-alkylammonium ions.

  16. Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

    Directory of Open Access Journals (Sweden)

    Amanda García-García

    2016-06-01

    Full Text Available Single-wall carbon nanotubes (SWCNT are anisotropic nanoparticles that can cause modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a system where the liquid crystal orientation effect has been isolated. Complementary studies including Raman spectroscopy, microscopic inspection and impedance studies were carried out. The results reveal an ordered reorientation of the CNTs induced by an electric field, which does not alter the orientation of the liquid crystal molecules. Moreover, impedance spectroscopy suggests a nonnegligible anchoring force between the CNTs and the liquid crystal molecules.

  17. Reorientation response of magnetic microspheres attached to gold electrodes under an applied magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    De Los Santos Valladares, L.; Reeve, R.M.; Mitrelias, T.; Langford, R.M.; Barnes, C.H.W., E-mail: luis_d_v@hotmail.com [Cavendish Laboratory, Department of Physics, University of Cambridge Materials and Structures Laboratory (United Kingdom); Bustamante Dominguez, A. [Laboratorio de Ceramicos y Nanomateriales, Facultad de Ciencias Fisicas, Universidad Nacional Mayor de San Marcos, Lima (Peru); Aguiar, J. Albino [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Fisica; Azuma, Y. [Materials and Structures Laboratory, Tokyo Institute of Technology, Midori-ku, Yokohama (Japan); Majima, Y. [CREST, Japan Science and Technology Agency (JST), Midori-ku, Yokohama (Japan)

    2013-08-15

    In this work, we report the mechanical reorientation of thiolated ferromagnetic microspheres bridging a pair of gold electrodes under an external magnetic field. When an external magnetic field (7 kG) is applied during the measurement of the current-voltage characteristics of a carboxyl ferromagnetic microsphere (4 μm diameter) attached to two gold electrodes by self-assembled monolayers (SAMs) of octane dithiol (C{sub 8}H{sub 18}S{sub 2}), the current signal is distorted. Rather than due to magnetoresistance, this effect is caused by a mechanical reorientation of the ferromagnetic sphere, which alters the number of SAMs between the sphere and the electrodes and therefore affects conduction. To study the physical reorientation of the ferromagnetic particles, we measure their hysteresis loops while suspended in a liquid solution. (author)

  18. Fluidization, resolidification, and reorientation of the endothelial cell in response to slow tidal stretches.

    Science.gov (United States)

    Krishnan, Ramaswamy; Canovic, Elizabeth Peruski; Iordan, Andreea L; Rajendran, Kavitha; Manomohan, Greeshma; Pirentis, Athanassios P; Smith, Michael L; Butler, James P; Fredberg, Jeffrey J; Stamenovic, Dimitrije

    2012-08-15

    Mechanical stretch plays an important role in regulating shape and orientation of the vascular endothelial cell. This morphological response to stretch is basic to angiogenesis, neovascularization, and vascular homeostasis, but mechanism remains unclear. To elucidate mechanisms, we used cell mapping rheometry to measure traction forces in primary human umbilical vein endothelial cells subjected to periodic uniaxial stretches. Onset of periodic stretch of 10% strain amplitude caused a fluidization response typified by attenuation of traction forces almost to zero. As periodic stretch continued, the prompt fluidization response was followed by a slow resolidification response typified by recovery of the traction forces, but now aligned along the axis perpendicular to the imposed stretch. Reorientation of the cell body lagged reorientation of the traction forces, however. Together, these observations demonstrate that cellular reorientation in response to periodic stretch is preceded by traction attenuation by means of cytoskeletal fluidization and subsequent traction recovery transverse to the stretch direction by means of cytoskeletal resolidification.

  19. Effect of spin reorientation on magnetocaloric and transport properties of NdAl2

    Science.gov (United States)

    de Souza, M. V.; da Silva, J. A.; Silva, L. S.

    2017-01-01

    We report the magneto-thermal and resistive properties of rare-earth dialuminide NdAl2, including spin reorientation transition. To this purpose, we used a theoretical model that considers the interactions of exchange and Zeeman, besides the anisotropy due to the electrical crystal field. The theoretical results obtained were compared to experimental data of the NdAl2 in single crystal and bulk forms. Explicitly, we have calculated the anisotropic variation of magnetic entropy with the magnetic field oriented along the three principal crystallographic directions: [100], [110], and [111] of NdAl2 single crystal, where a signature of the spin reorientation is observed in the [110] and [111] directions. Moreover, of magnetoresistivity we consider the applied magnetic field along the crystallographic directions [100] and [110]. In turn, for the polycrystalline form, the good agreement between theory and experiment confirms the presence of spin reorientation, which was predicted theoretically in magnetization curves.

  20. Chaotic attitude and reorientation maneuver for completely liquid-filled spacecraft with flexible appendage

    Institute of Scientific and Technical Information of China (English)

    Baozeng Yue

    2009-01-01

    The present paper investigates the chaotic attitude dynamics and reorientation maneuver for completely viscous liquid-filled spacecraft with flexible appendage. All of the equations of motion are derived by using Lagrangian mechanics and then transformed into a form consisting of an unperturbed part plus perturbed terms so that the system's nonlinear characteristics can be exploited in phase space.Emphases are laid on the chaotic attitude dynamics produced from certain sets of physical parameter values of the spacecraft when energy dissipation acts to derive the body from minor to major axis spin. Numerical solutions of these equations show that the attitude dynamics of liquid-filled flexible spacecraft possesses characteristics common to random, nonperiodic solutions and chaos, and it is demonstrated that the desired reorientation maneuver is guaranteed by using a pair of thruster impulses. The control strategy for reorientation maneuver is designed and the numerical simulation results are presented for both the uncontrolled and controlled spins transition.

  1. Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

    Science.gov (United States)

    García-García, Amanda; Vergaz, Ricardo; Algorri, José F; Zito, Gianluigi; Cacace, Teresa; Marino, Antigone; Otón, José M

    2016-01-01

    Summary Single-wall carbon nanotubes (SWCNT) are anisotropic nanoparticles that can cause modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a system where the liquid crystal orientation effect has been isolated. Complementary studies including Raman spectroscopy, microscopic inspection and impedance studies were carried out. The results reveal an ordered reorientation of the CNTs induced by an electric field, which does not alter the orientation of the liquid crystal molecules. Moreover, impedance spectroscopy suggests a nonnegligible anchoring force between the CNTs and the liquid crystal molecules. PMID:27547599

  2. Delirium prevention in critically ill adults through an automated reorientation intervention - A pilot randomized controlled trial.

    Science.gov (United States)

    Munro, Cindy L; Cairns, Paula; Ji, Ming; Calero, Karel; Anderson, W McDowell; Liang, Zhan

    Explore the effect of an automated reorientation intervention on ICU delirium in a prospective randomized controlled trial. Delirium is common in ICU patients, and negatively affects outcomes. Few prevention strategies have been tested. Thirty ICU patients were randomized to 3 groups. Ten received hourly recorded messages in a family member's voice during waking hours over 3 ICU days, 10 received the same messages in a non-family voice, and 10 (control) did not receive any automated reorientation messages. The primary outcome was delirium free days during the intervention period (evaluated by CAM-ICU). Groups were compared by Fisher's Exact Test. The family voice group had more delirium free days than the non-family voice group, and significantly more delirium free days (p = 0.0437) than the control group. Reorientation through automated, scripted messages reduced incidence of delirium. Using identical scripted messages, family voice was more effective than non-family voice. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Electron spin relaxation due to reorientation of a permanent zero field splitting tensor.

    Science.gov (United States)

    Schaefle, Nathaniel; Sharp, Robert

    2004-09-15

    Electron spin relaxation of transition metal ions with spin S> or =1 results primarily from thermal modulation of the zero field splitting (zfs) tensor. This occurs both by distortion of the zfs tensor due to intermolecular collisions and, for complexes with less than cubic symmetry, by reorientational modulation of the permanent zfs tensor. The reorientational mechanism is much less well characterized in previous work than the distortional mechanism although it is an important determinant of nuclear magnetic resonance (NMR) paramagnetic relaxation enhancement phenomena (i.e., the enhancement of NMR relaxation rates produced by paramagnetic ions in solution or NMR-PRE). The classical density matrix theory of spin relaxation does not provide an appropriate description of the reorientational mechanism at low Zeeman field strengths because the zero-order spin wave functions are stochastic functions of time. Using spin dynamics simulation techniques, the time correlation functions of the spin operators have been computed and used to determine decay times for the reorientational relaxation mechanism for S=1. In the zfs limit of laboratory field strengths (H(Zeem)spin decay is exponential, the spin relaxation time, tau(S) (composite function) approximately 0.53tau(R)((1)), where tau(R)((1)) is the reorientational correlation time of a molecule-fixed vector. The value of tau(S) (composite function) is independent of the magnitude of the cylindrical zfs parameter (D), but it depends strongly on low symmetry zfs terms (the E/D ratio). Other spin dynamics (SD) simulations examined spin decay in the intermediate regime of field strengths where H(Zeem) approximately H(zfs) (composite function), and in the vicinity of the Zeeman limit. The results demonstrate that the reorientational electron spin relaxation mechanism is often significant when H(zfs) (composite function)> or =H(Zeem), and that its neglect can lead to serious errors in the interpretation of NMR-PRE data.

  4. Winnicott's paradigm outlined

    Directory of Open Access Journals (Sweden)

    Zeljko Loparic

    Full Text Available The main objective of this paper is to present a unified view of Winnicott’s contribution to psychoanalysis. Part I (Sections 1-4 starts off by recalling that, according to some important commentators, Winnicott introduced a change in paradigms in psychoanalysis. In order to show that this change can be viewed as an overall “switch in paradigms”, in the sense given by T. S. Kuhn, this paper presents an account of the Kuhn’s view of science and offers a reconstruction of Freud’s Oedipal, Triangular or “Toddler-in-the-Mother’s-Bed” Paradigm. Part II (Sections 5-13 shows that as early as the 1920’s Winnicott encountered insurmountable anomalies in the Oedipal paradigm and, for that reason, started what can be called revolutionary research for a new framework of psychoanalysis. This research led Winnicott, especially during the last period of his life, to produce an alternative dual or “Baby-on-the-Mother’s-Lap” Paradigm. This new paradigm is described in some detail, especially the paradigmatic dual mother-baby relation and Winnicott’s dominant theory of maturation. Final remarks are made regarding Winnicott’s heritage and the future of psychoanalysis.

  5. Orbital magnetic moment instability at the spin reorientation transition of Nd2Fe14B

    Science.gov (United States)

    Garcia; Chaboy; Bartolome; Goedkoop

    2000-07-10

    Highly accurate soft-XMCD data recorded on a Nd2Fe14B single crystal, through the spin reorientation transition show that the average Fe orbital moment (a) is proportional to the macroscopic Fe anisotropy constant, and (b) diverges 15 K below the reorientation transition temperature. This divergence is indicative of a critical behavior and it is related to a tetragonal distortion. These results give experimental evidence of the mutual dependence between orbital moment, macroscopic magnetic anisotropy, and tetragonal distortion. Furthermore, it is argued that the critical behavior of the orbital moment is at the origin of similar divergences previously observed in Mossbauer and Hall-effect data.

  6. New fractal math tool providing simultaneous reorientation and acceleration of spacecraft

    Science.gov (United States)

    Yefremov, Alexander P.

    2017-10-01

    Quaternion based math system of spacecraft reorientation is extended by admitting imaginary rotation parameters, thus involving hyperbolic functions. For simplicity only one simple hyperbolic rotation is added as the last one in the series of orthogonal matrices. The scheme is reduced to a single rotation about instant axis, and to transformation of primitive basis on a 2D fractal space of dimension ½. This new tool is proved to simultaneously reorient the spacecraft and to accelerate it the kinematics automatically described as relativistic. With a small speed the problem becomes a classical one.

  7. Three paradigms of horror

    Directory of Open Access Journals (Sweden)

    Dejan Ognjanović

    2016-07-01

    Full Text Available Starting with the definition of horror as a literary genre the core story of which is based on a meeting with threatening Otherness whose influx into consensual reality and it’s tacit normality creates unrest and awakens fear in the protagonists and the audience, this paper defines the three key paradigms of the horror genre, based on the causes of fear, or rather the “monstrous” Otherness in them. Paradigm 1 concerns the “fear of one’s own self”: the root of the fear is inside, in the individual psyche, in the split, deceived, or in some other way unreliable self which is, consciously or unconsciously, harmful to others, and ultimately to itself. Paradigm 2 deals with the “Fear of others”: the root of fear is outside and is concerned with other people and other creatures which have an urge to occupy a certain human microcosm. Paradigm 3 is concerned with the “Fear of the numinous”: the root of the fear is mostly situated on the outside; however its shape is amorphous, ambivalent and unknowable. The “monster” is faceless; it touches on primary forces of the divine/demonic, and as such is situated on the very border between inside/outside. All three paradigms, with their main approaches and constitutive elements, are modulated through two basic possible treatments: the conservative and the progressive (liberal, which affords a total of six basic variations of horror. Starting from definitions given by John Carpenter, Robin Wood and his own, the author analyzes representative examples from horror literature and film for each paradigm and its variation, with a special accent on the image of Otherness and its connection to the norm, its intrusion into the status quo, anthropocentrism and the presence or absence of a happy ending. The paper demonstrates the richness of connotative potential within the horror genre and provides a basis for its taxonomy.

  8. Towards a New Paradigm

    DEFF Research Database (Denmark)

    Marsh, Rob; Larsen, Vibeke Grupe; Hacker, Jake

    2010-01-01

    for developing a new paradigm for zero-energy architecture. There has been a radical transformation in building energy consumption over the last 30 years, with an absolute reduction in heat consumption and a rapid growth in electricity consumption, reflecting wider technological and social transformations...... in the future. With this background, a new paradigm for zero-energy architecture is developed that re-flects the architectural design process. In this way, the architectural focus early in the de-sign process on functional disposition, spatial quality and built form can act as the driving force in the movement...

  9. Temperature-pressure-induced solid-solid to reorientation in FCC metallic nanowire: a molecular dynamic study.

    Science.gov (United States)

    Sutrakar, Vijay Kumar; Roy Mahapatra, D; Pillai, A C R

    2012-01-11

    Atomistic simulation of initial oriented FCC Cu nanowires shows a novel coupled temperature-pressure dependent reorientation from to phase. A temperature-pressure-induced solid-solid to reorientation diagram is generated for Cu nanowire with varying cross-sectional sizes. A critical pressure is reported for Cu nanowires with varying cross-sectional sizes, above which an initial oriented nanowire shows temperature independent reorientation into the phase. The effect of surface stresses on the to reorientation is also studied. The results indicate that above a critical cross-sectional size for a given temperature-pressure, to reorientation is not possible. It is also reported here that for a given applied pressure, an increase in temperature is required for the to reorientation with increasing cross-sectional size of the nanowire. The temperature-pressure-induced solid-solid to reorientation diagram reported in the present paper could further be used as guidelines for controlling the reorientations/shape memory in nano-scale applications of FCC metallic nanowires.

  10. Mental fatigue and task control : Planning and preparation

    NARCIS (Netherlands)

    Lorist, MM; Klein, M; Nieuwenhuis, S; De Jong, R; Mulder, G; Meijman, TF

    2000-01-01

    The effects of mental fatigue on planning and preparation for future actions were examined, using a task switching paradigm. Fatigue was induced by "time on task," with subjects performing a switch task continuously for 2 hr. Subjects had to alternate between tasks on every second trial, so that a n

  11. Long-term reliability of the visual EEG Poffenberger paradigm.

    Science.gov (United States)

    Friedrich, Patrick; Ocklenburg, Sebastian; Mochalski, Lisa; Schlüter, Caroline; Güntürkün, Onur; Genc, Erhan

    2017-07-14

    The Poffenberger paradigm is a simple perception task that is used to estimate the speed of information transfer between the two hemispheres, the so-called interhemispheric transfer time (IHTT). Although the original paradigm is a behavioral task, it can be combined with electroencephalography (EEG) to assess the underlying neurophysiological processes during task execution. While older studies have supported the validity of both paradigms for investigating interhemispheric interactions, their long-term reliability has not been assessed systematically before. The present study aims to fill this gap by determining both internal consistency and long-term test-retest reliability of IHTTs produced by using the two different versions of the Poffenberger paradigm in a sample of 26 healthy subjects. The results show high reliability for the EEG Poffenberger paradigm. In contrast, reliability measures for the behavioral Poffenberger paradigm were low. Hence, our results indicate that electrophysiological measures of interhemispheric transfer are more reliable than behavioral measures; the later should be used with caution in research investigating inter-individual differences of neurocognitive measures. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Alternative Evaluation Research Paradigm.

    Science.gov (United States)

    Patton, Michael Quinn

    This monograph is one of a continuing series initiated to provide materials for teachers, parents, school administrators, and governmental decision-makers that might encourage reexamination of a range of evaluation issues and perspectives about schools and schooling. This monograph is a description and analysis of two contrasting paradigms: one…

  13. Programming Language Paradigms

    Directory of Open Access Journals (Sweden)

    Bartoníček Jan

    2014-01-01

    Full Text Available This paper's goal is to briefly explain the basic theory behind programming languages and their history while taking a close look at different programming paradigms that are used today as well as describing their differences, benefits, and drawbacks

  14. RHO binding to FAM65A regulates Golgi reorientation during cell migration

    Science.gov (United States)

    Marshall, Christopher J.

    2016-01-01

    ABSTRACT Directional cell migration involves reorientation of the secretory machinery. However, the molecular mechanisms that control this reorientation are not well characterised. Here, we identify a new Rho effector protein, named FAM65A, which binds to active RHOA, RHOB and RHOC. FAM65A links RHO proteins to Golgi-localising cerebral cavernous malformation-3 protein (CCM3; also known as PDCD10) and its interacting proteins mammalian STE20-like protein kinases 3 and 4 (MST3 and MST4; also known as STK24 and STK26, respectively). Binding of active RHO proteins to FAM65A does not affect the kinase activity of MSTs but results in their relocation from the Golgi in a CCM3-dependent manner. This relocation is crucial for reorientation of the Golgi towards the leading edge and subsequent directional cell migration. Our results reveal a previously unidentified pathway downstream of RHO that regulates the polarity of migrating cells through Golgi reorientation in a FAM65A-, CCM3- and MST3- and MST4-dependent manner. PMID:27807006

  15. Social reorientation in adolescence : neurobiological changes and individual differences in empathic concern

    NARCIS (Netherlands)

    Overgaauw, Sandy

    2015-01-01

    One of the most prominent changes in adolescence is social reorientation. In other words, adolescents develop more intimate relationships with peers, they discover what it is like to be involved in a romantic relationship, and they take (social) risks by for example showing risky driving in the pres

  16. Use of Geometry for Spatial Reorientation in Children Applies Only to Symmetric Spaces

    Science.gov (United States)

    Lew, Adina R.; Gibbons, Bryony; Murphy, Caroline; Bremner, J. Gavin

    2010-01-01

    Proponents of the geometric module hypothesis argue that following disorientation, many species reorient by use of macro-environment geometry. It is suggested that attention to the surface layout geometry of natural terrain features may have been selected for over evolutionary time due to the enduring and unambiguous location information it…

  17. Why Size Counts: Children's Spatial Reorientation in Large and Small Enclosures

    Science.gov (United States)

    Learmonth, Amy E.; Newcombe, Nora S.; Sheridan, Natalie; Jones, Meredith

    2008-01-01

    When mobile organisms are spatially disoriented, for instance by rapid repetitive movement, they must re-establish orientation. Past research has shown that the geometry of enclosing spaces is consistently used for reorientation by a wide variety of species, but that non-geometric features are not always used. Based on these findings, some…

  18. Time-dependent solution for reorientation of rotating tidally deformed visco-elastic bodies

    Science.gov (United States)

    Hu, Haiyang; van der Wal, Wouter; Vermeersen, Bert

    2017-04-01

    Many icy satellites or planets contain features which suggest a (past) reorientation of the body, such as the tiger stripes on Enceladus and the heart-shaped Sputnik Planum on Pluto. Most of these icy bodies are tidally locked and this creates a large tidal bulge which is about three times of its centrifugal (equatorial) bulge. To study the reorientation of such rotating tidally deformed body is complicated and most previous studies apply the so-called fluid limit method. The fluid limit approach ignores the viscous response of the body and assumes that it immediately reaches its fluid limit when simulating the reorientation due to a changing load. As a result, this method can only simulate cases when the change in the load is much slower than the dominant viscous modes of the body. For other kinds of load, for instance, a Heaviside load due to an impact which creates an instant relocation of mass, it does not give us a prediction of how the reorientation is accomplished (e.g. How fast? Along which path?). We establish a new method which can give an accurate time-dependent solution for reorientation of rotating tidally deformed bodies. Our method can be applied both semi-analytically or numerically (with finite element method) to include features such as lateral heterogeneity or non-linear material. We also present an extension of our method to simulate the e ffect of a fossil bulge. With our method, we show that reorientation of a tidally deformed body driven by a positive mass anomaly near the poles has a preference for rotating around the tidal axis instead of towards it, contrary to predictions in previous studies. References Hu, H., W. van der Wal and L.L.A. Vermeersen (2017). A numerical method for reorientation of rotating tidally deformed visco-elastic bodies. Journal of Geophysical Research: Planets, doi:10.1002/2016JE005114, 2016JE005114. Matsuyama, I. and Nimmo, F. (2007). Rotational stability of tidally deformed planetary bodies. Journal of Geophysical

  19. Degrading emotional memories induced by a virtual reality paradigm.

    Science.gov (United States)

    Cuperus, Anne A; Laken, Maarten; van den Hout, Marcel A; Engelhard, Iris M

    2016-09-01

    In Eye Movement and Desensitization and Reprocessing (EMDR) therapy, a dual-task approach is used: patients make horizontal eye movements while they recall aversive memories. Studies showed that this reduces memory vividness and/or emotionality. A strong explanation is provided by working memory theory, which suggests that other taxing dual-tasks are also effective. Experiment 1 tested whether a visuospatial task which was carried out while participants were blindfolded taxes working memory. Experiment 2 tested whether this task degrades negative memories induced by a virtual reality (VR) paradigm. In experiment 1, participants responded to auditory cues with or without simultaneously carrying out the visuospatial task. In experiment 2, participants recalled negative memories induced by a VR paradigm. The experimental group simultaneously carried out the visuospatial task, and a control group merely recalled the memories. Changes in self-rated memory vividness and emotionality were measured. The slowing down of reaction times due to the visuospatial task indicated that its cognitive load was greater than the load of the eye movements task in previous studies. The task also led to reductions in emotionality (but not vividness) of memories induced by the VR paradigm. Weaknesses are that only males were tested in experiment 1, and the effectiveness of the VR fear/trauma induction was not assessed with ratings of mood or intrusions in experiment 2. The results suggest that the visuospatial task may be applicable in clinical settings, and the VR paradigm may provide a useful method of inducing negative memories. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Clinical fMRI of language function in aphasic patients: Reading paradigm successful, while word generation paradigm fails

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Maria; Landtblom, Anne-Marie; Ragnehed, Mattias; Lundberg, Peter (Center for Medical Image Science and Visualization (CMIV), Linkoeping Univ., Linkoeping (Sweden)), e-mail: maria.engstrom@liu.se; Karlsson, Marie; Crone, Marie (Dept. of Clinical and Experimental Medicine/Logopedics, Linkoeping Univ., Linkoeping (Sweden)); Antepohl, Wolfram (Dept. of Clinical and Experimental Medicine/Rehabilitation, Linkoeping Univ., Linkoeping (Sweden))

    2010-07-15

    Background: In fMRI examinations, it is very important to select appropriate paradigms assessing the brain function of interest. In addition, the patients' ability to perform the required cognitive tasks during fMRI must be taken into account. Purpose: To evaluate two language paradigms, word generation and sentence reading for their usefulness in examinations of aphasic patients and to make suggestions for improvements of clinical fMRI. Material and Methods: Five patients with aphasia after stroke or trauma sequelae were examined by fMRI. The patients' language ability was screened by neurolinguistic tests and elementary pre-fMRI language tests. Results: The sentence-reading paradigm succeeded to elicit adequate language-related activation in perilesional areas whereas the word generation paradigm failed. These findings were consistent with results on the behavioral tests in that all patients showed very poor performance in phonemic fluency, but scored well above mean at a reading comprehension task. Conclusion: The sentence-reading paradigm is appropriate to assess language function in this patient group, while the word-generation paradigm seems to be inadequate. In addition, it is crucial to use elementary pre-fMRI language tests to guide the fMRI paradigm decision.

  1. 2013 Winning Essay: The Accountable Care Paradigm Shift: New Ethical Considerations.

    Science.gov (United States)

    McNamara, Andrew R

    2015-07-01

    The current state of our health care system is analogous to the status of science that Kuhn describes as "a proliferation of compelling articulations, the willingness to try anything, the expression of explicit discontent, the recourse to philosophy and to debate over fundamentals" [27]. ACOs represent a paradigm shift in the way health care is delivered. As with any dramatic public policy change, ethical issues will arise. These are surmountable challenges, and with open communication, physicians such as the Midstate group can partner effectively with hospital systems to ensure the delivery of quality, evidence-based care while at the same reorienting the culture to be attentive to its fiduciary responsibilities.

  2. SemEval-2016 task 10

    DEFF Research Database (Denmark)

    Schneider, Nathan; Hovy, Dirk; Johannsen, Anders Trærup

    2016-01-01

    This task combines the labeling of multiword expressions and supersenses (coarse-grained classes) in an explicit, yet broad-coverage paradigm for lexical semantics. Nine systems participated; the best scored 57.7% F1 in a multi-domain evaluation setting, indicating that the task remains largely u...

  3. 注意训练对非流畅性失语患者双任务范式干扰效应影响的功能磁共振研究%Effects of Attention Training on Interference Effect of Dual-task Paradigm in Poststroke Nonfluent Aphasiacs:A Functional Magnet-ic Resonnce Imaging Study

    Institute of Scientific and Technical Information of China (English)

    裴倩; 宋鲁平; 张通

    2015-01-01

    目的:考察注意训练对非流畅性失语患者汉字加工任务中双任务范式干扰效应的激活区及偏侧化指数的影响。方法将20例脑卒中后非流畅性失语患者分成实验组及对照组各10例,分别给予注意训练和认知训练,每次30 min,每周5次,共4周。训练前后分别采用组块设计对患者汉字加工任务进行功能磁共振扫描,比较训练前后双任务范式干扰效应的激活区及偏侧化指数。结果训练前两组患者均为右侧额下回、双侧顶叶、双侧小脑显著激活;训练后,实验组各激活区更加显著,而对照组各激活区未见显著变化;训练前两组患者均呈右半球优势;训练后实验组呈左半球优势,而对照组仍呈右半球优势。结论在双任务范式干扰效应中,右侧额下回、双侧顶叶、双侧小脑可能在知觉注意阶段对解决双重任务干扰非常重要;注意训练后激活更加显著;注意训练可能使失语症患者语义加工产生了功能重组。%Objective To investigate the effect of attention training on cortical activation area and lateralization index in interference ef-fect of dual-task paradigm as the poststroke nonfluent aphasiacs processing the Chinese character tasks. Methods 20 cases with nonfluent aphasia after stroke were divided into the training group and the control group, who accepted attention training and cognitive training respec-tively, 30 min a time, 5 times a week, for 4 weeks. They were investigated the cortical activation area and lateralization index caused by in-terference effect of dual-task paradigm under block design. Results The right inferior frontal gyrus, bilateral parietal and cerebellar cortex were activated before training in both groups, and more activated after attention training, but no change after cognitive training. Lateraliza-tion index suggested that the right brain was more activated before training, while the left side was

  4. The resilience of paradigm mixes

    DEFF Research Database (Denmark)

    Daugbjerg, Carsten; Farsund, Arild Aurvåg; Langhelle, Oluf

    2017-01-01

    This paper argues that a policy regime based on a paradigm mix may be resilient when challenged by changing power balances and new agendas. Controversies between the actors can be contained within the paradigm mix as it enables them to legitimize different ideational positions. Rather than engaging...... context changed. The paradigm mix proved sufficiently flexible to accommodate food security concerns and at the same time continue to take steps toward further liberalization. Indeed, the main players have not challenged the paradigm mix....

  5. Mismatch negativity and P3a/reorienting complex in subjects with schizophrenia or at-risk mental state

    Directory of Open Access Journals (Sweden)

    Yuko eHiguchi

    2014-05-01

    Full Text Available Introduction: Shorter duration of untreated psychosis has been associated with better prognosis in patients with schizophrenia. In Introduction: In this study, we measured duration mismatch negativity (dMMN, P3a and reorienting negativity (RON in subjects with at-risk mental state (ARMS, patients with first-episode or chronic schizophrenia, and healthy volunteers. The main interest was to determine if these event-related potentials provide a biomarker associated with progression to overt schizophrenia in ARMS subjects.Methods: Seventeen ARMS subjects meeting the criteria of the Comprehensive Assessment of At-Risk Mental State, 38 patients with schizophrenia (19 first-episode and 19 chronic, and 19 healthy controls participated in the study. dMMN, P3a and RON were measured with an auditory odd-ball paradigm at baseline. Results: During the follow-up period (2.2 years, 4 out of the 19 ARMS subjects transitioned to schizophrenia (Converters while 15 did not (non-Converters. dMMN amplitudes of Converters were significantly smaller than those of non-Converters at frontal and central electrodes before onset of illness. dMMN amplitudes of non-Converters did not differ from those of healthy controls, while Converters showed significantly smaller dMMN amplitudes compared to control subjects. RON amplitudes were also reduced at frontal and central electrodes in subjects with schizophrenia, but not ARMS. Converter subjects tended to show smaller RON amplitudes compared to non-Converters. Conclusions: Our data confirm that diminished dMMN amplitudes provide a biomarker which is present before and after the development of psychosis. In this respect, RON amplitudes may also be useful, as suggested for the first time in this study.

  6. Optimized Motor Imagery Paradigm Based on Imagining Chinese Characters Writing Movement.

    Science.gov (United States)

    Qiu, Zhaoyang; Allison, Brendan Z; Jin, Jing; Zhang, Yu; Wang, Xingyu; Li, Wei; Cichocki, Andrzej

    2017-07-01

    motor imagery (MI) is a mental representation of motor behavior. The MI-based brain computer interfaces (BCIs) can provide communication for the physically impaired. The performance of MI-based BCI mainly depends on the subject's ability to self-modulate electroencephalogram signals. Proper training can help naive subjects learn to modulate brain activity proficiently. However, training subjects typically involve abstract motor tasks and are time-consuming. to improve the performance of naive subjects during motor imagery, a novel paradigm was presented that would guide naive subjects to modulate brain activity effectively. In this new paradigm, pictures of the left or right hand were used as cues for subjects to finish the motor imagery task. Fourteen healthy subjects (11 male, aged 22-25 years, and mean 23.6±1.16) participated in this study. The task was to imagine writing a Chinese character. Specifically, subjects could imagine hand movements corresponding to the sequence of writing strokes in the Chinese character. This paradigm was meant to find an effective and familiar action for most Chinese people, to provide them with a specific, extensively practiced task and help them modulate brain activity. results showed that the writing task paradigm yielded significantly better performance than the traditional arrow paradigm (p paradigm was easier. the proposed new motor imagery paradigm could guide subjects to help them modulate brain activity effectively. Results showed that there were significant improvements using new paradigm, both in classification accuracy and usability.

  7. Measuring molecular reorientation at liquid surfaces with time-resolved sum-frequency spectroscopy: a theoretical framework.

    Science.gov (United States)

    Nienhuys, Han-Kwang; Bonn, Mischa

    2009-05-28

    A theoretical framework is presented for the design and analysis of ultrafast time- and polarization-resolved surface vibrational spectroscopy, aimed at elucidating surface molecular reorientational motion in real time. Vibrational excitation with linearly polarized light lifts the azimuthal symmetry of the surface transition-dipole distribution, causing marked, time-dependent changes in the surface sum-frequency generation (SFG) intensity. The subsequent recovery of the SFG signal generally reflects both vibrational relaxation and reorientational motion of surface molecules. We present experimental schemes that allow direct quantification of the time scale of surface molecular reorientational diffusive motion.

  8. Effect of thermo-mechanical cycling on zirconium hydride reorientation studied in situ with synchrotron X-ray diffraction

    Science.gov (United States)

    Colas, Kimberly B.; Motta, Arthur T.; Daymond, Mark R.; Almer, Jonathan D.

    2013-09-01

    The circumferential hydrides normally present in nuclear reactor fuel cladding after reactor exposure may dissolve during drying for dry storage and re-precipitate when cooled under load into a more radial orientation, which could embrittle the fuel cladding. It is necessary to study the rates and conditions under which hydride reorientation may happen in order to assess fuel integrity in dry storage. The objective of this work is to study the effect of applied stress and thermal cycling on the hydride morphology in cold-worked stress-relieved Zircaloy-4 by combining conventional metallography and in situ X-ray diffraction techniques. Metallography is used to study the evolution of hydride morphology after several thermo-mechanical cycles. In situ X-ray diffraction performed at the Advanced Photon Source synchrotron provides real-time information on the process of hydride dissolution and precipitation under stress during several thermal cycles. The detailed study of diffracted intensity, peak position and full-width at half-maximum provides information on precipitation kinetics, elastic strains and other characteristics of the hydride precipitation process. The results show that thermo-mechanical cycling significantly increases the radial hydride fraction as well as the hydride length and connectivity. The radial hydrides are observed to precipitate at a lower temperature than circumferential hydrides. Variations in the magnitude and range of hydride strains due to reorientation and cycling have also been observed. These results are discussed in light of existing models and experiments on hydride reorientation. The study of hydride elastic strains during precipitation shows marked differences between circumferential and radial hydrides, which can be used to investigate the reorientation process. Cycling under stress above the threshold stress for reorientation drastically increases both the reoriented hydride fraction and the hydride size. The reoriented hydride

  9. Effect of dopant nanoparticles on reorientation process in polymer-dispersed liquid crystals

    Science.gov (United States)

    Zobov, K. V.; Zharkova, G. M.; Syzrantsev, V. V.

    2016-01-01

    The analysis of the experimental data of the nanoscale powders application for doping polymer-dispersed liquid crystals (PDLC) was represented in this work. A model based on the separation of the liquid crystals reorientation process on the surface mode and the volume mode was proposed and tested. In the research the wide-spread model mixture PDLC were used. But alumina nanoparticles were the distinctive ones obtained by electron beam evaporation. The proposed model allowed to conclude that the nanoparticles localization at the surface of the droplets (as in the Pickering emulsion) lead to the variation of the connection force between the liquid crystals and the polymer. The effect of nanoparticles resulted in an acceleration of the reorientation process near the surface when the control field is turned on and in a deceleration when it is turned off. The effect for the different size particles was confirmed.

  10. A mechanism for reorientation of cortical microtubule arrays driven by microtubule severing.

    Science.gov (United States)

    Lindeboom, Jelmer J; Nakamura, Masayoshi; Hibbel, Anneke; Shundyak, Kostya; Gutierrez, Ryan; Ketelaar, Tijs; Emons, Anne Mie C; Mulder, Bela M; Kirik, Viktor; Ehrhardt, David W

    2013-12-06

    Environmental and hormonal signals cause reorganization of microtubule arrays in higher plants, but the mechanisms driving these transitions have remained elusive. The organization of these arrays is required to direct morphogenesis. We discovered that microtubule severing by the protein katanin plays a crucial and unexpected role in the reorientation of cortical arrays, as triggered by blue light. Imaging and genetic experiments revealed that phototropin photoreceptors stimulate katanin-mediated severing specifically at microtubule intersections, leading to the generation of new microtubules at these locations. We show how this activity serves as the basis for a mechanism that amplifies microtubules orthogonal to the initial array, thereby driving array reorientation. Our observations show how severing is used constructively to build a new microtubule array.

  11. Transient Reorientation of a Doped Liquid Crystal System under a Short Laser Pulse

    Institute of Scientific and Technical Information of China (English)

    LI Tao; XIANG Ying; LIU Yi-Kun; WANG Jian; YANG Shun-Lin

    2009-01-01

    The transient optical nonlinearity of a nematic liquid crystal doped with azo-dye DRW is examined.The optical reorientation threshold of a 25-μm-thick planar-aligned sample of 5CB using a 50 ns pulse duration 532 nm YAG laser pulse is observed to decrease from 800 mJ/mm2 to 0.6 mJ/mm2 after the addition of 1 vol% azo dopant,a reduction of three orders of magnitude.When using a laser pulse duration of 10 ns,no such effect is observed.Experimental results indicate that the azo dopant molecules undergo photoisomerization from trans-isomer to cis-isomer under exposure to light,and this conformation change reorients the 5CB molecules via intermolecular coupling between guest and host.This guest-host couphng also affects the azo photoisomerization process.

  12. Optimal reorientation of underactuated spacecraft using genetic algorithm with wavelet approximation

    Institute of Scientific and Technical Information of China (English)

    Xinsheng Ge; Liqun Chen

    2009-01-01

    The optimal attitude control of an underactuated spacecraft is investigated in this paper. The flywheels of the spacecraft can somehow only provide control inputs in two independent directions. The dynamic equations are formulated for the spacecraft under a nonholonomic constraint resulting from the constant time-rate of the total angular momentum of the system. The reorientation of such underactuated spacecraft is transformed into an optimal control problem. A ggnetic algorithm is proposed to derive the control laws of the two flywheels angle velocity inputs. The control laws are approximated by the discrete orthogonal wavelets.The numerical simulations indicate that the genetic algorithm with the wavelet approximation is an effective approach to deal with the optimal reorientation of underactuated spacecraft.

  13. Paleomagnetic reorientation of San Andreas Fault Observatory at Depth (SAFOD) core

    Science.gov (United States)

    Pares, J.M.; Schleicher, A.M.; van der Pluijm, B.A.; Hickman, S.

    2008-01-01

    We present a protocol for using paleomagnetic analysis to determine the absolute orientation of core recovered from the SAFOD borehole. Our approach is based on determining the direction of the primary remanent magnetization of a spot core recovered from the Great Valley Sequence during SAFOD Phase 2 and comparing its direction to the expected reference field direction for the Late Cretaceous in North America. Both thermal and alternating field demagnetization provide equally resolved magnetization, possibly residing in magnetite, that allow reorientation. Because compositionally similar siltstones and fine-grained sandstones were encountered in the San Andreas Fault Zone during Stage 2 rotary drilling, we expect that paleomagnetic reorientation will yield reliable core orientations for continuous core acquired from directly within and adjacent to the San Andreas Fault during SAFOD Phase 3, which will be key to interpretation of spatial properties of these rocks. Copyright 2008 by the American Geophysical Union.

  14. Influence of an electric field on the spin-reorientation transition in Ni/Cu(100)

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard, Lukas [Institut für Nanotechnologie, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen (Germany); Bonell, Frédéric; Suzuki, Yoshishige [CREST, Japan Science Technology, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Graduate School of Engineering Science, Osaka University, Osaka 560-8531 (Japan); Wulfhekel, Wulf [Institut für Nanotechnologie, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen (Germany); Physikalisches Institut, Karlsruhe Institute of Technology, 76131 Karlsruhe (Germany)

    2014-10-13

    Magnetoelectric coupling offers the possibility to change the magnetic state of a material by an applied electric field. Over the last few years, metallic systems have come up as simple prototypes for this interaction. While the previous studies focused on Fe and Co thin films or their alloys, here we demonstrate magnetoelectric coupling in a Ni thin film which is close to a spin-reorientation transition. Our magneto-optic Kerr effect measurements on 10 ML of Ni/Cu(100) show a considerable influence of the applied electric field on the magnetism. This rounds off the range of magnetic metals that exhibit magnetoelectric coupling, and it reveals the possibility of an electric field control of a spin-reorientation transition.

  15. A structured continuum modelling framework for martensitic transformation and reorientation in shape memory materials.

    Science.gov (United States)

    Bernardini, Davide; Pence, Thomas J

    2016-04-28

    Models for shape memory material behaviour can be posed in the framework of a structured continuum theory. We study such a framework in which a scalar phase fraction field and a tensor field of martensite reorientation describe the material microstructure, in the context of finite strains. Gradients of the microstructural descriptors naturally enter the formulation and offer the possibility to describe and resolve phase transformation localizations. The constitutive theory is thoroughly described by a single free energy function in conjunction with a path-dependent dissipation function. Balance laws in the form of differential equations are obtained and contain both bulk and surface terms, the latter in terms of microstreses. A natural constraint on the tensor field for martensite reorientation gives rise to reactive fields in these balance laws. Conditions ensuring objectivity as well as the relation of this framework to that provided by currently used models for shape memory alloy behaviour are discussed.

  16. Software development: A paradigm for the future

    Science.gov (United States)

    Basili, Victor R.

    1989-01-01

    A new paradigm for software development that treats software development as an experimental activity is presented. It provides built-in mechanisms for learning how to develop software better and reusing previous experience in the forms of knowledge, processes, and products. It uses models and measures to aid in the tasks of characterization, evaluation and motivation. An organization scheme is proposed for separating the project-specific focus from the organization's learning and reuse focuses of software development. The implications of this approach for corporations, research and education are discussed and some research activities currently underway at the University of Maryland that support this approach are presented.

  17. SUSTAINABLE DEVELOPMENT PARADIGM - SYNOPSIS

    Directory of Open Access Journals (Sweden)

    Constantinescu Andreea

    2014-07-01

    Full Text Available Even if sustainable development is a concept that gained quite recently its scientific prestige, through contribution of researchers its content has upgraded to a high degree of conceptual luggage and, through contribution from governance representatives, has gained an impressive good-practice background. Allowing the use of different methodological premises and conceptual tools, sustainable development paradigm is equipped with all the elements that would allow the opening of new horizons of knowledge. Based on the facility which can operate the concept of sustainable development, the European Union aims to develop both a more competitive economy based on environmental protection as well as a new governance of economic policy. This on one hand demonstrates the sustainable development ability to irradiate creativity towards the establishment of interdisciplinary bridges and on the other hand explains the growing interest of researchers interested in the problem of analyzing in detail this fruitful concept. Launched first as a theoretical framework to serve justify actions responsible for weighting economic growth, the concept of Sustainable Development has quickly become a topic of ethical debate circumscribed to the area of perfectibility of human nature to the necessity registry. In this regard, the philosophical content of this paradigm could not remain outside researchers concerns, who want to provide both policy makers and the general public a wide range of evidence to demonstrate the viability of this paradigm. Academia waits until maximization of the contribution of governance to achieve sustainable economic development, which consists in conjunction of this upward path with the momentum given by public policy sync, perfectly adapted for globalization era and all crises to come. However, because this concept based its structure and composition on three pillars, equally important economy, society and environment any attempt to strengthen

  18. Challenging the Innovation Paradigm

    CERN Document Server

    Sveiby, Karl Erik; Segercrantz, Beata

    2012-01-01

    Innovation is almost always seen as a "good thing". Challenging the Innovation Paradigm is a critical analysis of the innovation frenzy and contemporary innovation research. The one-sided focus on desirable effects of innovation misses many opportunities to reduce the undesirable consequences. Authors in this book show how systemic effects outside the innovating firms reduce the net benefits of innovation for individual employees, customers, as well as for society as a whole - also the innovators' own organizations. This book analyzes the dominant discourses that construct and recons

  19. Pluto followed its heart: reorientation and faulting of Pluto due to volatile loading in Sputnik Planum

    Science.gov (United States)

    Tuttle Keane, James; Matsuyama, Isamu; Kamata, Shunichi; Steckloff, Jordan

    2016-10-01

    The New Horizons flyby of Pluto revealed the dwarf planet to be a strikingly diverse, geologically active world. Perhaps the most intriguing feature on the New Horizons encounter hemisphere is Sputnik Planum—a 1000 km diameter, probable impact basin, filled with several kilometers of actively convecting volatile ices (N2, CH4, CO). One salient characteristic of Sputnik Planum is its curious alignment with the Pluto-Charon tidal axis. The alignment of large geologic features with principal axis of inertia (such as the tidal axis) is the hallmark of global reorientation, i.e. true polar wander. Here we show that the present location of Sputnik Planum is a natural consequence of loading of 1-2 km of volatile ices within the Sputnik Planum basin. Larger volatile ice thicknesses (like those inferred from studies of ice convection within Sputnik Planum) betray an underlying negative gravity anomaly associated with the basin. As Pluto reoriented in response to the loading of volatile ices within Sputnik Planum, stresses accumulated within the lithosphere (as each geographic location experiences a change in tidal/rotational potential). These reorientation stresses, coupled with loading stresses, and stresses from the freezing of a subsurface ocean resulted in the fracturing of Pluto's lithosphere in a characteristic, global pattern of extensional faults. Our predicted pattern of extensional faults due to this reorientation closely replicates the observed distribution of faults on Pluto (more so than global expansion, orbit migration, de-spinning, or loading alone). Sputnik Planum likely formed ~60° northwest of its present location, and was loaded with volatile ices over millions of years due to seasonal volatile transport cycles. This result places Pluto in a truly unique category of planetary bodies where volatiles are not only controlling surface geology and atmospheric processes, but they are also directly controlling the orientation of the entire dwarf planet

  20. Geometric and featural systems, separable and combined: Evidence from reorientation in people with Williams syndrome

    Science.gov (United States)

    Ferrara, Katrina; Landau, Barbara

    2015-01-01

    Spatial reorientation by humans and other animals engages geometric representations of surface layouts as well as featural landmarks; however, the two types of information are thought to be behaviorally and neurally separable. In this paper, we examine the use of these two types of information during reorientation among children and adults with Williams syndrome (WS), a genetic disorder accompanied by abnormalities in brain regions that support use of both geometry and landmarks. Previous studies of reorientation in adolescents and adults with WS have shown deficits in the ability to use geometry for reorientation, but intact ability to use features, suggesting that the two systems can be differentially impaired by genetic disorder. Using a slightly modified layout, we found that many WS participants could use geometry, and most could use features along with geometry. However, the developmental trajectories for the two systems were quite different from one other, and different from those found in typical development. Purely geometric responding was not correlated with age in WS, and search processes appeared similar to those in typically developing (TD) children. In contrast, use of features in combination with geometry was correlated with age in WS, and search processes were distinctly different from TD children. The results support the view that use of geometry and features stem from different underlying mechanisms, that the developmental trajectories and operation of each are altered in WS, and that combination of information from the two systems is atypical. Given brain abnormalities in regions supporting the two kinds of information, our findings suggest that the co-operation of the two systems is functionally altered in this genetic syndrome. PMID:26275835

  1. Giant magnetostrictive superlattices: from spin reorientation transition to MEMS. Static and dynamical properties

    CERN Document Server

    Tiercelin, N; Preobrazhensky, V; Pernod, P; Gall, H L

    2002-01-01

    The results of development of 'giant magnetostrictive' multilayers with spin reorientation transition (SRT) for microactuators are presented. Manifestations of magneto-mechanical instability and nonlinearity near SRT are studied experimentally and simulated numerically. Improvement of magneto-mechanical sensitivity near SRT is demonstrated for various modes of linear and nonlinear actuation of magnetostrictive unimorph. Limitations of sensitivity caused by magnetic field distortions are described by a numerical model, the results are compared with the experimental data.

  2. GOLPH3 drives cell migration by promoting Golgi reorientation and directional trafficking to the leading edge.

    Science.gov (United States)

    Xing, Mengke; Peterman, Marshall C; Davis, Robert L; Oegema, Karen; Shiau, Andrew K; Field, Seth J

    2016-12-01

    The mechanism of directional cell migration remains an important problem, with relevance to cancer invasion and metastasis. GOLPH3 is a common oncogenic driver of human cancers, and is the first oncogene that functions at the Golgi in trafficking to the plasma membrane. Overexpression of GOLPH3 is reported to drive enhanced cell migration. Here we show that the phosphatidylinositol-4-phosphate/GOLPH3/myosin 18A/F-actin pathway that is critical for Golgi-to-plasma membrane trafficking is necessary and limiting for directional cell migration. By linking the Golgi to the actin cytoskeleton, GOLPH3 promotes reorientation of the Golgi toward the leading edge. GOLPH3 also promotes reorientation of lysosomes (but not other organelles) toward the leading edge. However, lysosome function is dispensable for migration and the GOLPH3 dependence of lysosome movement is indirect, via GOLPH3's effect on the Golgi. By driving reorientation of the Golgi to the leading edge and driving forward trafficking, particularly to the leading edge, overexpression of GOLPH3 drives trafficking to the leading edge of the cell, which is functionally important for directional cell migration. Our identification of a novel pathway for Golgi reorientation controlled by GOLPH3 provides new insight into the mechanism of directional cell migration with important implications for understanding GOLPH3's role in cancer. © 2016 Xing, Peterman, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  3. Reorientation and faulting of Pluto due to volatile loading within Sputnik Planitia.

    Science.gov (United States)

    Keane, James T; Matsuyama, Isamu; Kamata, Shunichi; Steckloff, Jordan K

    2016-12-01

    Pluto is an astoundingly diverse, geologically dynamic world. The dominant feature is Sputnik Planitia-a tear-drop-shaped topographic depression approximately 1,000 kilometres in diameter possibly representing an ancient impact basin. The interior of Sputnik Planitia is characterized by a smooth, craterless plain three to four kilometres beneath the surrounding rugged uplands, and represents the surface of a massive unit of actively convecting volatile ices (N2, CH4 and CO) several kilometres thick. This large feature is very near the Pluto-Charon tidal axis. Here we report that the location of Sputnik Planitia is the natural consequence of the sequestration of volatile ices within the basin and the resulting reorientation (true polar wander) of Pluto. Loading of volatile ices within a basin the size of Sputnik Planitia can substantially alter Pluto's inertia tensor, resulting in a reorientation of the dwarf planet of around 60 degrees with respect to the rotational and tidal axes. The combination of this reorientation, loading and global expansion due to the freezing of a possible subsurface ocean generates stresses within the planet's lithosphere, resulting in a global network of extensional faults that closely replicate the observed fault networks on Pluto. Sputnik Planitia probably formed northwest of its present location, and was loaded with volatiles over million-year timescales as a result of volatile transport cycles on Pluto. Pluto's past, present and future orientation is controlled by feedbacks between volatile sublimation and condensation, changing insolation conditions and Pluto's interior structure.

  4. Optimal reorientation of asymmetric underactuated spacecraft using differential flatness and receding horizon control

    Science.gov (United States)

    Cai, Wei-wei; Yang, Le-ping; Zhu, Yan-wei

    2015-01-01

    This paper presents a novel method integrating nominal trajectory optimization and tracking for the reorientation control of an underactuated spacecraft with only two available control torque inputs. By employing a pseudo input along the uncontrolled axis, the flatness property of a general underactuated spacecraft is extended explicitly, by which the reorientation trajectory optimization problem is formulated into the flat output space with all the differential constraints eliminated. Ultimately, the flat output optimization problem is transformed into a nonlinear programming problem via the Chebyshev pseudospectral method, which is improved by the conformal map and barycentric rational interpolation techniques to overcome the side effects of the differential matrix's ill-conditions on numerical accuracy. Treating the trajectory tracking control as a state regulation problem, we develop a robust closed-loop tracking control law using the receding-horizon control method, and compute the feedback control at each control cycle rapidly via the differential transformation method. Numerical simulation results show that the proposed control scheme is feasible and effective for the reorientation maneuver.

  5. Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state

    CERN Document Server

    Irudayam, Sheeba J; Berkowitz, Max L

    2013-01-01

    An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energy barrier. The PMFs were calculated for a peptide to lipid (P/L) ratio of 1/128 and 4/128. We observe that the free energy barrier is reduced when the P/L ratio increased. In addition, we study the cooperative effect; specifically we investigate if the barrier is smaller for a second melittin reorientation, given that another neighboring melittin was already in the transmembrane state. We observe that indeed the barrier of the PMF curve is reduced in this case, thus confirming the presence of a cooperative effect.

  6. Is height a core geometric cue for navigation? Young children's use of height in reorientation.

    Science.gov (United States)

    Hu, Qingfen; Zhang, Jing; Wu, Di; Shao, Yi

    2015-02-01

    With respect to reorientation, children older than 1.5 to 2 years can use geometric cues (distance and left/right sense). However, because previous studies have focused mainly on the plane geometric properties, little is known about the role of information with respect to vertical dimension in children's reorientation. The current study aimed to examine whether and how 3- and 4-year-old children use height information to search for a hidden toy when disoriented in a small enclosure. In a slant-ceiling rectangular room and a slant-ceiling square room, 4-year-olds were able to use height information to reorient and search for the toy in the correct corner, whereas 3-year-olds were not able to do so. Our results suggest that children can, at least by the age of 4 years, use height information and that height is not used as early as other geometric properties that are in the core geometry system for navigation. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Hypergravity induces reorientation of cortical microtubules and modifies growth anisotropy in azuki bean epicotyls.

    Science.gov (United States)

    Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Hoson, Takayuki

    2006-11-01

    We examined the changes in the orientation of cortical microtubules during the hypergravity-induced modification of growth anisotropy (inhibition of elongation growth and promotion of lateral growth) in azuki bean (Vigna angularis Ohwi et Ohashi) epicotyls. The percentage of cells with transverse microtubules was decreased, while that with longitudinal microtubules was increased, in proportion to the logarithm of the magnitude of gravity. The percentage of cells with longitudinal microtubules showed an increase within 0.5 h of transfer of the 1g-grown seedlings to a 300g-hypergravity condition. Lanthanum and gadolinium, blockers of calcium channels, nullified the modification of growth anisotropy and reorientation of microtubules by hypergravity. Horizontal and acropetal hypergravity modified growth anisotropy and reorientation of microtubules, as did basipetal hypergravity, and these changes were not seen in the presence of lanthanum or gadolinium. These results suggest that hypergravity changes activities of lanthanum- and gadolinium-sensitive calcium channels independently of its direction, which may lead to reorientation of cortical microtubules and modification of growth anisotropy in azuki bean epicotyls.

  8. Stable panoramic views facilitate snap-shot like memories for spatial reorientation in homing pigeons.

    Directory of Open Access Journals (Sweden)

    Tommaso Pecchia

    Full Text Available Following spatial disorientation, animals can reorient themselves by relying on geometric cues (metric and sense specified both by the macroscopic surface layout of an enclosed space and prominent visual landmarks in arrays. Whether spatial reorientation in arrays of landmarks is based on explicit representation of the geometric cues is a matter of debate. Here we trained homing pigeons (Columba livia to locate a food-reward in a rectangular array of four identical or differently coloured pipes provided with four openings, only one of which allowed the birds to have access to the reward. Pigeons were trained either with a stable or a variable position of the opening on pipes, so that they could view the array either from the same or a variable perspective. Explicit mapping of configural geometry would predict successful reorientation irrespective of access condition. In contrast, we found that a stable view of the array facilitated spatial learning in homing pigeons, likely through the formation of snapshot-like memories.

  9. Neural mechanisms underlying pain's ability to reorient attention: evidence for sensitization of somatic threat detectors.

    Science.gov (United States)

    Dowman, Robert

    2014-06-01

    Pain typically signals damage to the body, and as such can be perceived as threatening and can elicit a strong emotional response. This ecological significance undoubtedly underlies pain's well-known ability to demand attention. However, the neural mechanisms underlying this ability are poorly understood. Previous work from the author's laboratory has reported behavioral evidence suggesting that participants disengage their attention from an incorrectly cued visual target stimulus and reorient it toward a somatic target more rapidly when the somatic target is painful than when it is nonpainful. Furthermore, electrophysiological data suggest that this effect is mediated by a stimulus-driven process, in which somatic threat detectors located in the dorsal posterior insula activate the medial and lateral prefrontal cortex areas involved in reorienting attention toward the painful target. In these previous studies, the painful and nonpainful somatic targets were given in separate experiments involving different participants. Here, the nonpainful and painful somatic targets were presented in random order within the same block of trials. Unlike in the previous studies, both the nonpainful and painful somatic targets activated the somatic threat detectors, and the times taken to disengage and reorient attention were the same for both. These electrophysiological and behavioral data suggest that somatic threat detectors can become sensitized to nonpainful somatic stimuli that are presented in a context that includes painful stimuli.

  10. Reorientation dynamics of nematics encapsulated in microscopic volumes in a strong electric field

    Science.gov (United States)

    Zakharov, A. V.; Vakulenko, A. A.; Pasechnik, S. V.

    2016-09-01

    We theoretically describe a new regime of reorientation of the director field widehat n and velocity v of a nematic liquid crystal (LC) encapsulated in a rectangular cell under the action of strong electric field E directed at angle α ( π/2) to the horizontal surfaces bounding the LC cell. The numerical calculations in the framework of nonlinear generalization of the classical Eriksen-Leslie theory showed that at certain relations between the torques and momenta affecting the unit LC volume and E ≫ E th, transition periodic structures can arise during reorientation of widehat n, if the corresponding distortion mode has the fastest response and, thus, suppresses all the rest of the modes, including uniform ones. The position of sites of these periodic structures is affected by the value of field E, angle α, and the character of anchoring of LC molecules to the bounding surfaces. The calculations performed for the nematic formed by 4-n-penthyl-4'-cyanobiphenyl showed that several vortexes can form in an LC cell under the action of reorientation of the nematic field; the boundaries of these vortexes are determined by the positions of periodic structure sites.

  11. Task Complexity, Student Perceptions of Vocabulary Learning in EFL, and Task Performance

    Science.gov (United States)

    Wu, Xiaoli; Lowyck, Joost; Sercu, Lies; Elen, Jan

    2013-01-01

    Background: The study deepened our understanding of how students' self-ef?cacy beliefs contribute to the context of teaching English as a foreign language in the framework of cognitive mediational paradigm at a ?ne-tuned task-speci?c level. Aim: The aim was to examine the relationship among task complexity, self-ef?cacy beliefs, domain-related…

  12. Across-Task Priming Revisited: Response and Task Conflicts Disentangled Using Ex-Gaussian Distribution Analysis

    Science.gov (United States)

    Moutsopoulou, Karolina; Waszak, Florian

    2012-01-01

    The differential effects of task and response conflict in priming paradigms where associations are strengthened between a stimulus, a task, and a response have been demonstrated in recent years with neuroimaging methods. However, such effects are not easily disentangled with only measurements of behavior, such as reaction times (RTs). Here, we…

  13. A new biomarker to examine the role of hippocampal function in the development of spatial reorientation in children: a review

    OpenAIRE

    Vanessa eVieites; Alina eNazareth; Reeb-Sutherland, Bethany C.; Shannon M Pruden

    2015-01-01

    Spatial navigation is an adaptive skill that involves determining the route to a particular goal or location, and then travelling that path. A major component of spatial navigation is spatial reorientation, or the ability to reestablish a sense of direction after being disoriented. The hippocampus is known to be critical for navigating, and has more recently been implicated in reorienting in adults, but relatively little is known about the development of the hippocampus in relation to these l...

  14. Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials

    OpenAIRE

    2014-01-01

    The extended phenotype of autism spectrum disorders (ASD) includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs) and magnetic fields (ERFs) may help to reveal which processing stages underlying brain response to unattended but salient...

  15. Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials

    OpenAIRE

    2014-01-01

    The extended phenotype of autism spectrum disorders (ASD) includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs) and magnetic fields (ERFs) may help to reveal which processing stages underlying brain response to unattended but salien...

  16. PARADIGM IN THE PHILOSOPHY OF THE GENERAL THEORY OF CYCLES (CRISES

    Directory of Open Access Journals (Sweden)

    Laptev V. N.

    2014-06-01

    Full Text Available The article considers the special role of paradigms in the study (writing of the General theory of cycles. The authors ' task is systematization of knowledge in this area and obtain an objective assessment by means of retrospective material, which shows the change of one paradigm to another

  17. Conservation without Conversation? An Alternative, Non-Verbal Paradigm for Assessing Conservation of Liquid Quantity.

    Science.gov (United States)

    Wheldall, Kevin; Poborca, Barbara

    1980-01-01

    A nonverbal paradigm for assessing conservation based on an operant discrimination learning procedure is described. Initial results suggest that young children who could not conserve within the traditional verbal procedure were more likely to demonstrate conservation within the nonverbal paradigm and that traditional Piagetian tasks are verbally…

  18. Navigation as a Source of Geometric Knowledge: Young Children's Use of Length, Angle, Distance, and Direction in a Reorientation Task

    Science.gov (United States)

    Lee, Sang Ah; Sovrano, Valeria A.; Spelke, Elizabeth S.

    2012-01-01

    Geometry is one of the highest achievements of our species, but its foundations are obscure. Consistent with longstanding suggestions that geometrical knowledge is rooted in processes guiding navigation, the present study examines potential sources of geometrical knowledge in the navigation processes by which young children establish their sense…

  19. The Peter Pan paradigm.

    Science.gov (United States)

    Cohen, J Craig; Larson, Janet E

    2008-01-08

    Genetic and environmental agents that disrupt organogenesis are numerous and well described. Less well established, however, is the role of delay in the developmental processes that yield functionally immature tissues at birth. Evidence is mounting that organs do not continue to develop postnatally in the context of these organogenesis insults, condemning the patient to utilize under-developed tissues for adult processes. These poorly differentiated organs may appear histologically normal at birth but with age may deteriorate revealing progressive or adult-onset pathology. The genetic and molecular underpinning of the proposed paradigm reveals the need for a comprehensive systems biology approach to evaluate the role of maternal-fetal environment on organogenesis."You may delay, but time will not" Benjamin Franklin, USA Founding Father.

  20. The Peter Pan paradigm

    Directory of Open Access Journals (Sweden)

    Larson Janet E

    2008-01-01

    Full Text Available Abstract Genetic and environmental agents that disrupt organogenesis are numerous and well described. Less well established, however, is the role of delay in the developmental processes that yield functionally immature tissues at birth. Evidence is mounting that organs do not continue to develop postnatally in the context of these organogenesis insults, condemning the patient to utilize under-developed tissues for adult processes. These poorly differentiated organs may appear histologically normal at birth but with age may deteriorate revealing progressive or adult-onset pathology. The genetic and molecular underpinning of the proposed paradigm reveals the need for a comprehensive systems biology approach to evaluate the role of maternal-fetal environment on organogenesis. You may delay, but time will not Benjamin Franklin USA Founding Father

  1. PARADIGM OF ACCOUNTING CHANGE

    Directory of Open Access Journals (Sweden)

    Constanta Iacob

    2016-12-01

    Full Text Available The words and phrases swop with each other and the apparent stability of a word’s meaning sometimes change in time. This explains why the generic term of accounting is used when referring to the qualities attributed to accounting,but also when it comes to organizing financial accounting function within the entity, and when referring concretely to keeping a double record with its specific means, methods and tools specific, respectively seen as a technical accounting.Speaking about the qualities of accounting, but also about the organizational form it takes, we note that there is a manifold meaning of the word accounting, which is why the purpose of this article is to demonstrate that the paradigm shift aimed at a new set of rules and if the rules changes, then we can change the very purpose of accounting.

  2. Paradigms for parasite conservation.

    Science.gov (United States)

    Dougherty, Eric R; Carlson, Colin J; Bueno, Veronica M; Burgio, Kevin R; Cizauskas, Carrie A; Clements, Christopher F; Seidel, Dana P; Harris, Nyeema C

    2016-08-01

    Parasitic species, which depend directly on host species for their survival, represent a major regulatory force in ecosystems and a significant component of Earth's biodiversity. Yet the negative impacts of parasites observed at the host level have motivated a conservation paradigm of eradication, moving us farther from attainment of taxonomically unbiased conservation goals. Despite a growing body of literature highlighting the importance of parasite-inclusive conservation, most parasite species remain understudied, underfunded, and underappreciated. We argue the protection of parasitic biodiversity requires a paradigm shift in the perception and valuation of their role as consumer species, similar to that of apex predators in the mid-20th century. Beyond recognizing parasites as vital trophic regulators, existing tools available to conservation practitioners should explicitly account for the unique threats facing dependent species. We built upon concepts from epidemiology and economics (e.g., host-density threshold and cost-benefit analysis) to devise novel metrics of margin of error and minimum investment for parasite conservation. We define margin of error as the risk of accidental host extinction from misestimating equilibrium population sizes and predicted oscillations, while minimum investment represents the cost associated with conserving the additional hosts required to maintain viable parasite populations. This framework will aid in the identification of readily conserved parasites that present minimal health risks. To establish parasite conservation, we propose an extension of population viability analysis for host-parasite assemblages to assess extinction risk. In the direst cases, ex situ breeding programs for parasites should be evaluated to maximize success without undermining host protection. Though parasitic species pose a considerable conservation challenge, adaptations to conservation tools will help protect parasite biodiversity in the face of

  3. On the importance of Task 1 and error performance measures in PRP dual-task studies

    Directory of Open Access Journals (Sweden)

    Tilo eStrobach

    2015-04-01

    Full Text Available The Psychological Refractory Period (PRP paradigm is a dominant research tool in the literature on dual-task performance. In this paradigm a first and second component task (i.e., Task 1 and 2 are presented with variable stimulus onset asynchronies (SOAs and priority to perform Task 1. The main indicator of dual-task impairment in PRP situations is an increasing Task 2-RT with decreasing SOAs. This impairment is typically explained with some task components being processed strictly sequentially in the context of the prominent central bottleneck theory. This assumption could implicitly suggest that processes of Task 1 are unaffected by Task 2 and bottleneck processing, i.e. decreasing SOAs do not increase RTs and error rates of the first task. The aim of the present review is to assess whether PRP dual-task studies included both RT and error data presentations and statistical analyses and whether studies including both data types (i.e., RTs and error rates show data consistent with this assumption (i.e., decreasing SOAs and unaffected RTs and/ or error rates in Task 1. This review demonstrates that, in contrast to RT presentations and analyses, error data is underrepresented in a substantial number of studies. Furthermore, a substantial number of studies with RT and error data showed a statistically significant impairment of Task 1 performance with decreasing SOA. Thus, these studies produced data that is not primarily consistent with the strong assumption that processes of Task 1 are unaffected by Task 2 and bottleneck processing in the context of PRP dual-task situations; this calls for a more careful report and analysis of Task 1 performance in PRP studies and for a more careful consideration of theories proposing additions to the bottleneck assumption, which are sufficiently general to explain Task 1 and Task 2 effects.

  4. The Consumption Paradigm in Marketing

    OpenAIRE

    Ardianto, Eka

    2003-01-01

    This article elaborates consumption paradigm in marketing. In background, this paper reviews different perspectives of consumption: economic perspective and marketing perspective. In ontology, this work describes various issues regarding consumption view. In epistemology, this article demonstrates how marketers especially researches explore the consumption phenomena. In methodology, the article describes experiential marketing –one of applied consumption paradigm in marketing, which could be ...

  5. A numerical method for reorientation of rotating tidally deformed viscoelastic bodies

    Science.gov (United States)

    Hu, H.; Wal, W.; Vermeersen, L. L. A.

    2017-01-01

    Existing approaches for simulating the true polar wander (TPW) of a viscoelastic body can be divided into three categories: (i) a linear dynamic approach which uses the linearized Liouville equation (e.g., Wu and Peltier (1984) and Mitrovica et al. (2005)); (ii) a nonlinear dynamic approach which is based on the quasi-fluid approximation (e.g., Sabadini and Peltier (1981), Ricard et al. (1993), and Cambiotti et al. (2011)); and (iii) a long-term limit approach which only considers the fluid limit of a reorientation (e.g., Matsuyama and Nimmo (2007)). Several limitations of these approaches have not been studied: the range for which the linear approach is accurate, the validity of the quasi-fluid approximation, and the dynamic solution for TPW of a tidally deformed rotating body. We establish a numerical procedure which is able to determine the large-angle reorientation of a viscoelastic celestial body that can be both centrifugally and tidally deformed. We show that the linear approach leads to significant errors for loadings near the poles or the equator. Second, we show that slow relaxation modes can have a significant effect on large-angle TPW of Earth or other planets. Finally, we show that reorientation of a tidally deformed body driven by a positive mass anomaly near the poles has a preference for rotating around the tidal axis instead of toward it. At a tidally deformed body which does not have a remnant bulge, positive mass anomalies are more likely to be found near the equator and the plane perpendicular to the tidal axis, while negative mass anomalies tend to be near the great circle that contains the tidal and rotational axes.

  6. Reorientation of Magnetic Graphene Oxide Nanosheets in Crosslinked Quaternized Polyvinyl Alcohol as Effective Solid Electrolyte

    Directory of Open Access Journals (Sweden)

    Jia-Shuin Lin

    2016-11-01

    Full Text Available This work aims to clarify the effect of magnetic graphene oxide (GO reorientation in a polymer matrix on the ionic conduction and methanol barrier properties of nanocomposite membrane electrolytes. Magnetic iron oxide (Fe3O4 nanoparticles were prepared and dispersed on GO nanosheets (GO-Fe3O4. The magnetic GO-Fe3O4 was imbedded into a quaternized polyvinyl alcohol (QPVA matrix and crosslinked (CL- with glutaraldehyde (GA to obtain a polymeric nanocomposite. A magnetic field was applied in the through-plane direction during the drying and film formation steps. The CL-QPVA/GO-Fe3O4 nanocomposite membranes were doped with an alkali to obtain hydroxide-conducting electrolytes for direct methanol alkaline fuel cell (DMAFC applications. The magnetic field-reoriented CL-QPVA/GO-Fe3O4 electrolyte demonstrated higher conductivity and lower methanol permeability than the unoriented CL-QPVA/GO-Fe3O4 membrane or the CL-QPVA film. The reoriented CL-QPVA/GO-Fe3O4 nanocomposite was used as the electrolyte in a DMAFC and resulted in a maximum power density of 55.4 mW·cm−2 at 60 °C, which is 73.7% higher than that of the composite without the magnetic field treatment (31.9 mW·cm−2. In contrast, the DMAFC using the CL-QPVA electrolyte generated only 22.4 mW·cm−2. This research proved the surprising benefits of magnetic-field-assisted orientation of GO-Fe3O4 in facilitating the ion conduction of a polymeric electrolyte.

  7. Environment size and the use of feature and geometric cues for reorientation.

    Science.gov (United States)

    Sturz, Bradley R; Kelly, Debbie M

    2013-02-01

    We tested associative-based accounts of orientation by investigating the influence of environment size on the use of feature and geometric cues for reorientation. Two groups of participants were trained in dynamic three-dimensional virtual rectangular environments that differed in size to find a distinctly colored bin located at one of the four corners. Subsequently, we probed the reliance on feature and geometric cues for reorientation during test trials by presenting six trial types: Small Geometry Only, Large Geometry Only, Small Cue Conflict, Large Cue Conflict, Small Distal, and Large Distal. During Geometry Only test trials, all bins were black; thus, all distinctive featural information was removed leaving only geometric cues. For Cue Conflict test trials, all colored bins were shifted counter-clockwise one corner; thus, the geometric cues from the trained corner and the trained color were in direct conflict. During Distal test trials, the bin in the geometrically incorrect corner farthest from the trained corner was colored the same as during training; the remaining three bins were black. Thus, only this distant feature cue could be used to determine the location of the goal bin. Results suggested that geometric cues were used across changes in environment size, featural cues exerted greater influence when in conflict with geometric cues, and the far featural cue was used to disambiguate the correct from the rotationally equivalent location. In short, both feature and geometric cues were used for reorientation, and environment size influenced the relative use of feature and geometric cues. Collectively, our results provide evidence against associative-based accounts of orientation. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Reorientation and faulting of Pluto due to volatile loading within Sputnik Planitia

    Science.gov (United States)

    Keane, James T.; Matsuyama, Isamu; Kamata, Shunichi; Steckloff, Jordan K.

    2016-12-01

    Pluto is an astoundingly diverse, geologically dynamic world. The dominant feature is Sputnik Planitia—a tear-drop-shaped topographic depression approximately 1,000 kilometres in diameter possibly representing an ancient impact basin. The interior of Sputnik Planitia is characterized by a smooth, craterless plain three to four kilometres beneath the surrounding rugged uplands, and represents the surface of a massive unit of actively convecting volatile ices (N2, CH4 and CO) several kilometres thick. This large feature is very near the Pluto-Charon tidal axis. Here we report that the location of Sputnik Planitia is the natural consequence of the sequestration of volatile ices within the basin and the resulting reorientation (true polar wander) of Pluto. Loading of volatile ices within a basin the size of Sputnik Planitia can substantially alter Pluto’s inertia tensor, resulting in a reorientation of the dwarf planet of around 60 degrees with respect to the rotational and tidal axes. The combination of this reorientation, loading and global expansion due to the freezing of a possible subsurface ocean generates stresses within the planet’s lithosphere, resulting in a global network of extensional faults that closely replicate the observed fault networks on Pluto. Sputnik Planitia probably formed northwest of its present location, and was loaded with volatiles over million-year timescales as a result of volatile transport cycles on Pluto. Pluto’s past, present and future orientation is controlled by feedbacks between volatile sublimation and condensation, changing insolation conditions and Pluto’s interior structure.

  9. Spatial reorientation experiments for NMR of solids and partially oriented liquids.

    Science.gov (United States)

    Martin, Rachel W; Kelly, John E; Collier, Kelsey A

    2015-11-01

    Motional reorientation experiments are extensions of Magic Angle Spinning (MAS) where the rotor axis is changed in order to average out, reintroduce, or scale anisotropic interactions (e.g. dipolar couplings, quadrupolar interactions or chemical shift anisotropies). This review focuses on Variable Angle Spinning (VAS), Switched Angle Spinning (SAS), and Dynamic Angle Spinning (DAS), all of which involve spinning at two or more different angles sequentially, either in successive experiments or during a multidimensional experiment. In all of these experiments, anisotropic terms in the Hamiltonian are scaled by changing the orientation of the spinning sample relative to the static magnetic field. These experiments vary in experimental complexity and instrumentation requirements. In VAS, many one-dimensional spectra are collected as a function of spinning angle. In SAS, dipolar couplings and/or chemical shift anisotropies are reintroduced by switching the sample between two different angles, often 0° or 90° and the magic angle, yielding a two-dimensional isotropic-anisotropic correlation spectrum. Dynamic Angle Spinning (DAS) is a related experiment that is used to simultaneously average out the first- and second-order quadrupolar interactions, which cannot be accomplished by spinning at any unique rotor angle in physical space. Although motional reorientation experiments generally require specialized instrumentation and data analysis schemes, some are accessible with only minor modification of standard MAS probes. In this review, the mechanics of each type of experiment are described, with representative examples. Current and historical probe and coil designs are discussed from the standpoint of how each one accomplishes the particular objectives of the experiment(s) it was designed to perform. Finally, applications to inorganic materials and liquid crystals, which present very different experimental challenges, are discussed. The review concludes with perspectives

  10. The functional neuroanatomy of multitasking: combining dual tasking with a short term memory task.

    Science.gov (United States)

    Deprez, Sabine; Vandenbulcke, Mathieu; Peeters, Ron; Emsell, Louise; Amant, Frederic; Sunaert, Stefan

    2013-09-01

    Insight into the neural architecture of multitasking is crucial when investigating the pathophysiology of multitasking deficits in clinical populations. Presently, little is known about how the brain combines dual-tasking with a concurrent short-term memory task, despite the relevance of this mental operation in daily life and the frequency of complaints related to this process, in disease. In this study we aimed to examine how the brain responds when a memory task is added to dual-tasking. Thirty-three right-handed healthy volunteers (20 females, mean age 39.9 ± 5.8) were examined with functional brain imaging (fMRI). The paradigm consisted of two cross-modal single tasks (a visual and auditory temporal same-different task with short delay), a dual-task combining both single tasks simultaneously and a multi-task condition, combining the dual-task with an additional short-term memory task (temporal same-different visual task with long delay). Dual-tasking compared to both individual visual and auditory single tasks activated a predominantly right-sided fronto-parietal network and the cerebellum. When adding the additional short-term memory task, a larger and more bilateral frontoparietal network was recruited. We found enhanced activity during multitasking in components of the network that were already involved in dual-tasking, suggesting increased working memory demands, as well as recruitment of multitask-specific components including areas that are likely to be involved in online holding of visual stimuli in short-term memory such as occipito-temporal cortex. These results confirm concurrent neural processing of a visual short-term memory task during dual-tasking and provide evidence for an effective fMRI multitasking paradigm. © 2013 Elsevier Ltd. All rights reserved.

  11. Measuring the interrelations among multiple paradigms of visual attention: an individual differences approach.

    Science.gov (United States)

    Huang, Liqiang; Mo, Lei; Li, Ying

    2012-04-01

    A large part of the empirical research in the field of visual attention has focused on various concrete paradigms. However, as yet, there has been no clear demonstration of whether or not these paradigms are indeed measuring the same underlying construct. We collected a very large data set (nearly 1.3 million trials) to address this question. We tested 257 participants on nine paradigms: conjunction search, configuration search, counting, tracking, feature access, spatial pattern, response selection, visual short-term memory, and change blindness. A fairly general attention factor was identified. Some of the participants were also tested on eight other paradigms. This general attention factor was found to be correlated with intelligence, visual marking, task switching, mental rotation, and Stroop task. On the other hand, a few paradigms that are very important in the attention literature (attentional capture, consonance-driven orienting, and inhibition of return) were found to be dissociated from this general attention factor.

  12. Slosh wave excitation due to cryogenic liquid reorientation in space-based propulsion system

    Science.gov (United States)

    Hung, R. J.; Shyu, K. L.; Lee, C. C.

    1991-01-01

    The objective of the cryogenic fluid management of the spacecraft propulsion system is to develop the technology necessary for acquistion or positioning of liquid and vapor within a tank in reduced gravity to enable liquid outflow or vapor venting. In this study slosh wave excitation induced by the resettling flow field activated by 1.0 Hz medium frequency impulsive reverse gravity acceleration during the course of liquid fluid reorientation with the initiation of geyser for liquid filled levels of 30, 50, and 80 percent have been studied. Characteristics of slosh waves with various frequencies excited are discussed.

  13. Reaction and reorientation of electronically excited H{sub 2}(B)

    Energy Technology Data Exchange (ETDEWEB)

    Pibel, C.D.

    1992-09-01

    The room temperature rate (TR) constants for fluorescence quenching fluorescence of H{sub 2}, HD, and D{sub 2} B {sup 1}{Sigma}{sub u}{sup +} by {sup 4}He were measured as a function of the initially excited rotational and vibrational level of the hydrogen molecule, and the RT rate constants for molecular angular momentum reorientation of H{sub 2}, HD and D{sub 2} (B {sup 1}{Sigma}{sub u}{sup +}. v{prime}=0, J{prime}=1, M{sub J}=0) in collisions with He, Ne, Ar and H{sub 2}(X {sup 1}{Sigma}{sub g}{sup +}) were also measured. Vibrational state dependence of the quenching cross sections fits a vibrationally adiabatic model of the quenching process. From the vibrational state dependence of the quenching cross section, the barrier height for the quenching reaction is found to be 250{plus_minus}40 cm{sup {minus}1}, and the difference in the H-H stretching frequencies between H{sub 2}(B) and the H{sub 2}-He complex at the barrier to reaction is 140{plus_minus}80 cm{sup {minus}1}. The effective cross sections for angular momentum reorientation in collisions of H{sub 2}, HD, D{sub 2} with He and Ne were found to be about 30 {Angstrom}{sup 2} and were nearly the same for each isotope and with He and Ne as collision partners. Cross sections forreorientation of HD and D{sub 2} in collisions with Ar were 10.6{plus_minus}2.0 and 13.9{plus_minus}3.0 {Angstrom}{sup 2}, respectively. Reorientation of D{sub 2}(B) in collisions with room temperature H{sub 2}(X) occurs with a 7.6{plus_minus}3.4 {Angstrom}{sup 2} cross section. Calculated cross sections using semiclassical and quantum close coupled methods give cross sections for reorientation of H{sub 2}(B) and D{sub 2}(B) in collisions with He that agree quantitatively with experiment. Discrepancy between the calculated and experimental cross sections for HD(B)-HE are likely due to rotational relaxation in HD a Turbo PASCAL version of the data-taking program is included.

  14. Reaction and reorientation of electronically excited H[sub 2](B)

    Energy Technology Data Exchange (ETDEWEB)

    Pibel, C.D.

    1992-09-01

    The room temperature rate (TR) constants for fluorescence quenching fluorescence of H[sub 2], HD, and D[sub 2] B [sup 1][Sigma][sub u][sup +] by [sup 4]He were measured as a function of the initially excited rotational and vibrational level of the hydrogen molecule, and the RT rate constants for molecular angular momentum reorientation of H[sub 2], HD and D[sub 2] (B [sup 1][Sigma][sub u][sup +]. v[prime]=0, J[prime]=1, M[sub J]=0) in collisions with He, Ne, Ar and H[sub 2](X [sup 1][Sigma][sub g][sup +]) were also measured. Vibrational state dependence of the quenching cross sections fits a vibrationally adiabatic model of the quenching process. From the vibrational state dependence of the quenching cross section, the barrier height for the quenching reaction is found to be 250[plus minus]40 cm[sup [minus]1], and the difference in the H-H stretching frequencies between H[sub 2](B) and the H[sub 2]-He complex at the barrier to reaction is 140[plus minus]80 cm[sup [minus]1]. The effective cross sections for angular momentum reorientation in collisions of H[sub 2], HD, D[sub 2] with He and Ne were found to be about 30 [Angstrom][sup 2] and were nearly the same for each isotope and with He and Ne as collision partners. Cross sections forreorientation of HD and D[sub 2] in collisions with Ar were 10.6[plus minus]2.0 and 13.9[plus minus]3.0 [Angstrom][sup 2], respectively. Reorientation of D[sub 2](B) in collisions with room temperature H[sub 2](X) occurs with a 7.6[plus minus]3.4 [Angstrom][sup 2] cross section. Calculated cross sections using semiclassical and quantum close coupled methods give cross sections for reorientation of H[sub 2](B) and D[sub 2](B) in collisions with He that agree quantitatively with experiment. Discrepancy between the calculated and experimental cross sections for HD(B)-HE are likely due to rotational relaxation in HD a Turbo PASCAL version of the data-taking program is included.

  15. Dynamic Isovector Reorientation of Deuteron as a Probe to Nuclear Symmetry Energy.

    Science.gov (United States)

    Ou, Li; Xiao, Zhigang; Yi, Han; Wang, Ning; Liu, Min; Tian, Junlong

    2015-11-20

    We present the calculations on a novel reorientation effect of deuteron attributed to isovector interaction in the nuclear field of heavy target nuclei. The correlation angle determined by the relative momentum vector of the proton and the neutron originating from the breakup deuteron, which is experimentally detectable, exhibits significant dependence on the isovector nuclear potential but is robust against the variation of the isoscaler sector. In terms of sensitivity and cleanness, the breakup reactions induced by the polarized deuteron beam at about 100 MeV/u provide a more stringent constraint to the symmetry energy at subsaturation densities.

  16. Influence of family, religion, and social conformity on client participation in sexual reorientation therapy.

    Science.gov (United States)

    Maccio, Elaine M

    2010-01-01

    This study examined the likelihood of participating in sexual reorientation therapy (SRT) based on actual or expected family reactions to the disclosure of one's same-sex sexuality, religious fundamentalism, social conformity, and several demographic variables. A sample of 52 SRT participants and 211 SRT nonparticipants who had ever identified as gay, lesbian, or bisexual completed a survey either online or in hardcopy format. Actual or expected negative family reactions, high religious fundamentalism, and identifying as spiritual significantly increased one's odds of participating in SRT. The findings are essential for preparing practitioners in any clinical practice setting to work with clients struggling with their sexuality.

  17. Nd-induced Mn spin-reorientation transition in NdMnAsO

    OpenAIRE

    Marcinkova, A.; Hansen, T.C.; Curfs, C.; Margadonna, S.; Bos, J. -W. G.

    2010-01-01

    A combination of synchrotron x-ray, neutron powder-diffraction, magnetization, heat-capacity, and electrical-resistivity measurements reveals that NdMnAsO is an antiferromagnetic semiconductor with large Neel temperature [T-N=359(2) K]. At room temperature the magnetic propagation vector k=0 and the Mn moments are directed along the crystallographic c axis [m(Mn)=2.41(6) mu(B)]. Upon cooling a spin-reorientation (SR) transition of the Mn moments into the ab plane occurs (T-SR=23 K). This coin...

  18. Periodic structures induced by director reorientation in the lyotropic nematic phase of disodium cromoglycate-water

    Science.gov (United States)

    Hui, Y. W.; Kuzma, M. R.; San Miguel, M.; Labes, M. M.

    1985-07-01

    A nonequilibrium periodic structure is induced by a magnetic field H applied to an aligned lyotropic uniaxial nematic phase of disodium cromoglycate-water. A series of parallel lines perpendicular to H represents boundaries between 180° out-of-phase regions of director reorientation. The distance between the lines decreases with increasing H. The line spacing is also directly proportional to thickness of the sample (in a limited range of thickness), and a secondary periodicity, consisting of nodes in these lines, is observed in thicker samples. An extension of a theoretical model by Guyon et al. is used to qualitatively interpret the abovementioned dependencies.

  19. Time-perception network and default mode network are associated with temporal prediction in a periodic motion task

    Directory of Open Access Journals (Sweden)

    Fabiana Mesquita Carvalho

    2016-06-01

    Full Text Available The updating of prospective internal models is necessary to accurately predict future observations. Uncertainty-driven internal model updating has been studied using a variety of perceptual paradigms, and have revealed engagement of frontal and parietal areas. In a distinct literature, studies on temporal expectations have also characterized a time-perception network, which relies on temporal orienting of attention. However, the updating of prospective internal models is highly dependent on temporal attention, since temporal attention must be reoriented according to the current environmental demands. In this study we used fMRI to evaluate to what extend the continuous manipulation of temporal prediction would recruit update-related areas and the time-perception network areas. We developed an exogenous temporal task that combines rhythm cueing and time-to-contact principles to generate implicit temporal expectation. Two patterns of motion were created: periodic (simple harmonic oscillation and non-periodic (harmonic oscillation with variable acceleration. We found that non-periodic motion engaged the exogenous temporal orienting network, which includes the ventral premotor and inferior parietal cortices, and the cerebellum, as well as the presupplementary motor area, which has previously been implicated in internal model updating, and the motion-sensitive area MT+. Interestingly, we found a right-hemisphere preponderance suggesting the engagement of explicit timing mechanisms. We also show that the periodic motion condition, when compared to the non-periodic motion, activated a particular subset of the default-mode network (DMN midline areas, including the left dorsomedial prefrontal cortex, anterior cingulate cortex, and bilateral posterior cingulate cortex/precuneus. It suggests that the DMN plays a role in processing contextually expected information and supports recent evidence that the DMN may reflect the validation of prospective internal

  20. A three-dimensional model of magneto-mechanical behaviors of martensite reorientation in ferromagnetic shape memory alloys

    Science.gov (United States)

    Chen, Xue; Moumni, Ziad; He, Yongjun; Zhang, Weihong

    2014-03-01

    The large strain in Ferromagnetic Shape Memory Alloys (FSMA) is due to the martensite reorientation driven by mechanical stresses and/or magnetic fields. Although most experiments studying the martensite reorientation in FSMA are under 1D condition (uniaxial stress plus a perpendicular magnetic field), it has been shown that the 2D/3D configurations can improve the working stress and give much flexibility of the material's applications [He, Y.J., Chen, X., Moumni, Z., 2011. Two-dimensional analysis to improve the output stress in ferromagnetic shape memory alloys. Journal of Applied Physics 110, 063905]. To predict the material's behaviors in 3D loading conditions, a constitutive model is developed in this paper, based on the thermodynamics of irreversible processes with internal variables. All the martensite variants are considered in the model and the temperature effect is also taken into account. The model is able to describe all the behaviors of martensite reorientation in FSMA observed in the existing experiments: rotating/non-rotating magnetic-field-induced martensite reorientation, magnetic-field-assisted super-elasticity, super-elasticity under biaxial compressions and temperature-dependence of martensite reorientation. The model is further used to study the nonlinear bending behaviors of FSMA beams and provides some basic guidelines for designing the FSMA-based bending actuators.

  1. Low speed maneuvering flight of the rose-breasted cockatoo (Eolophus roseicapillus). II. Inertial and aerodynamic reorientation.

    Science.gov (United States)

    Hedrick, T L; Usherwood, J R; Biewener, A A

    2007-06-01

    The reconfigurable, flapping wings of birds allow for both inertial and aerodynamic modes of reorientation. We found evidence that both these modes play important roles in the low speed turning flight of the rose-breasted cockatoo Eolophus roseicapillus. Using three-dimensional kinematics recorded from six cockatoos making a 90 degrees turn in a flight corridor, we developed predictions of inertial and aerodynamic reorientation from estimates of wing moments of inertia and flapping arcs, and a blade-element aerodynamic model. The blade-element model successfully predicted weight support (predicted was 88+/-17% of observed, N=6) and centripetal force (predicted was 79+/-29% of observed, N=6) for the maneuvering cockatoos and provided a reasonable estimate of mechanical power. The estimated torque from the model was a significant predictor of roll acceleration (r(2)=0.55, Pflight dynamics (approximately -0.45), were required to bring our estimates of reorientation due to aerodynamic torque back into conjunction with the measured changes in orientation. Our estimates of inertial reorientation were statistically significant predictors of the measured reorientation within wingbeats (r(2) from 0.2 to 0.37, Pflight muscles: the pectoralis, supracoracoideus, biceps brachii and extensor metacarpi radialis (r(2) from 0.27 to 0.45, Pflight maneuvers rely on production of asymmetries throughout the flight apparatus rather than in a specific set of control or turning muscles.

  2. Nuclear magnetic resonance studies of atomic motion in borohydride-based materials: Fast anion reorientations and cation diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Skripov, A.V., E-mail: skripov@imp.uran.ru; Soloninin, A.V.; Babanova, O.A.; Skoryunov, R.V.

    2015-10-05

    Highlights: • Solid solutions LiBH{sub 4}–LiI: extremely fast BH{sub 4} reorientations down to low T. • LiLa(BH{sub 4}){sub 3}Cl: Li-ion diffusive jumps and BH{sub 4} reorientations at the same frequency scale. • Dramatic acceleration of B{sub 12}H{sub 12} reorientations in the disordered phase of Na{sub 2}B{sub 12}H{sub 12}. • Fast Na-ion diffusion in the disordered phase of Na{sub 2}B{sub 12}H{sub 12}. - Abstract: Two basic types of thermally activated atomic jump motion are known to exist in solid borohydrides and the related systems: the reorientations of complex anions ([BH{sub 4}]{sup −}, [B{sub 12}H{sub 12}]{sup 2−}) and the translational diffusion of metal cations or complex anions. This paper reviews recent progress in nuclear magnetic resonance (NMR) studies of these jump processes in complex hydrides, such as solid solutions of halide anions in borohydrides, bimetallic borohydrides and borohydride–chlorides, borohydride–amides, and B{sub 12}H{sub 12}-based compounds. The emphasis is put on the systems showing fast-ion conductivity. For these systems, we discuss a possible relation between the reorientational motion of complex anions and the translational motion of metal cations.

  3. Magnetic structure and spin reorientation of quaternary Dy2Fe2Si2C

    Science.gov (United States)

    Susilo, R. A.; Cadogan, J. M.; Hutchison, W. D.; Stewart, G. A.; Avdeev, M.; Campbell, S. J.

    2017-03-01

    We have investigated the low temperature magnetic properties of Dy2Fe2Si2C by using magnetisation, specific heat, x-ray diffraction, neutron powder diffraction and 57Fe Mössbauer spectroscopy measurements over the temperature range 1.5 K–300 K. Dy2Fe2Si2C exhibits two magnetic transitions at low temperatures: an antiferromagnetic transition at {{T}\\text{N}}∼ 26 K and a spin-reorientation transition at {{T}t}∼ 6 K. The magnetic structure above T t can be described with a propagation vector \\mathbf{k}~=~≤ft(0~0~\\frac{1}{2}\\right) with the ordering of the Dy magnetic moments along the monoclinic b-axis whereas on cooling below T t the Dy moment tips away from the b-axis towards the ac-plane. We find that the spin-reorientation in Dy2Fe2Si2C is mainly driven by the competition between the second-order crystal field term B 20 and the higher-order terms, in particular B 40 and B 64.

  4. Converse magnetoelectric effect via strain-driven magnetization reorientations in ultrathin ferromagnetic films on ferroelectric substrates

    Science.gov (United States)

    Pertsev, N. A.

    2015-07-01

    A phenomenological theory is developed for the strain-driven magnetization reorientations occurring in ultrathin ferromagnetic films coupled to ferroelectric substrates experiencing electric-field-induced piezoelectric deformations. The theory takes into account the surface/interface magnetic anisotropy playing an important role in the energetics of such films and first describes the thickness-driven spin reorientation transitions emerging in the presence of substrate-induced lattice strains. Then the threshold and critical intensities of the electric field created in a ferroelectric substrate are calculated, at which different magnetic states acquire the same energy or become unstable in a strained ferromagnetic overlayer. To demonstrate stability ranges of various possible magnetization orientations, we introduce magnetoelectric orientational diagrams, where the electric-field intensity and film thickness are employed as two variables. Such diagrams are constructed for ultrathin Ni, Fe, and F e60C o40 films coupled to single crystals of classical and relaxor ferroelectrics. The inspection of these diagrams shows that the use of multiferroic hybrids comprising ultrathin ferromagnetic films significantly enlarges the range of ferroic materials suitable for experimental observations of the strain-mediated converse magnetoelectric effect.

  5. Strain induced magnetic transitions and spin reorientations in quantum paraelectric EuTiO3 material

    Science.gov (United States)

    Li, Chengdi; Zhao, Jinglong; Dong, Zhengchao; Zhong, Chonggui; Huang, Yanyan; Min, Yi; Wang, Meng; Zhou, Pengxia

    2015-05-01

    Strain induced magnetic transitions and spin reorientations in quantum paraelectric EuTiO3 material have been investigated using the first-principles calculations based on density functional theory. Four kinds of magnetic configurations and three possible directions of magnetic moments in every configuration are taken into consideration, respectively, in paraelectric and ferroelectric phases induced by the biaxial compressive and tensile strains. The calculated results indicate that the strain, regardless of the compressive or tensile strain, can induce not only the magnetic transitions from G-type antiferromagnetic to ferromagnetic phase, but also the reorientation of spin polarization in EuTiO3. The compressive strain can induce a ferromagnetic phase with spin polarization along a axis while the tensile one make magnetic moments along c axis. The further analysis for the electronic density of states (DOS) discover that the magnetic moment direction of EuTiO3 have intrinsic correlation with these orbitals, where the density of states are the most localized. In addition, Anderson super-exchange model is proposed to explain the changes of exchange coupling properties induced by the biaxial strains.

  6. Fast local trust region technique for diffusion tensor registration using exact reorientation and regularization.

    Science.gov (United States)

    Li, Junning; Shi, Yonggang; Tran, Giang; Dinov, Ivo; Wang, Danny J J; Toga, Arthur

    2014-05-01

    Diffusion tensor imaging is widely used in brain connectivity research. As more and more studies recruit large numbers of subjects, it is important to design registration methods which are not only theoretically rigorous, but also computationally efficient. However, the requirement of reorienting diffusion tensors complicates and considerably slows down registration procedures, due to the correlated impacts of registration forces at adjacent voxel locations. Based on the diffeomorphic Demons algorithm (Vercauteren , 2009), we propose a fast local trust region algorithm for handling inseparable registration forces for quadratic energy functions. The method guarantees that, at any time and at any voxel location, the velocity is always within its local trust region. This local regularization allows efficient calculation of the transformation update with numeric integration instead of completely solving a large linear system at every iteration. It is able to incorporate exact reorientation and regularization into the velocity optimization, and preserve the linear complexity of the diffeomorphic Demons algorithm. In an experiment with 84 diffusion tensor images involving both pair-wise and group-wise registrations, the proposed algorithm achieves better registration in comparison with other methods solving large linear systems (Yeo , 2009). At the same time, this algorithm reduces the computation time and memory demand tenfold.

  7. Human sperm pattern of movement during chemotactic re-orientation towards a progesterone source

    Institute of Scientific and Technical Information of China (English)

    Cecilia Soledad Blengini; Maria Eugenia Teves; Diego Rafael Unates; Hector Alejandro Guidobaldi; Laura Virginia Gatica; Laura Cecilia Giojalas

    2011-01-01

    @@ Human spermatozoa may chemotactically find out the egg by following an increasing gradient of attractant molecules.Although human spermatozoa have been observed to show several of the physiological characteristics of chemotaxis,the chemotactic pattern of movement has not been easy to describe.However,it is apparent that chemotactic cells may be identified while returning to the attractant source.This study characterizes the pattern of movement of human spermatozoa during chemotactic re-orientation towards a progesterone source,which is a physiological attractant candidate.By means of videomicroscopy and image analysis,a chemotactic pattern of movement was identified as the spermatozoon returned towards the source of a chemotactic concentration of progesterone (10 pmol l-1).First,as a continuation of its original path,the spermatozoon swims away from the progesterone source with linear movement and then turns back with a transitional movement that can be characterized by an increased velocity and decreased linearity.This sperm behaviour may help the spermatozoon to re-orient itself towards a progesterone source and may be used to identify the few cells that are undergoing chemotaxis at a given time.

  8. Ion induced magnetization reorientation in Co/Pt multilayers for patterned media

    Energy Technology Data Exchange (ETDEWEB)

    Weller, D.; Baglin, J.E.E.; Kellock, A.J.; Hannibal, K.A.; Toney, M.F.; Kusinski, G.; Lang, S.; Best, M.E.; Terris, B.D.

    2000-01-01

    Co/Pt multilayer films with perpendicular magnetic anisotropy and large out-of-plane coercivities of 3.9 - 8.5 kOe have been found to undergo a spin reorientation transition from out-of-plane to in-plane upon irradiation with 700 keV nitrogen ions. X-ray reflectivity experiments show that the multilayer structure gets progressively disrupted with increasing ion dose, providing direct evidence for local atomic displacements at the Co/Pt interfaces. This effectively destroys the magnetic interface anisotropy, which was varied by about a factor of two, between KS@ 0.4 erg/cm2 and KS@ 0.85 erg/cm2 for two particular films. The dose required to initiate spin-reorientation, 6x1014 N+/cm2 and 1.5x1015 N+/cm2, respectively, scales with KS. It is roughly equal to the number of Co interface atoms per unit interface area contributing to KS.

  9. Towards reduction of Paradigm coordination models

    CERN Document Server

    Andova, Suzana; de Vink, Erik; 10.4204/EPTCS.60.1

    2011-01-01

    The coordination modelling language Paradigm addresses collaboration between components in terms of dynamic constraints. Within a Paradigm model, component dynamics are consistently specified at a detailed and a global level of abstraction. To enable automated verification of Paradigm models, a translation of Paradigm into process algebra has been defined in previous work. In this paper we investigate, guided by a client-server example, reduction of Paradigm models based on a notion of global inertness. Representation of Paradigm models as process algebraic specifications helps to establish a property-preserving equivalence relation between the original and the reduced Paradigm model. Experiments indicate that in this way larger Paradigm models can be analyzed.

  10. Pair Negotiation When Developing English Speaking Tasks

    Science.gov (United States)

    Bohórquez Suárez, Ingrid Liliana; Gómez Sará, Mary Mily; Medina Mosquera, Sindy Lorena

    2011-01-01

    This study analyzes what characterizes the negotiations of seventh graders at a public school in Bogotá when working in pairs to develop speaking tasks in EFL classes. The inquiry is a descriptive case study that follows the qualitative paradigm. As a result of analyzing the data, we obtained four consecutive steps that characterize students'…

  11. Logic and human reasoning: an assessment of the deduction paradigm.

    Science.gov (United States)

    Evans, Jonathan St B T

    2002-11-01

    The study of deductive reasoning has been a major paradigm in psychology for approximately the past 40 years. Research has shown that people make many logical errors on such tasks and are strongly influenced by problem content and context. It is argued that this paradigm was developed in a context of logicist thinking that is now outmoded. Few reasoning researchers still believe that logic is an appropriate normative system for most human reasoning, let alone a model for describing the process of human reasoning, and many use the paradigm principally to study pragmatic and probabilistic processes. It is suggested that the methods used for studying reasoning be reviewed, especially the instructional context, which necessarily defines pragmatic influences as biases.

  12. Peculiarities in the director reorientation and evolution of NMR spectra under the influence of crossed electric and magnetic fields

    Science.gov (United States)

    Zakharov, A. V.

    2016-12-01

    Theoretical description is proposed for new modes of reorientation of the director field widehat n and the evolution of the NMR spectrum I(ν) of a nematic liquid crystal (LC) formed by molecules of deuterated 4-n-pentyl-4'-cyanobiphenyl encapsulated in a rectangular LC cell under the action of crossed electric, E, and magnetic, B, fields directed at an angle of α to one another. Numerical calculations in the framework of the nonlinear generalization of the classical Ericksen-Leslie theory show that, under certain relations between the forces and moments acting upon a unit volume of the LC phase upon the reorientation of widehat n, transient periodic structures can arise if the corresponding distortion mode is characterized by the fastest response and thus suppresses all other modes, including uniform ones. It is shown that the rise of these periodic structures leads to a reduction in the time for the reorientation of the director field.

  13. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri

    2007-01-01

    patients with schizophrenia and matched controls in a new working memory paradigm involving dynamic (the Ball Flight Task - BFT) or static (the Static Pattern Task - SPT) visual stimuli. In the BFT, the responses of the patients were apparently based on the retention of the last set of segments...

  14. Evoked heart rate and blood pressure in an S1-S2 paradigm

    NARCIS (Netherlands)

    Koers, G; Gaillard, A.W K; Mulder, G.

    1997-01-01

    Phasic changes in heart rate (HR) and blood pressure (BP) in an S1-S2 paradigm were studied in three experiments. In each experiment, a memory search task was performed at S1. The outcome of this task indicated whether a fast or a delayed response had to be given after S2. Besides this response

  15. PARADIGM SHIFT IN ISLAMIC STUDIES

    Directory of Open Access Journals (Sweden)

    Editor Al-Jami'ah: Journal of Islamic Studies

    2008-08-01

    Full Text Available In the early 1990s, there was a heated debate among students ofIAIN (the State Institute for Islamic Studies Sunan KalijagaYogyakarta about the future of Islamic studies, focusing on the possibilityof incorporating Thomas Kuhn’s paradigm to the discourse ofIslamic studies. Kuhn explains in detail the rise and decline of scientificparadigm in his classic work, The Structure of Scientific Revolutions,firstly published in 1970. Paradigm is defined as a set of beliefs thatguides the researchers to address some important problems or issuesunder a certain theoretical framework and provides procedures how tosolve those problems. A paradigm shift is a process whereby a newway of perceiving the world comes into existence and is accepted byscholars in a given time. Kuhn proposed two conditions for paradigmshift; first, the presence of anomalies in ‘normal science’, and secondly,the presence of alternative paradigm.

  16. Giant rotating magnetocaloric effect in the region of spin-reorientation transition in the NdCo₅ single crystal.

    Science.gov (United States)

    Nikitin, S A; Skokov, K P; Koshkid'ko, Yu S; Pastushenkov, Yu G; Ivanova, T I

    2010-09-24

    We have investigated the anisotropy of the magnetocaloric effect in a NdCo₅ single crystal in a wide range of temperatures, including the spin-reorientation temperature region. In the field μ(0)H =1.3 T in the spin-reorientation region 250-310 K, we discovered a giant rotating magnetocaloric effect of ~ 1.6 K, caused by rotation of the magnetization vector. The calculations of the anisotropy magnetocaloric effect for the field μ(0)H =1.3 T have been carried out.

  17. Management as an innovation paradigm of education governance: philosophical analysis

    Directory of Open Access Journals (Sweden)

    E. G. Sytnychenko

    2014-08-01

    Full Text Available Value of management paradigm management determined that it is the most adequate model of implementation of educational innovations. Innovative approaches to governance, grounded in management theory, the needs reorientation of government to the needs of the consumer education. The main reason for this is the nature of activity management, its focus on management education as a social and cultural process determined in all the richness of social, organizational and personal relationships. In modern terms the greatest impact on innovation processes in governance provides administrative management. Distribution system innovations in the field of education creates opportunities to influence the system of government most directly dynamic management - innovation. Innovation Management - a purposeful innovation management system, its resources, people involved in developing and implementing innovations in order to maximize the effectiveness of innovation as the most important factor of the control system. The focus of innovation management in the management of education is to develop strategies of educational innovation as from within the educational sector, and about the management of innovation processes in its interaction with socio-cultural environment. Development and dissemination of innovation is a priority strategy of education in modern times, as it defines the rest of educational strategies.

  18. A geometrical approach to determine reorientation start and continuation conditions in ferromagnetic shape memory alloys considering the effects of loading history

    Science.gov (United States)

    Shirani, M.; Kadkhodaei, M.

    2014-12-01

    Ferromagnetic shape memory alloys (FSMAs) and magnetic shape memory alloys (MSMAs) are metallic alloys that can undergo inelastic responses when exposed to magnetic fields. Several constitutive models have been proposed so far to model the behaviors of FSMAs. In this work, the effects of loading history on reorientation start conditions are considered, and it is shown that reorientation start conditions are not fixed values; rather, they change with respect to the amount of loading history. To consider the effects of loading history on reorientation start conditions, an available phase diagram in stress-field space is generalized to reorientation surfaces in stress-field-loading history space. Correspondingly, kinetic laws are derived in a continuum framework to be used with the reorientation surfaces to determine the amount of the martensitic variant 2 volume fraction. Based on the geometry of the reorientation surfaces, conditions that must be satisfied to ensure the continuation of reorientations are obtained. Available experimental findings validate the proposed model and the reorientation surfaces.

  19. Young Children's Use of Features to Reorient Is More than Just Associative: Further Evidence against a Modular View of Spatial Processing

    Science.gov (United States)

    Newcombe, Nora S.; Ratliff, Kristin R.; Shallcross, Wendy L.; Twyman, Alexandra D.

    2010-01-01

    Proponents of a geometric module have argued that instances of young children's use of features as well as geometry to reorient can be explained by a two-stage process. In this model, only the first stage is a true reorientation, accomplished by using geometric information alone; features are considered in a second stage using association (Lee,…

  20. Health Inequities: Evaluation of Two Paradigms

    Science.gov (United States)

    Ashcroft, Rachelle

    2010-01-01

    Social work practice in health is shaped by underlying paradigms. To effectively target health inequities, practitioners need to consider appropriate paradigms. In this exploration of how six health paradigms shape theory and practice, the two health paradigms that most attended to health inequalities are social determinants of health and…

  1. Visuospatial tasks affect locomotor control more than nonspatial tasks in older people.

    Directory of Open Access Journals (Sweden)

    Jasmine C Menant

    Full Text Available Previous research has shown that visuospatial processing requiring working memory is particularly important for balance control during standing and stepping, and that limited spatial encoding contributes to increased interference in postural control dual tasks. However, visuospatial involvement during locomotion has not been directly determined. This study examined the effects of a visuospatial cognitive task versus a nonspatial cognitive task on gait speed, smoothness and variability in older people, while controlling for task difficulty.Thirty-six people aged ≥75 years performed three walking trials along a 20 m walkway under the following conditions: (i an easy nonspatial task; (ii a difficult nonspatial task; (iii an easy visuospatial task; and (iv a difficult visuospatial task. Gait parameters were computed from a tri-axial accelerometer attached to the sacrum. The cognitive task response times and percentage of correct answers during walking and seated trials were also computed.No significant differences in either cognitive task type error rates or response times were evident in the seated conditions, indicating equivalent task difficulty. In the walking trials, participants responded faster to the visuospatial tasks than the nonspatial tasks but at the cost of making significantly more cognitive task errors. Participants also walked slower, took shorter steps, had greater step time variability and less smooth pelvis accelerations when concurrently performing the visuospatial tasks compared with the nonspatial tasks and when performing the difficult compared with the easy cognitive tasks.Compared with nonspatial cognitive tasks, visuospatial cognitive tasks led to a slower, more variable and less smooth gait pattern. These findings suggest that visuospatial processing might share common networks with locomotor control, further supporting the hypothesis that gait changes during dual task paradigms are not simply due to limited attentional

  2. In-situ particles reorientation during magnetic hyperthermia application: Shape matters twice

    Science.gov (United States)

    Simeonidis, Konstantinos; Morales, M. Puerto; Marciello, Marzia; Angelakeris, Makis; de La Presa, Patricia; Lazaro-Carrillo, Ana; Tabero, Andrea; Villanueva, Angeles; Chubykalo-Fesenko, Oksana; Serantes, David

    2016-12-01

    Promising advances in nanomedicine such as magnetic hyperthermia rely on a precise control of the nanoparticle performance in the cellular environment. This constitutes a huge research challenge due to difficulties for achieving a remote control within the human body. Here we report on the significant double role of the shape of ellipsoidal magnetic nanoparticles (nanorods) subjected to an external AC magnetic field: first, the heat release is increased due to the additional shape anisotropy; second, the rods dynamically reorientate in the orthogonal direction to the AC field direction. Importantly, the heating performance and the directional orientation occur in synergy and can be easily controlled by changing the AC field treatment duration, thus opening the pathway to combined hyperthermic/mechanical nanoactuators for biomedicine. Preliminary studies demonstrate the high accumulation of nanorods into HeLa cells whereas viability analysis supports their low toxicity and the absence of apoptotic or necrotic cell death after 24 or 48 h of incubation.

  3. Temperature-dependent magnetostriction as the key factor for martensite reorientation in magnetic field

    Science.gov (United States)

    L'vov, Victor A.; Kosogor, Anna

    2016-09-01

    The magnetic field application leads to spatially inhomogeneous magnetostriction of twinned ferromagnetic martensite. When the increasing field and magnetostrictive strain reach certain threshold values, the motion of twin boundaries and magnetically induced reorientation (MIR) of twinned martensite start. The MIR leads to giant magnetically induced deformation of twinned martensite. In the present article, the threshold field (TF) and temperature range of observability of MIR were calculated for the Ni-Mn-Ga martensite assuming that the threshold strain (TS) is temperature-independent. The calculations show that if the TS is of the order of 10-4, the TF strongly depends on temperature and MIR can be observed only above the limiting temperature (~220 K). If the TS is of the order of 10-6, the TF weakly depends on temperature and MIR can be observed at extremely low temperatures. The obtained theoretical results are in agreement with available experimental data.

  4. Power-controlled transition from standard to negative refraction in reorientational soft matter.

    Science.gov (United States)

    Piccardi, Armando; Alberucci, Alessandro; Kravets, Nina; Buchnev, Oleksandr; Assanto, Gaetano

    2014-11-25

    Refraction at a dielectric interface can take an anomalous character in anisotropic crystals, when light is negatively refracted with incident and refracted beams emerging on the same side of the interface normal. In soft matter subject to reorientation, such as nematic liquid crystals, the nonlinear interaction with light allows tuning of the optical properties. We demonstrate that in such material a beam of light can experience either positive or negative refraction depending on input power, as it can alter the spatial distribution of the optic axis and, in turn, the direction of the energy flow when traveling across an interface. Moreover, the nonlinear optical response yields beam self-focusing and spatial localization into a self-confined solitary wave through the formation of a graded-index waveguide, linking the refractive transition to power-driven readdressing of copolarized guided-wave signals, with a number of output ports not limited by diffraction.

  5. Mechanism of dynamic reorientation of cortical microtubules due to mechanical stress

    CERN Document Server

    Muratov, Alexander

    2015-01-01

    Directional growth caused by gravitropism and corresponding bending of plant cells has been explored since 19th century, however, many aspects of mechanisms underlying the perception of gravity at the molecular level are still not well known. Perception of gravity in root and shoot gravitropisms is usually attributed to gravisensitive cells, called statocytes, which exploit sedimentation of macroscopic and heavy organelles, amyloplasts, to sense the direction of gravity. Gravity stimulus is then transduced into distal elongation zone, which is several mm far from statocytes, where it causes stretching. It is suggested that gravity stimulus is conveyed by gradients in auxin flux. We propose a theoretical model that may explain how concentration gradients and/or stretching may indirectly affect the global orientation of cortical microtubules, attached to the cell membrane and induce their dynamic reorientation perpendicular to the gradients. In turn, oriented microtubules arrays direct the growth and orientatio...

  6. Nonlinear continuous-wave optical propagation in nematic liquid crystals: Interplay between reorientational and thermal effects

    Science.gov (United States)

    Alberucci, Alessandro; Laudyn, Urszula A.; Piccardi, Armando; Kwasny, Michał; Klus, Bartlomiej; Karpierz, Mirosław A.; Assanto, Gaetano

    2017-07-01

    We investigate nonlinear optical propagation of continuous-wave (CW) beams in bulk nematic liquid crystals. We thoroughly analyze the competing roles of reorientational and thermal nonlinearity with reference to self-focusing/defocusing and, eventually, the formation of nonlinear diffraction-free wavepackets, the so-called spatial optical solitons. To this extent we refer to dye-doped nematic liquid crystals in planar cells excited by a single CW beam in the highly nonlocal limit. To adjust the relative weight between the two nonlinear responses, we employ two distinct wavelengths, inside and outside the absorption band of the dye, respectively. Different concentrations of the dye are considered in order to enhance the thermal effect. The theoretical analysis is complemented by numerical simulations in the highly nonlocal approximation based on a semi-analytic approach. Theoretical results are finally compared to experimental results in the Nematic Liquid Crystals (NLC) 4-trans-4'-n-hexylcyclohexylisothiocyanatobenzene (6CHBT) doped with Sudan Blue dye.

  7. Observation of second spin reorientation transition within ultrathin region in Fe films on Ag(001) surface

    Energy Technology Data Exchange (ETDEWEB)

    Khim, T.-Y. [c-CCMR and Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of); Shin, M.; Lee, H., E-mail: easyscan@sookmyung.ac.kr, E-mail: jhp@postech.ac.kr [Department of Chemistry, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Park, B.-G. [Pohang Accelerator Laboratory (PAL), Pohang 790-784 (Korea, Republic of); Park, J.-H., E-mail: easyscan@sookmyung.ac.kr, E-mail: jhp@postech.ac.kr [c-CCMR and Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of); Division of Advanced Materials Science, POSTECH, Pohang 790-784 (Korea, Republic of); Max Plank POSTECH Center for Complex Phase Materials, POSTECH, Pohang 790-784 (Korea, Republic of)

    2014-06-21

    We acquired direct measurements for in-plane and perpendicular-to-plane magnetic moments of Fe films using an x-ray magnetic circular dichroism technique with increase of the Fe thickness (up to 40 Å) on the Ag(001) surface. Epitaxial Fe/Ag(001) films were grown in situ with the thickness varying from 2 Å to 40 Å, and the magnetic anisotropy was carefully investigated as a function of the film thickness. We found re-entrance of the in-plane magnetic anisotropy of the Fe film in ultrathin region. The results manifest that the epitaxial Fe/Ag(001) film undergoes two distinct spin reorientation transitions from in-plane to out-of-plane at the film thickness t ≈ 9 Å and back to in-plane at t ≈ 18 Å as t increases.

  8. Rotational reorientation dynamics of C60 in various solvents. Picosecond transient grating experiments

    Science.gov (United States)

    Rubtsov, I. V.; Khudiakov, D. V.; Nadtochenko, V. A.; Lobach, A. S.; Moravskii, A. P.

    1994-11-01

    The picosecond transient grating technique has been used to study the rotational reorientation of C60 in various solvents: in toluene 7 +/- 1.5 ps, o-dichlorobenzene 10.3 +/- 1.5 ps, o-xylene 13 +/- 2 ps and in decalin 3.5 +/- 1.5 ps. The data obtained cannot be described by hydrodynamic Debye theory. Rough-sphere fluid theory predicts the correct values for C60 rotation in toluene, o-dichlorobenzene and in decalin. The deviations for o-xylene are probably connected with the specifics of the local solvent structure or with the stronger interaction of C60 with solvent molecules. The rotation of C60 in decalin is rapid and approaches the rotation in the gas phase determined by inertia.

  9. An image analysis approach for automatically re-orienteering CT images for dental implants.

    Science.gov (United States)

    Cucchiara, Rita; Lamma, Evelina; Sansoni, Tommaso

    2004-06-01

    In the last decade, computerized tomography (CT) has become the most frequently used imaging modality to obtain a correct pre-operative implant planning. In this work, we present an image analysis and computer vision approach able to identify, from the reconstructed 3D data set, the optimal cutting plane specific to each implant to be planned, in order to obtain the best view of the implant site and to have correct measures. If the patient requires more implants, different cutting planes are automatically identified, and the axial and cross-sectional images can be re-oriented accordingly to each of them. In the paper, we describe the defined algorithms in order to recognize 3D markers (each one aligned with a missed tooth for which an implant has to be planned) in the 3D reconstructed space, and the results in processing real exams, in terms of effectiveness and precision and reproducibility of the measure.

  10. An NMR study of molecular reorientations and diffusion in solid LiBF4

    Science.gov (United States)

    Reynhardt, E. C.; Lourens, J. A. J.

    1984-06-01

    The 19F second moment and the 19F, 11B, and 7Li spin-lattice relaxation times in a powdered sample of LiBF4 have been measured as a function of temperature. The results show that the BF-4 ion reorients isotropically while the Li+ ion remains stationary. The activation energy associated with the BF-4 motion is 8.5 kcal/mol. Above ˜385 K the BF-4 and Li+ diffuse through the lattice resulting in a 19F second moment which is almost zero. The activation energy of this process is 19.2 kcal/mol. A librational motion presumably influences the 19F T1ρ results just before diffusion sets in. The migration of Li+ around the BF-4 ion, which seems to be a strong possibility in the case of an isolated LiBF4 molecule, does not take place in the solid.

  11. Communication: On the origin of the non-Arrhenius behavior in water reorientation dynamics.

    Science.gov (United States)

    Stirnemann, Guillaume; Laage, Damien

    2012-07-21

    We combine molecular dynamics simulations and analytic modeling to determine the origin of the non-Arrhenius temperature dependence of liquid water's reorientation and hydrogen-bond dynamics between 235 K and 350 K. We present a quantitative model connecting hydrogen-bond exchange dynamics to local structural fluctuations, measured by the asphericity of Voronoi cells associated with each water molecule. For a fixed local structure the regular Arrhenius behavior is recovered, and the global anomalous temperature dependence is demonstrated to essentially result from a continuous shift in the unimodal structure distribution upon cooling. The non-Arrhenius behavior can thus be explained without invoking an equilibrium between distinct structures. In addition, the large width of the homogeneous structural distribution is shown to cause a growing dynamical heterogeneity and a non-exponential relaxation at low temperature.

  12. Dynamic selective switching in antiferromagnetically-coupled bilayers close to the spin reorientation transition

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Pacheco, A., E-mail: af457@cam.ac.uk; Mansell, R.; Petit, D.; Lee, J. H.; Cowburn, R. P. [Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Ummelen, F. C.; Swagten, H. J. M. [Department of Applied Physics, Center for NanoMaterials, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

    2014-09-01

    We have designed a bilayer synthetic antiferromagnet where the order of layer reversal can be selected by varying the sweep rate of the applied magnetic field. The system is formed by two ultra-thin ferromagnetic layers with different proximities to the spin reorientation transition, coupled antiferromagnetically using Ruderman-Kittel-Kasuya-Yosida interactions. The different dynamic magnetic reversal behavior of both layers produces a crossover in their switching fields for field rates in the kOe/s range. This effect is due to the different effective anisotropy of both layers, added to an appropriate asymmetric antiferromagnetic coupling between them. Field-rate controlled selective switching of perpendicular magnetic anisotropy layers as shown here can be exploited in sensing and memory applications.

  13. Early mammalian development under conditions of reorientation relative to the gravity vector

    Science.gov (United States)

    Wolgemuth, D. J.; Grills, G. S.

    1985-01-01

    A clinostat was used to assess the effects of reorientation relative to the gravity vector on mammalian germ cells cultured in vitro. Previous studies using this system revealed an inhibition of meiotic maturation of mouse oocytes. In the present study, the effects of clinostat rotation on in vitro fertilization were examined. The frequency of fertilization of experimental cultures did not vary from that of the clinostat vertical control cultures at either of the rotation rates examined. Importantly, no abnormalities of fertilization, such as parthenogenetic activation, fragmentation, or polyspermy were seen. It is concluded that the initial events of fertilization were unaffected by this treatment, although the developmental potential of these embryos remains to be assessed.

  14. Re-orienting a remote acute care model towards a primary health care approach: key enablers.

    Science.gov (United States)

    Carroll, Vicki; Reeve, Carole A; Humphreys, John S; Wakerman, John; Carter, Maureen

    2015-01-01

    The objective of this study was to identify the key enablers of change in re-orienting a remote acute care model to comprehensive primary healthcare delivery. The setting of the study was a 12-bed hospital in Fitzroy Crossing, Western Australia. Individual key informant, in-depth interviews were completed with five of six identified senior leaders involved in the development of the Fitzroy Valley Health Partnership. Interviews were recorded and transcripts were thematically analysed by two investigators for shared views about the enabling factors strengthening primary healthcare delivery in a remote region of Australia. Participants described theestablishment of a culturally relevant primary healthcare service, using a community-driven, 'bottom up' approach characterised by extensive community participation. The formal partnership across the government and community controlled health services was essential, both to enable change to occur and to provide sustainability in the longer term. A hierarchy of major themes emerged. These included community participation, community readiness and desire for self-determination; linkages in the form of a government community controlled health service partnership; leadership; adequate infrastructure; enhanced workforce supply; supportive policy; and primary healthcare funding. The strong united leadership shown by the community and the health service enabled barriers to be overcome and it maximised the opportunities provided by government policy changes. The concurrent alignment around a common vision enabled implementation of change. The key principle learnt from this study is the importance of community and health service relationships and local leadership around a shared vision for the re-orientation of community health services.

  15. The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hun; Jeong, Ho Gul; Hwang, Jae Joon; Lee, Jung Hee; Han, Sang Sun [Dept. of Oral and Maxillofacial Radiology, Yonsei University, College of Dentistry, Seoul (Korea, Republic of)

    2016-06-15

    The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions.

  16. Flux line lattice reorientation in the borocarbide superconductors with ¤H¤ parallel to ¤a¤

    DEFF Research Database (Denmark)

    Eskildsen, M.R.; Abrahamsen, A.B.; Lopez, D.

    2001-01-01

    Small angle neutron scattering studies of the flux line lattice in LuNi2B2C and ErNi2B2C induced by a held parallel to the a axis reveal a first order flux Line lattice reorientation transition. Below the transition the Bur line lattice nearest neighbor direction is parallel to the b axis, and ab...

  17. Symmetry breaking, slow relaxation dynamics, and topological defects at the field-induced helix reorientation in MnSi

    Science.gov (United States)

    Bauer, A.; Chacon, A.; Wagner, M.; Halder, M.; Georgii, R.; Rosch, A.; Pfleiderer, C.; Garst, M.

    2017-01-01

    We report a study of the reorientation of the helimagnetic order in the archetypal cubic chiral magnet MnSi as a function of magnetic field direction. The reorientation process as inferred from small-angle neutron scattering, the magnetization, and the ac susceptibility is in excellent agreement with an effective mean-field theory taking into account the precise symmetries of the crystallographic space group. Depending on the field and temperature history and the direction of the field with respect to the crystalline axes, the helix reorientation may exhibit a crossover, a first-order, or a second-order transition. The magnetization and ac susceptibility provide evidence that the reorientation of helimagnetic domains is associated with large relaxation times exceeding seconds. At the second-order transitions residual Ising symmetries are spontaneously broken at continuous elastic instabilities of the helimagnetic order. In addition, on the time scales explored in our experiments these transitions are hysteretic as a function of field suggesting, within the same theoretical framework, the formation of an abundance of plastic deformations of the helical spin order. These deformations comprise topologically nontrivial disclinations, reminiscent of the skyrmions discovered recently in the same class of materials.

  18. The impact of reorienting cone-beam computed tomographic images in varied head positions on the coordinates of anatomical landmarks

    Science.gov (United States)

    Kim, Jae Hun; Hwang, Jae Joon; Lee, Jung-Hee

    2016-01-01

    Purpose The aim of this study was to compare the coordinates of anatomical landmarks on cone-beam computed tomographic (CBCT) images in varied head positions before and after reorientation using image analysis software. Materials and Methods CBCT images were taken in a normal position and four varied head positions using a dry skull marked with 3 points where gutta percha was fixed. In each of the five radiographic images, reference points were set, 20 anatomical landmarks were identified, and each set of coordinates was calculated. Coordinates in the images from the normally positioned head were compared with those in the images obtained from varied head positions using statistical methods. Post-reorientation coordinates calculated using a three-dimensional image analysis program were also compared to the reference coordinates. Results In the original images, statistically significant differences were found between coordinates in the normal-position and varied-position images. However, post-reorientation, no statistically significant differences were found between coordinates in the normal-position and varied-position images. Conclusion The changes in head position impacted the coordinates of the anatomical landmarks in three-dimensional images. However, reorientation using image analysis software allowed accurate superimposition onto the reference positions. PMID:27358821

  19. MUSICAL LITERACY AND EDUCATIONAL PARADIGMS

    Directory of Open Access Journals (Sweden)

    Alboni Marisa Dudeque Pianovski Vieira

    2016-04-01

    Full Text Available The article presents us contemporary conceptions of musical literacy and its relation to educational paradigmatic issues, thus exposing different types of paradigms and their modifications. The possibility to relate and discuss issues related to these paradigms and to the contributions from different authors to musical literacy issues, characterizing graduates, are also among the objectives of this work. The relevance of these issues is in the few existing debates on the paradigms within music education as well as within the possibility of such a study being able to provide useful material for educators. Of bibliographical and documentary nature, this study is based on the works of Schafer (1992, 1997 and Swanwick (1979, 2003, 2014. The results point to the new trend of musical literacy, with an inclusive commitment, made accessible not only to the student who aims to be a professional musician, but also to people from different social contexts.

  20. Cultural Paradigms in Management Sciences

    Directory of Open Access Journals (Sweden)

    Lukasz Sulkowski

    2013-09-01

    Full Text Available Purpose: The purpose of this paper is to present an idea for understanding cultural processes in the organizational discourse from the perspective of four paradigms in management sciences based on the concept of G. Burrell and G. Morgan.Methodology: The author has elaborated a valuable list of structures of the scientifi c theory based on the respective paradigms and has compared cultural paradigms in management sciences. The methodology involves an analysis of classical and recent world literature. Nowadays there is no consensus on the defi nitions, types or research models of organizational culture.Originality: In the literature on the subject we can fi nd many, sometimes contradictory cultural research studies that require further analysis. Precisely because of the diversity and complexity of cultural issues in management sciences a multi-paradigmatic analysis is necessary. The paper presents a proposal for a pluralistic approach to the theory and methodology of cultural studies in management sciences.

  1. Transmission pricing: paradigms and methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Shirmohammadi, Dariush [Pacific Gas and Electric Co., San Francisco, CA (United States); Vieira Filho, Xisto; Gorenstin, Boris [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil); Pereira, Mario V.P. [Power System Research, Rio de Janeiro, RJ (Brazil)

    1994-12-31

    In this paper we describe the principles of several paradigms and methodologies for pricing transmission services. The paper outlines some of the main characteristics of these paradigms and methodologies such as where they may be used for best results. Due to their popularity, power flow based MW-mile and short run marginal cost pricing methodologies will be covered in some detail. We conclude the paper with examples of the application of these two pricing methodologies for pricing transmission services in Brazil. (author) 25 refs., 2 tabs.

  2. The synthesis paradigm in genetics.

    Science.gov (United States)

    Rice, William R

    2014-02-01

    Experimental genetics with model organisms and mathematically explicit genetic theory are generally considered to be the major paradigms by which progress in genetics is achieved. Here I argue that this view is incomplete and that pivotal advances in genetics--and other fields of biology--are also made by synthesizing disparate threads of extant information rather than generating new information from experiments or formal theory. Because of the explosive expansion of information in numerous "-omics" data banks, and the fragmentation of genetics into numerous subdisciplines, the importance of the synthesis paradigm will likely expand with time.

  3. Bayesian test and Kuhn's paradigm

    Institute of Scientific and Technical Information of China (English)

    Chen Xiaoping

    2006-01-01

    Kuhn's theory of paradigm reveals a pattern of scientific progress,in which normal science alternates with scientific revolution.But Kuhn underrated too much the function of scientific test in his pattern,because he focuses all his attention on the hypothetico-deductive schema instead of Bayesian schema.This paper employs Bayesian schema to re-examine Kuhn's theory of paradigm,to uncover its logical and rational components,and to illustrate the tensional structure of logic and belief,rationality and irrationality,in the process of scientific revolution.

  4. CNN a paradigm for complexity

    CERN Document Server

    Chua, Leon O

    1998-01-01

    Revolutionary and original, this treatise presents a new paradigm of EMERGENCE and COMPLEXITY, with applications drawn from numerous disciplines, including artificial life, biology, chemistry, computation, physics, image processing, information science, etc.CNN is an acronym for Cellular Neural Networks when used in the context of brain science, or Cellular Nonlinear Networks, when used in the context of emergence and complexity. A CNN is modeled by cells and interactions: cells are defined as dynamical systems and interactions are defined via coupling laws. The CNN paradigm is a universal Tur

  5. Design Paradigms in Car History

    OpenAIRE

    Dowlen, CMC

    2017-01-01

    The purpose of this research into Design Paradigms in Car History is to evaluate how production car design has changed over the last hundred and twenty-five years or so, using numerical analyses of specific cars, which act as exemplars. This evaluation should lead to a better understanding of car design history and how car designers think. Design thinking can be evidenced from how products have changed over the course of time. Design paradigms have been used to produce a structured analysis o...

  6. Explaining (Missing) Regulator Paradigm Shifts

    DEFF Research Database (Denmark)

    Wigger, Angela; Buch-Hansen, Hubert

    2014-01-01

    of competition regulation is heaving into sight. It sets out to explain this from the vantage point of a critical political economy perspective, which identifies the circumstances under which a crisis can result in a regulatory paradigm shift. Contrasting the current situation with the shift in EC/EU competition...... capitalism; the social power configuration underpinning the neoliberal order remains unaltered; no clear counter-project has surfaced; the European Commission has been (and remains) in a position to oppose radical changes; and finally, there are no signs of a wider paradigm shift in the EU's regulatory...

  7. Paradigms in Physics Education Research

    CERN Document Server

    Robertson, Amy D; McKagan, Sarah B

    2013-01-01

    Physics education research (PER) includes three distinct paradigms: quantitative research, qualitative research, and question-driven research. Quantitative PER seeks reproducible, representative patterns and relationships; human behavior is seen as dictated by lawful (albeit probabilistic) relationships. Qualitative PER seeks to refine and develop theory by linking theory to cases; human action is seen as shaped by the meanings that participants make of their local environments. Question-driven physics education researchers prioritize questions over the pursuit of local meanings or abstract relationships. We illustrate each paradigm with interviews with physics education researchers and examples of published PER.

  8. Political Rents of European Farmers in the Sustainable Development Paradigm. International, national and regional perspective

    OpenAIRE

    Czyżewski, Bazyli

    2016-01-01

    To make a summary of a book that contains so many different threads is no easy task. One should, on the one hand, refer to its conceptual contribution to the paradigm of sustainable agriculture, and on the other hand, consider the conclusions drawn from the studies conducted at international, national and regional level. It is clear that changing the paradigm of agricultural development from an industrial to a sustainable one will be neither easy nor quick. Agriculture must sat...

  9. Effort-Based Decision-Making Paradigms for Clinical Trials in Schizophrenia: Part 1—Psychometric Characteristics of 5 Paradigms.

    Science.gov (United States)

    Reddy, L Felice; Horan, William P; Barch, Deanna M; Buchanan, Robert W; Dunayevich, Eduardo; Gold, James M; Lyons, Naomi; Marder, Stephen R; Treadway, Michael T; Wynn, Jonathan K; Young, Jared W; Green, Michael F

    2015-09-01

    Impairments in willingness to exert effort contribute to the motivational deficits characteristic of the negative symptoms of schizophrenia. The current study evaluated the psychometric properties of 5 new or adapted paradigms to determine their suitability for use in clinical trials of schizophrenia. This study included 94 clinically stable participants with schizophrenia and 40 healthy controls. The effort-based decision-making battery was administered twice to the schizophrenia group (baseline, 4-week retest) and once to the control group. The 5 paradigms included 1 that assesses cognitive effort, 1 perceptual effort, and 3 that assess physical effort. Each paradigm was evaluated on (1) patient vs healthy control group differences, (2) test-retest reliability, (3) utility as a repeated measure (ie, practice effects), and (4) tolerability. The 5 paradigms showed varying psychometric strengths and weaknesses. The Effort Expenditure for Rewards Task showed the best reliability and utility as a repeated measure, while the Grip Effort Task had significant patient-control group differences, and superior tolerability and administration duration. The other paradigms showed weaker psychometric characteristics in their current forms. These findings highlight challenges in adapting effort and motivation paradigms for use in clinical trials. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center 2015.

  10. Paradigm Statements of Educational Objectives.

    Science.gov (United States)

    Gray, Peter J.

    Five distinct format categories are used in this study to describe the form of educational objectives: clarity, range, level of abstractness, behavioralness, and observability. These form concepts are used to describe paradigm statements of three kinds of educational objectives: goals, intended learning outcomes, and behavioral evidence. Goals are…

  11. The Paradigm of Distributed Creativity

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre

    This presentation aims to focus on and develop the notion of distributed creativity from a cultural psychological perspective. It will start by outlining the need for a cultural psychological paradigm of creative expression and argue that this perspective is primarily concerned with what can...

  12. The emerging land management paradigm

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    Manchet: This paper was first presented by Professor Enemark at the RICS Christmas Lecture in December last year. It provides a cogent and detailed reference point for the current state of land management in developed countries, charts a course for the future and looks at how education must chang...... to meet the new paradigm....

  13. A new paradigm for evaluating avoidance/escape motivation.

    Science.gov (United States)

    Tsutsui-Kimura, Iku; Bouchekioua, Youcef; Mimura, Masaru; Tanaka, Kenji F

    2017-05-06

    Organisms have evolved to approach pleasurable opportunities and to avoid or escape from aversive experiences. These two distinct motivations are referred to as approach and avoidance/escape motivations and are both considered vital for survival. Despite several recent advances in understanding the neurobiology of motivation, most studies addressed approach but not avoidance/escape motivation. Here we develop a new experimental paradigm to quantify avoidance/escape motivation and examine the pharmacological validity. We set up an avoidance variable ratio 5 (VR-5) task in which mice were required to press a lever for variable times to avoid an upcoming aversive stimulus (foot shock) or to escape the ongoing aversive event if mice failed to avoid it. We intraperitoneally injected ketamine (0, 1, or 5 mg/kg) or buspirone (0, 5, or 10 mg/kg) 20 or 30 minutes before the behavioral task in order to see if ketamine enhanced avoidance/escape behavior and buspirone diminished it as previously reported. We found that the performance on the avoidance VR-5 task was sensitive to the intensity of the aversive stimulus. Treatment with ketamine increased, while that with buspirone decreased, the probability of avoidance from an aversive stimulus in the VR-5 task, being consistent with previous reports. Our new paradigm will prove usefulness for quantifying avoidance/escape motivation and will contribute to a more comprehensive understanding of motivation.

  14. [Functional MRI at 1 Tesla. Basic paradigms and clinical application].

    Science.gov (United States)

    Schwarcz, Attila; Auer, Tibor; Komoly, Sámuel; Dóczi, Tamás; Janszky, József

    2007-07-30

    To perform functional MRI experiments at low magnetic field, and to set up routine protocol to help the planning of neurosurgical operations and the examination of epilepsy patients. An optimized 2D EPI sequence was applied to yield functional MR images in basic paradigms such as finger tapping and internal word generation. Further, activation was induced also by a task involving mental navigation based on the retrieval of individually familiar visuo-spatial knowledge. Low resolution (matrix of 64x64) functional MR images satisfactorily visualized moto-sensor strip and speech centers. In the mental navigation task bilateral activation of the hippocampal formation was observed. Determination of motor area was also performed in an epilepsy patient whose seizure focus had been found in the area of pre- and post-central gyrus. The dislocation of the motor cortex was demonstrated. Functional MR images with fine quality can be obtained in basic paradigms even at low magnetic field if MR imaging parameters and paradigms are optimized.

  15. Reorienting land degradation towards sustainable land management: linking sustainable livelihoods with ecosystem services in rangeland systems.

    Science.gov (United States)

    Reed, M S; Stringer, L C; Dougill, A J; Perkins, J S; Atlhopheng, J R; Mulale, K; Favretto, N

    2015-03-15

    This paper identifies new ways of moving from land degradation towards sustainable land management through the development of economic mechanisms. It identifies new mechanisms to tackle land degradation based on retaining critical levels of natural capital whilst basing livelihoods on a wider range of ecosystem services. This is achieved through a case study analysis of the Kalahari rangelands in southwest Botswana. The paper first describes the socio-economic and ecological characteristics of the Kalahari rangelands and the types of land degradation taking place. It then focuses on bush encroachment as a way of exploring new economic instruments (e.g. Payments for Ecosystem Services) designed to enhance the flow of ecosystem services that support livelihoods in rangeland systems. It does this by evaluating the likely impacts of bush encroachment, one of the key forms of rangeland degradation, on a range of ecosystem services in three land tenure types (private fenced ranches, communal grazing areas and Wildlife Management Areas), before considering options for more sustainable land management in these systems. We argue that with adequate policy support, economic mechanisms could help reorient degraded rangelands towards more sustainable land management.

  16. A study of methyl reorientation in solid nitromethane by neutron scattering

    Science.gov (United States)

    Trevino, S. F.; Rymes, W. H.

    1980-09-01

    The geometrical and dynamical properties of the reorientation of the methyl group of nitromethane in the solid state have been studied by inelastic neutron scattering. Quasielastic scattering spectra have been obtained for several values of momentum transfer at five temperatures between 50° and 150 °K. The spectra are shown to be consistent with jumps of 120 ° about an axis coincident with the C-N bond. The temperature dependence of the residence time yields a barrier of 234 cal/mole. An inelastic neutron spectrum obtained at 4.2 °K suggests a tunnel splitting of the torsional ground state of 0.045±0.005 meV, which is consistent with the derived activation energy. Inelastic neutron scattering has also been used to determine the energy of the tunnel split first excited state which in CH3NO2 has a mean energy of 7.4 meV above the ground state and is split by 1.8 meV. In the deuterated compound, the first excited stated is at 5.3 meV above the ground state and its splitting is less than the instrumental resolution.

  17. Quantifying Signaling-Induced Reorientation of TCR's During Immunological Synapse Formation

    Energy Technology Data Exchange (ETDEWEB)

    Moss, W C; Irvine, D J; Davis, M M; Krummel, M F

    2002-10-17

    Productive T cell recognition of antigen-presenting cells (APCs) is normally accompanied by the formation of a cell-cell contact called the 'immunological synapse.' Our understanding of the steps leading up to this formation has been limited by the absence of tools for analyzing 3D surfaces and surface distributions as they change over time. Here we use a 3D fluorescence quantitation method to show that T cell receptors are recruited in bulk within the first minute after the onset of activation and with velocities ranging from 0.04 to 0.1 {micro}m/s; a speed significantly greater than unrestricted diffusion. Our method reveals a second feature of this reorientation: a conformational change as the T cell pushes more total membrane into the interface creating a larger contact area for additional receptors. Analysis of individual T cell receptor velocities using a single-particle tracking method confirms our velocity measurement. This method should permit the quantitation of other dynamic membrane events and the associated movement of cell-surface molecules.

  18. Teaching-Service integration within the National Professional Health Education Reorientation Program.

    Science.gov (United States)

    Vendruscolo, Carine; Prado, Marta Lenise do; Kleba, Maria Elisabeth

    2016-09-01

    This integrative literature review aimed at identifying the characteristics and describing how teaching-service integration is expressed in studies on Pró-Saúde (Charitable institution for social and hospital assistance) published in Brazil in the period 2007-2012. For the search, the term National Professional Health Education Reorientation Program was entered in the following databases: Virtual Health Library (BVS), Google Scholar and the Bank of Theses of the Coordination for the Improvement of Higher Education Personnel (CAPES). Forty-one publications were selected with the following inclusion criteria: scientific papers; theses and dissertations; studies in English, Portuguese or Spanish. The critical review of studies was performed through a comprehensive reading of the texts. Outcomes are presented in two categories: Dialogue and partnership as tools for teaching-service integration and Movements of change in teaching-service through Pró-Saúde. Studies have shown that changes in professional education and practice are possible and necessary, especially when supported by strategies that encourage active participation of subjects and confirm teaching-service integration as opportunity for dialogue, promoted by this inducing policy.

  19. Noble metal capping effects on the spin-reorientation transitions of Co/Ru(0001)

    Energy Technology Data Exchange (ETDEWEB)

    El Gabaly, Farid; Figuera, Juan de la [Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, Madrid 28049 (Spain); McCarty, Kevin F [Sandia National Laboratories, Livermore, CA 94550 (United States); Schmid, Andreas K [Lawrence Berkeley National Laboratory, Berkeley 94720 (United States); Munoz, M Carmen; Gallego, Silvia [Instituto de Ciencia de Materiales de Madrid, CSIC, Madrid 28049 (Spain); Szunyogh, Laszlo [Department of Theoretical Physics, Institute of Physics, Budapest University of Technology and Economics, H-111 Budapest (Hungary); Weinberger, Peter [Center for Computational Nanoscience, A-1010 Wien (Austria)], E-mail: juan.delafiguera@iqfr.csic.es

    2008-07-15

    Thin films of Co/Ru(0001) are known to exhibit an unusual spin reorientation transition (SRT) coupled to the completion of Co atomic layers for Co thicknesses under four layers. By means of spin-polarized low-energy electron microscopy, we follow in real space the magnetization orientation during the growth of atomically thick capping layers on Co/Ru(0001). Capping with noble metal (Cu, Ag and Au) elements modifies the SRT depending on the Co and overlayer thickness and on the overlayer material, resulting in an expanded range of structures with high perpendicular magnetic anisotropy. The origin of the SRT can be explained in terms of ab initio calculations of the layer-resolved contributions to the magnetic anisotropy energy. Besides the changes in the SRT introduced by the capping, a quantitative enhancement of the magnetic anisotropy is identified. A detailed analysis of the interplay between strain and purely electronic effects allows us to identify the conditions that lead to a high perpendicular magnetic anisotropy in thin hcp Co films.

  20. Structural changes induced spin-reorientation of ultrathin Mn films grown on Ag(001)

    Energy Technology Data Exchange (ETDEWEB)

    Ouarab, N., E-mail: ouarab_nourdine@yahoo.fr [Quantum Physics and Dynamical Systems Laboratory, Ferhat Abbas University of Sétif (Algeria); Semiconductor Technology Research Center for Energetic-(CRTSE), 02, Bd Frantz Fanon Algiers, BP N° 140 (Algeria); Haroun, A. [Quantum Physics and Dynamical Systems Laboratory, Ferhat Abbas University of Sétif (Algeria); Baadji, N. [School of Physics and CRANN, Trinity College, Dublin 2 (Ireland)

    2016-12-01

    The strained body centered tetragonal (bct) Mn ultrathin film from lattice parameter a=2.89 Å to lattice value of 2.73 Å induces anti-ferromagnetic behavior between Mn layers. The magnetic easy axis of Mn film was demonstrated theoretically to switch from the in-plane to out-of-plane by magneto-optical Kerr effect investigation. By including spin–orbit coupling in full potential linearized augmented plane waves and linearized muffin-tin orbitals methods, manganese ultrathin film displays different magnetic behaviors and the spin-reorientation transition is shown to be correlated to these structural changes. The calculated magnetic moment of manganese planes are enhanced and reach a value of ~4.02 μ{sub B}. The polar magneto-optical Kerr effect is calculated for a photon energy range extended to 15 eV. It shows a pronounced peak in visible light. - Highlights: • The applied strain in Mn-bct structure induces anti-ferromagnetic behavior. • The easy magnetization axis is demonstrated to be out-of-plane. • The magnetic moment of Mn-layers are enhanced and reach a value of ~4.02 μ{sub B}. • Kerr spectra show significant polar responses for Mn films in the visible range. • The prominent structures in the Kerr spectra have been identified.

  1. Microscopic structure and reorientation kinetics of B-H complexes in silicon

    Science.gov (United States)

    Noya, José C.; Herrero, Carlos P.; Ramírez, Rafael

    1997-12-01

    Structural and dynamical properties of hydrogen and deuterium in boron-doped silicon have been studied by the path-integral Monte Carlo method as a function of temperature in the range between 30 and 400 K. The Si-Si and Si-B interactions were modeled by Stillinger-Weber-type potentials, and the Si-H and B-H interactions were parametrized by following the results of earlier pseudopotential-density-functional calculations for this system. Impurity energy, nuclei delocalization, and lattice relaxation are analyzed, the latter resulting to be mass dependent. The reorientation rate of the complex is obtained from quantum transition-state theory. A break in the slope of the Arrhenius plot for the jump rate of hydrogen is obtained at T~60 K, indicating a crossover from thermally activated quasiclassical motion over a barrier to thermally assisted quantum tunneling, in good agreement with previous experimental results. For deuterium, this deviation from an Arrhenius law is found at T~35 K. Both the impurity and the host nuclei are treated quantum mechanically, and it is shown that the defect complex undergoing quantum tunneling consists of hydrogen, boron, and the nearest silicon atoms.

  2. Estrogen-induced collagen reorientation correlates with sympathetic denervation of the rat myometrium.

    Science.gov (United States)

    Martínez, G F; Bianchimano, P; Brauer, M M

    2016-12-01

    Estrogen inhibits the growth and causes the degeneration (pruning) of sympathetic nerves supplying the rat myometrium. Previous cryoculture studies evidenced that substrate-bound signals contribute to diminish the ability of the estrogenized myometrium to support sympathetic nerve growth. Using electron microscopy, here we examined neurite-substrate interactions in myometrial cryocultures, observing that neurites grew associated to collagen fibrils present in the surface of the underlying cryosection. In addition, we assessed quantitatively the effects of estrogen on myometrial collagen organization in situ, using ovariectomized rats treated with estrogen and immature females undergoing puberty. Under low estrogen levels, most collagen fibrils were oriented in parallel to the muscle long axis (83% and 85%, respectively). Following estrogen treatment, 89% of fibrils was oriented perpendicularly to the muscle main axis; while after puberty, 57% of fibrils acquired this orientation. Immunohistochemistry combined with histology revealed that the vast majority of fine sympathetic nerve fibers supplying the myometrium courses within the areas where collagen realignment was observed. Finally, to assess whether depending on their orientation collagen fibrils can promote or inhibit neurite outgrowth, we employed cryocultures, now using as substrate tissue sections of rat-tail tendon. We observed that neurites grew extensively in the direction of the parallel-aligned collagen fibrils in the tendon main axis but were inhibited to grow perpendicularly to this axis. Collectively, these findings support the hypothesis that collagen reorientation may be one of the factors contributing to diminish the neuritogenic capacity of the estrogen-primed myometrial substrate.

  3. Individuation instructions decrease the Cross-Race Effect in a face matching task

    Directory of Open Access Journals (Sweden)

    2015-09-01

    Conclusions: Individuation instructions are an effective moderator of the CRE even within a face matching paradigm. Since unfamiliar face matching tasks most closely simulate document verification tasks, specifically passport screening, instructional techniques such as these may improve task performance within applied settings of significant practical importance.

  4. Conjunctive Continuous Performance Task (CCPT)--A Pure Measure of Sustained Attention

    Science.gov (United States)

    Shalev, Lilach; Ben-Simon, Anat; Mevorach, Carmel; Cohen, Yoav; Tsal, Yehoshua

    2011-01-01

    Among the large variety of attentional tasks that have been used to study sustained attention, the Continuous Performance Task (CPT) is perhaps the most widely used. Despite substantial differences in task characteristics and demands, all CPT paradigms have been referred to as measures of sustained attention. In the present study we introduce a…

  5. Negative Priming Effect after Inhibition of Weight/Number Interference in a Piaget-Like Task

    Science.gov (United States)

    Schirlin, Olivier; Houde, Olivier

    2007-01-01

    Piagetian tasks have more to do with the child's ability to inhibit interference than they do with the ability to grasp their underlying logic. Here we used a chronometric paradigm with 11-year-olds, who succeed in Piaget's conservation-of-weight task, to test the role of cognitive inhibition in a priming version of this classical task. The…

  6. Evaluating the Fabreville Heart Health Program in Laval, Canada: a dialogue between two paradigms, positivism and constructivism.

    Science.gov (United States)

    Nguyen, Minh Nguyet; Otis, Joanne

    2003-06-01

    As part of the Canadian Federal-Provincial Initiative in Heart Health, the goal of the Fabreville Heart Health Program was to sensitize a district of Laval, Quebec's second most populous city, to heart-healthy behaviours. The program was planned and implemented by a committee composed of Fabreville community leaders and professionals from the Public Health Department. Between 1992 and 1994, intervention objectives were defined by the department in terms of changing individual behaviours associated with cardiovascular risk factors, namely diet, sedentariness and smoking, as well as adapting physical and social environments to facilitate these changes. However, from 1994 to its conclusion in 1997, the program was re-oriented to engage the population in mobilizing their own community and taking charge of interventions themselves. Actions then became dependent on the interests and motivation of Fabreville residents to transform their lifestyles and aspects of their physical environment. The initial evaluation process, based on the positivist paradigm, was designed to measure changes in individual behaviours and certain physical environments, such as an increase in designated non-smoking areas. However, following the re-orientation towards community mobilization, it was decided that evaluation should go beyond the professional production of data to include a process of the collective construction of knowledge. Evaluation methodology then became based on the constructivist paradigm. Yet field constraints such as lack of community involvement in both leadership and process evaluation, and the need to ensure evaluation standards and fulfil sponsor obligations, compelled the Public Health Department to return to using a certain number of positivist methods. The ensuing inter-paradigm dialogue helped broaden the scope of evaluation and contributed to gaining a more in-depth understanding of the processes and outcomes of community mobilization.

  7. Understanding the land management paradigm

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    There is a worldwide need to build understanding of the land management paradigm and for institutional development to establish sustainable national concepts. This includes creation and adoption of a policy on land development, and an approach that combines the land administration/cadastre/land r......There is a worldwide need to build understanding of the land management paradigm and for institutional development to establish sustainable national concepts. This includes creation and adoption of a policy on land development, and an approach that combines the land administration....../cadastre/land registration function with topographic mapping. The author seeks to awaken more awareness of global trends in this area, recognising that the systems design involved is always unique....

  8. A novel computational modelling to describe the anisotropic, remodelling and reorientation behaviour of collagen fibrres in articular cartilage

    CERN Document Server

    Cortez, S; Alves, J L

    2016-01-01

    In articular cartilage the orientation of collagen fibres is not uniform, varying mostly with the depth on the tissue. Besides, the biomechanical response of each layer of the articular cartilage differs from the neighbouring ones, evolving through thickness as a function of the distribution, density and orientation of the collagen fibres. Based on a finite element implementation, a new continuum formulation is proposed to describe the remodelling and reorientation of the collagen fibres under arbitrary mechanical loads: the cartilaginous tissue is modelled based on a hyperelastic formulation, being the ground isotropic matrix described by a neo-Hookean law and the fibrillar anisotropic part modelled by a new anisotropic formulation introduced for the first time in the present work, in which both reorientation and remodelling are taken into account. To characterize the orientation of fibres, a structure tensor is defined to represent the expected distribution and orientation of fibres around a reference direc...

  9. A 3D finite-strain-based constitutive model for shape memory alloys accounting for thermomechanical coupling and martensite reorientation

    Science.gov (United States)

    Wang, Jun; Moumni, Ziad; Zhang, Weihong; Xu, Yingjie; Zaki, Wael

    2017-06-01

    The paper presents a finite-strain constitutive model for shape memory alloys (SMAs) that accounts for thermomechanical coupling and martensite reorientation. The finite-strain formulation is based on a two-tier, multiplicative decomposition of the deformation gradient into thermal, elastic, and inelastic parts, where the inelastic deformation is further split into phase transformation and martensite reorientation components. A time-discrete formulation of the constitutive equations is proposed and a numerical integration algorithm is presented featuring proper symmetrization of the tensor variables and explicit formulation of the material and spatial tangent operators involved. The algorithm is used for finite element analysis of SMA components subjected to various loading conditions, including uniaxial, non-proportional, isothermal and adiabatic loading cases. The analysis is carried out using the FEA software Abaqus by means of a user-defined material subroutine, which is then utilized to simulate a SMA archwire undergoing large strains and rotations.

  10. The Afrocentric Paradigm: Contours and Definitions.

    Science.gov (United States)

    Mazama, Ama

    2001-01-01

    Defines and describes Afrocentricity, suggesting that Afrocentricity within the academic context is best understood as a paradigm. Explains how Afrocentricity meets the definition of a paradigm, examining the affective, cognitive, and conative aspects of the Afrocentric paradigm (metaphysical and sociological) and looking at the structural and…

  11. Towards reduction of Paradigm coordination models

    NARCIS (Netherlands)

    S. Andova; L.P.J. Groenewegen; E.P. de Vink (Erik Peter)

    2011-01-01

    htmlabstractThe coordination modelling language Paradigm addresses collaboration between components in terms of dynamic constraints. Within a Paradigm model, component dynamics are consistently specified at a detailed and a global level of abstraction. To enable automated verification of Paradigm mo

  12. Paradigm Lost: Reclaiming America's Educational Future.

    Science.gov (United States)

    Spady, William G.

    The ways in which a paradigm of empowerment can be adopted in schools are explored in this book. The book is divided into two sections--the importance of being a paradigm pioneer and the Future Empowerment Paradigm--and focuses on four points: (1) The systemic inertia that keeps schools tied to a familiar, comfortable, unproductive, and…

  13. Exploring Paradigms of Crime Reduction

    DEFF Research Database (Denmark)

    Soothill, Keith; Christoffersen, Mogens N.; Hussain, Azhar

    2010-01-01

    Using Danish registers for a 1980 birth cohort of 29,944 males with parental information and following up these cases for 25 years, the study considers four paradigms of crime reduction (parental child rearing, structural factors around adolescence, locality and individual resources). Focusing...... have more widespread benefits, but the assumed causal links need to be further explored. The use of population registers, under controlled conditions, provides an important window on criminal careers....

  14. Employee discipline: a changing paradigm.

    Science.gov (United States)

    Raper, J L; Myaya, S N

    1993-12-01

    To increase the receptiveness of health care supervisors to a broader meaning of discipline and to simulate investigation of nontraditional methods of encouragement to employees who fail to meet minimum standards of conduct and thereby negatively affect the quality of patient care, a subjectively realistic view of the implications of the traditional punitive disciplinary paradigm is presented. Through the use of a case study, the authors present, explain, and apply the contemporary concept of discipline without punishment as first described by J. Huberman.

  15. Poverty eradication: a new paradigm.

    Science.gov (United States)

    Pethe, V P

    1998-08-01

    This article offers a new paradigm for eradicating poverty in India. It was assumed incorrectly by Mahatma Gandhi that a good society without mass poverty would follow after independence. India copied Western models of development and developed giant factories, big dams, and megacities. Agriculture did not expand the number of jobs for people. The Western paradigm failed in India because of the false assumption of "trickle down" of income to the masses. The targeted programs to the poor did not directly benefit enough of the poor. Mega-industrialization led to reduced employment and higher skill needs. The model failed mainly because it was a proxy and relied on indirect ways of reaching the poor. The models failed to be adapted to conditions in India. The Swadeshi paradigm is a direct model for addressing mass poverty. Poverty is affected by immediate, intermediate, and ultimate determinants. Poverty begets social and economic problems, such as ignorance, ill health, high fertility, unemployment, and crime. In India and developing countries, mass poverty results from under use of human resources; lack of equal opportunities; and an outdated non-egalitarian social structure, an unjust global economic order, human cruelty, and erosion of ethical values. Indians are squandering their precious resources mimicking Western consumerism. Poverty leads to rapid population growth. People become productive assets with universal literacy, compulsory and free education, health services and sanitation, vocational training, and work ethics. India needs people-oriented policies with less emphasis on capital accumulation.

  16. Orphism as a scientific paradigm

    Directory of Open Access Journals (Sweden)

    Biernat Przemyslaw

    2012-01-01

    Full Text Available In my essay I would like to examine current interpretative paradigm, which western scholarship cast on heterogenous and ambiguous data first to create and then to modify the notion of ‘orphism’. In case of paradigms preceding the actual one, the role which ‘orphism’ played in contemporary theories and controversies centered around the question of its significance for emergence of Christianity is well known. That is why in my work I would like to focus on deconstruction of interpretative consensus, elaborated in recent years, which is to be found in such works as Martin West’s The Orphic Poems (1983, Ritual Texts for the Afterlife. Orpheus and the Bacchic Gold Tablets by Fritz Graf and Sarah Iles-Johnston (2007 or monumental Orfeo y la tradición órfica. Un reencuentro (2008 edited by Alberto Bernabé. What is significant, inasmuch as we can write the history of Athenian religion or the history of Hellenistic kings’ worship, we still cannot write the history of orphism. In formulation of all these scholars it is an ahistorical phenomenon, a hidden constant in the sphere of Greek religion, never expressed directly and entirely, but always alluded to y ancient authors. I find difficult to agree with such a statement. The aim of my inquiry is to reveal assumptions of current paradigm, which are hidden in it, but leave a distinct impression on data.

  17. Reorientable dipolar CuCa antisite and anomalous screening in CaCu3Ti4O12

    Science.gov (United States)

    Delugas, Pietro; Alippi, Paola; Fiorentini, Vincenzo; Raineri, Vito

    2010-02-01

    Based on first-principles calculations, we show that the abundant CuCa antisite defect contributes sizably to dielectric screening in single-crystal CaCu3Ti4O12 . CuCa has a multi-minimum off-center equilibrium configuration, whereby it possesses a large and easily reorientable dipole moment. The low-temperature and frequency cut-off behavior of CuCa -induced response is consistent with experiment.

  18. Observation of re-entrant spin reorientation in TbFe1-xMnxO3

    Science.gov (United States)

    Fang, Yifei; Yang, Ya; Liu, Xinzhi; Kang, Jian; Hao, Lijie; Chen, Xiping; Xie, Lei; Sun, Guangai; Chandragiri, Venkatesh; Wang, Chin-Wei; Cao, Yiming; Chen, Fei; Liu, Yuntao; Chen, Dongfeng; Cao, Shixun; Lin, Chengtian; Ren, Wei; Zhang, Jincang

    2016-09-01

    We report a spin reorientation from Γ4(Gx, Ay, Fz) to Γ1(Ax, Gy, Cz) magnetic configuration near room temperature and a re-entrant transition from Γ1(Ax, Gy, Cz) to Γ4(Gx, Ay, Fz) at low temperature in TbFe1-xMnxO3 single crystals by performing both magnetization and neutron diffraction measurements. The Γ4 - Γ1 spin reorientation temperature can be enhanced to room temperature when x is around 0.5 ~ 0.6. These new transitions are distinct from the well-known Γ4 - Γ2 transition observed in TbFeO3, and the sinusoidal antiferromagnetism to complex spiral magnetism transition observed in multiferroic TbMnO3. We further study the evolution of magnetic entropy change (-ΔSM) versus Mn concentration to reveal the mechanism of the re-entrant spin reorientation behavior and the complex magnetic phase at low temperature. The variation of -ΔSM between a and c axes indicates the significant change of magnetocrystalline anisotropy energy in the TbFe1-xMnxO3 system. Furthermore, as Jahn-Teller inactive Fe3+ ions coexist with Jahn-Teller active Mn3+ ions, various anisotropy interactions, compete with each other, giving rise to a rich magnetic phase diagram. The large magnetocaloric effect reveals that the studied material could be a potential magnetic refrigerant. These findings expand our knowledge of spin reorientation phenomena and offer the alternative realization of spin-switching devices at room temperature in the rare-earth orthoferrites.

  19. Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials.

    Science.gov (United States)

    Orekhova, Elena V; Stroganova, Tatiana A

    2014-01-01

    The extended phenotype of autism spectrum disorders (ASD) includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs) and magnetic fields (ERFs) may help to reveal which processing stages underlying brain response to unattended but salient sensory event are affected in individuals with ASD. Previous research focusing on two sequential stages of the brain response-automatic detection of physical changes in auditory stream, indexed by mismatch negativity (MMN), and evaluation of stimulus novelty, indexed by P3a component,-found in individuals with ASD either increased, decreased, or normal processing of deviance and novelty. The review examines these apparently conflicting results, notes gaps in previous findings, and suggests a potentially unifying hypothesis relating the dampened responses to unattended sensory events to the deficit in rapid arousal process. Specifically, "sensory gating" studies focused on pre-attentive arousal consistently demonstrated that brain response to unattended and temporally novel sound in ASD is already affected at around 100 ms after stimulus onset. We hypothesize that abnormalities in nicotinic cholinergic arousal pathways, previously reported in individuals with ASD, may contribute to these ERP/ERF aberrations and result in attention re-orienting deficit. Such cholinergic dysfunction may be present in individuals with ASD early in life and can influence both sensory processing and attention re-orienting behavior. Identification of early neurophysiological biomarkers for cholinergic deficit would help to detect infants "at risk" who can potentially benefit from particular types of therapies or interventions.

  20. Arousal and attention re-orienting in autism spectrum disorders: evidence from auditory event-related potentials

    Directory of Open Access Journals (Sweden)

    Elena V Orekhova

    2014-02-01

    Full Text Available The extended phenotype of autism spectrum disorders (ASD includes a combination of arousal regulation problems, sensory modulation difficulties, and attention re-orienting deficit. A slow and inefficient re-orienting to stimuli that appear outside of the attended sensory stream is thought to be especially detrimental for social functioning. Event-related potentials (ERPs and magnetic fields (ERFs may help to reveal which processing stages underlying brain response to unattended but salient sensory event are affected in individuals with ASD. Previous research focusing on two sequential stages of the brain response - automatic detection of physical changes in auditory stream, indexed by mismatch negativity (MMN, and evaluation of stimulus novelty, indexed by P3a component, - found in individuals with ASD either increased, decreased or normal processing of deviance and novelty. The review examines these apparently conflicting results, notes gaps in previous findings, and suggests a potentially unifying hypothesis relating the dampened responses to unattended sensory events to the deficit in rapid arousal process. Specifically, ‘sensory gating’ studies focused on pre-attentive arousal consistently demonstrated that brain response to unattended and temporally novel sound in ASD is already affected at around 100 ms after stimulus onset. We hypothesize that abnormalities in nicotinic cholinergic arousal pathways, previously reported in individuals with ASD, may contribute to these ERP/ERF aberrations and result in attention re-orienting deficit. Such cholinergic dysfunction may be present in individuals with ASD early in life and can influence both sensory processing and attention re-orienting behavior. Identification of early neurophysiological biomarkers for cholinergic deficit would help to detect infants at risk who can potentially benefit from particular types of therapies or interventions.

  1. Dual reorientation relaxation routes of water molecules in oxyanion’s hydration shell: A molecular geometry perspective

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wen Jun; Yang, Yi Isaac; Gao, Yi Qin, E-mail: gaoyq@pku.edu.cn [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering and Biodynamic Optical Imaging Center, Peking University, Beijing 100871 (China)

    2015-12-14

    In this study, we examine how complex ions such as oxyanions influence the dynamic properties of water and whether differences exist between simple halide anions and oxyanions. Nitrate anion is taken as an example to investigate the hydration properties of oxyanions. Reorientation relaxation of its hydration water can occur through two different routes: water can either break its hydrogen bond with the nitrate to form one with another water or switch between two oxygen atoms of the same nitrate. The latter molecular mechanism increases the residence time of oxyanion’s hydration water and thus nitrate anion slows down the translational motion of neighbouring water. But it is also a “structure breaker” in that it accelerates the reorientation relaxation of hydration water. Such a result illustrates that differences do exist between the hydration of oxyanions and simple halide anions as a result of different molecular geometries. Furthermore, the rotation of the nitrate solute is coupled with the hydrogen bond rearrangement of its hydration water. The nitrate anion can either tilt along the axis perpendicularly to the plane or rotate in the plane. We find that the two reorientation relaxation routes of the hydration water lead to different relaxation dynamics in each of the two above movements of the nitrate solute. The current study suggests that molecular geometry could play an important role in solute hydration and dynamics.

  2. Role of rare earth on the Mn3+ spin reorientation in multiferroic Ho1-xLuxMnO3

    Science.gov (United States)

    Magesh, J.; Murugavel, P.; Mangalam, R. V. K.; Singh, K.; Simon, Ch.; Prellier, W.

    2013-09-01

    The role of rare earth ion R3+ in spin reorientation and magneto dielectric response is investigated by substitution of non-magnetic smaller ionic radii Lu3+ in multiferroic hexagonal HoMnO3. The XRD analysis suggests that the dopant may preferably goes to C3V site up to 1/3rd of the composition in order to reduce the lattice distortion. We suggest that the R3+ ion at C3 site could play a strong role in spin reorientation than the C3V site. The observation of TSR even in LuMnO3 precludes the role of rare earth magnetic moment in driving the spin reorientation. Surprisingly, the magneto dielectric response of HoMnO3 is dominated by the rare earth RO8 dipoles. The oppositely oriented RO8 dipole at the C3V and C3 determines the magneto dielectric response in various magnetic phases reaffirming the site specific substitution. Thus, site specific doping could be a way to enhance the magnetoelectric coupling strength.

  3. Tooth reorientation affects tooth function during prey processing and tooth ontogeny in the lesser electric ray, Narcine brasiliensis.

    Science.gov (United States)

    Dean, Mason N; Ramsay, Jason B; Schaefer, Justin T

    2008-01-01

    The dental anatomy of elasmobranch fishes (sharks, rays and relatives) creates a functional system that is more dynamic than that of mammalian dentition. Continuous dental replacement (where new teeth are moved rostrally to replace older ones) and indirect fibrous attachment of the dentition to the jaw allow teeth to reorient relative to the jaw over both long- and short-term scales, respectively. In this study, we examine the processing behavior and dental anatomy of the lesser electric ray Narcine brasiliensis (Olfers, 1831) to illustrate that the freedom of movement of elasmobranch dentition allows a functional flexibility that can be important for complex prey processing behaviors. From static manipulations of dissected jaws and observations of feeding events in live animals, we show that the teeth rotate during jaw protrusion, resulting in a secondary grasping mechanism that likely serves to hold prey while the buccal cavity is flushed free of sediment. The function of teeth is not always readily apparent from morphology; in addition to short-term reorientation, the long-term dental reorientation during replacement allows a given tooth to serve multiple functions during tooth ontogeny. Unlike teeth inside the mouth, the cusps of external teeth (on the portion of the tooth pad that extends past the occlusal plane) lay flat, such that the labial faces act as a functional battering surface, protecting the jaws during prey excavation.

  4. Spin reorientation driven by the interplay between spin-orbit coupling and Hund's rule coupling in iron pnictides

    Science.gov (United States)

    Christensen, Morten H.; Kang, Jian; Andersen, Brian M.; Eremin, Ilya; Fernandes, Rafael M.

    2015-12-01

    In most magnetically-ordered iron pnictides, the magnetic moments lie in the FeAs planes, parallel to the modulation direction of the spin stripes. However, recent experiments in hole-doped iron pnictides have observed a reorientation of the magnetic moments from in-plane to out-of-plane. Interestingly, this reorientation is accompanied by a change in the magnetic ground state from a stripe antiferromagnet to a tetragonal nonuniform magnetic configuration. Motivated by these recent observations, here we investigate the origin of the spin anisotropy in iron pnictides using an itinerant microscopic electronic model that respects all the symmetry properties of a single FeAs plane. We find that the interplay between the spin-orbit coupling and the Hund's rule coupling can account for the observed spin anisotropies, including the spin reorientation in hole-doped pnictides, without the need to invoke orbital or nematic order. Our calculations also reveal an asymmetry between the magnetic ground states of electron- and hole-doped compounds, with only the latter displaying tetragonal magnetic states.

  5. Reorientational eigenmode dynamics: a combined MD/NMR relaxation analysis method for flexible parts in globular proteins.

    Science.gov (United States)

    Prompers, J J; Brüschweiler, R

    2001-08-01

    An approach is presented for the interpretation of heteronuclear NMR spin relaxation data in mobile protein parts in terms of reorientational eigenmode dynamics. The method is based on the covariance matrix of the spatial functions of the nuclear spin interactions that cause relaxation expressed as spherical harmonics of rank 2. The approach was applied to characterize the dynamics of a loop region of ubiquitin. The covariance matrix was determined from a conformational ensemble generated by a 5 ns molecular dynamics simulation. It was found that the time correlation functions of the dominant eigenmodes decay in good approximation with a single correlation time. From the reorientational eigenmodes, their eigenvalues, and correlation times, NMR relaxation data were calculated in accordance with Bloch-Wangsness-Redfield relaxation theory and directly compared with experimental (15)N relaxation parameters. Using a fitting procedure, agreement between calculated and experimental data was improved significantly by adjusting eigenvalues and correlation times of the dominant modes. The presented procedure provides detailed information on correlated reorientational dynamics of flexible parts in globular proteins. The covariance matrix was linked to the covariance matrix of backbone dihedral angle fluctuations, allowing one to study the motional behavior of these degrees of freedom on nano- and subnanosecond time scales.

  6. The neurodynamics underlying attentional control in set shifting tasks.

    Science.gov (United States)

    Stemme, Anja; Deco, Gustavo; Busch, Astrid

    2007-09-01

    In this work we address key phenomena observed with classical set shifting tasks as the "Wisconsin Card Sorting Test" or the "Stroop" task: Different types of errors and increased response times reflecting decreased attention. A component of major importance in these tasks is referred to as the "attentional control" thought to be implemented by the prefrontal cortex which acts primarily by an amplification of task relevant information. This mode of operation is illustrated by a neurodynamical model developed for a new kind of set shifting experiment: The Wisconsin-Delayed-Match-to-Sample task combines uninstructed shifts as investigated in Wisconsin-like tasks with a Delayed-Match-to-Sample paradigm. These newly developed WDMS experiments in conjunction with the neurodynamical simulations are able to explain the reason for decreased attention in set shifting experiments as well the different consequences of decreased attention in tasks requiring bivalent yes/no responses compared to tasks requiring multivalent responses.

  7. On the nonlinear problem of the three-axis reorientation of a three-rotor gyrostat in the game noise model

    Science.gov (United States)

    Vorotnikov, V. I.; Martyshenko, Yu. G.

    2013-09-01

    The nonlinear game problem of the three-axis reorientation of an asymmetric solid body with three flywheels (rotors) has been solved. Acceptable levels of uncontrollable noise depending on given constraints of control moments have been estimated.

  8. Eliminating dual-task costs by minimizing crosstalk between tasks: The role of modality and feature pairings.

    Science.gov (United States)

    Göthe, Katrin; Oberauer, Klaus; Kliegl, Reinhold

    2016-05-01

    We tested the independent influences of two content-based factors on dual-task costs, and on the parallel processing ability: The pairing of S-R modalities and the pairing of relevant features between stimuli and responses of two tasks. The two pairing factors were realized across four dual-task groups. Within each group the two tasks comprised two different stimulus modalities (visual and auditory), two different relevant stimulus features (spatial and verbal) and two response modalities (manual and vocal). Pairings of S-R modalities (standard: visual-manual and auditory-vocal, non-standard: visual-vocal and auditory-manual) and feature pairings (standard: spatial-manual and verbal-vocal, non-standard: spatial-vocal and verbal-manual) varied across groups. All participants practiced their respective dual-task combination in a paradigm with simultaneous stimulus onset before being transferred to a psychological refractory period paradigm varying stimulus-onset asynchrony. A comparison at the end of practice revealed similar dual-task costs and similar pairing effects in both paradigms. Dual-task costs depended on modality and feature pairings. Groups training with non-standard feature pairings (i.e., verbal stimulus features mapped to spatially separated response keys, or spatial stimulus features mapped to verbal responses) and non-standard modality pairings (i.e., auditory stimulus mapped to manual response, or visual stimulus mapped to vocal responses) had higher dual-task costs than respective standard pairings. In contrast, irrespective of modality pairing dual-task costs virtually disappeared with standard feature pairings after practice in both paradigms. The results can be explained by crosstalk between feature-binding processes for the two tasks. Crosstalk was present for non-standard but absent for standard feature pairings. Therefore, standard feature pairings enabled parallel processing at the end of practice.

  9. Quantifying the clinical relevance of a laboratory observer performance paradigm.

    Science.gov (United States)

    Chakraborty, D P; Haygood, T M; Ryan, J; Marom, E M; Evanoff, M; McEntee, M F; Brennan, P C

    2012-09-01

    Laboratory observer performance measurements, receiver operating characteristic (ROC) and free-response ROC (FROC) differ from actual clinical interpretations in several respects, which could compromise their clinical relevance. The objective of this study was to develop a method for quantifying the clinical relevance of a laboratory paradigm and apply it to compare the ROC and FROC paradigms in a nodule detection task. The original prospective interpretations of 80 digital chest radiographs were classified by the truth panel as correct (C=1) or incorrect (C=0), depending on correlation with additional imaging, and the average of C was interpreted as the clinical figure of merit. FROC data were acquired for 21 radiologists and ROC data were inferred using the highest ratings. The areas under the ROC and alternative FROC curves were used as laboratory figures of merit. Bootstrap analysis was conducted to estimate conventional agreement measures between laboratory and clinical figures of merit. Also computed was a pseudovalue-based image-level correctness measure of the laboratory interpretations, whose association with C as measured by the area (rAUC) under an appropriately defined relevance ROC curve, is as a measure of the clinical relevance of a laboratory paradigm. Low correlations (e.g. κ=0.244) and near chance level rAUC values (e.g. 0.598), attributable to differences between the clinical and laboratory paradigms, were observed. The absolute width of the confidence interval was 0.38 for the interparadigm differences of the conventional measures and 0.14 for the difference of the rAUCs. The rAUC measure was consistent with the traditional measures but was more sensitive to the differences in clinical relevance. A new relevance ROC method for quantifying the clinical relevance of a laboratory paradigm is proposed.

  10. School on Cloud: Towards a paradigm shift

    Directory of Open Access Journals (Sweden)

    Kostis C. Koutsopoulos

    2014-09-01

    Full Text Available This paper presents the basic concept of the EU Network School on Cloud: Namely, that present conditions require a new teaching and learning paradigm based on the integrated dimension of education, when considering the use of cloud computing. In other words, it is suggested that there is a need for an integrated approach which is simultaneously pedagogic (i.e. new role of teachers, technical/technological (i.e. use of the internet, administrative (i.e. new role of school administrators, social (i.e. a different disposition of parents towards school, political (i.e. a different approach of government to school and cultural (i.e. new role of students, being in dialectic harmony and respecting all aspects of teaching and learning, an integral part of which are pupils, teachers and school administrators. As a result, the principal tasks in the area at the interface between education and cloud technology, which are presented in this paper, are to determine and describe the nature of the basic education stakeholders: i-Students, i-Teachers and i-Administrators.

  11. Big Data, new epistemologies and paradigm shifts

    Directory of Open Access Journals (Sweden)

    Rob Kitchin

    2014-07-01

    Full Text Available This article examines how the availability of Big Data, coupled with new data analytics, challenges established epistemologies across the sciences, social sciences and humanities, and assesses the extent to which they are engendering paradigm shifts across multiple disciplines. In particular, it critically explores new forms of empiricism that declare ‘the end of theory’, the creation of data-driven rather than knowledge-driven science, and the development of digital humanities and computational social sciences that propose radically different ways to make sense of culture, history, economy and society. It is argued that: (1 Big Data and new data analytics are disruptive innovations which are reconfiguring in many instances how research is conducted; and (2 there is an urgent need for wider critical reflection within the academy on the epistemological implications of the unfolding data revolution, a task that has barely begun to be tackled despite the rapid changes in research practices presently taking place. After critically reviewing emerging epistemological positions, it is contended that a potentially fruitful approach would be the development of a situated, reflexive and contextually nuanced epistemology.

  12. Reorientation Timescales and Pattern Dynamics for Titan's Dunes: Does the Tail Wag the Dog or the Dragon?

    Science.gov (United States)

    Ewing, R. C.; Hayes, A. G.; McCormick, C.; Ballard, C.; Troy, S. A.

    2012-04-01

    Fields of bedform patterns persist across many orders of magnitude, from cm-scale sub-aqueous current ripples to km-scale aeolian dunes, and form with surprisingly little difference in expression despite a range of formative environments. Because of the remarkable similarity among bedform patterns, extracting information about climate and environment from these patterns is a challenge. For example, crestline orientation is not diagnostic of a particular flow regime; similar patterns form under many different flow configurations. On Titan, these challenges have played out with many attempts to reconcile dune crestline orientation with modeled and expected wind regimes. We propose that thinking about the time-scale of the change in dune orientation, rather than the orientation itself, can provide new insights on the long-term stability of the dune-field patterns and the formative wind regime. In this work, we apply the crestline re-orientation model developed by Werner and Kocurek [Geology, 1997] to the equatorial dune fields of Titan. We use Cassini Synthetic Aperture Radar images processed through a de-noising algorithm recently developed by Lucas et al. [LPSC, 2012] to measure variations in pattern parameters (crest spacing, crest length and defect density, which is the number of defect pairs per total crest length) both within and between Titan's dune fields to describe pattern maturity and identify areas where changes in dune orientation are likely to occur (or may already be occurring). Measured defect densities are similar to Earth's largest linear dune fields, such as the Namib Sand Sea and the Simpson Desert. We use measured defect densities in the Werner and Kocurek model to estimate crestline reorientation rates. We find reorientation timescales varying from ten to a hundred thousand times the average migration timescale (time to migrate a bedform one meter, ~1 Titan year according to Tokano (Aeolian Research, 2010)). Well-organized patterns have the

  13. Reorientation mechanisms of phyllosilicates in the mudstone-to-slate transition at Lehigh Gap, Pennsylvania

    Science.gov (United States)

    Ho, Nei-Che; Peacor, Donald R.; van der Pluijm, Ben A.

    1995-03-01

    The mudstone-to-slate transition of the Martinsburg Formation at Lehigh Gap, Pennsylvania, was re-examined using a new transmission-mode X-ray texture goniometer, supplemented by SEM, XRD, and optical studies. Three mesoscopic zones are recognized in the outcrop: (I) mudstone, (II) transition, and (III) slate zone. In the mudstone zone, the mica basal planes are parallel to bedding whereas the preferred orientation of the chlorite basal planes is up to 30° shallower than bedding. The angular difference between chlorite and mica decreases towards the transition zone, becoming subparallel at ca. 50 m from the contact with the overlying Shawangunk Formation. In the transition zone, the preferred orientations of both mica and chlorite are intermediate to bedding and cleavage orientations, which is consistent with mechanical reorientation of phyllosilicates. This is supported by a decrease in March strain with a minimum at ca. 95 m from the contact for both mica and chlorite. SEM observations similarly show the importance of grain rotation in large detrital grains. In the slate zone, both chlorite and mica orientations are parallel to cleavage. Chlorite and mica in the cleavage orientation of the slate zone have high Fe contents, whereas low-Fe mica and Mg > Fe chlorite dominate in the mudstone and transition zone, which indicates that dissolution-neocrystallization is the dominant mechanism in the slate zone. Thus, mechanical rotation of large detrital grains is important in the early stages of cleavage development, with dissolution—neocrystallization occurring at all stages and becoming dominant in the more evolved stages.

  14. Re-orienting crop improvement for the changing climatic conditions of the 21st century

    Directory of Open Access Journals (Sweden)

    Mba Chikelu

    2012-06-01

    Full Text Available Abstract A 70% increase in food production is required over the next four decades to feed an ever-increasing population. The inherent difficulties in achieving this unprecedented increase are exacerbated by the yield-depressing consequences of climate change and variations and by the pressures on food supply by other competing demographic and socioeconomic demands. With the dwindling or stagnant agricultural land and water resources, the sought-after increases will therefore be attained mainly through the enhancement of crop productivity under eco-efficient crop production systems. ‘Smart’ crop varieties that yield more with fewer inputs will be pivotal to success. Plant breeding must be re-oriented in order to generate these ‘smart’ crop varieties. This paper highlights some of the scientific and technological tools that ought to be the staple of all breeding programs. We also make the case that plant breeding must be enabled by adequate policies, including those that spur innovation and investments. To arrest and reverse the worrisome trend of declining capacities for crop improvement, a new generation of plant breeders must also be trained. Equally important, winning partnerships, including public-private sector synergies, are needed for 21st century plant breeding to bear fruits. We also urge the adoption of the continuum approach to the management of plant genetic resources for food and agriculture as means to improved cohesion of the components of its value chain. Compellingly also, the National Agricultural Research and Extension System of developing countries require comprehensive overhauling and strengthening as crop improvement and other interventions require a sustained platform to be effective. The development of a suite of actionable policy interventions to be packaged for assisting countries in developing result-oriented breeding programs is also called for.

  15. Magnetic reorientation induced by pressure solution: A potential mechanism for orogenic-scale remagnetizations

    Science.gov (United States)

    Oliva-Urcia, Belén; Pueyo, Emilio L.; Larrasoaña, Juan C.

    2008-01-01

    New paleomagnetic analyses of Triassic, Cretaceous and Eocene strata in the south-central Pyrenees show evidence for a widespread remagnetization, located along the southern border of the Axial Zone, the Internal Sierras, and the northern part of the Jaca-Pamplona basin. This remagnetization, always reversed in polarity, was acquired after an extensive period of Late Eocene-Early Oligocene folding and tilting in the area, and affects limestones, sandstones, marls and red beds. In addition, a characteristic prefolding component was identified in 30% of Upper Cretaceous and Triassic red beds. These results, together with a revaluation of previously published paleomagnetic data from the central Pyrenees, indicate that the spatial distribution of the postfolding remagnetization coincides with that of a domain of pressure solution cleavage. A relationship between the intensity of the remagnetization and the characteristic (prefolding component) with respect to the density of cleavage surfaces, leads us to propose a mechanism for the remagnetization related to the development of pressure solution cleavage that is framed within the tectonic evolution of the central Pyrenees. Partial dissolution of rock under tectonic compression leads to the liberation and subsequent accumulation of insoluble minerals in cleavage planes. Magnetic grains are part of the relatively insoluble residue, and they reorient in the presence of the ambient field after they are freed during dissolution of the rock matrix. Chemical reequilibrium (dissolution and/or neoformation of magnetic carriers) during this process cannot be excluded. The remagnetization mechanism we propose can help to explain widespread remagnetizations in low to moderately deformed rocks without the need of large-scale migration of orogenic fluids.

  16. Pressure-induced spin fluctuations and spin reorientation in hexagonal manganites

    Science.gov (United States)

    Kozlenko, D. P.; Kichanov, S. E.; Lee, S.; Park, J.-G.; Savenko, B. N.

    2007-04-01

    The magnetic structures of hexagonal manganites YMnO3 and LuMnO3 have been studied by powder neutron diffraction up to 6 GPa in the temperature range 10-295 K. At ambient pressure, a triangular antiferromagnetic (AFM) state of a Γ1 irreducible representation is stable below TN = 70 K in YMnO3. Upon the application of high pressure, a spin reorientation is induced and the triangular AFM structure evolves from Γ1 to Γ1+Γ2 representations. On the other hand, in LuMnO3 the triangular AFM state of a Γ2 irreducible representation with TNap90 K remains stable over the entire pressure range investigated. The ordered magnetic moment values decrease under pressure with dM/dP = -0.35 μB GPa-1 in YMnO3 and -0.08 μB GPa-1 in LuMnO3. Simultaneously, a considerable increase in diffuse scattering intensity was found in YMnO3, while it was much less pronounced for LuMnO3. Both features indicate the enhancement of spin fluctuations due to geometrical frustration effects and an increase in the volume fraction of the spin-liquid state coexisting with the ordered AFM phase. The characteristic spin correlation length is weakly affected by pressure. The relationship between the pressure-induced behaviour of magnetic structure and the structural characteristics of the quasi-two-dimensional (2D) triangular network formed by Mn and O ions in hexagonal RMnO3 is analysed.

  17. Re-orientation transition in molecular thin films: Potts model with dipolar interaction.

    Science.gov (United States)

    Hoang, Danh-Tai; Kasperski, Maciej; Puszkarski, Henryk; Diep, H T

    2013-02-06

    We study the low-temperature behavior and the phase transition of a thin film by Monte Carlo simulation. The thin film has a simple cubic lattice structure where each site is occupied by a Potts parameter which indicates the molecular orientation of the site. We take only three molecular orientations in this paper, which correspond to the three-state Potts model. The Hamiltonian of the system includes (i) the exchange interaction J(ij) between nearest-neighbor sites i and j, (ii) the long-range dipolar interaction of amplitude D truncated at a cutoff distance r(c), and (iii) a single-ion perpendicular anisotropy of amplitude A. We allow J(ij) = J(s) between surface spins, and J(ij) = J otherwise. We show that the ground state depends on the ratio D/A and r(c). For a single layer, for a given A, there is a critical value D(c) below (above) which the ground-state (GS) configuration of molecular axes is perpendicular (parallel) to the film surface. When the temperature T is increased, a re-orientation transition occurs near D(c): the low-T in-plane ordering undergoes a transition to the perpendicular ordering at a finite T, below the transition to the paramagnetic phase. The same phenomenon is observed in the case of a film with a thickness. Comparison with the Fe/Gd experiment is given. We show that the surface phase transition can occur below or above the bulk transition depending on the ratio J(s)/J. Surface and bulk order parameters as well as other physical quantities are shown and discussed.

  18. Motor skill experience modulates executive control for task switching.

    Science.gov (United States)

    Yu, Qiuhua; Chan, Chetwyn C H; Chau, Bolton; Fu, Amy S N

    2017-09-15

    This study aimed to investigate the effect of types of motor skills, including open and closed skills on enhancing proactive and reactive controls for task switching. Thirty-six athletes in open (n=18) or closed (n=18) sports and a control group (n=18) completed the task-switching paradigm and the simple reaction task. The task-switching paradigm drew on the proactive and reactive control of executive functions, whereas the simple reaction task assessed the processing speed. Significant Validity×Group effect revealed that the participants with open skills had a lower switch cost of response time compared to the other two groups when the task cue was 100% valid; whereas the participants regardless of motor skills had a lower switch cost of response time compared to the control group when the task cue was 50% valid. Hierarchical stepwise regression analysis further confirmed these findings. For the simple reaction task, there were no differences found among the three groups. These findings suggest that experience in open skills has benefits of promoting both proactive and reactive controls for task switching, which corresponds to the activity context exposed by the participants. In contrast, experience in closed skills appears to only benefit development of reactive control for task switching. The neural mechanisms for the proactive and reactive controls of executive functions between experts with open and closed skills call for future study. Copyright © 2017. Published by Elsevier B.V.

  19. [Paradigm shift in bancroftian filariasis].

    Science.gov (United States)

    Dreyer, Gerusa; Mattos, Denise; Figueredo-Silva, José; Norões, Joaquim

    2009-01-01

    The way a particular subject is understood changes over time as a result of scientific research. In most cases, these changes are minor, with limited effect on the overall knowledge on the subject. Sometimes, however, revolutionary changes occur and not only modify the understanding of the subject but open perspectives that can trigger new interpretations and new ways for expansion of scientific knowledge. The studies of Gregor Johann Mendel were a good example. They led to discovery of the laws of inheritance which, in turn, have revolutionized biology and provided the foundation for genetics. In certain situations, changes not only alter ways of thinking, but have practical implications, also improving the quality of life for many people. In his book The Structure of Scientific Revolutions, Thomas Kuhn refers to discontinuities in scientific development as a 'change of paradigm', a term now used in a generic manner to describe a profound changes in our reference points. For lymphatic filariasis the old paradigm stated that Wuchereria bancrofti at the adult stage causes lymphatic vessel obstruction, triggering an inevitable immune response in predisposed individuals and leading to elephantiasis. This has been replaced by a new paradigm, which offers hope that W. bancrofti infection does not necessarily predispose to the disfiguring outward manifestation of lymphatic dysfunction. Repeated secondary bacterial infections (erysipela-like) are now recognized as the most important factor for initiation and progression of chronic lymphedema in individuals living in filariasis-endemic areas. Most inhabitants of endemic communities can prevent and minimize the acute bacterial episodes by regular use of soap and water, the simplest form of hygiene already well known to human beings.

  20. Challenging the Service Cost Paradigm.

    Science.gov (United States)

    Seibert, Sandra

    2015-01-01

    Most healthcare organizations are looking to find more efficient and cost-effective ways of delivering service as they are challenged to assume more risk in order to provide timely and cost effective care. Alternative service with an independent service organization or third party may be an easy and rewarding solution. Serious consideration should be given purchase/service cycle and into a lower cost service paradigm designed to provide excellent service tailored to a facility's specific needs. In this article, an evaluation of all service model options is provided, as well as examples including a CT acquisition, pro formas, and program development.

  1. The Paradigm of Distributed Creativity

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre

    This presentation aims to focus on and develop the notion of distributed creativity from a cultural psychological perspective. It will start by outlining the need for a cultural psychological paradigm of creative expression and argue that this perspective is primarily concerned with what can...... be called ‘distributed creativity’. Drawing on related literature on distributed cognition (Hutchins, 2000), I will consider here the three inter-related ways in which creative action is distributed: across people, across people and objects, and across time. This particular understanding of creativity...

  2. International Politics: A Desirable Paradigm

    Institute of Scientific and Technical Information of China (English)

    Xia Aiding; Feng Shuai

    2007-01-01

    This article first traces the origin of four concepts: International Politics (IP), International Relations (IR), World Politics (WP) and Global Politics (GP) and discusses the similarities among these four paradigms. It then analyses their application both at home and abroad. Finally, it argues for the desirability of selecting the concept of IP in academic training, thus facilitating practical application of concepts. It asserts that this will not only enhance academic discussion about IP among different Chinese schools of thought, but also help blazing new ideas.

  3. Psychiatry beyond the current paradigm.

    LENUS (Irish Health Repository)

    Bracken, Pat

    2012-12-01

    A series of editorials in this Journal have argued that psychiatry is in the midst of a crisis. The various solutions proposed would all involve a strengthening of psychiatry\\'s identity as essentially \\'applied neuroscience\\'. Although not discounting the importance of the brain sciences and psychopharmacology, we argue that psychiatry needs to move beyond the dominance of the current, technological paradigm. This would be more in keeping with the evidence about how positive outcomes are achieved and could also serve to foster more meaningful collaboration with the growing service user movement.

  4. Minipig negative slow wave demonstrates target/nontarget differences in P300 paradigm

    DEFF Research Database (Denmark)

    Arnfred, Sidse Marie; Lind, Nanna Marie; Moustgaard, Anette Caroline;

    2003-01-01

    The negative slow wave (NSW) is a late component of the event-related potential (ERP) in man modulated like the P300 by the stimulus, the task, and the response demand. Aiming at the development of a minipig model of schizophrenia, we investigated scalp ERPs in an auditory P300 paradigm in six...

  5. Hypothesis Formation, Paradigms, and Openness

    Directory of Open Access Journals (Sweden)

    Conrad P. Pritscher

    2008-01-01

    Full Text Available A part of hypothesis formation, while necessary for scientific investigation, is beyond direct observation. Powerful hypothesis formation is more than logical and is facilitated by mind­opening. As Percy Bridgeman, Nobel laureate, said, science is: “Nothing more than doing one's damnedest with one's mind, no holds barred.” This paper suggests more open schooling helps generate more open hypothesizing which helps one do one's damnedest with one's mind. It is hypothesized that a more open process of hypothesis formation may help schools and society forge new ways of living and learning so that more people more often can do their damnedest with their mind. This writing does not offer a new paradigm but rather attempts to elaborate on the notion that new paradigms are difficult to form without openness to what was previously quasi­unthinkable. More on these topics and issues is included in the author's Reopening Einstein's Thought: About What Can't Be Learned From Textbooks ­­to be published by Sense Publishers in June 2008.

  6. New Paradigm of Power System Planning under Competitive Environment

    Science.gov (United States)

    Mori, Hiroyuki

    This paper presents a new paradigm of power system planning under competitive environment. As the liberalization of power systems become more competitive, power systems are faced with new aspects that the conventional bundled power company has never encountered. The conventional power system planning methods do not match the requirements of competitive environment. In practice, the power system liberalization brings about new environment that puts emphasis on the profit maximization and the risk minimization. Thus, the problem formulation of power system planning should be reformulated to reflect the new aspects in power systems. As the tasks of power system planning, this paper outlines transmission network expansion planning, distribution network expansion planning, and unit commitment under competitive environment. In addition, new tasks such as very short-term load forecasting, electricity price forecasting, and wind power forecasting are described.

  7. Survival Processing and the Stroop Task

    Directory of Open Access Journals (Sweden)

    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.

  8. Connectivity measures in the Poffenberger paradigm indicate hemispheric asymmetries

    Science.gov (United States)

    Erbil, Nurhan; Yagcioglu, Suha

    2016-01-01

    Summary The Poffenberger paradigm is a well-known measure of interhemispheric transfer delays, calculated on the basis of the crossed vs uncrossed reaction time difference (CUD). However, the proper interpretation of CUD is extensively debated in the literature. In this study we used connectivity measures in an attempt to interpret CUD from the perspective of functional connectivity. Accordingly, we tried to define functional couplings in the Poffenberger paradigm; we used a simple choice version of the paradigm, and included a stimulation only (SO) condition for comparison. As an index of functional coupling we employed partial directed coherence, exploiting bilateral grouping of the electrodes to compute intra- and interhemispheric connection weight ratios (CWRs). Our findings indicated modulations in functional weights in relation to the SO condition, rather than the crossed and uncrossed conditions, such that the response executed by the right hemisphere yielded a decrease in intra-, yet an increase in interhemispheric CWRs, whereas the left hemisphere interactions showed connectivity patterns similar to the SO condition irrespective of the side of movement. Overall, our results suggest modulation of connectivity in the same/similar system, which was found to be optimized, in terms of hemispheric asymmetries, to different tasks. PMID:28072385

  9. EVALUATIVE RESEARCH PARADIGMS IN EDUCATIONAL PROGRAMS

    OpenAIRE

    Flores Barboza, José; Universidad Nacional Mayor de San Marcos

    2014-01-01

    The article focuses on the confrontation /comparison? between the naturalistic and the experimental paradigms to evaluate educational programs. It examines the theoretical framework of each paradigm and the proposed methodology to pursue an evaluation. Finally, the article addresses the possibility of a reconciliation between both paradigms. El artículo trata de la confrontación entre los paradigmas naturalista y experimental para la evaluación de programas educacionales. Examina los argum...

  10. PSYCHOLOGICAL PARADIGMS USED IN TEACHING ANALYSIS

    Directory of Open Access Journals (Sweden)

    Sorin CRISTEA

    2015-11-01

    Full Text Available In this article, teaching as a subject of instruction, will be examined in terms of some actual psychological paradigms of communication: structural-expressive, formal-transactional, relational-systemic, and phenomenal-praxis. Reporting these paradigms, thispaper highlights the importance of psychological processes involved in teaching process. Related to various paradigms described, the author demonstrates the importance of addressing teaching from a high level participation in the elaboration of a mutual action.

  11. Musical training, bilingualism, and executive function: a closer look at task switching and dual-task performance.

    Science.gov (United States)

    Moradzadeh, Linda; Blumenthal, Galit; Wiseheart, Melody

    2015-07-01

    This study investigated whether musical training and bilingualism are associated with enhancements in specific components of executive function, namely, task switching and dual-task performance. Participants (n = 153) belonging to one of four groups (monolingual musician, bilingual musician, bilingual non-musician, or monolingual non-musician) were matched on age and socioeconomic status and administered task switching and dual-task paradigms. Results demonstrated reduced global and local switch costs in musicians compared with non-musicians, suggesting that musical training can contribute to increased efficiency in the ability to shift flexibly between mental sets. On dual-task performance, musicians also outperformed non-musicians. There was neither a cognitive advantage for bilinguals relative to monolinguals, nor an interaction between music and language to suggest additive effects of both types of experience. These findings demonstrate that long-term musical training is associated with improvements in task switching and dual-task performance.

  12. FY 2016 Status Report: CIRFT Testing on Spent Nuclear Fuels and Hydride Reorientation Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Yan, Yong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Bevard, Bruce B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Scaglione, John M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-08-04

    This report provides a detailed description of the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) testing conducted on spent nuclear fuel (SNF) rods in FY 2016, including hydride reorientation test results. Contact-based measurement, or three-LVDT-based curvature measurement, of SNF rods has proven to be quite reliable in CIRFT testing. However, how the linear variable differential transformer (LVDT) head contacts the SNF rod may have a significant effect on the curvature measurement, depending on the magnitude and direction of rod curvature. To correct such contact/curvature issues, sensor spacing, defined as the amount of separation between the three LVDT probes, is a critical measurement that can be used to calculate rod curvature once the deflections are obtained. Recently developed CIRFT data analyses procedures were integrated into FY 2016 CIRFT testing results for the curvature measurements. The variations in fatigue life are provided in terms of moment, equivalent stress, curvature, and equivalent strain for the tested SNFs. The equivalent stress plot collapsed the data points from all of the SNFs into a single zone. A detailed examination revealed that, at same stress level, fatigue lives display a descending order as follows: H. B. Robinson Nuclear Power Station (HBR), Limerick Nuclear Power Station (LMK), mixed uranium-plutonium oxide (MOX). If looking at the strain, then LMK fuel has a slightly longer fatigue life than HBR fuel, but the difference is subtle. The knee point of endurance limit in the curve of moment and curvature or equivalent quantities is more clearly defined for LMK and HBR fuels. The treatment affects the fatigue life of specimens. Both a drop of 12 in. and radial hydride treatment (RHT) have a negative impact on fatigue life. The effect of thermal annealing on MOX fuel rods was relatively small at higher amplitude but became significant at low amplitude of moment. Thermal annealing tended to extend the fatigue life of

  13. FY 2016 Status Report: Documentation of All CIRFT Data including Hydride Reorientation Tests (Draft M2)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Wang, Hong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Jiang, Hao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Yan, Yong [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Bevard, Bruce B. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Scaglione, John M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-09-04

    The first portion of this report provides a detailed description of fiscal year (FY) 2015 test result corrections and analysis updates based on FY 2016 updates to the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) program methodology, which is used to evaluate the vibration integrity of spent nuclear fuel (SNF) under normal conditions of transport (NCT). The CIRFT consists of a U-frame test setup and a real-time curvature measurement method. The three-component U-frame setup of the CIRFT has two rigid arms and linkages connecting to a universal testing machine. The curvature SNF rod bending is obtained through a three-point deflection measurement method. Three linear variable differential transformers (LVDTs) are clamped to the side connecting plates of the U-frame and used to capture deformation of the rod. The second portion of this report provides the latest CIRFT data, including data for the hydride reorientation test. The variations in fatigue life are provided in terms of moment, equivalent stress, curvature, and equivalent strain for the tested SNFs. The equivalent stress plot collapsed the data points from all of the SNF samples into a single zone. A detailed examination revealed that, at the same stress level, fatigue lives display a descending order as follows: H. B. Robinson Nuclear Power Station (HBR), LMK, and mixed uranium-plutonium oxide (MOX). Just looking at the strain, LMK fuel has a slightly longer fatigue life than HBR fuel, but the difference is subtle. The third portion of this report provides finite element analysis (FEA) dynamic deformation simulation of SNF assemblies . In a horizontal layout under NCT, the fuel assembly’s skeleton, which is formed by guide tubes and spacer grids, is the primary load bearing apparatus carrying and transferring vibration loads within an SNF assembly. These vibration loads include interaction forces between the SNF assembly and the canister basket walls. Therefore, the integrity of the guide

  14. FY 2016 Status Report: Documentation of All CIRFT Data including Hydride Reorientation Tests (Draft M2)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Wang, Hong [ORNL

    2016-09-01

    The first portion of this report provides a detailed description of fiscal year (FY) 2015 test result corrections and analysis updates based on FY 2016 updates to the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) program methodology, which is used to evaluate the vibration integrity of spent nuclear fuel (SNF) under normal conditions of transport (NCT). The CIRFT consists of a U-frame test setup and a real-time curvature measurement method. The three-component U-frame setup of the CIRFT has two rigid arms and linkages connecting to a universal testing machine. The curvature SNF rod bending is obtained through a three-point deflection measurement method. Three linear variable differential transformers (LVDTs) are clamped to the side connecting plates of the U-frame and used to capture deformation of the rod. The second portion of this report provides the latest CIRFT data, including data for the hydride reorientation test. The variations in fatigue life are provided in terms of moment, equivalent stress, curvature, and equivalent strain for the tested SNFs. The equivalent stress plot collapsed the data points from all of the SNF samples into a single zone. A detailed examination revealed that, at the same stress level, fatigue lives display a descending order as follows: H. B. Robinson Nuclear Power Station (HBR), LMK, and mixed uranium-plutonium oxide (MOX). Just looking at the strain, LMK fuel has a slightly longer fatigue life than HBR fuel, but the difference is subtle. The third portion of this report provides finite element analysis (FEA) dynamic deformation simulation of SNF assemblies . In a horizontal layout under NCT, the fuel assembly’s skeleton, which is formed by guide tubes and spacer grids, is the primary load bearing apparatus carrying and transferring vibration loads within an SNF assembly. These vibration loads include interaction forces between the SNF assembly and the canister basket walls. Therefore, the integrity of the guide

  15. Class analysis and the reorientation of class theory: the case of persisting differentials in educational attainment. 1996.

    Science.gov (United States)

    Goldthorpe, John H

    2010-01-01

    In class analysis the main regularities that have been established by empirical research are not ones of long-term class formation or decomposition, as envisaged in Marxist or liberal theory, but rather ones that exhibit the powerful resistance to change of class relations and associated life-chances and patterns of social action. If these regularities are to be explained, theory needs to be correspondingly reoriented, and must abandon functionalist and teleological assumptions in favour of providing more secure micro-foundations. This argument is developed and illustrated in the course of an attempt to apply rational action theory to the explanation of persisting class differentials in educational attainment.

  16. Reorientation of the high mobility plane in pentacene-based carbon nanotube enabled vertical field effect transistors.

    Science.gov (United States)

    McCarthy, Mitchell A; Liu, Bo; Jayaraman, Ramesh; Gilbert, Stephen M; Kim, Do Young; So, Franky; Rinzler, Andrew G

    2011-01-25

    The large current densities attained by carbon nanotube enabled vertical field effect transistors using crystalline organic channel materials are somewhat unexpected given the known large anisotropy in the mobility of crystalline organics and their conventional ordering on dielectric surfaces which tends to orient their high mobility axes parallel to the surface. This seeming contradiction is resolved by the finding that the nanotubes induce a molecular ordering that reorients the high mobility axes to favor current flow in a direction perpendicular to the substrate surface.

  17. Temperature-Induced Magnetization Reorientation in GdFeCo/TbFeCo Exchange-Coupled Double Layer Films

    Institute of Scientific and Technical Information of China (English)

    王现英; 张约品; 李佐宜; 沈德芳; 干福熹

    2003-01-01

    GdFeCo/TbFeCo exchange-coupled double-layer (ECDL) films used for centre aperture type magnetically in duced super resolution were investigated through experiments and theoretical calculation. The ECDL films were prepared by the magnetron sputtering method. Polar Kerr effect measurements showed that magnetization reorientation occurred in the GdFeCo layer with the temperature rising, which was subsequently analysed by the micromagnetic calculation based on the mean-field theory and a continuum model. Theoretical analysis is in agreement well with the experimental results.

  18. Emerging Paradigms in Machine Learning

    CERN Document Server

    Jain, Lakhmi; Howlett, Robert

    2013-01-01

    This  book presents fundamental topics and algorithms that form the core of machine learning (ML) research, as well as emerging paradigms in intelligent system design. The  multidisciplinary nature of machine learning makes it a very fascinating and popular area for research.  The book is aiming at students, practitioners and researchers and captures the diversity and richness of the field of machine learning and intelligent systems.  Several chapters are devoted to computational learning models such as granular computing, rough sets and fuzzy sets An account of applications of well-known learning methods in biometrics, computational stylistics, multi-agent systems, spam classification including an extremely well-written survey on Bayesian networks shed light on the strengths and weaknesses of the methods. Practical studies yielding insight into challenging problems such as learning from incomplete and imbalanced data, pattern recognition of stochastic episodic events and on-line mining of non-stationary ...

  19. New Paradigms For Asteroid Formation

    CERN Document Server

    Johansen, Anders; Cuzzi, Jeffrey N; Morbidelli, Alessandro; Gounelle, Matthieu

    2015-01-01

    Asteroids and meteorites provide key evidence on the formation of planetesimals in the Solar System. Asteroids are traditionally thought to form in a bottom-up process by coagulation within a population of initially km-scale planetesimals. However, new models challenge this idea by demonstrating that asteroids of sizes from 100 to 1000 km can form directly from the gravitational collapse of small particles which have organised themselves in dense filaments and clusters in the turbulent gas. Particles concentrate passively between eddies down to the smallest scales of the turbulent gas flow and inside large-scale pressure bumps and vortices. The streaming instability causes particles to take an active role in the concentration, by piling up in dense filaments whose friction on the gas reduces the radial drift compared to that of isolated particles. In this chapter we review new paradigms for asteroid formation and compare critically against the observed properties of asteroids as well as constraints from meteo...

  20. The Oral Paradigm and Snapchat

    Directory of Open Access Journals (Sweden)

    Oren Soffer

    2016-09-01

    Full Text Available In this short essay, I argue that the ephemeral nature of emerging instant-messaging applications, such as Snapchat, applies an oral paradigm. While online discourse of computer-mediated communication shares many qualities with oral communication, the case of ephemeral applications is unique, as the oral features are already integrated in the application technology design and as orality is often implemented on highly visual products. Snapchat applies technology that fades visual contents as if they were spoken words fading in the air after utterance. Moreover, Snapchat’s promise to delete all messages from its database after they are viewed echoes a key characteristic of primary oral culture: that is, the inability (and in our case, the obligation not to store knowledge. In this, Snapchat demonstrates counter-logic to the contemporary grammar of new media, which is based on information aggregation.

  1. Datacubes as a Service Paradigm

    Science.gov (United States)

    Rossi, Angelo Pio; Baumann, Peter

    2016-04-01

    Spatio-temporal data sets often can be represented conveniently through datacubes as a common unifying paradigm. Flexible, scalable services can be offered based on the concept of a datacube query language while hiding the technicalities, thereby allowing user-friendly visual data interaction. One of today's most influential initiatives in Big Geo Data is EarthServer which is paving the way for flexible, scalable datacube services based on innovative NewSQL technology (Fig. 1). Researchers from Europe, the US and recently Australia have teamed up to rigorously materialize the datacube paradigm for Earth Observation, ocean, meteorological, and planetary science. EarthServer has established client and server technology for such spatio-temporal datacubes strictly based on the open datacube standards, OGC WCS and WPCS. The underlying scalable array engine, rasdaman, enables direct interaction, including 3-D visualization, what-if scenarios, common EO data processing, and general analytics on regular and irregular grids. Integration of datacube and metadata retrieval, together with advanced visualization based on NASA WorldWind, are geared towards an effective, user-friendly access and analysis. Conversely, EarthServer is significantly shaping the ISO, OGC, and INSPIRE Big Data standards landscape by being specification editor. Phase 1 of EarthServer has advanced scalable array data¬base technology into 100+ TB services; in phase 2, a federation of Petabyte datacubes is being built in Europe and Australia to perform ad-hoc querying and merging. Phase 1 reviewers have attested rasdaman to "significantly transform the way that scientists in different areas of Earth Science will be able to access and use data in a way that hitherto was not possible". Altogether, these large-scale deployments prove that datacubes are a convenient model for presenting users with a simple, consolidated view on the massive amount of data files gathered - "a cube tells more than a million

  2. A Novel Risk-Based Decision Making Paradigm

    Directory of Open Access Journals (Sweden)

    Pedro eMorgado

    2014-02-01

    Full Text Available This paper presents a novel rodent decision-making task that explores uncertainty, independently of expectation and predictability. Using a 5-hole operating box, adult male Wistar rats were given choices between a small certain (safe food reward and a large uncertain (risk food reward. We found that animals strongly preferred the safe option when it had a fixed position or was cued with a light in a random placement scheme, but had no preference for safe or risk options when the latter were associated with light. Importantly, when the reward was manipulated animals could perceive alterations in the outcome value and biased their choice pattern to the most profitable option. In addition, we found that the D2/D3 agonist quinpirole biased all decisions towards risk in this paradigm. Finally, a c-fos analysis revealed that several brain areas known to be involved in decision-making mechanisms, including the medial prefrontal cortex, the orbitofrontal cortex, the nucleus accumbens and the striatum, were activated by the task. In summary, this paradigm is a useful and highly reliable tool to explore decision-making processes in contexts of uncertainty.

  3. A novel risk-based decision-making paradigm.

    Science.gov (United States)

    Morgado, Pedro; Marques, Fernanda; Silva, Miguel B; Sousa, Nuno; Cerqueira, João J

    2014-01-01

    This paper presents a novel rodent decision-making task that explores uncertainty, independently of expectation and predictability. Using a 5-hole operating box, adult male Wistar rats were given choices between a small certain (safe) food reward and a large uncertain (risk) food reward. We found that animals strongly preferred the safe option when it had a fixed position or was cued with a light in a random placement scheme, but had no preference for safe or risk options when the latter were associated with light. Importantly, when the reward was manipulated animals could perceive alterations in the outcome value and biased their choice pattern to the most profitable option. In addition, we found that the D2/D3 agonist quinpirole biased all decisions toward risk in this paradigm. Finally, a c-fos analysis revealed that several brain areas known to be involved in decision-making mechanisms, including the medial prefrontal cortex, the orbitofrontal cortex, the nucleus accumbens and the striatum, were activated by the task. In summary, this paradigm is a useful and highly reliable tool to explore decision-making processes in contexts of uncertainty.

  4. Electroencephalography of response inhibition tasks : functional networks and cognitive contributions

    NARCIS (Netherlands)

    Huster, René J; Enriquez-Geppert, Stefanie; Lavallee, Christina F; Falkenstein, Michael; Herrmann, Christoph S

    2013-01-01

    Response inhibition paradigms, as for example stop signal and go/no-go tasks, are often used to study cognitive control processes. Because of the apparent demand to stop a motor reaction, the electrophysiological responses evoked by stop and no-go trials have sometimes likewise been interpreted as i

  5. Task Dissociation in Prospective Memory Performance in Individuals With ADHD

    NARCIS (Netherlands)

    Altgassen, A.M.; Kretschmer, A.; Kliegel, M.

    2014-01-01

    OBJECTIVE: The present study investigated, for the first time, event- and time-based prospective memory (PM) in the same sample of adults with ADHD within one paradigm using parallel task constraints. METHOD: A total of 25 individuals with ADHD and 25 matched neurotypical controls completed a comput

  6. The Role of Children's Expertise in a Strategic Memory Task.

    Science.gov (United States)

    Gaultney, Jane F.; And Others

    1992-01-01

    Two experiments with 42 second graders, 55 fourth graders, and 36 fifth graders investigated previous findings of a lack of strategic advantage for expert children dealing with information in their area of expertise. Results from using an expert-novice paradigm suggest that expert children's task advantage is mediated primarily by nonstrategic…

  7. ERP indices of persisting and current inhibitory control: a study of saccadic task switching.

    Science.gov (United States)

    Mueller, S C; Swainson, R; Jackson, G M

    2009-03-01

    Previous studies have found that inhibition of a biologically dominant prepotent response tendency is required during the execution of a less familiar, non-prepotent response. However, the lasting impact of this inhibition and the cognitive mechanisms to flexibly switch between prepotent and non-prepotent responses are poorly understood. We examined the neurophysiological (ERP) correlates of switching between prosaccade and antisaccade responses in 22 healthy volunteers. The behavioural data showed significant switch costs in terms of response latency for the prosaccade task only. These costs occurred exclusively in trials when preparation for the switch was limited to 300 ms, suggesting that inhibition of the prepotent prosaccade task either passively dissipated or was actively overcome during the longer 1000 ms preparation interval. In the neurophysiological data, a late frontal negativity (LFN) was visible during preparation for a switch to the prosaccade task that was absent when switching to the antisaccade task, which may reflect the overcoming of persisting inhibition. During task implementation both saccade types were associated with a late parietal positivity (LPP) for switch relative to repetition trials, possibly indicating attentional reorienting to the switched-to task, and visible only with short preparation intervals. When the prosaccade and antisaccade task were contrasted directly during task implementation, the antisaccade task exhibited increased stimulus-locked N2 and decreased P3 amplitudes indicative of active inhibition. The present findings indicate that neurophysiological markers of persisting and current inhibition can be revealed using a prosaccade/antisaccade-switching task.

  8. Linking metacommunity paradigms to spatial coexistence mechanisms.

    Science.gov (United States)

    Shoemaker, Lauren G; Melbourne, Brett A

    2016-09-01

    Four metacommunity paradigms-usually called neutral, species sorting, mass effects, and patch dynamics, respectively-are widely used for empirical and theoretical studies of spatial community dynamics. The paradigm framework highlights key ecological mechanisms operating in metacommunities, such as dispersal limitation, competition-colonization tradeoffs, or species equivalencies. However, differences in coexistence mechanisms between the paradigms and in situations with combined influences of multiple paradigms are not well understood. Here, we create a common model for competitive metacommunities, with unique parameterizations for each metacommunity paradigm and for scenarios with multiple paradigms operating simultaneously. We derive analytical expressions for the strength of Chesson's spatial coexistence mechanisms and quantify these for each paradigm via simulation. For our model, fitness-density covariance, a concentration effect measuring the importance of intraspecific aggregation of individuals, is the dominant coexistence mechanism in all three niche-based metacommunity paradigms. Increased dispersal between patches erodes intraspecific aggregation, leading to lower coexistence strength in the mass effects paradigm compared to species sorting. Our analysis demonstrates the potential importance of aggregation of individuals (fitness-density covariance) over co-variation in abiotic environments and competition between species (the storage effect), as fitness-density covariance can be stronger than the storage effect and is the sole stabilizing mechanism in the patch dynamics paradigm. As expected, stable coexistence does not occur in the neutral paradigm, which requires species to be equal and emphasizes the role of stochasticity. We show that stochasticity also plays an important role in niche-structured metacommunities by altering coexistence strength. We conclude that Chesson's spatial coexistence mechanisms provide a flexible framework for comparing

  9. Why SIT works: normal function despite typical myofiber pattern in Situs Inversus Totalis (SIT) hearts derived by shear-induced myofiber reorientation.

    Science.gov (United States)

    Pluijmert, Marieke; Kroon, Wilco; Rossi, Alessandro C; Bovendeerd, Peter H M; Delhaas, Tammo

    2012-01-01

    The left ventricle (LV) of mammals with Situs Solitus (SS, normal organ arrangement) displays hardly any interindividual variation in myofiber pattern and experimentally determined torsion. SS LV myofiber pattern has been suggested to result from adaptive myofiber reorientation, in turn leading to efficient pump and myofiber function. Limited data from the Situs Inversus Totalis (SIT, a complete mirror image of organ anatomy and position) LV demonstrated an essential different myofiber pattern, being normal at the apex but mirrored at the base. Considerable differences in torsion patterns in between human SIT LVs even suggest variation in myofiber pattern among SIT LVs themselves. We addressed whether different myofiber patterns in the SIT LV can be predicted by adaptive myofiber reorientation and whether they yield similar pump and myofiber function as in the SS LV. With a mathematical model of LV mechanics including shear induced myofiber reorientation, we predicted myofiber patterns of one SS and three different SIT LVs. Initial conditions for SIT were based on scarce information on the helix angle. The transverse angle was set to zero. During reorientation, a non-zero transverse angle developed, pump function increased, and myofiber function increased and became more homogeneous. Three continuous SIT structures emerged with a different location of transition between normal and mirrored myofiber orientation pattern. Predicted SIT torsion patterns matched experimentally determined ones. Pump and myofiber function in SIT and SS LVs are similar, despite essential differences in myocardial structure. SS and SIT LV structure and function may originate from same processes of adaptive myofiber reorientation.

  10. Transcranial magnetic stimulation intensities in cognitive paradigms.

    Directory of Open Access Journals (Sweden)

    Jakob A Kaminski

    Full Text Available BACKGROUND: Transcranial magnetic stimulation (TMS has become an important experimental tool for exploring the brain's functional anatomy. As TMS interferes with neural activity, the hypothetical function of the stimulated area can thus be tested. One unresolved methodological issue in TMS experiments is the question of how to adequately calibrate stimulation intensities. The motor threshold (MT is often taken as a reference for individually adapted stimulation intensities in TMS experiments, even if they do not involve the motor system. The aim of the present study was to evaluate whether it is reasonable to adjust stimulation intensities in each subject to the individual MT if prefrontal regions are stimulated prior to the performance of a cognitive paradigm. METHODS AND FINDINGS: Repetitive TMS (rTMS was applied prior to a working memory task, either at the 'fixed' intensity of 40% maximum stimulator output (MSO, or individually adapted at 90% of the subject's MT. Stimulation was applied to a target region in the left posterior middle frontal gyrus (pMFG, as indicated by a functional magnetic resonance imaging (fMRI localizer acquired beforehand, or to a control site (vertex. Results show that MT predicted the effect size after stimulating subjects with the fixed intensity (i.e., subjects with a low MT showed a greater behavioral effect. Nevertheless, the individual adaptation of intensities did not lead to stable effects. CONCLUSION: Therefore, we suggest assessing MT and account for it as a measure for general cortical TMS susceptibility, even if TMS is applied outside the motor domain.

  11. Differential effects of wake promoting drug Modafinil in aversive learning paradigms

    Directory of Open Access Journals (Sweden)

    Bharanidharan eShanmugasundaram

    2015-08-01

    Full Text Available Modafinil (MO an inhibitor of the dopamine transporter was initially approved to treat narcolepsy, a sleep related disorder in humans. One interesting side-effect of this drug, which emerged from preclinical and clinical studies, is the facilitation of cognitive performance. So far, this was primarily shown in appetitive learning paradigms, but it is yet unclear whether MO exerts a more general cognitive enhancement effect. Thus, the aim of the present study in rats was to extend these findings by testing the effects of MO in two aversive paradigms, Pavlovian fear conditioning (FC and the operant two-way active avoidance (TWA learning paradigms. We discovered a differential, task-dependent effect of MO. In the FC paradigm MO treated rats showed a dose-dependent enhancement of fear memory compared to vehicle treated rats, indicated by increased context-related freezing. Cue related fear memory remained unaffected. In the TWA paradigm MO induced a slight, but significant decrease of avoidance responses compared to vehicle treated animals, while the number of escape reactions during the acquisition of the TWA task remained unaffected. These findings expand the knowledge in the regulation of cognitive abilities and may contribute to the understanding of the contraindicative effects of MO in anxiety related mental disorders.

  12. Man-machine interaction in the 21st century--new paradigms through dynamic scene analysis and synthesis (Keynote Speech)

    Science.gov (United States)

    Huang, Thomas S.; Orchard, Michael T.

    1992-11-01

    The past twenty years have witnessed a revolution in the use of computers in virtually every facet of society. While this revolution has been largely fueled by dramatic technological advances, the efficient application of this technology has been made possible through advances in the paradigms defining the way users interact with computers. Today's massive computational power would probably have limited sociological impact is users still communicated with computers via the binary machine language codes used in the 1950's. Instead, this primitive paradigm was replaced by keyboards and ASCII character displays in the 1970's, and the 'mouse' and multiple-window bit-mapped displays in the 1980's. As continuing technological advances make even larger computational power available in the future, advanced paradigms for man-machine interaction will be required to allow this power to be used efficiently in a wide range of applications. Looking ahead into the 21st century, we see paradigms supporting radically new ways of interacting with computers. Ideally, we would like these interactions to mimic the ways we interact with objects and people in the physical world, and, to achieve this goal, we believe that it is essential to consider the exchange of video data into and out of the computer. Paradigms based on visual interactions represent a radical departure from existing paradigms, because they allow the computer to actively seek out information from the user via dynamic scene analysis. For example, the computer might enlarge the display when it detects that the user if squinting, or it might reorient a three- dimensional object on the screen in response to detected hand motions. This contrasts with current paradigms in which the computer relies on passive switching devices (keyboard, mouse, buttons, etc.) to receive information. Feedback will be provided to the user via dynamic scene synthesis, employing stereoscopic three-dimensional display systems. To exploit the

  13. The Three Paradigms of Mass Media Research.

    Science.gov (United States)

    Potter, W. James; And Others

    A study examined the mass media research literature to determine if there was a dominant paradigm in the field. The mass media research published in eight communication journals from 1965 to 1989 was content analyzed to identify paradigm, orientation (focus and theory), data (type, source, and sample), methodology (type and manipulation), and…

  14. The New Paradigm Dialogs and Qualitative Inquiry

    Science.gov (United States)

    Denzin, Norman K.

    2008-01-01

    This paper re-engages the paradigm wars of the 1980s, discussing their relevance in the current historical moment. It extends Egon Guba's call for dialogue across paradigm communities. Ten theses and three agenda items are advanced. (Contains 4 notes.)

  15. The cognitive paradigm and the immunological homunculus.

    Science.gov (United States)

    Cohen, I R

    1992-12-01

    In last month's issue of Immunology Today, Irun Cohen discussed the inadequacies of the clonal selection paradigm and proposed a cognitive paradigm in which preformed internal images guide and restrict the process of clonal activation. Here he clarifies the nature of these internal images, during on concrete examples from the image of infection and the image of self, the immunological homunculus.

  16. Towards a New Paradigm of Moral Personhood

    Science.gov (United States)

    Frimer, Jeremy A.; Walker, Lawrence J.

    2008-01-01

    Moral psychology is between paradigms. Kohlberg's model of moral rationality has proved inadequate in explaining action; yet its augmentation--moral personality--awaits empirical embodiment. This article addresses some critical issues in developing a comprehensive empirical paradigm of moral personhood. Is a first-person or a third-person…

  17. Is This the Paradigm Shift We Need?

    Science.gov (United States)

    Mirvis, Jonathan

    2012-01-01

    Dr. Woocher's essay, states Mirvis, is seminal in the field of Jewish education. It proposes a new paradigm for Jewish education in North America. This proposed paradigm is supported by a comprehensive multi-disciplinary research drawing on literature from education, philosophy, history, sociology, psychology, and economics. The essay reflects a…

  18. Paradigm Lost: The Human Chromosome Story.

    Science.gov (United States)

    Unger, Lawrence; Blystone, Robert V.

    1996-01-01

    Discusses whether the discovery in 1956 that humans have a chromosome number of 46, as opposed to 47 or 48 as previously thought, fits into a paradigm shift of the Kuhnian type. Concludes that Kuhn probably would not have considered the chromosome number shift to be large enough to be a focus for one of his paradigms. (AIM)

  19. Reforming the Paradigm of American Education.

    Science.gov (United States)

    Leonard, B. Charles; Messner, Phillip E.

    1991-01-01

    The current crisis of U.S. public education cannot be addressed through reforms to the existing paradigm. In fact, the current paradigm is being challenged and shifted bringing in a new perception of the educational process. Because of resistance in the education profession, that change may be variously applied. (JB)

  20. Emergence and decline of scientific paradigms

    DEFF Research Database (Denmark)

    Bornholdt, S.; Jensen, Mogens Høgh; Sneppen, Kim

    2011-01-01

    deals with this asymmetry by constraining the ability of agents to return to already abandoned concepts. The model exhibits a fairly regular pattern of global paradigm shifts, where older paradigms are eroded and subsequently replaced by new ones. The model sets the theme for a new class of pattern...

  1. The Technological Paradigm of Psychological Research

    Science.gov (United States)

    Kvale, Steinar

    1973-01-01

    The experiment in physics has often been pictured as an ideal for the less mature social sciences, especially by positivist philosophy of science. The thesis to be presented here is that the physical experiment as a paradigm for psychology is merely a pretext, a smoke-screen for a more fundamental and concealed technological paradigm for the study…

  2. Holism and Empiricism as Complementary Paradigms.

    Science.gov (United States)

    Kronick, Doreen

    1990-01-01

    In response to Poplin (EC 210 561) and Heshusius (EC 220 916), the paper stresses that holism and empiricism are not dichotomous paradigms and that learning-disabled students require instruction which recognizes individual differences, the meaning inherent in structure and pattern, and accountability consistent with the paradigm being applied. (DB)

  3. The Technological Paradigm of Psychological Research

    Science.gov (United States)

    Kvale, Steinar

    1973-01-01

    The experiment in physics has often been pictured as an ideal for the less mature social sciences, especially by positivist philosophy of science. The thesis to be presented here is that the physical experiment as a paradigm for psychology is merely a pretext, a smoke-screen for a more fundamental and concealed technological paradigm for the study…

  4. Derfor har vi brug for paradigmer

    DEFF Research Database (Denmark)

    Kragh, Kirsten A. Jeppesen; Schøsler, Lene

    2016-01-01

    Based on previous studies on verbs of perception in French and Ita- lian, this study claims that the notion of paradigm is useful for the understanding of grammatical structure. Our case-study concerns the status of Modern French voir in the paradigms of presentation and of progressivity....

  5. Towards a New Paradigm of Moral Personhood

    Science.gov (United States)

    Frimer, Jeremy A.; Walker, Lawrence J.

    2008-01-01

    Moral psychology is between paradigms. Kohlberg's model of moral rationality has proved inadequate in explaining action; yet its augmentation--moral personality--awaits empirical embodiment. This article addresses some critical issues in developing a comprehensive empirical paradigm of moral personhood. Is a first-person or a third-person…

  6. The Failure of Progressive Paradigm Reversal

    Science.gov (United States)

    Guthrie, Gerard

    2017-01-01

    The student-centred, progressive paradigm has not had sustained success in changing teacher-centred, formalistic practices in "developing" country classrooms. Does "Gestalt-switch" and paradigm reversal demonstrate that progressive theory has realigned with formalistic reality, or has it remained axiomatic in the research and…

  7. A task is a task is a task: Putting complex span, n-back, and other working memory indicators in psychometric context

    Directory of Open Access Journals (Sweden)

    Florian eSchmiedek

    2014-12-01

    Full Text Available Based on a meta-analysis, Redick and Lindsey (2013 found that complex span and n-back tasks show an average correlation of r = .20, and concluded that complex span and n-back tasks cannot be used interchangeably as working memory measures in research applications (p. 1102. Here, we comment on this conclusion from a psychometric perspective. In addition to construct variance, performance on a test contains measurement error, task-specific variance, and paradigm-specific variance. Hence, low correlations among dissimilar indicators do not provide strong evidence for the existence, or absence, of a construct common to both indicators. One way to arrive at such evidence is to fit hierarchical latent factors that model task-specific, paradigm-specific, and construct variance. We report analyses for 101 younger and 103 older adults who worked on 9 different working memory tasks. The data are consistent with a hierarchical model of working memory, according to which both complex span and n-back tasks are valid indicators of working memory. The working memory factor predicts 71% of the variance in a factor of reasoning among younger adults (83% for among older adults. When the working memory factor was restricted to any possible triplet of working memory tasks, the correlation between working memory and reasoning was inversely related to the average magnitude of the correlations among the indicators, indicating that more highly intercorrelated indicators may provide poorer coverage of the construct space. We stress the need to go beyond specific tasks and paradigms when studying higher-order cognitive constructs, such as working memory.

  8. A task is a task is a task: putting complex span, n-back, and other working memory indicators in psychometric context.

    Science.gov (United States)

    Schmiedek, Florian; Lövdén, Martin; Lindenberger, Ulman

    2014-01-01

    Based on a meta-analysis, Redick and Lindsey (2013) found that complex span and n-back tasks show an average correlation of r = 0.20, and concluded that "complex span and n-back tasks cannot be used interchangeably as working memory measures in research applications" (p. 1102). Here, we comment on this conclusion from a psychometric perspective. In addition to construct variance, performance on a test contains measurement error, task-specific variance, and paradigm-specific variance. Hence, low correlations among dissimilar indicators do not provide strong evidence for the existence, or absence, of a construct common to both indicators. One way to arrive at such evidence is to fit hierarchical latent factors that model task-specific, paradigm-specific, and construct variance. We report analyses for 101 younger and 103 older adults who worked on nine different working memory tasks. The data are consistent with a hierarchical model of working memory, according to which both complex span and n-back tasks are valid indicators of working memory. The working memory factor predicts 71% of the variance in a factor of reasoning among younger adults (83% for among older adults). When the working memory factor was restricted to any possible triplet of working memory tasks, the correlation between working memory and reasoning was inversely related to the average magnitude of the correlations among the indicators, indicating that more highly intercorrelated indicators may provide poorer coverage of the construct space. We stress the need to go beyond specific tasks and paradigms when studying higher-order cognitive constructs, such as working memory.

  9. Reorientation of M{sub A}{sup +}-centres in CaF{sub 2}:Me{sup +} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Chornyi, Z.P.; Shchur, G.O.; Salapak, V.M. [Ukrainian State Univ. of Forestry and Wood Technology, Lviv (Ukraine); Kravchuk, I.M.; Kachan, S.I. [State Univ. ' ' Lvivska Polytekhnika' ' , Lviv (Ukraine)

    2001-02-01

    Studies of photoinductive dichroism allow to define the orientation of colour centres. The photo-inductive dichroism of absorption testifies the fact that oscillators, responsible for the long-wave absorption band of M{sub A}{sup +}-centres, are located along left angle 100 right angle crystallographic directions, and high-energetic oscillators, along left angle 110 right angle crystallographic directions. Various impurities cause unequal perturbations in the crystal lattice. The determination of the kinetic parameters of the reorientation processes in simple and complex colour centres allows establishing the structure of the aggregative centre. The size of the impurity ion influences the energy of reorientation of M{sub A}{sup +}-centres, and this, in turn, is connected with the displacement of vacancies towards the anion sites of the crystal. It is found that the anion vacancy in M{sub A}{sup +}-centres jumps in left angle 110 right angle directions, but in F{sub A}{sup +}-centres it jumps in left angle 100 right angle directions. (orig.)

  10. [The trajectory of the national policy for the reorientation of professional training in health in the Unified Health System (SUS)].

    Science.gov (United States)

    Dias, Henrique Sant'anna; Lima, Luciana Dias de; Teixeira, Márcia

    2013-06-01

    This paper examines the national policy and its antecedents for reorientation of professional health training implemented after 2003. It highlights landmarks and transformations in the course of policies between 1980 and 2010, elements of continuity and change and the connections between past and current policy initiatives. The study involved a review of the literature on the subject and document analysis supported by theoretical analysis of public policies, particularly historical institutionalism. The results point to four different moments during the trajectory of the policy, marked by changes in the initiatives of reorientation of higher education in health: antecedents; initial experiences; university protagonism; broadening and enhancement. As an element of continuity, there is the permanence of objects in the guiding principles advocated in the policies. The evidence of implementation expresses prospects of enhancement, with diversification of mobilized actors and organizations, and more projects implemented. The accumulated experience suggests structural maturity of the structural bases of action and the main changes relate to the enhancement of decision-making bodies of the SUS and the approximation to the process of decentralization and regionalization of national health policy.

  11. Beacons and surface features differentially influence human reliance on global and local geometric cues when reorienting in a virtual environment.

    Science.gov (United States)

    Bodily, Kent D; Kilday, Zachary A; Eastman, Caroline K; Gaskin, Katherine A; Graves, April A; Roberts, Jonathan E; Sturz, Bradley R

    2013-02-01

    In the reorientation literature, non-geometric cues include discrete objects (e.g., beacons) and surface-based features (e.g., colors, textures, and odors). To date, these types of non-geometric cues have been considered functionally similar, and it remains unknown whether beacons and surface features differentially influence the extent to which organisms reorient via global and local geometric cues. In the present experiment, we trained human participants to approach a location in a trapezoid-shaped enclosure uniquely specified by global and local geometric cues. We explored the role of beacons on the use of geometric cues by training participants in the presence or absence of uniquely-colored beacons. We explored the role of surface features on the use of geometric cues by recoloring two adjacent walls at the correct location and/or adding a line on the floor which corresponded to the major principal axis of the enclosure. All groups were then tested in novel-shaped enclosures in the absence of unique beacons and surface features to assess the relative use of global and local geometric cues. Results suggested that beacons facilitated the use of global geometric cues, whereas surface features either facilitated or hindered the use of geometric cues, depending on the feature. Published by Elsevier B.V.

  12. Reorientation of lineation in the Central Crystalline Zone, Munsiari–Milam area of the Kumaun Greater Himalaya

    Indian Academy of Sciences (India)

    A K Verma; A R Bhattacharya

    2015-03-01

    During large scale ductile shear deformation, linear features of the rocks tend to be reoriented towards the direction of bulk shear. This is demonstrated in a crustal scale shear zone of the Himalaya, the Main Central Thrust (MCT), typically exposed in the Munsiari–Milam area of eastern Kumaun Greater Himalaya. Along the MCT, the crystalline rocks of the Greater Himalaya are thrust over the younger sedimentary belt of the Lesser Himalaya. In the study area, the scatter of lineation orientation in the vicinity of the MCT has been observed to drastically reduce within 27° in a zone of about 18 km (about 13 km in the crystalline rocks and about 5 km in the sedimentary rocks). Beyond this zone, the scatter is very high, up to 70° or more. The low scatter of lineation orientation around the MCT could be related to the strong ductile shear deformation associated with the movement along this thrust due to which the linear features got reoriented towards the direction of bulk shear. Away from this zone, ductile shearing had negligible or no effect on the rocks and, therefore, the scatter of lineation remains very high.

  13. Development of skin conductance orienting, habituation, and reorienting from ages 3 to 8 years: a longitudinal latent growth curve analysis.

    Science.gov (United States)

    Gao, Yu; Raine, Adrian; Dawson, Michael E; Venables, Peter H; Mednick, Sarnoff A

    2007-11-01

    Little is known about the development of the skin conductance orienting response (SCOR) in childhood. This longitudinal study examines the effects of age on initial SCOR, habituation, and reorienting. Skin conductance responses to nonsignal auditory stimuli were recorded from 200 male and female children at five different time points (ages 3, 4, 5, 6, and 8 years). Longitudinal latent growth curve analyses were used to determine the trajectory of each SCOR measure during this period. Results indicated that (a) initial SCOR is present at age 3, increases thereafter to peak at age 6, and then levels off, (b) habituation is absent at age 3, but becomes apparent at age 4 years and increases thereafter with increasing age, (c) SC reorienting is absent from ages 3 to 8, and (d) boys and girls do not exhibit different developmental trajectories. Results suggest that from age 3 to 8 years, the transition from the functionally immature to mature neural network underlying orienting and habituation is a continuous process and may be related to children's cognitive development during this period.

  14. Ab initio prediction of giant magnetostriction and spin-reorientation in strained Au/FeCo/MgO heterostructure

    Energy Technology Data Exchange (ETDEWEB)

    Ong, P.V., E-mail: phuongvu.ong@csun.edu; Kioussis, Nicholas, E-mail: nick.kioussis@csun.edu

    2016-02-15

    Employing ab initio electronic structure calculations we have investigated the magnetostrictive properties and the effect of epitaxial strain on the magnetic anisotropy (MA) of Au/FeCo/MgO heterostructure. Under small expansive strain on the FeCo layer the system exhibits an in-plane MA. The calculations reveal that the strain dependence of the MA is nonlinear and that the FeCo film undergoes a spin reorientation at a critical strain between 2 and 4%. The underlying mechanism is the strain-induced shift of the spin–orbit coupled d-states of the Fe atoms. We predict a giant magnetostriction coefficient of about 420×10{sup −6} in the heterostructure. - Highlights: • Nonlinear strain dependence of magnetic anisotropy. • The FeCo film undergoes a spin reorientation at a critical strain between 2 and 4%. • The underlying mechanism is the strain-induced shift of the spin–orbit coupled d-states of the Fe atoms. • Giant magnetostriction coefficient of about 420×10{sup -6} in the heterostructure.

  15. A New Paradigm for Chemical Engineering?

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    businesses has been observed. There is an increasing trend within the chemical industry to focus on products and the sustainable processes that can make them. Do these changes point to a paradigm shift in chemical engineering as a discipline? Historically, two previous paradigm shifts in chemical engineering...... corresponded to major shifts in chemical engineering as a discipline, which affected not only the education of chemical engineers, but also the development of chemical engineering as a discipline. Has the time come for a new paradigm shift that will prepare the current and future chemical engineering graduates...... to tackle the complex problems facing the chemicals based industries and serve the modern society more efficiently? The lecture will review the current status of chemical engineering as a discipline, the proposals for the third paradigm, the need for such a paradigm shift and related educational issues....

  16. Attentional biases in social anxiety: an investigation using the inattentional blindness paradigm.

    Science.gov (United States)

    Lee, Han-Joo; Telch, Michael J

    2008-07-01

    One line of research has examined attentional bias as a potential maintenance factor in social anxiety using cognitive experiment paradigms. The present study sought to examine the utility of the inattentional blindness (IB) paradigm for assessing attentional bias in social anxiety. Unlike other existing paradigms such as the emotional Stroop or dot-probe tasks, the IB paradigm has the advantage of eliminating the individual's expectation and intention to search for social cues, which would reduce strategic or effortful responses. Two independent experiments were conducted using college students scoring high or low on the Fear of Negative Evaluation Scale. In both Experiments 1 and 2, participants were randomized to one of three IB experiment conditions, in which a positive face, a negative face, or a neutral item was unexpectedly presented, in the presence/absence of a bogus-speech threat. The overall pattern of our data suggests the presence of hypervigilant attentional processing in social anxiety. The IB paradigm appears to be a useful addition to existing experiment paradigms for investigating attentional bias in social anxiety and perhaps other psychopathology.

  17. The Physical and Cognitive Paradigms in Information Retrieval Research.

    Science.gov (United States)

    Ellis, David

    1992-01-01

    Explores the role of paradigms in information retrieval research and discusses the nature of a paradigm and the applicability of the paradigm concept to a multidisciplinary field such as information science. The features of the physical paradigm and the cognitive paradigm are outlined, and their origins, nature, and role are examined. (55…

  18. Recalling academic tasks

    Science.gov (United States)

    Draper, Franklin Gno

    This study was focused on what students remembered about five middle school science tasks when they were juniors and seniors in high school. Descriptions of the five tasks were reconstructed from available artifacts and teachers' records, notes and recollections. Three of the five tasks were "authentic" in the sense that students were asked to duplicate the decisions practitioners make in the adult world. The other two tasks were more typical school tasks involving note taking and preparation for a quiz. All five tasks, however, involved use of computers. Students were interviewed to examine what and how well they recalled the tasks and what forms or patterns of recall existed. Analysis of their responses indicated that different kinds of tasks produced different levels of recall. Authentically situated tasks were remembered much better than routine school tasks. Further, authentic tasks centered on design elements were recalled better than those for which design was not as pivotal. Patterns of recall indicated that participants most often recalled the decisions they made, the scenarios of the authentically situated tasks, the consequences of their tasks and the social contexts of the classroom. Task events, in other words, appeared to form a framework upon which students constructed stories of the tasks. The more salient the events, the richer the story, the deeper and more detailed the recall of the task. Thus, authentic tasks appeared to lend themselves to creating stories better than regular school tasks and therefore such tasks were recalled better. Implications of these patterns of recall are discussed with respect to issues of school learning and assessment.

  19. Magnetization reorientation induced by interfacial structures in ultrathin disordered FePt film sandwiched by SiO{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Guang; Zhang, Jing-Yan [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wang, Shou-Guo, E-mail: sgwang@iphy.ac.cn [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Jiang, Shao-Long; Zhao, Yun-Chi [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Ma, Qi-Di; Wang, Chao; Dong, Bo-Wen; Liu, Jia-Long; Zhang, Ying; Sun, Young [State Key Laboratory of Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Zheng-Long [Analytical and Testing Center, Beijing Normal University, Beijing 100875 (China); Yu, Guang-Hua, E-mail: ghyu@mater.ustb.edu.cn [Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-10-30

    In general, ultrathin disordered FePt film exhibits in-plane magnetic anisotropy due to large demagnetization fields and negligible volume anisotropy. Here, we demonstrated that magnetization reorientation from in-plane to out-of-plane takes place when ultrathin disordered FePt film is sandwiched by amorphous SiO{sub 2} layers and annealed at 350 °C. Based on the interfacial and structural analysis from X-ray photoelectron spectroscopy and high resolution transmission electron microscopy, the reorientation originates from the electronic structural changes because of strong bonding between Fe and O atoms at the top FePt/SiO{sub 2} interface. This interface anisotropy plays a crucial role in the magnetic behaviour, resulting in magnetization reorientation of ultrathin disordered FePt film.

  20. Electric field triggering the spin reorientation and controlling the absorption and release of heat in the induced multiferroic compound EuTiO3

    Science.gov (United States)

    von Ranke, P. J.; Gama, S.; Ribeiro, P. O.; Carvalho, A. Magnus G.; Alho, B. P.; Alvarenga, T. S. T.; Nobrega, E. P.; Caldas, A.; de Sousa, V. S. R.; Lopes, P. H. O.; de Oliveira, N. A.

    2015-12-01

    We report remarkable results due to the coupling between the magnetization and the electric field induced polarization in EuTiO3. Using a microscopic model Hamiltonian to describe the three coupled sublattices, Eu-(spin-up), Eu-(spin-down), and Ti-(moment), the spin flop and spin reorientation phase transitions were described with and without the electric-magnetic coupling interaction. The external electric field can be used to tune the temperature of the spin reorientation phase transition TSR = TSR(E). When the TSR is tuned around the EuTiO3—Néel temperature (TN = 5.5 K), an outstanding effect emerges in which EuTiO3 releases heat under magnetic field change. The electric field controlling the spin reorientation transition and the endo-exothermic processes are discussed through the microscopic interactions model parameters.

  1. Magnetic anisotropy and spin reorientation effects in Gd/Fe and Gd/(FeCo) multilayers for high density magneto-optical recording

    Science.gov (United States)

    Stavrou, E.; Sbiaa, R.; Suzuki, T.; Knappmann, S.; Röll, K.

    2000-05-01

    We have investigated the anisotropy behavior and temperature dependent changes of the magnetic anisotropy in Gd/Fe and Gd/(FeCo) multilayers. The spin reorientation effects are very important for the super resolution readout in new methods for high-density magneto-optical recording. Gd/(Fe, Co) multilayered films are a good alternative to the common Gd(Fe, Co) alloy films, because the magnetic anisotropy and also spin reorientation effects can be comfortably adjusted by varying the interface and volume anisotropy components and the composition using experimental parameters such as the periodicity λ=tGd+tTM [tGd,tTM: the sublayer thicknesses of the Gd and transition metal Fe, FeCo (TM)] and the ratio of the sublayer thicknesses tGd/tTM. We have found the mechanisms for spin reorientation, which are explained qualitatively with a new model.

  2. Passive Motion Paradigm: an alternative to Optimal Control

    Directory of Open Access Journals (Sweden)

    Vishwanathan eMohan

    2011-12-01

    Full Text Available In the last years, optimal control theory (OCT has emerged as the leading approach for investigating neural control of movement and motor cognition for two complementary research lines: behavioural neuroscience and humanoid robotics. In both cases, there are general problems that need to be addressed, such as the ‘degrees of freedom problem’, the common core of production, observation, reasoning, and learning of ‘actions’. OCT, directly derived from engineering design techniques of control systems quantifies task goals as ‘cost functions’ and uses the sophisticated formal tools of optimal control to obtain desired behaviour (and predictions. We propose an alternative ‘softer’ approach (PMP: Passive Motion Paradigm that we believe is closer to the biomechanics and cybernetics of action. The basic idea is that actions (overt and overt are the consequences of an internal simulation process that ‘animates’ the body schema with the attractor dynamics of force fields induced by the goal and task specific constraints. This internal simulation offers the brain a way to dynamically link motor redundancy with task oriented constraints ‘at runtime’, hence solving the ‘degrees of freedom problem’ without explicit kinematic inversion and cost function computation. We argue that the function of such computational machinery is not only to shape motor output during action execution but also to provide the self with information on the feasibility, consequence, understanding and meaning of ‘potential actions’. In this sense, taking into account recent developments in neuroscience (motor imagery, simulation theory, mirror neurons and in embodied robotics, PMP offers a novel framework for understanding motor cognition that goes beyond the engineering control paradigm provided by OCT. Therefore, the paper is at the same time a review of the PMP rationale, as a computational theory, and a perspective presentation of how to develop it

  3. Passive Motion Paradigm: An Alternative to Optimal Control

    Science.gov (United States)

    Mohan, Vishwanathan; Morasso, Pietro

    2011-01-01

    In the last years, optimal control theory (OCT) has emerged as the leading approach for investigating neural control of movement and motor cognition for two complementary research lines: behavioral neuroscience and humanoid robotics. In both cases, there are general problems that need to be addressed, such as the “degrees of freedom (DoFs) problem,” the common core of production, observation, reasoning, and learning of “actions.” OCT, directly derived from engineering design techniques of control systems quantifies task goals as “cost functions” and uses the sophisticated formal tools of optimal control to obtain desired behavior (and predictions). We propose an alternative “softer” approach passive motion paradigm (PMP) that we believe is closer to the biomechanics and cybernetics of action. The basic idea is that actions (overt as well as covert) are the consequences of an internal simulation process that “animates” the body schema with the attractor dynamics of force fields induced by the goal and task-specific constraints. This internal simulation offers the brain a way to dynamically link motor redundancy with task-oriented constraints “at runtime,” hence solving the “DoFs problem” without explicit kinematic inversion and cost function computation. We argue that the function of such computational machinery is not only restricted to shaping motor output during action execution but also to provide the self with information on the feasibility, consequence, understanding and meaning of “potential actions.” In this sense, taking into account recent developments in neuroscience (motor imagery, simulation theory of covert actions, mirror neuron system) and in embodied robotics, PMP offers a novel framework for understanding motor cognition that goes beyond the engineering control paradigm provided by OCT. Therefore, the paper is at the same time a review of the PMP rationale, as a computational theory, and a perspective presentation of

  4. Kokkos? Task DAG Capabilities.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Harold C.; Ibanez, Daniel Alejandro

    2017-09-01

    This report documents the ASC/ATDM Kokkos deliverable "Production Portable Dy- namic Task DAG Capability." This capability enables applications to create and execute a dynamic task DAG ; a collection of heterogeneous computational tasks with a directed acyclic graph (DAG) of "execute after" dependencies where tasks and their dependencies are dynamically created and destroyed as tasks execute. The Kokkos task scheduler executes the dynamic task DAG on the target execution resource; e.g. a multicore CPU, a manycore CPU such as Intel's Knights Landing (KNL), or an NVIDIA GPU. Several major technical challenges had to be addressed during development of Kokkos' Task DAG capability: (1) portability to a GPU with it's simplified hardware and micro- runtime, (2) thread-scalable memory allocation and deallocation from a bounded pool of memory, (3) thread-scalable scheduler for dynamic task DAG, (4) usability by applications.

  5. A handy new design paradigm

    Directory of Open Access Journals (Sweden)

    B. Bergelin

    2011-02-01

    Full Text Available In light of technological advances, researchers have lost sight of robotic grippers/end effectors design intent. In a semi-structured environment the biomimetic approach is impractical due to the high complexity of the mechanism and control algorithms. Current industrial grippers are robust, but lack the flexibility that allows for in hand manipulation. The authors believe that underactuated grippers provide the best approach to allow for in hand manipulation along with being rugged enough for an industrial setting. Thinking of the robotic gripper and the robotic arm as one system (as opposed to two separate subsystems, one is capable of using the degrees of freedom of the robot in conjunction with that of the gripper to provide the desired motion profile without the complexity of running two subsystems. This paper will outline where recent grippers have failed and will introduce a new design paradigm for grippers along with several underactuated gripper ideas.

    This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010, 19 August 2010, Montréal, Canada.

  6. Human Amebiasis: Breaking the Paradigm?

    Directory of Open Access Journals (Sweden)

    Oswaldo Partida

    2010-03-01

    Full Text Available For over 30 years it has been established that the Entamoeba histolytica protozoan included two biologically and genetically different species, one with a pathogenic phenotype called E. histolytica and the other with a non-pathogenic phenotype called Entamoeba dispar. Both of these amoebae species can infect humans. E. histolytica has been considered as a potential pathogen that can cause serious damage to the large intestine (colitis, dysentery and other extraintestinal organs, mainly the liver (amebic liver abscess, whereas E. dispar is a species that interacts with humans in a commensal relationship, causing no symptoms or any tissue damage. This paradigm, however, should be reconsidered or re-evaluated. In the present work, we report the detection and genotyping of E. dispar sequences of DNA obtained from patients with amebic liver abscesses, including the genotyping of an isolate obtained from a Brazilian patient with a clinical diagnosis of intestinal amebiasis that was previously characterized as an E. dispar species. The genetic diversity and phylogenetic analysis performed by our group has shown the existence of several different genotypes of E. dispar that can be associated to, or be potentiality responsible for intestinal or liver tissue damage, similar to that observed with E. histolytica.

  7. Human Amebiasis: Breaking the Paradigm?

    Science.gov (United States)

    Ximénez, Cecilia; Cerritos, Rene; Rojas, Liliana; Dolabella, Silvio; Morán, Patricia; Shibayama, Mineko; González, Enrique; Valadez, Alicia; Hernández, Eric; Valenzuela, Olivia; Limón, Angélica; Partida, Oswaldo; Silva, Edwards F

    2010-01-01

    For over 30 years it has been established that the Entamoeba histolytica protozoan included two biologically and genetically different species, one with a pathogenic phenotype called E. histolytica and the other with a non-pathogenic phenotype called Entamoeba dispar. Both of these amoebae species can infect humans. E. histolytica has been considered as a potential pathogen that can cause serious damage to the large intestine (colitis, dysentery) and other extraintestinal organs, mainly the liver (amebic liver abscess), whereas E. dispar is a species that interacts with humans in a commensal relationship, causing no symptoms or any tissue damage. This paradigm, however, should be reconsidered or re-evaluated. In the present work, we report the detection and genotyping of E. dispar sequences of DNA obtained from patients with amebic liver abscesses, including the genotyping of an isolate obtained from a Brazilian patient with a clinical diagnosis of intestinal amebiasis that was previously characterized as an E. dispar species. The genetic diversity and phylogenetic analysis performed by our group has shown the existence of several different genotypes of E. dispar that can be associated to, or be potentiality responsible for intestinal or liver tissue damage, similar to that observed with E. histolytica. PMID:20617021

  8. MDMA and the "ecstasy paradigm".

    Science.gov (United States)

    Cole, Jon C

    2014-01-01

    For nearly 30 years, there has been a steady flow of research papers highlighting the dangers of MDMA and the implications for ecstasy users. After such a long time, it would be reasonable to expect that these dangers would be obvious due to the large number of ecstasy users. The available evidence does not indicate that there are millions of ecstasy users experiencing any problems linked to their ecstasy use. The "precautionary principle" suggests that, in the absence of knowing for certain, "experts" should argue that MDMA be avoided. However, this may have been taken too far, as the dire warnings do not seem to be reducing with the lack of epidemiological evidence of clinically relevant problems. The "ecstasy paradigm" is one way of articulating this situation, in that the needs of research funders and publication bias lead to a specific set of subcultural norms around what information is acceptable in the public domain. By digging a little deeper, it is easy to find problems with the evidence base that informs the public debate around MDMA. The key question is whether it is acceptable to maintain this status quo given the therapeutic potential of MDMA.

  9. Metacognition: A new cognitive paradigm

    Directory of Open Access Journals (Sweden)

    Kankaraš Miloš

    2004-01-01

    Full Text Available This article reviews concept of metacognition, defined as: (a knowledge about ones own cognitive activity, (b strategies to monitor and regulate cognitive activity and behavior, and (c subjective or metacognitive experiences which comes from some changes or temporary difficulties in cognitive functioning. While describing different conceptualizations of metacognition, its development, fields of application, relation with intelligence, and its constrictions and ambiguity, we attempt to present new and emerging metacognitive paradigm, which is, for a relatively short period, succeeded to improve, expand, and redefine wide range of theoretical and practical fields in psychology, on new and original way. How do we become conscious of our own cognitive processes? What role and significance that consciousness has, what is the functional level above thinking processes and how that level, which monitor and control cognitive activity, works. Metacognition is concept that presents, as so far, the most important insight in those human mind areas, which, although very important, remained on the margin of psychological investigations until now.

  10. New Indivisible Planetary Science Paradigm

    CERN Document Server

    Herndon, J Marvin

    2013-01-01

    I present here a new, indivisible planetary science paradigm, a wholly self-consistent vision of the nature of matter in the Solar System, and dynamics and energy sources of planets. Massive-core planets formed by condensing and raining-out from within giant gaseous protoplanets at high pressures and high temperatures. Earth's complete condensation included a 300 Earth-mass gigantic gas/ice shell that compressed the rocky kernel to about 66% of Earth's present diameter. T-Tauri eruptions stripped the gases away from the inner planets and stripped a portion of Mercury's incompletely condensed protoplanet, and transported it to the region between Mars and Jupiter where it fused with in-falling oxidized condensate from the outer regions of the Solar System and formed the parent matter of ordinary chondrite meteorites, the main-Belt asteroids, and veneer for the inner planets, especially Mars. In response to decompression-driven planetary volume increases, cracks form to increase surface area and mountain ranges ...

  11. Life behind cell walls: paradigm lost, paradigm regained.

    Science.gov (United States)

    Lamport, D T

    2001-09-01

    This review of the living cell wall and its protein components is in two parts. The first is anecdotal. A personal account spanning over 40 years research may perhaps be an antidote to one stereotypical view of scientists as detached and humorless. The second part deals with the meaning of function, particularly as it applies to hydroxyproline-rich glycoproteins. Function is a difficult word to define objectively. However, with help from such luminaries as Humpty Dumpty: "A word means what I want it to mean, neither more nor less," and Wittgenstein: "Giving examples of usage ... is the only way to talk about meaning," it is possible to construct a ziggurat representing increasingly complex levels of organization from molecular structure to ecology. Forty years ago I suggested that hydroxyproline-rich structural proteins played a key role in cell wall functioning. But because the bulk of the wall is carbohydrate, there has been an understandable resistance to paradigm change. Expansins, paradoxically, contribute greatly to this resistance because their modus operandi as cell-wall-loosening proteins is based on the idea that they break hydrogen bonds between polysaccharide chains allowing slippage. However, this view is not consistent with the recent discovery [Grobe et al. (1999) Eur. J. Biochem 263: 33-40] that beta-expansins may be proteases, as it implies that the extensin network is not a straightjacket but a substrate for expansin in muro. Such a direct role for extensins in both negative and positive regulation of cell expansion and elongation may constitute a major morphogenetic mechanism operating at all levels of plant growth and development.

  12. Pre-stimulus EEG effects related to response speed, task switching and upcoming response hand

    NARCIS (Netherlands)

    Gladwin, T.E.; Lindsen, J.P.; Jong, R. de

    2006-01-01

    The task-switching paradigm provides an opportunity to study whether oscillatory relations in neuronal activity are involved in switching between and maintaining task sets. The EEG of subjects performing an alternating runs [Rogers, R.D., Monsell, S., 1995. Costs of a predictable switch between simp

  13. The dynamics of development on the Dimensional Change Card Sorting task

    NARCIS (Netherlands)

    van Bers, B.M.C.W.; Visser, I.; van Schijndel, T.J.P.; Mandell, D.J.; Raijmakers, M.E.J.

    2011-01-01

    A widely used paradigm to study cognitive flexibility in preschoolers is the Dimensional Change Card Sorting (DCCS) task. The developmental dynamics of DCCS performance was studied in a cross-sectional design (N = 93, 3 to 5 years of age) using a computerized version of the standard DCCS task. A

  14. Revisiting the age-prospective memory-paradox: the role of planning and task experience

    NARCIS (Netherlands)

    Hering, A.; Cortez, S.A.; Kliegel, M.; Altgassen, A.M.

    2014-01-01

    The present study aimed at investigating age-related differences in prospective memory performance using a paradigm with high ecological validity and experimental control. Thirty old and 30 young adults completed the Dresden Breakfast task; a meal preparation task in the lab that comprises several s

  15. The Effects of Delay of Feedback on a Delayed Concept Formation Transfer Task.

    Science.gov (United States)

    Schroth, Marvin L.

    1992-01-01

    Delay and completeness of verbal information feedback were investigated within a transfer of learning paradigm involving concept formation. An experiment with 192 undergraduates indicates that, although delay of feedback (up to 30 seconds) slows speed of learning on the initial task, it has positive effects on the transfer task. (SLD)

  16. The dynamics of development on the Dimensional Change Card Sorting task

    NARCIS (Netherlands)

    van Bers, B.M.C.W.; Visser, I.; van Schijndel, T.J.P.; Mandell, D.J.; Raijmakers, M.E.J.

    2011-01-01

    A widely used paradigm to study cognitive flexibility in preschoolers is the Dimensional Change Card Sorting (DCCS) task. The developmental dynamics of DCCS performance was studied in a cross-sectional design (N = 93, 3 to 5 years of age) using a computerized version of the standard DCCS task. A mod

  17. Ostracism Online: A social media ostracism paradigm.

    Science.gov (United States)

    Wolf, Wouter; Levordashka, Ana; Ruff, Johanna R; Kraaijeveld, Steven; Lueckmann, Jan-Matthis; Williams, Kipling D

    2015-06-01

    We describe Ostracism Online, a novel, social media-based ostracism paradigm designed to (1) keep social interaction experimentally controlled, (2) provide researchers with the flexibility to manipulate the properties of the social situation to fit their research purposes, (3) be suitable for online data collection, (4) be convenient for studying subsequent within-group behavior, and (5) be ecologically valid. After collecting data online, we compared the Ostracism Online paradigm with the Cyberball paradigm (Williams & Jarvis Behavior Research Methods, 38, 174-180, 2006) on need-threat and mood questionnaire scores (van Beest & Williams Journal of Personality and Social Psychology 91, 918-928, 2006). We also examined whether ostracized targets of either paradigm would be more likely to conform to their group members than if they had been included. Using a Bayesian analysis of variance to examine the individual effects of the different paradigms and to compare these effects across paradigms, we found analogous effects on need-threat and mood. Perhaps because we examined conformity to the ostracizers (rather than neutral sources), neither paradigm showed effects of ostracism on conformity. We conclude that Ostracism Online is a cost-effective, easy to use, and ecologically valid research tool for studying the psychological and behavioral effects of ostracism.

  18. Exogenous orienting of attention in hearing: a virtual reality paradigm to assess auditory attention in neglect patients.

    Science.gov (United States)

    Guilbert, Alma; Clément, Sylvain; Martin, Yves; Feuillet, Alexia; Moroni, Christine

    2016-10-01

    While mechanisms of orienting attention in unilateral spatial neglect (USN) have frequently been studied in the visual domain, these mechanisms remain relatively unexplored in the auditory domain. Our first goal was to replicate Spence and Driver's (J Exp Psychol Hum 22:1005-1030, 1994) results with a virtual reality paradigm. This paradigm simulated a 3-dimensional auditory space with headphones. Our second aim was to study auditory profiles of orienting attention in USN. In a first experiment, 18 healthy participants performed an auditory cueing spatial paradigm (either a target-detection task or a target-lateralization task). In a second experiment, 14 right-stroke patients (10 with USN and 4 without USN) performed these two same tasks. As in Spence and Driver's (J Exp Psychol Hum 22:1005-1030, 1994), our first experiment showed that spatial representations are not utilized for the detection of auditory stimuli. However, during the lateralization task, participants were quicker to detect targets preceded by a spatially congruent cue, which suggests that our paradigm could be suitable for studying orienting attention in hearing. Our second experiment found that patients with USN also needed an explicit spatial task to be sensitive to auditory spatial cueing. In the target-lateralization task, they showed effects lateralized only to one side of space, whereas patients without USN did not. Although our paradigm needs replications to better understand orienting attention impairments in hearing in USN, this study could have implications for the development of clinical tasks that could assess auditory spatial attention in USN syndrome.

  19. Ozone depletion, paradigms, and politics

    Energy Technology Data Exchange (ETDEWEB)

    Iman, R.L.

    1993-10-01

    The destruction of the Earth`s protective ozone layer is a prime environmental concern. Industry has responded to this environmental problem by: implementing conservation techniques to reduce the emission of ozone-depleting chemicals (ODCs); using alternative cleaning solvents that have lower ozone depletion potentials (ODPs); developing new, non-ozone-depleting solvents, such as terpenes; and developing low-residue soldering processes. This paper presents an overview of a joint testing program at Sandia and Motorola to evaluate a low-residue (no-clean) soldering process for printed wiring boards (PWBs). Such processes are in widespread use in commercial applications because they eliminate the cleaning operation. The goal of this testing program was to develop a data base that could be used to support changes in the mil-specs. In addition, a joint task force involving industry and the military has been formed to conduct a follow-up evaluation of low-residue processes that encompass the concerns of the tri-services. The goal of the task force is to gain final approval of the low-residue technology for use in military applications.

  20. Fuzzy Hybrid Deliberative/Reactive Paradigm (FHDRP)

    Science.gov (United States)

    Sarmadi, Hengameth

    2004-01-01

    This work aims to introduce a new concept for incorporating fuzzy sets in hybrid deliberative/reactive paradigm. After a brief review on basic issues of hybrid paradigm the definition of agent-based fuzzy hybrid paradigm, which enables the agents to proceed and extract their behavior through quantitative numerical and qualitative knowledge and to impose their decision making procedure via fuzzy rule bank, is discussed. Next an example performs a more applied platform for the developed approach and finally an overview of the corresponding agents architecture enhances agents logical framework.

  1. PARADIGM OF EDUCATION FOR THE INFORMATION SOCIETY

    Directory of Open Access Journals (Sweden)

    Yuriy M. Bogachkov

    2015-10-01

    Full Text Available Considering total crisis in education in Informational Age, we suggest that to overcome the crisis, it is necessary to promote pedagogical science up from "pre-paradigm stage” to the "paradigm stage". For this purpose it is necessary to separate the "educational science" from "education." “Educational paradigm” in such study will be the subject of the science. The key concepts for the "pedagogical paradigm" should be the concepts of "educational practice", "class of problems" and "educational text". We offer some axioms around these concepts.

  2. Pair Negotiation When Developing English Speaking Tasks

    Directory of Open Access Journals (Sweden)

    Ingrid Liliana Bohórquez Suárez

    2011-12-01

    Full Text Available This study analyzes what characterizes the negotiations of seventh graders at a public school in Bogotá when working in pairs to develop speaking tasks in EFL classes. The inquiry is a descriptive case study that follows the qualitative paradigm. As a result of analyzing the data, we obtained four consecutive steps that characterize students’ negotiations: Establishing a connection with a partner to work with, proposing practical alternatives, refusing mates’ propositions, and making practical decisions. Moreover, we found that the constant performance of the process of negotiation provokes students to construct a sociolinguistic identity that allows agreements to emerge.

  3. Contemporary Treatment Paradigms in Keratoconus.

    Science.gov (United States)

    McGhee, Charles N J; Kim, Bia Z; Wilson, Peter J

    2015-10-01

    The past 20 years have witnessed an explosion in our knowledge of keratoconus, accompanied by a radical transformation of management options. A 2-hit hypothesis proposes an underlying genetic predisposition coupled with external environmental factors, including eye rubbing and atopy. The variable prevalence and natural history have been better defined including significant cone progression in middle age. Therefore, current management must include early diagnosis, regular monitoring, and treatment of environmental cofactors. Spectacles and contact lenses remain fundamental to the optical management of keratoconus. Intrastromal corneal ring segments have been increasingly used, providing improvement in the corneal shape, corrected visual acuity, and contact lens wear. However, like contact lenses, intrastromal corneal ring segments do not treat the underlying disease process. Therefore, current approaches must also consider treatments to minimize keratoconus progression. Fortunately, there is increasing evidence that corneal collagen crosslinking will halt or slow progression in most cases. Until relatively recently, penetrating keratoplasty was the preferred intervention for advanced keratoconus, with long-term success in the region of 90%; however, the greatest risk of failure remains endothelial allograft rejection. Deep anterior lamellar keratoplasty has emerged in the new millennium as a preferred approach to conserve the host endothelium and avoid rejection. Nonetheless, the overall superiority of deep anterior lamellar keratoplasty compared with penetrating keratoplasty, in terms of optical and survival benefits, is still debated. This perspective provides an overview of our current knowledge of keratoconus and current management options. A step-ladder approach to managing keratoconus is outlined to provide the practitioner with a contemporary management paradigm.

  4. Unintentional activation of translation equivalents in bilinguals leads to attention capture in a cross-modal visual task

    National Research Council Canada - National Science Library

    Singh, Niharika; Mishra, Ramesh Kumar

    2015-01-01

    Using a variant of the visual world eye tracking paradigm, we examined if language non-selective activation of translation equivalents leads to attention capture and distraction in a visual task in bilinguals...

  5. Unintentional Activation of Translation Equivalents in Bilinguals Leads to Attention Capture in a Cross-Modal Visual Task: e0120131

    National Research Council Canada - National Science Library

    Niharika Singh; Ramesh Kumar Mishra

    2015-01-01

      Using a variant of the visual world eye tracking paradigm, we examined if language non- selective activation of translation equivalents leads to attention capture and distraction in a visual task in bilinguals...

  6. Project Tasks in Robotics

    DEFF Research Database (Denmark)

    Sørensen, Torben; Hansen, Poul Erik

    1998-01-01

    Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics......Description of the compulsary project tasks to be carried out as a part of DTU course 72238 Robotics...

  7. Launching Complex Tasks

    Science.gov (United States)

    Jackson, Kara J.; Shahan, Emily C.; Gibbons, Lynsey K.; Cobb, Paul A.

    2012-01-01

    Mathematics lessons can take a variety of formats. In this article, the authors discuss lessons organized around complex mathematical tasks. These lessons usually unfold in three phases. First, the task is introduced to students. Second, students work on solving the task. Third, the teacher "orchestrates" a concluding whole-class discussion in…

  8. Task assignment and coaching

    NARCIS (Netherlands)

    Dominguez-Martinez, S.

    2009-01-01

    An important task of a manager is to motivate her subordinates. One way in which a manager can give incentives to junior employees is through the assignment of tasks. How a manager allocates tasks in an organization, provides information to the junior employees about his ability. Without coaching fr

  9. The safety implications of emerging software paradigms

    Energy Technology Data Exchange (ETDEWEB)

    Suski, G.J.; Persons, W.L.; Johnson, G.L.

    1994-10-01

    This paper addresses some of the emerging software paradigms that may be used in developing safety-critical software applications. Paradigms considered in this paper include knowledge-based systems, neural networks, genetic algorithms, and fuzzy systems. It presents one view of the software verification and validation activities that should be associated with each paradigm. The paper begins with a discussion of the historical evolution of software verification and validation. Next, a comparison is made between the verification and validation processes used for conventional and emerging software systems. Several verification and validation issues for the emerging paradigms are discussed and some specific research topics are identified. This work is relevant for monitoring and control at nuclear power plants.

  10. a postfoundationalist research paradigm of practical theology

    African Journals Online (AJOL)

    2010-07-18

    Jul 18, 2010 ... part of the research paradigm of postfoundational practical theology. ... appealing to some item of knowledge that is self-evident or indubitable' (Van Huyssteen .... individual or subjective construction, and emphasises the.

  11. Levelling in the German Verb Paradigm

    Science.gov (United States)

    Newman, John

    1974-01-01

    Levelling processes in the history of the German verb paradigm from Old High German to the present are discussed. It is asserted that the theory of transformational generative grammar provides a proper framework for the study of linguistic change. (RM)

  12. Levelling in the German Verb Paradigm

    Science.gov (United States)

    Newman, John

    1974-01-01

    Levelling processes in the history of the German verb paradigm from Old High German to the present are discussed. It is asserted that the theory of transformational generative grammar provides a proper framework for the study of linguistic change. (RM)

  13. Major Development Communication Paradigms and Practices ...

    African Journals Online (AJOL)

    info

    major paradigms of development and communication practices on graphic communication. ... media to the success of development initiatives. ...... in relation with sex. Also ..... Development communication in India: Prospect, issues and trends.

  14. The Emerging Paradigm in Black Studies.

    Science.gov (United States)

    Kershaw, Terry

    1989-01-01

    Argues that traditional sociology has treated Black studies as peripheral to the study of human behavior. Proposes a paradigm that includes an emphasis on Afrocentric perspective and a methodology that combines positivist and critical methodologies. (FMW)

  15. Yakov Zeldovich and the Cosmic Web Paradigm

    CERN Document Server

    Einasto, Jaan

    2014-01-01

    I discuss the formation of the modern cosmological paradigm. In more detail I describe the early study of dark matter and cosmic web and the role of Yakov Zeldovich in the formation of the present concepts on these subjects.

  16. Yakov Zeldovich and the Cosmic Web Paradigm

    Science.gov (United States)

    Einasto, Jaan

    2016-10-01

    I discuss the formation of the modern cosmological paradigm. In more detail I describe the early study of dark matter and cosmic web and the role of Yakov Zeldovich in the formation of the present concepts on these subjects.

  17. Engineering paradigms and anthropogenic global change

    Science.gov (United States)

    Bohle, Martin

    2016-04-01

    This essay discusses 'paradigms' as means to conceive anthropogenic global change. Humankind alters earth-systems because of the number of people, the patterns of consumption of resources, and the alterations of environments. This process of anthropogenic global change is a composite consisting of societal (in the 'noosphere') and natural (in the 'bio-geosphere') features. Engineering intercedes these features; e.g. observing stratospheric ozone depletion has led to understanding it as a collateral artefact of a particular set of engineering choices. Beyond any specific use-case, engineering works have a common function; e.g. civil-engineering intersects economic activity and geosphere. People conceive their actions in the noosphere including giving purpose to their engineering. The 'noosphere' is the ensemble of social, cultural or political concepts ('shared subjective mental insights') of people. Among people's concepts are the paradigms how to shape environments, production systems and consumption patterns given their societal preferences. In that context, engineering is a means to implement a given development path. Four paradigms currently are distinguishable how to make anthropogenic global change happening. Among the 'engineering paradigms' for anthropogenic global change, 'adaptation' is a paradigm for a business-as-usual scenario and steady development paths of societies. Applying this paradigm implies to forecast the change to come, to appropriately design engineering works, and to maintain as far as possible the current production and consumption patterns. An alternative would be to adjust incrementally development paths of societies, namely to 'dovetail' anthropogenic and natural fluxes of matter and energy. To apply that paradigm research has to identify 'natural boundaries', how to modify production and consumption patterns, and how to tackle process in the noosphere to render alterations of common development paths acceptable. A further alternative

  18. Ferroelectricity and magnetoelectric coupling in h-YbMnO{sub 3}: Spin reorientation and defect effect

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Gang; Fang, Yifei; Lu, Xiaowen; Cao, Shixun; Zhang, Jincang, E-mail: jczhang@shu.edu.cn [Materials Genome Institute and Department of Physics, Shanghai University, Shanghai 200444 (China)

    2016-01-11

    Low-temperature magnetic and electric properties in hexagonal multiferroic compound YbMnO{sub 3} were studied. The Mn{sup 3+} spin moments order at T{sub N} = 85 K and reoriented around 43.5 K, leading to the magnetic phase transition from B{sub 2}(P6{sub 3}cm) → A{sub 2}(P6{sub 3}cm). The concomitant ferroelectric polarization is observed and explained microscopically by the destruction of initial symmetric relationship of the polarization between the upper and lower half of the magnetic unit cell. The asymmetry of the polarization vs temperature curves under opposite poling voltage revealed the pinning effect of the defects on the electrical polarization.

  19. Element-resolved magnetism across the temperature- and pressure-induced spin reorientation in MnBi

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yongseong; Jiang, Xiujuan; Bi, Wenli; Lapa, Pavel; Chouhan, Rajiv K.; Paudyal, D.; Varga, Tamas; Popov, Dmitry; Cui, Jun; Haskel, Daniel; Jiang, J. S.

    2016-11-01

    Rare-earth free permanent magnet MnBi (NiAs-type crystal structure) displays strong magnetic anisotropy above its 90 K spin reorientation transition (SRT). X-ray magnetic circular dichroism (XMCD) shows induced magnetism in Bi 5d band, which is strongly coupled to the magnetism of Mn. A clear increase in Bi orbital-to-spin moment ratio is observed above the SRT. Hydrostatic pressure mimics the e*ect of temperature on the SRT, and the pressure effect also leads to anisotropic lattice contraction, which is known to be induced by cooling. These results reveal that temperature and pressure can similarly induce the coupled structural and magnetic responses, suggesting the importance of the anisotropic lattice change and Mn-Bi hybridization to the magnetic anisotropy change across the SRT.

  20. Stripe-to-bubble transition of magnetic domains at the spin reorientation of (Fe/Ni)/Cu/Ni/Cu(001)

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.; Choi, J.; Won, C.; Wu, Y. Z.; Scholl, A.; Doran, A.; Hwang, Chanyong; Qiu, Z.

    2010-06-09

    Magnetic domain evolution at the spin reorientation transition (SRT) of (Fe/Ni)/Cu/Ni/Cu(001) is investigated using photoemission electron microscopy. While the (Fe/Ni) layer exhibits the SRT, the interlayer coupling of the perpendicularly magnetized Ni layer to the (Fe/Ni) layer serves as a virtual perpendicular magnetic field exerted on the (Fe/Ni) layer. We find that the perpendicular virtual magnetic field breaks the up-down symmetry of the (Fe/Ni) stripe domains to induce a net magnetization in the normal direction of the film. Moreover, as the virtual magnetic field increases to exceed a critical field, the stripe domain phase evolves into a bubble domain phase. Although the critical field depends on the Fe film thickness, we show that the area fraction of the minority domain exhibits a universal value that determines the stripe-to-bubble phase transition.

  1. [Hallux valgus and hypermobility of the first ray--causal treatment using tarso-metatarsal reorientation arthrodesis].

    Science.gov (United States)

    Klaue, K

    1991-12-01

    Today, bunion surgery is still very controversial. Considering that a bunion deformity is actually a result of multiple possible causes, the rationale of the currently applied techniques has not been conclusively demonstrated. Multiple techniques are still applied with uncertain outcome, as shown by the not insignificant recurrence rate. The tarsometatarsal reorientation arthrodesis addresses the deficient anteromedial buttress which is due to the most often concomittent hypermobile first ray. This is an important aspect of treating hallux valgus deformity and includes the sagittal alignment besides the horizontal reposition of the metatarsal over the sesamoid complex. Since in hallux valgus, the first metatarsal looses its position also by the insufficiency of the intrinsic musculature and the ligamento-capsular structures, the arthrodesis regulates the elasticity of the multiarticular first ray within the sagittal plane. Recurrences are less likely after this operation, even when performed on the adolescent hallux which is known as very difficult to be treated successfully.

  2. Probing temperature-driven spin reorientation transition of GdFeCo film by Kerr loops and ferromagnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    He, Wei, E-mail: hewei@aphy.iphy.ac.cn; Liu, Hao-Liang; Cai, Jian-Wang; Cheng, Zhao-Hua, E-mail: zhcheng@aphy.iphy.ac.cn [State Key Laboratory of Magnetism and Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Hong-Ye [Department of Physics, Baotou Teachers College, Baotou 014030 (China)

    2015-01-26

    The magnetic anisotropy is of both scientific and technological interest for magneto-optical material GdFeCo film. We characterize the magnetic anisotropy of a 20 nm GdFeCo film from 265 K to 320 K via Kerr loops and ferromagnetic resonance. With increasing temperature, both of the first-order uniaxial magnetic anisotropy and shape anisotropy increase. However, the competition between them causes a temperature-driven spin reorientation transition (SRT) and the effective perpendicular magnetic anisotropy decrease from 2.22 × 10{sup 4 }ergs/cm{sup 3} (288 K) to −1.56 × 10{sup 4 }ergs/cm{sup 3} (317 K). The positive second-order uniaxial magnetic anisotropy determines an easy-cone state as the mediated state during SRT.

  3. Microscopic analysis of the composition driven spin-reorientation transition in Ni(x)Pd(1-x)/Cu(001).

    Science.gov (United States)

    Gottlob, Daniel M; Doğanay, Hatice; Nickel, Florian; Cramm, Stefan; Krug, Ingo P; Nemšák, Slavomír; Schneider, Claus M

    2015-12-01

    The spin-reorientation transition (SRT) in epitaxial NixPd1-x/Cu(001) is studied by photoemission microscopy utilizing the X-ray magnetic circular dichroism effect at the Ni L2,3 edge. In a composition/thickness wedged geometry, a composition driven SRT could be observed between 37 ML and 60 ML, and 0 and 38% of Pd. Microspectroscopy in combination with azimuthal sample rotation confirms a magnetization preference changing from the [001] to an in-plane easy axis. At this increased thickness, the domain patterns arrange comparable to SRTs in ultrathin films. The images document domains equivalent to a canted state SRT, at which an additional effect of in-plane anisotropies could be identified.

  4. Changing paradigms in the diagnosis of urolithiasis.

    Science.gov (United States)

    Lulich, Jody P; Osborne, Carl A

    2009-01-01

    A paradigm shift is a fundamental change from a traditional model of thinking. This article presents four paradigm shifts in the diagnoses of urolithiasis, based on the experiences of the authors in the treatment of uroliths in dogs and cats. Case examples are provided to illustrate points regarding urine storage, ultrasonography, use of radiography to assure complete removal of uroliths, and the frequency of upper tract uroliths in cats.

  5. International business and the eclectic paradigm

    DEFF Research Database (Denmark)

    The eclectic paradigm has become the dominant theoretical basis in the study of international business, multinational corporations and internationalization since 1980. However, developments such as economic globalization and the subsequent growth of global and alliance capitalism have fundamentally......, finance, evolutionary economics, resource-based theory or strategic management? Can it be utilized to explain new developments in international business and economics? Do these require new ideas and concepts to be integrated within the eclectic paradigm? What are the new challenges to which international...

  6. New Indivisible Planetary Science Paradigm: Consequence of Questioning Popular Paradigms

    Science.gov (United States)

    Marvin Herndon, J.

    2014-05-01

    Progress in science involves replacing less precise understanding with more precise understanding. In science and in science education one should always question popular ideas; ask "What's wrong with this picture?" Finding limitations, conflicts or circumstances that require special ad hoc consideration sometimes is the key to making important discoveries. For example, from thermodynamic considerations, I found that the 'standard model of solar system formation' leads to insufficiently massive planetary cores. That understanding led me to discover a new indivisible planetary science paradigm. Massive-core planets formed by condensing and raining-out from within giant gaseous protoplanets at high pressures and high temperatures, accumulating heterogeneously on the basis of volatility with liquid core-formation preceding mantle-formation; the interior states of oxidation resemble that of the Abee enstatite chondrite. Core-composition was established during condensation based upon the relative solubilities of elements, including uranium, in liquid iron in equilibrium with an atmosphere of solar composition at high pressures and high temperatures. Uranium settled to the central region and formed planetary nuclear fission reactors, producing heat and planetary magnetic fields. Earth's complete condensation included a ~300 Earth-mass gigantic gas/ice shell that compressed the rocky kernel to about 66% of Earth's present diameter. T-Tauri eruptions, associated with the thermonuclear ignition of the Sun, stripped the gases away from the Earth and the inner planets. The T-Tauri outbursts stripped a portion of Mercury's incompletely condensed protoplanet and transported it to the region between Mars and Jupiter where it fused with in-falling oxidized condensate from the outer regions of the Solar System, forming the parent matter of ordinary chondrite meteorites, the main-Belt asteroids, and veneer for the inner planets, especially Mars. With its massive gas/ice shell

  7. The Underlying Social Dynamics of Paradigm Shifts.

    Directory of Open Access Journals (Sweden)

    Carlos Rodriguez-Sickert

    Full Text Available We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm; and ii radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm.

  8. Non-programmed versus programmed aging paradigm.

    Science.gov (United States)

    Libertini, Giacinto

    2015-01-01

    There are two opposite paradigms to explain aging, here precisely defined as "age-related progressive mortality increase, i.e. fitness decline, in the wild". The first maintains that natural selection is unable to maintain fitness as age increases. The second asserts that, in particular ecological conditions, natural selection favors specific mechanisms for limiting the lifespan. The predictions derived from the two paradigms are quite different and often opposing. A series of empirical data and certain theoretical considerations (non-universality of aging; great inter-specific variation of aging rates; effects of caloric restriction on lifespan; damage of aging for the senescing individual but its advantage in terms of supra-individual selection; existence of fitness decline in the wild; proportion of deaths due to intrinsic mortality inversely related to extrinsic mortality, when various species are compared; impossibility of explaining the age-related fitness decline as a consequence of genes that are harmful at a certain age; age-related progressive decline of cell turnover capacities; on/off cell senescence; gradual cell senescence) are compared with the predictions of the two paradigms and their compatibility with each paradigm is considered. The result is that the abovementioned empirical data and theoretical considerations strongly contradict and falsify in many ways all theories belonging to the first paradigm. On the contrary, they are consistent or compatible with the predictions of the second paradigm.

  9. Project management: a new service delivery paradigm

    Directory of Open Access Journals (Sweden)

    G. van der Walt

    2007-07-01

    Full Text Available In line with international trends in governance, the South African Government’s initial focus on the development of policy frameworks, structures and systems in order to give effect to the values and principles of the Constitution, shifted to the most critical issue, namely service delivery. The Government became increasingly aware that a significant expansion in the scope and quality of service provision was not possible with traditional delivery settings and approaches. There is growing evidence that there is a need for a significant departure from conventional approaches and that a leap into a new service delivery paradigm is necessary. Increasingly this new paradigm highlights the need to further develop the government’s project management skills and applications with a view to achieving improved delivery capability. In this article the focus will be placed on the changing service delivery paradigm – from an “old” traditional model through the transition to a “new” paradigm. This paradigm is shaped by international and national trends and events in government. The contribution and advantages of project management applications for effective governance are highlighted and the article concludes with an explanation of project management organisational arrangements necessary to support the new paradigm.

  10. The Underlying Social Dynamics of Paradigm Shifts

    Science.gov (United States)

    Claro, Francisco; Fuentes, Miguel Angel

    2015-01-01

    We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution) within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i) marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm); and ii) radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology) that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm. PMID:26418255

  11. The Underlying Social Dynamics of Paradigm Shifts.

    Science.gov (United States)

    Rodriguez-Sickert, Carlos; Cosmelli, Diego; Claro, Francisco; Fuentes, Miguel Angel

    2015-01-01

    We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution) within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i) marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm); and ii) radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology) that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm.

  12. Eye dominance influences triggering action: the Poffenberger paradigm revisited.

    Science.gov (United States)

    Chaumillon, Romain; Blouin, Jean; Guillaume, Alain

    2014-09-01

    Our dominant eye (DE) is the one we unconsciously choose when performing a monocular task. Although it has been recognized for centuries, eye dominance and its behavioral consequences remain poorly understood. Here we used the simple and well-known Poffenberger paradigm (1912) in which participants press a button with the right or left index finger, in reaction to the appearance of a lateralized visual stimulus. By selecting participants according to their DE and handedness, we were able to decipher the impact of eye dominance on visuomotor transformation speed. We show, for the first time, that in right-handers simple reaction times (RT) in response to a lateralized visual target are shorter when it appears in the contralateral visual hemifield with respect to the DE. In left-handers, only those with a right DE exhibit a shorter RT with the left hand and they show no hemifield difference. Additionally, the Poffenberger paradigm has been used to estimate the interhemispheric transfer time (IHTT) in both directions, from the right to the left hemisphere or the reverse, by comparing hand RTs following stimulation of each visual hemifield. The present study demonstrates that this paradigm leads to biased estimations of these directionally considered IHTT and provides an explanation to the often reported IHTT negative values that otherwise appear implausible. These new findings highlight the need to consider eye dominance in studies investigating the neural processes underlying visually-guided actions. More generally, they demonstrate a substantial impact of eye dominance on the neural mechanisms involved in converting visual inputs into motor commands. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Flexibility in task switching by monolinguals and bilinguals*

    Science.gov (United States)

    WISEHEART, MELODY; VISWANATHAN, MYTHILI; BIALYSTOK, ELLEN

    2015-01-01

    Many bilinguals routinely switch between their languages, yet mixed evidence exists about the transfer of language switching skills to broader domains that require attentional control such as task switching. Monolingual and bilingual young adults performed a nonverbal task-switching paradigm in which they viewed colored pictures of animals and indicated either the animal or its color in response to a cue. Monolinguals and bilinguals performed similarly when switching between tasks (local switch cost) in a mixed-task block, but bilinguals demonstrated a smaller mixing effect (global switch cost) than monolinguals, indicating better ability to reconfigure stimulus–response associations. These results suggest that regular practice using multiple languages confers a broader executive function advantage shown as improved flexibility in task switching. PMID:26877705

  14. Budget-Optimal Task Allocation for Reliable Crowdsourcing Systems

    CERN Document Server

    Karger, David R; Shah, Devavrat

    2011-01-01

    Crowdsourcing systems, in which numerous tasks are electronically distributed to numerous "information piece-workers", have emerged as an effective paradigm for human-powered solving of large scale problems in domains such as image classification, data entry, optical character recognition, recommendation, and proofreading. Because these low-paid workers can be unreliable, nearly all crowdsourcers must devise schemes to increase confidence in their answers, typically by assigning each task multiple times and combining the answers in some way such as majority voting. In this paper, we consider a general model of such crowdsourcing tasks and pose the problem of minimizing the total price (i.e., number of task assignments) that must be paid to achieve a target overall reliability. We give a new algorithm for deciding which tasks to assign to which workers and for inferring correct answers from the workers' answers. We show that our algorithm, inspired by belief propagation and low-rank matrix approximation, signi...

  15. Spin reorientation in α-Fe2O3 nanoparticles induced by interparticle exchange interactions in alpha-Fe2O3/NiO nanocomposites

    DEFF Research Database (Denmark)

    Frandsen, Cathrine; Lefmann, Kim; Lebech, Bente

    2011-01-01

    We report that the spin structure of alpha-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to similar to 70 degrees) in alpha-Fe2O3 nanoparticles has, in appearan...

  16. Spin reorientation in α-Fe2O3 nanoparticles induced by interparticle exchange interactions in alpha-Fe2O3/NiO nanocomposites

    DEFF Research Database (Denmark)

    Frandsen, Cathrine; Lefmann, Kim; Lebech, Bente;

    2011-01-01

    We report that the spin structure of alpha-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to similar to 70 degrees) in alpha-Fe2O3 nanoparticles has, in appearan...

  17. Cellular basis for the automorphic curvature of rice coleoptiles on a three-dimensional clinostat: possible involvement of reorientation of cortical microtubules.

    Science.gov (United States)

    Saiki, Mizue; Fujita, Hiroshi; Soga, Kouichi; Wakabayashi, Kazuyuki; Kamisaka, Seiichiro; Yamashita, Masamichi; Hoson, Takayuki

    2005-06-01

    Coleoptiles of rice (Oryza sativa L.) show a spontaneous (automorphic) curvature toward the caryopsis under microgravity conditions. The possible involvement of the reorientation of cortical microtubules in automorphic curvature was studied in rice coleoptiles grown on a three-dimensional clinostat. When rice seedlings that had been grown in the normal gravitational field were transferred to the clinostat in the dark, cortical microtubules of epidermal cells in the dorsal side of the coleoptiles oriented more transversely than the ventral side within 0.5 h. The rotation on the clinostat also increased the cell wall extensibility in the dorsal side and decreased the extensibility in the ventral side, and induced automorphic curvature. The reorientation of cortical microtubules preceded the changes in the cell wall extensibility and the curvature. The irradiation of rice seedlings with white light from above inhibited microtubule reorientation and changes in the cell wall extensibility, as well as curvature of coleoptiles. Also, colchicine, applied to the bending region of coleoptiles, partially inhibited the automorphic curvature. These results suggest that reorientation of cortical microtubules is involved in causing automorphic curvature in rice coleoptiles on the clinostat.

  18. Transient increase in the levels of γ-tubulin complex and katanin are responsible for reorientation by ethylene and hypergravity of cortical microtubules.

    Science.gov (United States)

    Soga, Kouichi; Yamaguchi, Aya; Kotake, Toshihisa; Wakabayashi, Kazuyuki; Hoson, Takayuki

    2010-11-01

    The body shape of a plant is primarily regulated by orientation of cortical microtubules. γ-Tubulin complex and katanin are required for the nucleation and the severing of microtubules, respectively. Here we discuss the role of γ-tubulin complex and katanin during reorientation of cortical microtubules. 1-Aminocyclopropane-1-carboxylic acid (ACC), the immediate precursor of ethylene, modifies growth anisotropy of azuki bean epicotyls; it inhibits elongation growth and promotes lateral growth. The ACC-induced reorientation of cortical microtubules from transverse to longitudinal directions preceded the modification of growth anisotropy. The transcript level of γ-tubulin complex (VaTUG and VaGCP3) and katanin (VaKTN1) was increased transiently by ACC treatment. During reorientation of cortical microtubules by hypergravity, which also modifies growth anisotropy of shoots, the expression levels of both γ-tubulin complex and katanin genes were increased transiently. The increase in the number of the nucleated microtubule branch as well as the microtubule-severing activity via upregulation of γ-tubulin complex genes and katanin genes may be involved in the reorientation of cortical microtubules, and contribute to the regulation of the shape of plant body.

  19. (1)H and (19)F spin-lattice relaxation and CH3 or CF3 reorientation in molecular solids containing both H and F atoms.

    Science.gov (United States)

    Beckmann, Peter A; Rheingold, Arnold L

    2016-04-21

    The dynamics of methyl (CH3) and fluoromethyl (CF3) groups in organic molecular (van der Waals) solids can be exploited to survey their local environments. We report solid state (1)H and (19)F spin-lattice relaxationexperiments in polycrystalline 3-trifluoromethoxycinnamic acid, along with an X-ray diffraction determination of the molecular and crystal structure, to investigate the intramolecular and intermolecular interactions that determine the properties that characterize the CF3 reorientation. The molecule is of no particular interest; it simply provides a motionless backbone (on the nuclear magnetic resonance(NMR) time scale) to investigate CF3 reorientation occurring on the NMR time scale. The effects of (19)F-(19)F and (19)F-(1)H spin-spin dipolar interactions on the complicated nonexponential NMRrelaxation provide independent inputs into determining a model for CF3 reorientation. As such, these experiments provide much more information than when only one spin species (usually (1)H) is present. In Sec. IV, which can be read immediately after the Introduction without reading the rest of the paper, we compare the barrier to CH3 and CF3 reorientation in seven organic solids and separate this barrier into intramolecular and intermolecular components.

  20. [Rethinking addictions: the cognitive paradigm and substance dependence disorder].

    Science.gov (United States)

    Capece, José

    2008-01-01

    The aim of this task is to review some psychotherapeutic strategies used for the treatment of Substance Dependence Disorder. Different distorted beliefs, from the cognitive paradigm, which are usually assumed in our society, are studied here. These beliefs reveal difficulty in facing the drug problem, from the scientific knowledge based on evidence. Different problems are set up, such us the illness pattern, therapeutic alliance, treatment aims, unlawful acts, medication, ideologies and implications for the social interventions. Different strategies that have proved effectiveness are reviewed. Motivational Interview, Contingencies Management, Standard Cognitive Therapy and Harm Reduction have been pointed out. We come to an end with the recommendation to use the scientific knowledge for the treatment programs and preventive policies.

  1. The twinship: a paradigm towards separation and integration.

    Science.gov (United States)

    von Broembsen, F

    1988-01-01

    The twinship paradigm describes a pattern of dyadic, quasi-object relationship, the purpose of which is to facilitate differentiation, separation, and integration. Twinships can arise at any point in the life cycle, when the self faces a developmental impasse. The twin functions as an alter-ego. Twin selection is based on two principles, namely, sympathetic resonance of experience, and difference. The two essentials of the resonance are similarity of developmental task, and similarity of obstacles to its accomplishment. The essentials of the difference lie in the fact that the twin is seen either as an idealized alter-ego, or as the carrier of the self's intolerable aspects. Twinships can collapse, in the presence of massive investment in the archaic symbiotic bond. They then lose their transitional status, and can degenerate into a fixation on a separation-impeding dyadic mode of relating.

  2. Examining theories of cognitive ageing using the false memory paradigm.

    Science.gov (United States)

    Askey, Charlotte; Playfoot, David

    2017-03-15

    Changes in memory performance with advancing age have been well-documented, even in the absence of brain injury or dementia. The mechanisms underlying cognitive ageing are still a matter of debate. The current paper describes a comparison between young (18-25 year old) and older (60+ years) adults using the Deese-Roediger-McDermott false memory paradigm and manipulating the number of words included in the memory lists. Two key theories of cognitive ageing (the Inhibitory Deficit Hypothesis and the Transmission Deficit Hypothesis) predict opposing patterns on this task. Results showed that longer lists increase the likelihood that a lure is retrieved and that older adults are more susceptible to false memories than are younger adults. We argue that these findings are supportive of the Inhibitory Deficit Hypothesis and cannot easily be reconciled with the Transmission Deficit Hypothesis account.

  3. Context-Oriented Programming: A Programming Paradigm for Autonomic Systems

    CERN Document Server

    Salvaneschi, Guido; Pradella, Matteo

    2011-01-01

    Dynamic software adaptability is one of the central features leveraged by autonomic computing. However, developing software that changes its behavior at run time adapting to the operational conditions is a challenging task. Several approaches have been proposed in the literature to attack this problem at different and complementary abstraction levels: software architecture, middleware, and programming level. We focus on the support that ad-hoc programming language constructs may provide to support dynamically adaptive behaviors. We introduce context-oriented programming languages and we present a framework that positions the supported paradigm in the MAPE-K autonomic loop. We discuss the advantages of using context-oriented programming languages instead of other mainstream approaches based on dynamic aspect oriented programming languages and present a case study that shows how the proposed programming style naturally fits dynamic adaptation requirements. Finally, we discuss some known problems and outline a n...

  4. Granular-relational data mining how to mine relational data in the paradigm of granular computing ?

    CERN Document Server

    Hońko, Piotr

    2017-01-01

    This book provides two general granular computing approaches to mining relational data, the first of which uses abstract descriptions of relational objects to build their granular representation, while the second extends existing granular data mining solutions to a relational case. Both approaches make it possible to perform and improve popular data mining tasks such as classification, clustering, and association discovery. How can different relational data mining tasks best be unified? How can the construction process of relational patterns be simplified? How can richer knowledge from relational data be discovered? All these questions can be answered in the same way: by mining relational data in the paradigm of granular computing! This book will allow readers with previous experience in the field of relational data mining to discover the many benefits of its granular perspective. In turn, those readers familiar with the paradigm of granular computing will find valuable insights on its application to mining r...

  5. Task representation in individual and joint settings

    Directory of Open Access Journals (Sweden)

    Wolfgang ePrinz

    2015-05-01

    Full Text Available This paper outlines a framework for task representation and discusses applications to interference tasks in individual and joint settings. The framework is derived from the Theory of Event Coding. This theory regards task sets as transient assemblies of event codes in which stimulus and response codes interact and shape each other in particular ways. On the one hand, stimulus and response codes compete with each other within their respective subsets (horizontal interactions. On the other hand, stimulus and response code cooperate with each other (vertical interactions. Code interactions instantiating competition and cooperation apply to two time scales: on-line performance (i.e., doing the task and off-line implementation (i.e., setting the task. Interference arises when stimulus and response codes overlap in features that are irrelevant for stimulus identification, but relevant for response selection. To resolve this dilemma, the feature profiles of event codes may become restructured in various ways. The framework is applied to three kinds of interference paradigms. Special emphasis is given to joint settings where tasks are shared between two participants. Major conclusions derived from these applications include: (1 Response competition is the chief driver of interference. Likewise, different modes of response competition give rise to different patterns of interference. (2 The type of features in which stimulus and response codes overlap is also a crucial factor. Different types of such features give likewise rise to different patterns of interference. (3 Task sets for joint settings conflate intraindividual conflicts between responses (what, with interindividual conflicts between responding agents (whom. Features of response codes may, therefore, not only address responses, but also responding agents (both physically and socially.

  6. Deficient Biological Motion Perception in Schizophrenia: Results from a Motion Noise Paradigm

    Directory of Open Access Journals (Sweden)

    Jejoong eKim

    2013-07-01

    Full Text Available Background: Schizophrenia patients exhibit deficient processing of perceptual and cognitive information. However, it is not well understood how basic perceptual deficits contribute to higher level cognitive problems in this mental disorder. Perception of biological motion, a motion-based cognitive recognition task, relies on both basic visual motion processing and social cognitive processing, thus providing a useful paradigm to evaluate the potentially hierarchical relationship between these two levels of information processing. Methods: In this study, we designed a biological motion paradigm in which basic visual motion signals were manipulated systematically by incorporating different levels of motion noise. We measured the performances of schizophrenia patients (n=21 and healthy controls (n=22 in this biological motion perception task, as well as in coherent motion detection, theory of mind, and a widely used biological motion recognition task. Results: Schizophrenia patients performed the biological motion perception task with significantly lower accuracy than healthy controls when perceptual signals were moderately degraded by noise. A more substantial degradation of perceptual signals, through using additional noise, impaired biological motion perception in both groups. Performance levels on biological motion recognition, coherent motion detection and theory of mind tasks were also reduced in patients. Conclusion: The results from the motion-noise biological motion paradigm indicate that in the presence of visual motion noise, the processing of biological motion information in schizophrenia is deficient. Combined with the results of poor basic visual motion perception (coherent motion task and biological motion recognition, the association between basic motion signals and biological motion perception suggests a need to incorporate the improvement of visual motion perception in social cognitive remediation.

  7. Keep flexible - Keep switching! The influence of forced task switching on voluntary task switching.

    Science.gov (United States)

    Fröber, Kerstin; Dreisbach, Gesine

    2017-05-01

    Goal directed behavior depends on a dynamic balance between cognitive flexibility and stability. Identifying factors that modulate the balance between these control states is therefore of major interest for the understanding of human action control. In two experiments we used a hybrid paradigm combining forced- and free-choice task switching and measured spontaneous voluntary switch rate (VSR) as an indicator of cognitive flexibility. In Experiment 1 participants were free to choose a given task on 75%, 50%, or 25% of all trials. In the remaining forced-choice trials task repetitions and switches were roughly equally distributed. Results showed that VSR increases with increasing proportion of forced choices. To clarify whether the frequency of forced choices per se or the frequency of forced task switches in particular drives this effect we conducted Experiment 2. In a fully orthogonal between design participants were free to choose a given task on 75% or 25% of all trials with a predetermined switch rate in the remaining forced-choice trials of 75% or 25%, respectively. Results revealed an interaction of both manipulations: The highest VSR was found for the combination of 75% forced-choice trials with 75% forced switch rate, while VSR for 75% forced-choice trials with 25% forced switch rate was still higher than VSRs in both conditions with 25% forced-choice trials. This suggests that a context of frequent forced task switching changes global control parameters towards more flexible behavior. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A Paradigm of Uphill Running

    Science.gov (United States)

    Padulo, Johnny; Powell, Douglas; Milia, Raffaele; Ardigò, Luca Paolo

    2013-01-01

    The biomechanical management of bioenergetics of runners when running uphill was investigated. Several metabolic and mechanical variables have been studied simultaneously to spread light on the locomotory strategy operated by humans for effective locomotion. The studied variables were: heart rate, heart rate variability, oxygen intake and blood lactate, metabolic cost, kinematics, ground reaction force and muscular activity. 18 high-level competitive male runners ran at 70% VO2max on different uphill slope conditions: 0%, 2% and 7%. Modifications were significant in almost all variables studied, and were more pronounced with increasing incline. Step frequency/length and ground reaction force are adjusted to cope with both the task of uphill progression and the available (limited) metabolic power. From 0% to 7% slope, step frequency and ground reaction force and metabolic cost increased concurrently by 4%, 12% and 53%, respectively (with a 4% step length decrease as well). It is hypothesised that this biomechanical management is allowed by an environment-body communication performed by means of specific muscular activity. PMID:23874850

  9. JView: an information visualization paradigm

    Science.gov (United States)

    Moore, Jason A.

    2002-07-01

    The framework for JView, a Java based runtime re-configurable simulation visualizer, was described in two previous publications1. Many augmentations and substitutions have taken place in the JView API, brought about by working closely with customers from various agencies as well using the API on internal projects. However, the core mantra that JView is based upon has made it through these alterations unscathed and with more concrete proof of its utility. JView demystifies the world of 3D graphics programming, allowing users to concentrate solely on the task of visualization instead of concentrating their efforts on the art of complicated 3D graphics. It is a cross platform technology that is engineered to save time, money, and effort while meeting a variety of visualization needs. Its Java implementation, which provides cross-platform functionality while utilizing the OpenGL API, allows for platform dependent hardware acceleration. This paper contains concepts that the JView architecture utilizes as well as a brief introduction to its new 2D engine concepts.

  10. Effect of attention division on movement detection and execution in dual-task conditions

    DEFF Research Database (Denmark)

    Aliakbaryhosseinabadi, Susan; Kamavuako, Ernest Nlandu; Farina, Dario

    2017-01-01

    -invasive electroencephalographic (EEG). Participants were asked to perform a series of cue-based ankle dorsiflexions as the primary task (single task level). In some experimental runs, in addition to the primary task they concurrently attended an auditory oddball paradigm consisting of three tones while they were asked to count...... the number of sequences of special tones (dual task level). EEG signals were recorded from nine channels centered on Cz. Analysis of event-related potential (ERP) signals from Cz confirmed that the oddball task decreased the attention to the ankle dorsiflexion significantly. Furthermore, movement...

  11. Reliability of fMRI Associative Encoding Memory Paradigm in Non-Demented Elderly Adults

    OpenAIRE

    Putcha, Deepti; O'Keefe, Kelly; LaViolette, Pete; O'Brien, Jackie; Greve, Doug; Rentz, Dorene M.; Locascio, Joseph; Atri, Alireza; Sperling, Reisa

    2011-01-01

    Functional MRI holds significant potential to aid in the development of early interventions to improve memory function, and to assess longitudinal change in memory systems in aging and early Alzheimer's disease. However, the test-retest reliability of hippocampal activation and of “beneficial” deactivation in the precuneus has yet to be fully established during memory encoding tasks in older subjects. Using a mixed block and event-related face-name associative encoding paradigm, the reliabili...

  12. Case-Based Reasoning in Mixed Paradigm Settings and with Learning

    Science.gov (United States)

    1994-04-30

    concerning the use of CBR in a mixed paradigm setting in several blackboard-based systems: GBB- CABARET , ABISS, and particularly, FRANK. Our goal was to...tasks. GBB- CABARET and ABISS During the first year of this project, we built two precursors to FRANK. Both were built in the Blackboard Development (GBB...environment. GBB- CABARET was a variant of our previous CABARET system [Rissland & Skalak, 19911. (Work on CABARET was supported under previous

  13. Active training paradigm for motor imagery BCI.

    Science.gov (United States)

    Li, Junhua; Zhang, Liqing

    2012-06-01

    Brain-computer interface (BCI) allows the use of brain activities for people to directly communicate with the external world or to control external devices without participation of any peripheral nerves and muscles. Motor imagery is one of the most popular modes in the research field of brain-computer interface. Although motor imagery BCI has some advantages compared with other modes of BCI, such as asynchronization, it is necessary to require training sessions before using it. The performance of trained BCI system depends on the quality of training samples or the subject engagement. In order to improve training effect and decrease training time, we proposed a new paradigm where subjects participated in training more actively than in the traditional paradigm. In the traditional paradigm, a cue (to indicate what kind of motor imagery should be imagined during the current trial) is given to the subject at the beginning of a trial or during a trial, and this cue is also used as a label for this trial. It is usually assumed that labels for trials are accurate in the traditional paradigm, although subjects may not have performed the required or correct kind of motor imagery, and trials may thus be mislabeled. And then those mislabeled trials give rise to interference during model training. In our proposed paradigm, the subject is required to reconfirm the label and can correct the label when necessary. This active training paradigm may generate better training samples with fewer inconsistent labels because it overcomes mistakes when subject's motor imagination does not match the given cues. The experiments confirm that our proposed paradigm achieves better performance; the improvement is significant according to statistical analysis.

  14. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri

    2007-01-01

    patients with schizophrenia and matched controls in a new working memory paradigm involving dynamic (the Ball Flight Task - BFT) or static (the Static Pattern Task - SPT) visual stimuli. In the BFT, the responses of the patients were apparently based on the retention of the last set of segments...... of the perceived trajectory, whereas control subjects relied on a more global strategy. We assume that the patients' performances are the result of a reduced capacity in chunking visual information since they relied mainly on the retention of the last set of segments. This assumption is confirmed by the poor...

  15. Eye-Hand Coordination in Children with High Functioning Autism and Asperger's Disorder Using a Gap-Overlap Paradigm

    Science.gov (United States)

    Crippa, Alessandro; Forti, Sara; Perego, Paolo; Molteni, Massimo

    2013-01-01

    We investigated eye-hand coordination in children with autism spectrum disorders (ASD) in comparison with age-matched normally developing peers. The eye-hand correlation was measured by putting fixation latencies in relation with pointing and key pressing responses in visual detection tasks where a gap-overlap paradigm was used and compared to…

  16. Cnn: a Paradigm for Complexity

    Science.gov (United States)

    Chua, Leon O.

    The following sections are included: * What is a CNN? * Part I: Standard CNNs * Standard CNNs are uniquely specified by CNN genes * Oscillations and chaos from standard CNNs * Complete stability criteria for standard CNNs * Bistable criterion * Coding the CNN gene * Edge detection CNN * Corner detection CNN * A gallery of basic CNN genes * Does there exist a CNN gene for solving Minsky's global connectivity problem? * Decoding the CNN gene * Examples of input-output CNN operators * Uncoupled CNN genes * Boolean CNN genes and truth tables * What task can an uncoupled Boolean CNN gene Perform? * Bifurcation of CNN genes * The game-of-life CNN gene * The CNN universal machine * Generalized cellular automata * A glimpse at some real-world CNN applications * Part II: Autonomous CNNs * Pattern formation in standard CNNs * Characterization of stable equilibria * The dynamics of pattern formation * CNN pattern formation in biology and physics * Pattern formation in reaction-diffusion CNNs * Nonlinear waves in reaction-diffusion CNNs * Simulating nonlinear PDEs via autonomous CNNs * Part III: Local Activity: The Genesis of Complexity * Transistors and local activity: What do they have to common? * Nonlinear circuit models for reaction-diffusion CNNs * What is local activity? * Cell equilibrium points * Local state equations and local power flows * Local activity in reaction-diffusion CNN cells * Testing for local activity * Testing one-port CNN cells for local activity * Testing two-port CNN cells for local activity * Why is local activity necessary for pattern formation? * How to choose locally-active CNN parameters? * Local activity and stability are different concepts * The local activity dogma

  17. Display Sharing: An Alternative Paradigm

    Science.gov (United States)

    Brown, Michael A.

    2010-01-01

    The current Johnson Space Center (JSC) Mission Control Center (MCC) Video Transport System (VTS) provides flight controllers and management the ability to meld raw video from various sources with telemetry to improve situational awareness. However, maintaining a separate infrastructure for video delivery and integration of video content with data adds significant complexity and cost to the system. When considering alternative architectures for a VTS, the current system's ability to share specific computer displays in their entirety to other locations, such as large projector systems, flight control rooms, and back supporting rooms throughout the facilities and centers must be incorporated into any new architecture. Internet Protocol (IP)-based systems also support video delivery and integration. IP-based systems generally have an advantage in terms of cost and maintainability. Although IP-based systems are versatile, the task of sharing a computer display from one workstation to another can be time consuming for an end-user and inconvenient to administer at a system level. The objective of this paper is to present a prototype display sharing enterprise solution. Display sharing is a system which delivers image sharing across the LAN while simultaneously managing bandwidth, supporting encryption, enabling recovery and resynchronization following a loss of signal, and, minimizing latency. Additional critical elements will include image scaling support, multi -sharing, ease of initial integration and configuration, integration with desktop window managers, collaboration tools, host and recipient controls. This goal of this paper is to summarize the various elements of an IP-based display sharing system that can be used in today's control center environment.

  18. Paradigm formation and paradigm change in the EU’s Stability and Growth Pact

    NARCIS (Netherlands)

    Princen, Sebastiaan; van Esch, Femke

    2016-01-01

    This article analyses whether the European Union’s (EU) Stability and Growth Pact (SGP) has been underpinned by a policy paradigm. In doing so, it seeks to contribute to the debate on the existence and importance of paradigms in policy-making. It uses a causal mapping technique to reconstruct the be

  19. ENVIRONMENTALISM AND CLASSIC PARADIGMS OF INTERNATIONAL RELATIONS

    Directory of Open Access Journals (Sweden)

    D. D. Miniaeva

    2014-06-01

    Full Text Available This article examines an environmentalism integration process into Three classical paradigms of international relations theory (Liberalism, Realism and Marxism into Three classical paradigms of international relations theory (Liberalism, Realism and Marxism. The main purpose of this study is to reveal the result of this integration. Methods used in this article include analysis and comparison of "ecological" paradigms on selected parameters (the nature of international relations, actors, targets, tools, processes. Results of research show that the beginning of the XXI century is distinguished by the development of new types of political concepts that explain interaction of elements in modern international relations in the area of environmental protection. The reason of these changes lies in the phenomena of environmentalism integration into Three paradigms of international relations. However, we cannot say that any of the examined paradigms accumulated all features of environmentalism without their modification. Better to say, it's rather similar to adaptation of environmental ideas. Therefore, to understand modern international relations processes, it is necessary to take into account their environmental element. Purchase on Elibrary.ru > Buy nowDOI: http://dx.doi.org/10.12731/2070-7568-2014-3-4

  20. Overtraining and the use of feature and geometric cues for reorientation.

    Science.gov (United States)

    Sturz, Bradley R; Gaskin, Katherine A; Bodily, Kent D

    2013-03-01

    Using a dynamic three-dimensional virtual environment task, we investigated the influence of overtraining of feature and geometric cues on preferential spatial cue use. We trained two groups of human participants to respond to feature and geometric cues in separate enclosures before placing these cues in conflict on a critical test trial. All participants learned to respond to rewarded features located along the principal axis of a rectangular search space and to rewarded geometric cues of a rectangular search space in separate training phases followed by a single test trial. During the test trial, we situated the rewarded features in the unrewarded geometric corners and the unrewarded features in rewarded geometric corners. For one group, participants were overtrained with feature cues compared to geometric cues before experiencing the conflict test; whereas, for another group, participants were overtrained with geometric cues compared to feature cues before experiencing the conflict test. Although both groups learned to respond to both feature and geometric cues at an equivalent rate and to an equivalent level of terminal accuracy, testing results revealed no difference between the groups with respect to their preference for feature or geometric cues. Despite a lack of influence of overtraining on spatial cue preference, participants showed an overall preference for feature cues. We discuss the results with respect to implications for theoretical accounts of spatial learning.

  1. Cue salience influences the use of height cues in reorientation in pigeons (Columba livia).

    Science.gov (United States)

    Du, Yu; Mahdi, Nuha; Paul, Breanne; Spetch, Marcia L

    2016-07-01

    Although orienting ability has been examined with numerous types of cues, most research has focused only on cues from the horizontal plane. The current study investigated pigeons' use of wall height, a vertical cue, in an open-field task and compared it with their use of horizontal cues. Pigeons were trained to locate food in 2 diagonal corners of a rectangular enclosure with 2 opposite high walls as height cues. Before each trial, pigeons were rotated to disorient them. In training, pigeons could use either the horizontal cues from the rectangular enclosure or the height information from the walls to locate the food. In testing, the apparatus was modified to provide (a) horizontal cues only, (b) height cues only, and (c) both height and horizontal cues in conflict. In Experiment 1 the lower and high walls, respectively, were 40 and 80 cm, whereas in Experiment 2 they were made more perceptually salient by shortening them to 20 and 40 cm. Pigeons accurately located the goal corners with horizontal cues alone in both experiments, but they searched accurately with height cues alone only in Experiment 2. When the height cues conflicted with horizontal cues, pigeons preferred the horizontal cues over the height cues in Experiment 1 but not in Experiment 2, suggesting that perceptual salience influences the relative weighting of cues. (PsycINFO Database Record

  2. Transfer of a serial representation between two distinct tasks by rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Greg Jensen

    Full Text Available Do animals form task-specific representations, or do those representations take a general form that can be applied to qualitatively different tasks? Rhesus monkeys (Macaca mulatta learned the ordering of stimulus lists using two different serial tasks, in order to test whether prior experience in each task could be transfered to the other, enhancing performance. The simultaneous chaining paradigm delivered rewards only after subjects responded in the correct order to all stimuli displayed on a touch sensitive video monitor. The transitive inference paradigm presented pairs of items and delivered rewards when subjects selected the item with the lower ordinal rank. After learning a list in one paradigm, subjects' knowledge of that list was tested using the other paradigm. Performance was enhanced from the very start of transfer training. Transitive inference performance was characterized by 'symbolic distance effects,' whereby the ordinal distance between stimuli in the implied list ordering was strongly predictive of the probability of a correct response. The patterns of error displayed by subjects in both tasks were best explained by a spatially coded representation of list items, regardless of which task was used to learn the list. Our analysis permits properties of this representation to be investigated without the confound of verbal reasoning.

  3. A Paradigm for Spreadsheet Engineering Methodologies

    CERN Document Server

    Grossman, Thomas A

    2008-01-01

    Spreadsheet engineering methodologies are diverse and sometimes contradictory. It is difficult for spreadsheet developers to identify a spreadsheet engineering methodology that is appropriate for their class of spreadsheet, with its unique combination of goals, type of problem, and available time and resources. There is a lack of well-organized, proven methodologies with known costs and benefits for well-defined spreadsheet classes. It is difficult to compare and critically evaluate methodologies. We present a paradigm for organizing and interpreting spreadsheet engineering recommendations. It systematically addresses the myriad choices made when developing a spreadsheet, and explicitly considers resource constraints and other development parameters. This paradigm provides a framework for evaluation, comparison, and selection of methodologies, and a list of essential elements for developers or codifiers of new methodologies. This paradigm identifies gaps in our knowledge that merit further research.

  4. Introduction. Les paradigmes de la justice

    Directory of Open Access Journals (Sweden)

    Cornelui Bîlbă

    2009-12-01

    Full Text Available Theories of justice are marred by a permanent state of conflict because they express prejudices whose source lies in the lifeworld. One may regard these theories as interpretations of the concept of justice. Assuming a strong meaning of “theory,” one can legitimately ask if it is possible to reduce a theory of justice to its underlying paradigm. Several different paradigms coexist in modernity; the tension between them has intensified with the advent of political ideologies. The newest paradigm of justice is global justice. Yet the epistemic status of all theories of justice is ambiguous. A theory ofjustice is true to the extent that it is right, and false if it is not. This applies toRawls’ theory, as well.

  5. 企业经营投资调整分析%The Analysis of Business Investment Reorientation

    Institute of Scientific and Technical Information of China (English)

    王欢; 陈收; 毛超

    2011-01-01

    企业在寻求内外部因素匹配的过程中,存在内部演化机制,在不断适应、试错中形成投资调整模式.为探索企业经营投资调整的影响因素及其对竞争优势的影响,引入空间向量模型度量企业经营投资调整程度,对我国酒业20家上市公司进行实证分析.结果显示,企业经营投资调整受到了主营产品利润增长率的市场激励信号、财务杠杆的正向作用,内部专用性资产规模的负向作用影响.影响因素的共同作用下形成了一定的调整轨迹,在酒业这样的成熟且竞争激烈的行业中,企业调整程度越低,越利于生存发展和竞争优势的巩固.本文力求为企业制定经营投资调整决策提供有益思路.%In the proeess of matching internal and external factors, the internal evolutionary mechanism will cause the formation of a certain investment adjustment mode in its adapting and trial process. In order to explore the influencing factors of business investment reorientation and its effect on competitive advantage, this paper introduces the vector space model to measure the level of business investment adjustment, and then analyzes 20 Chinese listed wine corporations. The results show that: (l) corporate business investment adjustment has a significantly positive correlation with the growth rate of main products and the level of long-term debt ratio while it negatively correlates with the size of corporate specific assets;(2) All of these factors form a certain adjustment path and in such a mature and highly competitive wine industry, the lower level the adjustment is at, the more beneficial it is for industry survival and its competirive advantage. This paper seeks to provide useful suggestions for Chinese enterprises to plan business investment reorientation.

  6. Convergence Analysis of a Domain Decomposition Paradigm

    Energy Technology Data Exchange (ETDEWEB)

    Bank, R E; Vassilevski, P S

    2006-06-12

    We describe a domain decomposition algorithm for use in several variants of the parallel adaptive meshing paradigm of Bank and Holst. This algorithm has low communication, makes extensive use of existing sequential solvers, and exploits in several important ways data generated as part of the adaptive meshing paradigm. We show that for an idealized version of the algorithm, the rate of convergence is independent of both the global problem size N and the number of subdomains p used in the domain decomposition partition. Numerical examples illustrate the effectiveness of the procedure.

  7. Paradigms for Realizing Machine Learning Algorithms.

    Science.gov (United States)

    Agneeswaran, Vijay Srinivas; Tonpay, Pranay; Tiwary, Jayati

    2013-12-01

    The article explains the three generations of machine learning algorithms-with all three trying to operate on big data. The first generation tools are SAS, SPSS, etc., while second generation realizations include Mahout and RapidMiner (that work over Hadoop), and the third generation paradigms include Spark and GraphLab, among others. The essence of the article is that for a number of machine learning algorithms, it is important to look beyond the Hadoop's Map-Reduce paradigm in order to make them work on big data. A number of promising contenders have emerged in the third generation that can be exploited to realize deep analytics on big data.

  8. International business and the eclectic paradigm

    DEFF Research Database (Denmark)

    The eclectic paradigm has become the dominant theoretical basis in the study of international business, multinational corporations and internationalization since 1980. However, developments such as economic globalization and the subsequent growth of global and alliance capitalism have fundamentally......, finance, evolutionary economics, resource-based theory or strategic management? Can it be utilized to explain new developments in international business and economics? Do these require new ideas and concepts to be integrated within the eclectic paradigm? What are the new challenges to which international...... business theorizing must respond?...

  9. What Task Designers Do.

    Science.gov (United States)

    Johnson, Keith

    2000-01-01

    Describes a research project that is concerned with the design procedures followed by those engaged in designing pedagogic tasks for use in classrooms. Focuses on the part of the project that involves actual observation of designers in the process of developing one specific task for class use. Findings are presented under three headers: control…

  10. E-learning, dual-task, and cognitive load: The anatomy of a failed experiment.

    Science.gov (United States)

    Van Nuland, Sonya E; Rogers, Kem A

    2016-01-01

    The rising popularity of commercial anatomy e-learning tools has been sustained, in part, due to increased annual enrollment and a reduction in laboratory hours across educational institutions. While e-learning tools continue to gain popularity, the research methodologies used to investigate their impact on learning remain imprecise. As new user interfaces are introduced, it is critical to understand how functionality can influence the load placed on a student's memory resources, also known as cognitive load. To study cognitive load, a dual-task paradigm wherein a learner performs two tasks simultaneously is often used, however, its application within educational research remains uncommon. Using previous paradigms as a guide, a dual-task methodology was developed to assess the cognitive load imposed by two commercial anatomical e-learning tools. Results indicate that the standard dual-task paradigm, as described in the literature, is insensitive to the cognitive load disparities across e-learning tool interfaces. Confounding variables included automation of responses, task performance tradeoff, and poor understanding of primary task cognitive load requirements, leading to unreliable quantitative results. By modifying the secondary task from a basic visual response to a more cognitively demanding task, such as a modified Stroop test, the automation of secondary task responses can be reduced. Furthermore, by recording baseline measures for the primary task as well as the secondary task, it is possible for task performance tradeoff to be detected. Lastly, it is imperative that the cognitive load of the primary task be designed such that it does not overwhelm the individual's ability to learn new material.

  11. Influence of gap and overlap paradigms on saccade latencies and vergence eye movements in seven-year-old children.

    Science.gov (United States)

    Bucci, Maria Pia; Pouvreau, Nathalie; Yang, Qing; Kapoula, Zoï

    2005-07-01

    The latency of eye movements is influenced by the fixation task; when the fixation stimulus is switched off before the target presentation (gap paradigm) the latency becomes short and express movements occur. In contrast, when the fixation stimulus remains on when the target appears (overlap paradigm), eye movement latency is longer. Several previous studies have shown increased rates of express saccades in children; however the presence of an express type of latency for vergence and combined movements in children has never been explored. The present study examines the effects of the gap and the overlap paradigms on horizontal saccades at far (150 cm) and at close (20 cm) viewing distances, on vergence along the median plane, and on saccades combined with convergence or divergence in 15 normal seven-year-old children. The results show that the gap paradigm produced shorter latency for all eye movements than the overlap paradigm, but the difference was only significant for saccades at close viewing distances, for divergence (pure and combined), and for saccades combined with vergence. The gap paradigm produced significantly higher rates of express latencies for saccades at close viewing distances, for divergence, and for saccades combined with divergence; in contrast, the frequencies of express latencies for saccades at far viewing distances and for convergence (pure or combined) were similar in the gap and the overlap paradigms. Interestingly, the rate of anticipatory latencies (gap paradigm. Our collective findings suggest that the initiation of saccades at close viewing distances and of divergence is more reflexive, particularly in the gap paradigm. The finding of frequent anticipatory divergence that occurs at similar rates for seven-year-old children (this study) and for adults (Coubard et al., 2004, Exp Brain Res 154:368-381) indicates that predictive initiation of divergence is dominant.

  12. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks, is fragme......There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, and recommendations, and supporting exploratory search to sensemaking and analytics, UI and UX design pose an overconstrained challenge. How do we know that our approach is any good? Supporting complex search task requires new collaborations across the whole field of IR, and the proposed workshop will bring together...

  13. Supporting complex search tasks

    DEFF Research Database (Denmark)

    Gäde, Maria; Hall, Mark; Huurdeman, Hugo;

    2015-01-01

    There is broad consensus in the field of IR that search is complex in many use cases and applications, both on the Web and in domain specific collections, and both professionally and in our daily life. Yet our understanding of complex search tasks, in comparison to simple look up tasks......, is fragmented at best. The workshop addressed the many open research questions: What are the obvious use cases and applications of complex search? What are essential features of work tasks and search tasks to take into account? And how do these evolve over time? With a multitude of information, varying from...... introductory to specialized, and from authoritative to speculative or opinionated, when to show what sources of information? How does the information seeking process evolve and what are relevant differences between different stages? With complex task and search process management, blending searching, browsing...

  14. mSpace Mobile: Exploring Support for Mobile Tasks

    OpenAIRE

    Wilson, Max L.; Russell, Alistair; Smith, Daniel A.; Schraefel, M. C.

    2006-01-01

    In the following paper we present a formative study comparing two Web application interfaces, mSpace Mobile and Google Local in supporting Web-based location discovery tasks on mobile devices while stationary and while on the move. While mSpace Mobile performed well in both stationary and mobile conditions, performance in Google Local dropped significantly in the mobile condition. We postulate that mSpace Mobile performed better because it breaks the paradigm of the page for delivering Web co...

  15. Cortisol reactions to a social evaluative paradigm in 5- and 6-year-old children.

    Science.gov (United States)

    de Weerth, C; Zijlmans, M A C; Mack, S; Beijers, R

    2013-01-01

    The goal of the present study was to develop a stress paradigm to elicit cortisol secretory responses in a group of 5- and 6-year-old children as a whole. To this end, we tested a paradigm containing elements of social evaluative threat, unpredictability and uncontrollability, and with a duration of 20 min. The Children's Reactions to Evaluation Stress Test is composed of three short tasks that children have to perform in front of a judge. The tasks are rigged so as to provoke (partial) failure in the child's performance. Participants were 42 children (M = 68.0 months, SD = 4.3). Six saliva samples were taken during the testing session to obtain cortisol measurements of baseline concentrations, stress reactivity, and recovery. Our findings showed that this paradigm was effective in provoking a significant increase in salivary cortisol concentration in the group as a whole, with no effects of possible confounders (child's sex, age or school, parental educational level, time of testing, sex of experimenter, and sex of judge). The mean cortisol concentration increase for the group was 127.5% (SD = 190.9); 61% of the children could be classified as reactors (mean increase of 214%, SD = 201.5), and 39% as non-reactors (mean decrease of 7.8%, SD = 16.8). To our knowledge, this is the first study in this age group that shows a significant cortisol response for the group as a whole to a standardized laboratory paradigm. As such, this paradigm is a promising tool to be used in future research on early life interactions between physiology and psychology.

  16. The go/no-go priming task: automatic evaluation and categorisation beyond response interference.

    Science.gov (United States)

    de Paula Couto, Maria Clara P; Wentura, Dirk

    2017-08-01

    The response-window version of a go/no-go (GNG) response priming task is introduced using both evaluative (Experiment 1) and animacy decision (Experiment 2). In each trial a cue indicates which target category should lead to a key-press. The target is preceded by either a congruent or incongruent prime. The standard priming task was added as well. Both tasks yielded robust priming effects. However, they differed regarding a signature of response activation paradigms, that is, the Gratton effect (i.e. smaller priming effects following incongruent trials compared to congruent trials), which is present in the standard task but absent in the GNG task. This indicates that effects found with the GNG task are caused by different processes compared to the standard task. Experiment 3 tested an alternative account to explain priming effects in the GNG task. By manipulating response biases, Experiment 3 provides evidence for this account.

  17. Conformity in the Asch task as a function of age.

    Science.gov (United States)

    Walker, M B; Andrade, M G

    1996-06-01

    The social conformity paradigm of Asch (1956) was replicated to investigate the relationship between age and conformist behavior. One hundred ten Australian school children and adolescents between 3 and 17 years of age participated in the study. Each participant was placed in the position of being a minority of 1 against a wrong but unanimous majority of 3. The results indicate that conformity decreases with age in perceptually unambiguous tasks. Conflicting evidence from earlier studies can be attributed to task ambiguity in those studies.

  18. What are task-sets: a single, integrated representation or a collection of multiple control representations?

    Directory of Open Access Journals (Sweden)

    Dragan eRangelov

    2013-09-01

    Full Text Available Performing two randomly alternating tasks typically results in higher reaction times (RTs following a task switch, relative to a task repetition. These task switch costs (TSC reflect processes of switching between control settings for different tasks. The present study investigated whether task sets operate as a single, integrated representation or as an agglomeration of relatively independent components. In a cued task switch paradigm, target detection (present/absent and discrimination (blue/green/right-/left-tilted tasks alternated randomly across trials. The target was either a color or an orientation singleton among homogeneous distractors. Across two trials, the task and target-defining dimension repeated or changed randomly. For task switch trials, agglomerated task sets predict a difference between dimension changes and repetitions: joint task and dimension switches require full task set reconfiguration, while dimension repetitions permit re-using some control settings from the previous trial. By contrast, integrated task sets always require full switches, predicting dimension repetition effects (DREs to be absent across task switches. RT analyses showed significant DREs across task switches as well as repetitions supporting the notion of agglomerated task sets. Additionally, two event-related potentials (ERP were analyzed: the Posterior-Contralateral-Negativity (PCN indexing spatial selection dynamics, and the Sustained-Posterior-Contralateral-Negativity (SPCN indexing post-selective perceptual/semantic analysis. Significant DREs across task switches were observed for both the PCN and SPCN components. Together, DREs across task switches for RTs and two functionally distinct ERP components suggest that re-using control settings across different tasks is possible. The results thus support the ‘agglomerated-task-set’ hypothesis, and are inconsistent with ‘integrated task sets’.

  19. Impatient Task Mapping in Elastic Cloud using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Nawfal A. Mehdi

    2011-01-01

    Full Text Available Problem statement: Task scheduling is the main factor that determines the performance of any distributed system. Cloud computing comes with a paradigm of distributed datacenters. Each datacenter consists of physical machines that host virtual machines to execute customers’ tasks. Resources allocation on the cloud is different from other paradigms and the mapping algorithms need to be adapted to the new characteristics. This study takes the problem of immediate task scheduling under an intercloud infrastructure using a genetic algorithm. An impatient task needs to be scheduled as soon as it enters the system taking into account the input and output files location and its QoS requirements. Approach: This study proposes an algorithm that can find a fast mapping using genetic algorithms with "exist if satisfy" condition to speed up the mapping process and ensures the respecting of all task deadlines. Cloudsim simulator was used to test the proposed algorithm with real datasets collected as a cloud benchmark. Mapping time and makespan are the performance metrics that are used to evaluate the proposed system. Results: The results show an improvement in the proposed system compared to MCT algorithm as illustrated throughout the study. Conclusion: Batch mapping via genetic algorithms with throughput as a fitness function can be used to map jobs to cloud resources.

  20. Reliability of functional magnetic resonance imaging associative encoding memory paradigms in non-demented elderly adults.

    Science.gov (United States)

    Putcha, Deepti; O'Keefe, Kelly; LaViolette, Pete; O'Brien, Jackie; Greve, Doug; Rentz, Dorene M; Locascio, Joseph; Atri, Alireza; Sperling, Reisa

    2011-12-01

    Functional magnetic resonance imaging (fMRI) holds significant potential to aid in the development of early interventions to improve memory function, and to assess longitudinal change in memory systems in aging and early Alzheimer's disease (AD). However, the test-retest reliability of hippocampal activation and of "beneficial" deactivation in the precuneus has yet to be fully established during memory encoding tasks in older subjects. Using a mixed block and event-related face-name associative encoding paradigm, we assessed the reliability of hippocampal activation and default network deactivation over a 4- to 6-week interscan interval in 27 older individuals who were cognitively normal [Clinical Dementia Rating (CDR) Scale = 0; n = 18] or mildly impaired (CDR = 0.5; n = 9). Reliability was assessed in whole brain maps and regions of interest using both a full-task paradigm of six functional runs as well as an abbreviated paradigm of the first two functional runs, which would be advantageous for use in clinical trials. We found reliable hippocampal signal response across both block- and event-related designs in the right hippocampus. Comparable reliability in hippocampal activation was found in the full and the abbreviated paradigm. Similar reliability in hippocampal activation was observed across both CDR groups overall, but the CDR 0.5 group was more variable in left hippocampal activity. Task-related deactivation in the precuneus demonstrated much greater variability than hippocampal activation in all analyses. Overall, these results are encouraging for the utility of fMRI in "Proof of Concept" clinical trials investigating the efficacy of potentially therapeutic agents for treatment of age-related memory changes, cognitive impairment, and early AD. Copyright © 2011 Wiley Periodicals, Inc.