The effects of feedback format, and egocentric & allocentric relative phase on coordination stability.

PubMed

Pickavance, John; Azmoodeh, Arianne; Wilson, Andrew D

2018-06-01

The stability of coordinated rhythmic movement is primarily affected by the required mean relative phase. In general, symmetrical coordination is more stable than asymmetrical coordination; however, there are two ways to define relative phase and the associated symmetries. The first is in an egocentric frame of reference, with symmetry defined relative to the sagittal plane down the midline of the body. The second is in an allocentric frame of reference, with symmetry defined in terms of the relative direction of motion. Experiments designed to separate these constraints have shown that both egocentric and allocentric constraints contribute to overall coordination stability, with the former typically showing larger effects. However, separating these constraints has meant comparing movements made either in different planes of motion, or by limbs in different postures. In addition, allocentric information about the coordination is either in the form of the actual limb motion, or a transformed, Lissajous feedback display. These factors limit both the comparisons that can be made and the interpretations of these comparisons. The current study examined the effects of egocentric relative phase, allocentric relative phase, and allocentric feedback format on coordination stability in a single task. We found that while all three independently contributed to stability, the egocentric constraint dominated. This supports previous work. We examine the evidence underpinning theoretical explanations for the egocentric constraint, and describe how it may reflect the haptic perception of relative phase. Copyright © 2018 Elsevier B.V. All rights reserved.

Spatial vision within egocentric and exocentric frames of reference

NASA Technical Reports Server (NTRS)

Howard, Ian P.

1991-01-01

It is remarkable that we are able to perceive a stable visual world and judge the directions, orientations, and movements of visual objects given that images move on the retina, the eyes move in the head, the head moves on the body, and the body moves in space. An understanding of the mechanisms underlying perceptual stability and spatial judgements requires precise definitions of relevant coordinate systems. An egocentric frame of reference is defined with respect to some part of the observer. There are four principal egocentric frames of reference, a station-point frame associated with the nodal point of the eye, an retinocentric frame associated with the retina, a headcentric frame associated with the head, and a bodycentric frame (torsocentric) associated with the torso. Additional egocentric frames can be identified with respect to any segment of the body. An egocentric task is one in which the position, orientation, or motion of an object is judged with respect to an egocentric frame of reference. A proprioceptive is a special kind of egocentric task in which the object being judged is also part of the body. An example of a proprioceptive task is that of directing the gaze toward the seen or unseen toe. An exocentric frame of reference is external to the observer. Geographical coordinates and the direction of gravity are examples of exocentric frames of reference. These various frames are listed in tabular form, together with examples of judgements of each type.

An unsupervised method for summarizing egocentric sport videos

NASA Astrophysics Data System (ADS)

Habibi Aghdam, Hamed; Jahani Heravi, Elnaz; Puig, Domenec

2015-12-01

People are getting more interested to record their sport activities using head-worn or hand-held cameras. This type of videos which is called egocentric sport videos has different motion and appearance patterns compared with life-logging videos. While a life-logging video can be defined in terms of well-defined human-object interactions, notwithstanding, it is not trivial to describe egocentric sport videos using well-defined activities. For this reason, summarizing egocentric sport videos based on human-object interaction might fail to produce meaningful results. In this paper, we propose an unsupervised method for summarizing egocentric videos by identifying the key-frames of the video. Our method utilizes both appearance and motion information and it automatically finds the number of the key-frames. Our blind user study on the new dataset collected from YouTube shows that in 93:5% cases, the users choose the proposed method as their first video summary choice. In addition, our method is within the top 2 choices of the users in 99% of studies.

Inferring global network properties from egocentric data with applications to epidemics.

PubMed

Britton, Tom; Trapman, Pieter

2015-03-01

Social networks are often only partly observed, and it is sometimes desirable to infer global properties of the network from 'egocentric' data. In the current paper, we study different types of egocentric data, and show which global network properties are consistent with data. Two global network properties are considered: the size of the largest connected component (the giant) and the size of an epidemic outbreak taking place on the network. The main conclusion is that, in most cases, egocentric data allow for a large range of possible sizes of the giant and the outbreak, implying that egocentric data carry very little information about these global properties. The asymptotic size of the giant and the outbreak is also characterized, assuming the network is selected uniformly among networks with prescribed egocentric data. © The Authors 2013. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Right supramarginal gyrus is crucial to overcome emotional egocentricity bias in social judgments.

PubMed

Silani, Giorgia; Lamm, Claus; Ruff, Christian C; Singer, Tania

2013-09-25

Humans tend to use the self as a reference point to perceive the world and gain information about other people's mental states. However, applying such a self-referential projection mechanism in situations where it is inappropriate can result in egocentrically biased judgments. To assess egocentricity bias in the emotional domain (EEB), we developed a novel visuo-tactile paradigm assessing the degree to which empathic judgments are biased by one's own emotions if they are incongruent to those of the person we empathize with. A first behavioral experiment confirmed the existence of such EEB, and two independent fMRI experiments revealed that overcoming biased empathic judgments is associated with increased activation in the right supramarginal gyrus (rSMG), in a location distinct from activations in right temporoparietal junction reported in previous social cognition studies. Using temporary disruption of rSMG with repetitive transcranial magnetic stimulation resulted in a substantial increase of EEB, and so did reducing visuo-tactile stimulation time as shown in an additional behavioral experiment. Our findings provide converging evidence from multiple methods and experiments that rSMG is crucial for overcoming emotional egocentricity. Effective connectivity analyses suggest that this may be achieved by early perceptual regulation processes disambiguating proprioceptive first-person information (touch) from exteroceptive third-person information (vision) during incongruency between self- and other-related affective states. Our study extends previous models of social cognition. It shows that although shared neural networks may underlie emotional understanding in some situations, an additional mechanism subserved by rSMG is needed to avoid biased social judgments in other situations.

Egocentrism: Its Effect on the Form and Use of Grammar.

ERIC Educational Resources Information Center

Zubin, David A.

The concept of cognitive egocentrism is presented, supported with experimental evidence, and operationally defined on a scale of egocentric distance from "ego" ("speaker") to "hearer," to "other," to "concrete entity." This concept is used in evaluating the hypothesis that the nominative case in…

Automatic food detection in egocentric images using artificial intelligence technology

USDA-ARS?s Scientific Manuscript database

Our objective was to develop an artificial intelligence (AI)-based algorithm which can automatically detect food items from images acquired by an egocentric wearable camera for dietary assessment. To study human diet and lifestyle, large sets of egocentric images were acquired using a wearable devic...

Mental space travel: damage to posterior parietal cortex prevents egocentric navigation and reexperiencing of remote spatial memories.

PubMed

Ciaramelli, Elisa; Rosenbaum, R Shayna; Solcz, Stephanie; Levine, Brian; Moscovitch, Morris

2010-05-01

The ability to navigate in a familiar environment depends on both an intact mental representation of allocentric spatial information and the integrity of systems supporting complementary egocentric representations. Although the hippocampus has been implicated in learning new allocentric spatial information, converging evidence suggests that the posterior parietal cortex (PPC) might support egocentric representations. To date, however, few studies have examined long-standing egocentric representations of environments learned long ago. Here we tested 7 patients with focal lesions in PPC and 12 normal controls in remote spatial memory tasks, including 2 tasks reportedly reliant on allocentric representations (distance and proximity judgments) and 2 tasks reportedly reliant on egocentric representations (landmark sequencing and route navigation; see Rosenbaum, Ziegler, Winocur, Grady, & Moscovitch, 2004). Patients were unimpaired in distance and proximity judgments. In contrast, they all failed in route navigation, and left-lesioned patients also showed marginally impaired performance in landmark sequencing. Patients' subjective experience associated with navigation was impoverished and disembodied compared with that of the controls. These results suggest that PPC is crucial for accessing remote spatial memories within an egocentric reference frame that enables both navigation and reexperiencing. Additionally, PPC was found to be necessary to implement specific aspects of allocentric navigation with high demands on spontaneous retrieval. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Adolescents, Egocentrism, and Mortality

ERIC Educational Resources Information Center

Hanna, Jennie L.

2017-01-01

Adolescents are often described as egocentric, but a major source of this external behavior is the internal fear of adolescents have about feeling invisible, being different, and even their own mortality. Facing this fear through a curricular focus on death can help to combat this behavior. This can be accomplished through novel studies of books…

Adolescent Egocentrism and Formal Operations: Tests of a Theoretical Assumption.

ERIC Educational Resources Information Center

Lapsley, David K.; And Others

1986-01-01

Describes two studies of the theoretical relation between adolescent egocentrism and formal operations. Study 1 used the Adolescent Egocentrism Scale (AES) and Lunzer's battery of formal reasoning tasks to assess 183 adolescents. Study 2 administered the AES, the Imaginary Audience Scale (IAS), and the Test of Logical Thinking to 138 adolescents.…

Cue reliability and a landmark stability heuristic determine relative weighting between egocentric and allocentric visual information in memory-guided reach.

PubMed

Byrne, Patrick A; Crawford, J Douglas

2010-06-01

It is not known how egocentric visual information (location of a target relative to the self) and allocentric visual information (location of a target relative to external landmarks) are integrated to form reach plans. Based on behavioral data from rodents and humans we hypothesized that the degree of stability in visual landmarks would influence the relative weighting. Furthermore, based on numerous cue-combination studies we hypothesized that the reach system would act like a maximum-likelihood estimator (MLE), where the reliability of both cues determines their relative weighting. To predict how these factors might interact we developed an MLE model that weighs egocentric and allocentric information based on their respective reliabilities, and also on an additional stability heuristic. We tested the predictions of this model in 10 human subjects by manipulating landmark stability and reliability (via variable amplitude vibration of the landmarks and variable amplitude gaze shifts) in three reach-to-touch tasks: an egocentric control (reaching without landmarks), an allocentric control (reaching relative to landmarks), and a cue-conflict task (involving a subtle landmark "shift" during the memory interval). Variability from all three experiments was used to derive parameters for the MLE model, which was then used to simulate egocentric-allocentric weighting in the cue-conflict experiment. As predicted by the model, landmark vibration--despite its lack of influence on pointing variability (and thus allocentric reliability) in the control experiment--had a strong influence on egocentric-allocentric weighting. A reduced model without the stability heuristic was unable to reproduce this effect. These results suggest heuristics for extrinsic cue stability are at least as important as reliability for determining cue weighting in memory-guided reaching.

The Relationship Between Perceptual Egocentrism and Field Dependence in Early Childhood

ERIC Educational Resources Information Center

Bowd, Alan D.

1975-01-01

Kindergarten children were administered tests of inductive reasoning and field dependence and a series of perceptual egocentrism tasks. Results confirm a positive relation between field dependence and perceptual egocentrism; they also question the validity of the field-dependence construct in early childhood. (GO)

Screening of egocentric and unemotional characteristics in incarcerated and community children.

PubMed

Scholte, E M; Stoutjesdijk, R; Van Oudheusden, M A G; Lodewijks, H; Van der Ploeg, J D

2010-01-01

A two-dimensional instrument to screen egocentric and unemotional traits in children was tested in this study, and the associations with the aggressive and the antisocial symptoms of conduct disorder were determined. To this end the narcissistic-egocentric and callous-unemotional characteristics associated with psychopathy were, along with the symptoms of conduct disorder, rated by teachers in a general community sample of 1179 four-to-eighteen-year-old Dutch children, and by professional care takers in a sample of 145 twelve-to eighteen-year-old incarcerated adolescents. Confirmatory factor analysis showed that the ratings of the psychopathic characteristics indeed clustered into a dimension with egocentric characteristics and a dimension with unemotional characteristics. Both dimensions were reliable and stable across age and gender groups. In both samples aggressive behavior was primarily linked to the interaction of egocentric and unemotional characteristics, while antisocial behavior was primarily linked to egocentric characteristics only. The incarcerated adolescents showed substantially more characteristics on both psychopathic dimensions than a comparable age and gender matched group with adolescents from the general community sample. The discrimination between normal and incarcerated adolescent youngsters and the linkage with aggressive behavior suggests the existence of a subtype of conduct disordered children displaying narcissism, deficient affect and disruptive social problem behavior.

Projecting my envy onto you: neurocognitive mechanisms of an offline emotional egocentricity bias.

PubMed

Steinbeis, Nikolaus; Singer, Tania

2014-11-15

Humans often project their own beliefs, desires and emotions onto others, indicating an inherent egocentrism. In five studies we investigated the neurocognitive mechanisms underlying emotional egocentricity bias (EEB) and specifically an offline EEB, defined as the projection of one's own tendency to react with a certain emotional response pattern in a given situation onto other people. We used a competitive reaction time game associated with monetary gains and losses that allowed inducing feelings of envy and Schadenfreude. While we found evidence for the first hand experience of envy and Schadenfreude, we also observed an offline bias, that is participants on average projected feelings of envy and Schadenfreude when having to judge others. Importantly the extent of experienced and projected social emotions were highly correlated. This bias was observed when participants were both directly involved and also as an uninvolved party, suggesting the offline bias to be independent of the presently experienced emotion. Under increased time pressure however an online bias emerged whereby participants just projected their presently experienced emotions onto the other. Finally, we show that on the neural level shared neuronal networks underlie the offline EEB at least for envy. Thus, for envy, activity of the same part of anterior insula was sensitive to individual differences both in the experience and the projection of envy. These findings outline the set of circumstances leading to specific types of empathic attribution biases and show that individual differences in the experience of social emotions are predictive of the offline egocentricity bias both on a behavioral as well as a neural level. These data extend present models on the neurocognitive mechanisms of interpersonal understanding in the socio-affective domain. Copyright © 2014 Elsevier Inc. All rights reserved.

What Makes Us More Egocentric in Communication? The Role of Referent Features and Individual Differences

ERIC Educational Resources Information Center

Debska, Agnieszka; Raczaszek-Leonardi, Joanna

2018-01-01

The perspective-adjustment model of language interpretation assumes an initial egocentric stage in comprehension that is only later adjusted to the interlocutor's perspective. Moreover, substantial processing resources are involved in perspective-taking. However, many experiments in the perspective-adjustment framework do not control for visual…

Targeting adolescent risk-taking behaviors: the contributions of egocentrism and sensation-seeking.

PubMed

Greene, K; Krcmar, M; Walters, L H; Rubin, D L; Jerold; Hale, L

2000-08-01

Tremendous resources are spent each year developing programs and messages targeting adolescent risk behavior. Adolescents are often reasonably well educated about methods for health promotion such as preventing HIV infection, yet they fail to act accordingly. One widely used individual difference variable, sensation-seeking, has been incorporated in health message design to some extent, but it fails to take development into account. Research on adolescent egocentrism suggests adolescents experience personal fable which can lead to an exaggerated sense of invulnerability. The present study sampled adolescents and college students to examine relative contributions of egocentrism and sensation-seeking to risk-taking behavior. Results indicate a latent factor labeled risk-seeking (primarily indicated by disinhibition and risk-taking personality, and to a lesser degree by invulnerability, experience-seeking, boredom susceptibility, and thrill and adventure-seeking) indeed predicted a latent factor labeled delinquent behavior (primarily indicated by alcohol consumption and delinquency, and to a lesser degree by drug use, drinking and driving, and risky driving). Other results indicate consistently high personal fable combined with high sensation-seeking explained most risk-taking behavior. Implications and directions for future research are discussed. Copyright 2000 The Association for Professionals in Services for Adolescents.

As the world turns: short-term human spatial memory in egocentric and allocentric coordinates.

PubMed

Banta Lavenex, Pamela; Lecci, Sandro; Prêtre, Vincent; Brandner, Catherine; Mazza, Christian; Pasquier, Jérôme; Lavenex, Pierre

2011-05-16

We aimed to determine whether human subjects' reliance on different sources of spatial information encoded in different frames of reference (i.e., egocentric versus allocentric) affects their performance, decision time and memory capacity in a short-term spatial memory task performed in the real world. Subjects were asked to play the Memory game (a.k.a. the Concentration game) without an opponent, in four different conditions that controlled for the subjects' reliance on egocentric and/or allocentric frames of reference for the elaboration of a spatial representation of the image locations enabling maximal efficiency. We report experimental data from young adult men and women, and describe a mathematical model to estimate human short-term spatial memory capacity. We found that short-term spatial memory capacity was greatest when an egocentric spatial frame of reference enabled subjects to encode and remember the image locations. However, when egocentric information was not reliable, short-term spatial memory capacity was greater and decision time shorter when an allocentric representation of the image locations with respect to distant objects in the surrounding environment was available, as compared to when only a spatial representation encoding the relationships between the individual images, independent of the surrounding environment, was available. Our findings thus further demonstrate that changes in viewpoint produced by the movement of images placed in front of a stationary subject is not equivalent to the movement of the subject around stationary images. We discuss possible limitations of classical neuropsychological and virtual reality experiments of spatial memory, which typically restrict the sensory information normally available to human subjects in the real world. Copyright © 2011 Elsevier B.V. All rights reserved.

Perception of Egocentric Distance during Gravitational Changes in Parabolic Flight.

PubMed

Clément, Gilles; Loureiro, Nuno; Sousa, Duarte; Zandvliet, Andre

2016-01-01

We explored the effect of gravity on the perceived representation of the absolute distance of objects to the observers within the range from 1.5-6 m. Experiments were performed on board the CNES Airbus Zero-G during parabolic flights eliciting repeated exposures to short periods of microgravity (0 g), hypergravity (1.8 g), and normal gravity (1 g). Two methods for obtaining estimates of perceived egocentric distance were used: verbal reports and visually directed motion toward a memorized visual target. For the latter method, because normal walking is not possible in 0 g, blindfolded subjects translated toward the visual target by pulling on a rope with their arms. The results showed that distance estimates using both verbal reports and blind pulling were significantly different between normal gravity, microgravity, and hypergravity. Compared to the 1 g measurements, the estimates of perceived distance using blind pulling were shorter for all distances in 1.8 g, whereas in 0 g they were longer for distances up to 4 m and shorter for distances beyond. These findings suggest that gravity plays a role in both the sensorimotor system and the perceptual/cognitive system for estimating egocentric distance.

Perception of Egocentric Distance during Gravitational Changes in Parabolic Flight

PubMed Central

Clément, Gilles; Loureiro, Nuno; Sousa, Duarte; Zandvliet, Andre

2016-01-01

We explored the effect of gravity on the perceived representation of the absolute distance of objects to the observers within the range from 1.5–6 m. Experiments were performed on board the CNES Airbus Zero-G during parabolic flights eliciting repeated exposures to short periods of microgravity (0 g), hypergravity (1.8 g), and normal gravity (1 g). Two methods for obtaining estimates of perceived egocentric distance were used: verbal reports and visually directed motion toward a memorized visual target. For the latter method, because normal walking is not possible in 0 g, blindfolded subjects translated toward the visual target by pulling on a rope with their arms. The results showed that distance estimates using both verbal reports and blind pulling were significantly different between normal gravity, microgravity, and hypergravity. Compared to the 1 g measurements, the estimates of perceived distance using blind pulling were shorter for all distances in 1.8 g, whereas in 0 g they were longer for distances up to 4 m and shorter for distances beyond. These findings suggest that gravity plays a role in both the sensorimotor system and the perceptual/cognitive system for estimating egocentric distance. PMID:27463106

Exploratory Movement Generates Higher-Order Information That Is Sufficient for Accurate Perception of Scaled Egocentric Distance

PubMed Central

Mantel, Bruno; Stoffregen, Thomas A.; Campbell, Alain; Bardy, Benoît G.

2015-01-01

Body movement influences the structure of multiple forms of ambient energy, including optics and gravito-inertial force. Some researchers have argued that egocentric distance is derived from inferential integration of visual and non-visual stimulation. We suggest that accurate information about egocentric distance exists in perceptual stimulation as higher-order patterns that extend across optics and inertia. We formalize a pattern that specifies the egocentric distance of a stationary object across higher-order relations between optics and inertia. This higher-order parameter is created by self-generated movement of the perceiver in inertial space relative to the illuminated environment. For this reason, we placed minimal restrictions on the exploratory movements of our participants. We asked whether humans can detect and use the information available in this higher-order pattern. Participants judged whether a virtual object was within reach. We manipulated relations between body movement and the ambient structure of optics and inertia. Judgments were precise and accurate when the higher-order optical-inertial parameter was available. When only optic flow was available, judgments were poor. Our results reveal that participants perceived egocentric distance from the higher-order, optical-inertial consequences of their own exploratory activity. Analysis of participants’ movement trajectories revealed that self-selected movements were complex, and tended to optimize availability of the optical-inertial pattern that specifies egocentric distance. We argue that accurate information about egocentric distance exists in higher-order patterns of ambient energy, that self-generated movement can generate these higher-order patterns, and that these patterns can be detected and used to support perception of egocentric distance that is precise and accurate. PMID:25856410

Are people excessive or judicious in their egocentrism? A modeling approach to understanding bias and accuracy in people's optimism.

PubMed

Windschitl, Paul D; Rose, Jason P; Stalkfleet, Michael T; Smith, Andrew R

2008-08-01

People are often egocentric when judging their likelihood of success in competitions, leading to overoptimism about winning when circumstances are generally easy and to overpessimism when the circumstances are difficult. Yet, egocentrism might be grounded in a rational tendency to favor highly reliable information (about the self) more so than less reliable information (about others). A general theory of probability called extended support theory was used to conceptualize and assess the role of egocentrism and its consequences for the accuracy of people's optimism in 3 competitions (Studies 1-3, respectively). Also, instructions were manipulated to test whether people who were urged to avoid egocentrism would show improved or worsened accuracy in their likelihood judgments. Egocentrism was found to have a potentially helpful effect on one form of accuracy, but people generally showed too much egocentrism. Debias instructions improved one form of accuracy but had no impact on another. The advantages of using the EST framework for studying optimism and other types of judgments (e.g., comparative ability judgments) are discussed. (c) 2008 APA, all rights reserved

THE LIMITED EFFECT OF COINCIDENT ORIENTATION ON THE CHOICE OF INTRINSIC AXIS (.).

PubMed

Li, Jing; Su, Wei

2015-06-01

The allocentric system computes and represents general object-to-object spatial relationships to provide a spatial frame of reference other than the egocentric system. The intrinsic frame-of-reference system theory, which suggests people learn the locations of objects based upon an intrinsic axis, is important in research about the allocentric system. The purpose of the current study was to determine whether the effect of coincident orientation on the choice of intrinsic axis was limited. Two groups of participants (24 men, 24 women; M age = 24 yr., SD = 2) encoded different spatial layouts in which the objects shared the coincident orientation of 315° and 225° separately at learning perspective (0°). The response pattern of partial-scene-recognition task following learning reflected different strategies for choosing the intrinsic axis under different conditions. Under the 315° object-orientation condition, the objects' coincident orientation was as important as the symmetric axis in the choice of the intrinsic axis. However, participants were more likely to choose the symmetric axis as the intrinsic axis under the 225° object-orientation condition. The results suggest the effect of coincident orientation on the choice of intrinsic axis is limited.

Egocentric and allocentric visuospatial working memory in premotor Huntington's disease: A double dissociation with caudate and hippocampal volumes.

PubMed

Possin, Katherine L; Kim, Hosung; Geschwind, Michael D; Moskowitz, Tacie; Johnson, Erica T; Sha, Sharon J; Apple, Alexandra; Xu, Duan; Miller, Bruce L; Finkbeiner, Steven; Hess, Christopher P; Kramer, Joel H

2017-07-01

Our brains represent spatial information in egocentric (self-based) or allocentric (landmark-based) coordinates. Rodent studies have demonstrated a critical role for the caudate in egocentric navigation and the hippocampus in allocentric navigation. We administered tests of egocentric and allocentric working memory to individuals with premotor Huntington's disease (pmHD), which is associated with early caudate nucleus atrophy, and controls. Each test had 80 trials during which subjects were asked to remember 2 locations over 1-sec delays. The only difference between these otherwise identical tests was that locations could only be coded in self-based or landmark-based coordinates. We applied a multiatlas-based segmentation algorithm and computed point-wise Jacobian determinants to measure regional variations in caudate and hippocampal volumes from 3T MRI. As predicted, the pmHD patients were significantly more impaired on egocentric working memory. Only egocentric accuracy correlated with caudate volumes, specifically the dorsolateral caudate head, right more than left, a region that receives dense efferents from dorsolateral prefrontal cortex. In contrast, only allocentric accuracy correlated with hippocampal volumes, specifically intermediate and posterior regions that connect strongly with parahippocampal and posterior parietal cortices. These results indicate that the distinction between egocentric and allocentric navigation applies to working memory. The dorsolateral caudate is important for egocentric working memory, which can explain the disproportionate impairment in pmHD. Allocentric working memory, in contrast, relies on the hippocampus and is relatively spared in pmHD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interplay of Gravicentric, Egocentric, and Visual Cues About the Vertical in the Control of Arm Movement Direction.

PubMed

Bock, Otmar; Bury, Nils

2018-03-01

Our perception of the vertical corresponds to the weighted sum of gravicentric, egocentric, and visual cues. Here we evaluate the interplay of those cues not for the perceived but rather for the motor vertical. Participants were asked to flip an omnidirectional switch down while their egocentric vertical was dissociated from their visual-gravicentric vertical. Responses were directed mid-between the two verticals; specifically, the data suggest that the relative weight of congruent visual-gravicentric cues averages 0.62, and correspondingly, the relative weight of egocentric cues averages 0.38. We conclude that the interplay of visual-gravicentric cues with egocentric cues is similar for the motor and for the perceived vertical. Unexpectedly, we observed a consistent dependence of the motor vertical on hand position, possibly mediated by hand orientation or by spatial selective attention.

Dissociating object-based from egocentric transformations in mental body rotation: effect of stimuli size.

PubMed

Habacha, Hamdi; Moreau, David; Jarraya, Mohamed; Lejeune-Poutrain, Laure; Molinaro, Corinne

2018-01-01

The effect of stimuli size on the mental rotation of abstract objects has been extensively investigated, yet its effect on the mental rotation of bodily stimuli remains largely unexplored. Depending on the experimental design, mentally rotating bodily stimuli can elicit object-based transformations, relying mainly on visual processes, or egocentric transformations, which typically involve embodied motor processes. The present study included two mental body rotation tasks requiring either a same-different or a laterality judgment, designed to elicit object-based or egocentric transformations, respectively. Our findings revealed shorter response times for large-sized stimuli than for small-sized stimuli only for greater angular disparities, suggesting that the more unfamiliar the orientations of the bodily stimuli, the more stimuli size affected mental processing. Importantly, when comparing size transformation times, results revealed different patterns of size transformation times as a function of angular disparity between object-based and egocentric transformations. This indicates that mental size transformation and mental rotation proceed differently depending on the mental rotation strategy used. These findings are discussed with respect to the different spatial manipulations involved during object-based and egocentric transformations.

Egocentric Mapping of Body Surface Constraints.

PubMed

Molla, Eray; Debarba, Henrique Galvan; Boulic, Ronan

2018-07-01

The relative location of human body parts often materializes the semantics of on-going actions, intentions and even emotions expressed, or performed, by a human being. However, traditional methods of performance animation fail to correctly and automatically map the semantics of performer postures involving self-body contacts onto characters with different sizes and proportions. Our method proposes an egocentric normalization of the body-part relative distances to preserve the consistency of self contacts for a large variety of human-like target characters. Egocentric coordinates are character independent and encode the whole posture space, i.e., it ensures the continuity of the motion with and without self-contacts. We can transfer classes of complex postures involving multiple interacting limb segments by preserving their spatial order without depending on temporal coherence. The mapping process exploits a low-cost constraint relaxation technique relying on analytic inverse kinematics; thus, we can achieve online performance animation. We demonstrate our approach on a variety of characters and compare it with the state of the art in online retargeting with a user study. Overall, our method performs better than the state of the art, especially when the proportions of the animated character deviate from those of the performer.

Re-conceptualizing Neurosis as a Degree of Egocentricity: Ethical Issues in Psychological Theory.

PubMed

Alvarez-Segura, M; Echavarria, M F; Vitz, P C

2015-10-01

Psychology's historical rejection of ethics has led to an oversimplification of the origins and treatments of mental disorders. In this article, we present an analysis of how classical neurosis can be reformulated from an ethical and psychological interaction. We focus on the crucial role that egocentricity plays and argue that this term can help to clarify how ego defensive ethical decisions can undermine psychological capacities and contribute to a progressive depersonalization that can result in typical clinical disorders. In Christian anthropology, the virtues, especially humility and love have a crucial role in the positive growth of human affective and cognitive capacities. In addition, the person in his/her nature is endowed with the capacity to transcend the self and to escape egocentricity through self-giving love of God and of others. This capacity of self-giving is diametrically opposed to egocentricity and opens a new way for possible psychological recovery.

The Egocentric Reference for Visual Exploration and Orientation

ERIC Educational Resources Information Center

Nico, Daniele; Daprati, Elena

2009-01-01

Clinical signs of damage to the egocentric reference system range from the inability to detect stimuli in the real environment to a defect in recovering items from an internal representation. Despite clinical dissociations, current interpretations consider all symptoms as due to a single perturbation, differentially expressed according to the…

Visual navigation in insects: coupling of egocentric and geocentric information

PubMed

Wehner; Michel; Antonsen

1996-01-01

Social hymenopterans such as bees and ants are central-place foragers; they regularly depart from and return to fixed positions in their environment. In returning to the starting point of their foraging excursion or to any other point, they could resort to two fundamentally different ways of navigation by using either egocentric or geocentric systems of reference. In the first case, they would rely on information continuously collected en route (path integration, dead reckoning), i.e. integrate all angles steered and all distances covered into a mean home vector. In the second case, they are expected, at least by some authors, to use a map-based system of navigation, i.e. to obtain positional information by virtue of the spatial position they occupy within a larger environmental framework. In bees and ants, path integration employing a skylight compass is the predominant mechanism of navigation, but geocentred landmark-based information is used as well. This information is obtained while the animal is dead-reckoning and, hence, added to the vector course. For example, the image of the horizon skyline surrounding the nest entrance is retinotopically stored while the animal approaches the goal along its vector course. As shown in desert ants (genus Cataglyphis), there is neither interocular nor intraocular transfer of landmark information. Furthermore, this retinotopically fixed, and hence egocentred, neural snapshot is linked to an external (geocentred) system of reference. In this way, geocentred information might more and more complement and potentially even supersede the egocentred information provided by the path-integration system. In competition experiments, however, Cataglyphis never frees itself of its homeward-bound vector - its safety-line, so to speak - by which it is always linked to home. Vector information can also be transferred to a longer-lasting (higher-order) memory. There is no need to invoke the concept of the mental analogue of a topographic

Detecting allocentric and egocentric navigation deficits in patients with schizophrenia and bipolar disorder using virtual reality.

PubMed

Mohammadi, Alireza; Hesami, Ehsan; Kargar, Mahmoud; Shams, Jamal

2018-04-01

Present evidence suggests that the use of virtual reality has great advantages in evaluating visuospatial navigation and memory for the diagnosis of psychiatric or other neurological disorders. There are a few virtual reality studies on allocentric and egocentric memories in schizophrenia, but studies on both memories in bipolar disorder are lacking. The objective of this study was to compare the performance of allocentric and egocentric memories in patients with schizophrenia and bipolar disorder. For this resolve, an advanced virtual reality navigation task (VRNT) was presented to distinguish the navigational performances of these patients. Twenty subjects with schizophrenia and 20 bipolar disorder patients were compared with 20 healthy-matched controls on the newly developed VRNT consisting of a virtual neighbourhood (allocentric memory) and a virtual maze (egocentric memory). The results demonstrated that schizophrenia patients were significantly impaired on all allocentric, egocentric, visual, and verbal memory tasks compared with patients with bipolar disorder and normal subjects. Dissimilarly, the performance of patients with bipolar disorder was slightly lower than that of control subjects in all these abilities, but no significant differences were observed. It was concluded that allocentric and egocentric navigation deficits are detectable in patients with schizophrenia and bipolar disorder using VRNT, and this task along with RAVLT and ROCFT can be used as a valid clinical tool for distinguishing these patients from normal subjects.

Optimal switching between geocentric and egocentric strategies in navigation

PubMed Central

Mahadevan, L.

2016-01-01

Animals use a combination of egocentric navigation driven by the internal integration of environmental cues, interspersed with geocentric course correction and reorientation. These processes are accompanied by uncertainty in sensory acquisition of information, planning and execution. Inspired by observations of dung beetle navigational strategies that show switching between geocentric and egocentric strategies, we consider the question of optimal reorientation rates for the navigation of an agent moving along a preferred direction in the presence of multiple sources of noise. We address this using a model that takes the form of a correlated random walk at short time scales that is punctuated by reorientation events leading to a biased random walks at long time scales. This allows us to identify optimal alternation schemes and characterize their robustness in the context of noisy sensory acquisition as well as performance errors linked with variations in environmental conditions and agent–environment interactions. PMID:27493769

Egocentric Fairness Perception: Emotional Reactions and Individual Differences in Overt Responses

PubMed Central

Bediou, Benoit; Scherer, Klaus R.

2014-01-01

Extensive research documents the existence of egocentric biases in the perception and application of justice norms. The origin of these biases remains poorly understood. We investigated both inter- and intra-individual differences in egocentric justice biases. Participants played an ultimatum game presumably with different anonymous players (simulated by a computer) in which they contributed differentially to the joint production of the initial endowment. We examined how contributions (low vs. high) affect proposers' offers and responders' acceptance decisions, as well as their fairness judgments and their emotional reactions to different types of offers (equal, equitable, unfair, and hyperfair). An egocentric bias in proposers' offers (indicating more flexible preferences) was found only in individualists and not in prosocials, suggesting differences in the motivations (or cognitions) underlying their choice of justice norms. Responders also showed egocentric biases in their judgments of fairness and in their emotional reactions to equal and equitable offers, but not in their acceptance decisions. Such dissociation might suggest that some form of emotion regulation occurred. Responders may evaluate offers on valence dimensions (e.g., goal conduciveness/outcome favorability and norm compatibility/justice) that are multiply interacting and potentially conflicting. The individual's acceptance/rejection decision reflects the relative weight attributed to competing appraisals. For this overt behavioral decision, the (personal) appraisal of outcome favorability that drives (analytical) acceptance of goal-conducive outcome seems to be stronger than the (social) appraisal of outcome fairness, which may trigger covert (emotional) rejection of offers that are incompatible with justice norms. Our data show that the emotional reaction patterns provide a more fine-grained readout of the overall evaluation of the proposer's action, the underlying emotional dynamics of which may

Does Sleep Facilitate the Consolidation of Allocentric or Egocentric Representations of Implicitly Learned Visual-Motor Sequence Learning?

ERIC Educational Resources Information Center

Viczko, Jeremy; Sergeeva, Valya; Ray, Laura B.; Owen, Adrian M.; Fogel, Stuart M.

2018-01-01

Sleep facilitates the consolidation (i.e., enhancement) of simple, explicit (i.e., conscious) motor sequence learning (MSL). MSL can be dissociated into egocentric (i.e., motor) or allocentric (i.e., spatial) frames of reference. The consolidation of the allocentric memory representation is sleep-dependent, whereas the egocentric consolidation…

Erratum: Developmental Changes in Mental Rotation: A Dissociation Between Object-Based and Egocentric Transformations

PubMed Central

Kaltner, Sandra; Jansen, Petra

2017-01-01

This erratum reports an error in “Developmental changes in mental rotation: A dissociation between object-based and egocentric transformations” by Sandra Kaltner & Petra Jansen (Advances in Cognitive Psychology, 12, 67-78. doi: 10.5709/acp-0187-y). The error addresses the fact, that regarding developmental changes in object-based and egocentric transformations, there is only a difference found in children. The incorrect version found changes only in the adult group, but not within children or older adults. PMID:29201259

The elevator illusion results from the combination of body orientation and egocentric perception.

PubMed

Paillard, A; Denise, P; Barraud, P-A; Roux, A; Cian, C

2009-10-30

Perception of body orientation and apparent location of objects are altered when humans are using assisted means of locomotion and the resultant of the imposed acceleration and gravity is no longer aligned with the gravitational vertical. As the otolithic system cannot discriminate the acceleration of gravity from sustained inertial accelerations, individuals would perceive the resultant acceleration vector (GiA) as the vertical. However, when subjects are aligned on the GiA, an increase in the magnitude of GiA induced a lowering of the apparent visual horizon (i.e. "elevator illusion"). The main aim of this study was to quantify the contribution of body and egocentric perception in the elevator illusion. While being exposed to 1G and 1.3G and aligned on the GiA acceleration, subjects (N=20) were asked (1) to set a luminous target to the subjective horizon, (2) to set a luminous target on "straight ahead" position (egocentric task) and (3) to rotate a tilting tube to their subjective perception of body orientation. Results showed that increasing GiA lowered horizon and egocentric settings and induces a backward body tilt perception. Moreover, the elevator illusion can be expressed as the additive combination of two processes: one that is dependent on body tilt perception, and the other that is dependent on egocentric perception. Both misperceptions in hypergravity may be considered to be a consequence of excessive shearing of the otolith organs. However large inter-individual differences in body tilt perception were observed. This last result was discussed in terms of the contribution of extravestibular graviceptors.

Selective Effects of Sport Expertise on the Stages of Mental Rotation Tasks With Object-Based and Egocentric Transformations

PubMed Central

Feng, Tian; Zhang, Zhongqiu; Ji, Zhiguang; Jia, Binbin; Li, Yawei

2017-01-01

It is well established that motor expertise is linked to superior mental rotation ability, but few studies have attempted to explain the factors that influence the stages of mental rotation in sport experts. Some authors have argued that athletes are faster in the perceptual and decision stages but not in the rotation stages of object-based transformations; however, stimuli related to sport have not been used to test mental rotation with egocentric transformations. Therefore, 24 adolescent elite divers and 23 adolescent nonathletes completed mental rotation tasks with object-based and egocentric transformations. The results showed faster reaction times (RTs) for the motor experts in tasks with both types of transformations (object-based cube, object-based body, and egocentric body). Additionally, the differences in favour of motor experts in the perceptual and decision stages were confirmed. Interestingly, motor experts also outperformed nonathletes in the rotation stages in the egocentric transformations. These findings are discussed against the background of the effects of sport expertise on mental rotation. PMID:29071008

The oblique effect is both allocentric and egocentric

PubMed Central

Mikellidou, Kyriaki; Cicchini, Guido Marco; Thompson, Peter G.; Burr, David C.

2016-01-01

Despite continuous movements of the head, humans maintain a stable representation of the visual world, which seems to remain always upright. The mechanisms behind this stability are largely unknown. To gain some insight on how head tilt affects visual perception, we investigate whether a well-known orientation-dependent visual phenomenon, the oblique effect—superior performance for stimuli at cardinal orientations (0° and 90°) compared with oblique orientations (45°)—is anchored in egocentric or allocentric coordinates. To this aim, we measured orientation discrimination thresholds at various orientations for different head positions both in body upright and in supine positions. We report that, in the body upright position, the oblique effect remains anchored in allocentric coordinates irrespective of head position. When lying supine, gravitational effects in the plane orthogonal to gravity are discounted. Under these conditions, the oblique effect was less marked than when upright, and anchored in egocentric coordinates. The results are well explained by a simple “compulsory fusion” model in which the head-based and the gravity-based signals are combined with different weightings (30% and 70%, respectively), even when this leads to reduced sensitivity in orientation discrimination. PMID:26129862

Egocentric empathy gaps between owners and buyers: misperceptions of the endowment effect.

PubMed

Van Boven, L; Dunning, D; Loewenstein, G

2000-07-01

In 5 studies, the authors examined people's perceptions of the endowment effect, or the tendency to value an object more once one owns it. In the 1st 2 studies, the authors documented egocentric empathy gaps between owners and buyers regarding the endowment effect: Both owners and buyers overestimated the similarity between their own valuation of a commodity and the valuation of people in the other role. The next 2 studies showed that these empathy gaps may lead to reduced earnings in a market setting. The final study showed that egocentric empathy gaps stem partly from people's misprediction of what their own valuation would be if they were in the other role.

Effects of head orientation and lateral body tilt on egocentric coding: cognitive and sensory-motor accuracy.

PubMed

Prieur, J-M; Bourdin, C; Sarès, F; Vercher, J-L

2006-01-01

A major issue in motor control studies is to determine whether and how we use spatial frames of reference to organize our spatially oriented behaviors. In previous experiments we showed that simulated body tilt during off-axis rotation affected the performance in verbal localization and manual pointing tasks. It was hypothesized that the observed alterations were at least partly due to a change in the orientation of the egocentric frame of reference, which was indeed centered on the body but aligned with the gravitational vector. The present experiments were designed to test this hypothesis in a situation where no inertial constraints (except the usual gravitational one) exist and where the orientation of the body longitudinal z-axis was not aligned with the direction of the gravity. Eleven subjects were exposed to real static body tilt and were required to verbally localize (experiment 1) and to point as accurately as possible towards (experiment 2) memorized visual targets, in two conditions, Head-Free and Head-Fixed conditions. Results show that the performance was only affected by real body tilt in the localization task performed when the subject's head was tilted relative to the body. Thus, dissociation between gravity and body longitudinal z-axis alone is not responsible for localization nor for pointing errors. Therefore, the egocentric frame of reference seems independent from the orientation of the gravity with regard to body z-axis as expected from our previous studies. Moreover, the use of spatial referentials appears to be less mandatory than expected for pointing movements (motor task) than for localization task (cognitive task).

Disentangling neural processes of egocentric and allocentric mental spatial transformations using whole-body photos of self and other.

PubMed

Ganesh, Shanti; van Schie, Hein T; Cross, Emily S; de Lange, Floris P; Wigboldus, Daniël H J

2015-08-01

Mental imagery of one's body moving through space is important for imagining changing visuospatial perspectives, as well as for determining how we might appear to other people. Previous neuroimaging research has implicated the temporoparietal junction (TPJ) in this process. It is unclear, however, how neural activity in the TPJ relates to the rotation perspectives from which mental spatial transformation (MST) of one's own body can take place, i.e. from an egocentric or an allocentric perspective. It is also unclear whether TPJ involvement in MST is self-specific or whether the TPJ may also be involved in MST of other human bodies. The aim of the current study was to disentangle neural processes involved in egocentric versus allocentric MSTs of human bodies representing self and other. We measured functional brain activity of healthy participants while they performed egocentric and allocentric MSTs in relation to whole-body photographs of themselves and a same-sex stranger. Findings indicated higher blood oxygen level-dependent (BOLD) response in bilateral TPJ during egocentric versus allocentric MST. Moreover, BOLD response in the TPJ during egocentric MST correlated positively with self-report scores indicating how awkward participants felt while viewing whole-body photos of themselves. These findings considerably advance our understanding of TPJ involvement in MST and its interplay with self-awareness. Copyright © 2015 Elsevier Inc. All rights reserved.

Children's Increased Emotional Egocentricity Compared to Adults Is Mediated by Age-Related Differences in Conflict Processing.

PubMed

Hoffmann, Ferdinand; Singer, Tania; Steinbeis, Nikolaus

2015-01-01

This study investigated the cognitive mechanisms underlying age-related differences in emotional egocentricity bias (EEB) between children (aged 7-12 years, n = 30) and adults (aged 20-30 years, n = 30) using a novel paradigm of visuogustatory stimulation to induce pleasant and unpleasant emotions. Both children and adults showed an EBB, but that of children was larger. The EEB did not correlate with other measures of egocentricity. Crucially, the developmental differences in EEB were mediated by age-related changes in conflict processing and not visual perspective taking, response inhibition, or processing speed. This indicates that different types of egocentricity develop independently of one another and that the increased ability to overcome EEB can be explained by age-related improvements in conflict processing. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

Automatic food detection in egocentric images using artificial intelligence technology.

PubMed

Jia, Wenyan; Li, Yuecheng; Qu, Ruowei; Baranowski, Thomas; Burke, Lora E; Zhang, Hong; Bai, Yicheng; Mancino, Juliet M; Xu, Guizhi; Mao, Zhi-Hong; Sun, Mingui

2018-03-26

To develop an artificial intelligence (AI)-based algorithm which can automatically detect food items from images acquired by an egocentric wearable camera for dietary assessment. To study human diet and lifestyle, large sets of egocentric images were acquired using a wearable device, called eButton, from free-living individuals. Three thousand nine hundred images containing real-world activities, which formed eButton data set 1, were manually selected from thirty subjects. eButton data set 2 contained 29 515 images acquired from a research participant in a week-long unrestricted recording. They included both food- and non-food-related real-life activities, such as dining at both home and restaurants, cooking, shopping, gardening, housekeeping chores, taking classes, gym exercise, etc. All images in these data sets were classified as food/non-food images based on their tags generated by a convolutional neural network. A cross data-set test was conducted on eButton data set 1. The overall accuracy of food detection was 91·5 and 86·4 %, respectively, when one-half of data set 1 was used for training and the other half for testing. For eButton data set 2, 74·0 % sensitivity and 87·0 % specificity were obtained if both 'food' and 'drink' were considered as food images. Alternatively, if only 'food' items were considered, the sensitivity and specificity reached 85·0 and 85·8 %, respectively. The AI technology can automatically detect foods from low-quality, wearable camera-acquired real-world egocentric images with reasonable accuracy, reducing both the burden of data processing and privacy concerns.

Gaze behavior and the perception of egocentric distance

PubMed Central

Gajewski, Daniel A.; Wallin, Courtney P.; Philbeck, John W.

2014-01-01

The ground plane is thought to be an important reference for localizing objects, particularly when angular declination is informative, as it is for objects seen resting at floor level. A potential role for eye movements has been implicated by the idea that information about the nearby ground is required to localize objects more distant, and by the fact that the time course for the extraction of distance extends beyond the duration of a typical eye fixation. To test this potential role, eye movements were monitored when participants previewed targets. Distance estimates were provided by walking without vision to the remembered target location (blind walking) or by verbal report. We found that a strategy of holding the gaze steady on the object was as frequent as one where the region between the observer and object was fixated. There was no performance advantage associated with making eye movements in an observational study (Experiment 1) or when an eye-movement strategy was manipulated experimentally (Experiment 2). Observers were extracting useful information covertly, however. In Experiments 3 through 5, obscuring the nearby ground plane had a modest impact on performance; obscuring the walls and ceiling was more detrimental. The results suggest that these alternate surfaces provide useful information when judging the distance to objects within indoor environments. Critically, they constrain the role for the nearby ground plane in theories of egocentric distance perception. PMID:24453346

Acute stress switches spatial navigation strategy from egocentric to allocentric in a virtual Morris water maze.

PubMed

van Gerven, Dustin J H; Ferguson, Thomas; Skelton, Ronald W

2016-07-01

Stress and stress hormones are known to influence the function of the hippocampus, a brain structure critical for cognitive-map-based, allocentric spatial navigation. The caudate nucleus, a brain structure critical for stimulus-response-based, egocentric navigation, is not as sensitive to stress. Evidence for this comes from rodent studies, which show that acute stress or stress hormones impair allocentric, but not egocentric navigation. However, there have been few studies investigating the effect of acute stress on human spatial navigation, and the results of these have been equivocal. To date, no study has investigated whether acute stress can shift human navigational strategy selection between allocentric and egocentric navigation. The present study investigated this question by exposing participants to an acute psychological stressor (the Paced Auditory Serial Addition Task, PASAT), before testing navigational strategy selection in the Dual-Strategy Maze, a modified virtual Morris water maze. In the Dual-Strategy maze, participants can chose to navigate using a constellation of extra-maze cues (allocentrically) or using a single cue proximal to the goal platform (egocentrically). Surprisingly, PASAT stress biased participants to solve the maze allocentrically significantly more, rather than less, often. These findings have implications for understanding the effects of acute stress on cognitive function in general, and the function of the hippocampus in particular. Copyright © 2016 Elsevier Inc. All rights reserved.

Egocentric and allocentric representations in auditory cortex

PubMed Central

Brimijoin, W. Owen; Bizley, Jennifer K.

2017-01-01

A key function of the brain is to provide a stable representation of an object’s location in the world. In hearing, sound azimuth and elevation are encoded by neurons throughout the auditory system, and auditory cortex is necessary for sound localization. However, the coordinate frame in which neurons represent sound space remains undefined: classical spatial receptive fields in head-fixed subjects can be explained either by sensitivity to sound source location relative to the head (egocentric) or relative to the world (allocentric encoding). This coordinate frame ambiguity can be resolved by studying freely moving subjects; here we recorded spatial receptive fields in the auditory cortex of freely moving ferrets. We found that most spatially tuned neurons represented sound source location relative to the head across changes in head position and direction. In addition, we also recorded a small number of neurons in which sound location was represented in a world-centered coordinate frame. We used measurements of spatial tuning across changes in head position and direction to explore the influence of sound source distance and speed of head movement on auditory cortical activity and spatial tuning. Modulation depth of spatial tuning increased with distance for egocentric but not allocentric units, whereas, for both populations, modulation was stronger at faster movement speeds. Our findings suggest that early auditory cortex primarily represents sound source location relative to ourselves but that a minority of cells can represent sound location in the world independent of our own position. PMID:28617796

Angular Declination and the Dynamic Perception of Egocentric Distance

PubMed Central

Gajewski, Daniel A.; Philbeck, John W.; Wirtz, Philip W.; Chichka, David

2014-01-01

The extraction of the distance between an object and an observer is fast when angular declination is informative, as it is with targets placed on the ground. To what extent does angular declination drive performance when viewing time is limited? Participants judged target distances in a real-world environment with viewing durations ranging from 36–220 ms. An important role for angular declination was supported by experiments showing that the cue provides information about egocentric distance even on the very first glimpse, and that it supports a sensitive response to distance in the absence of other useful cues. Performance was better at 220 ms viewing durations than for briefer glimpses, suggesting that the perception of distance is dynamic even within the time frame of a typical eye fixation. Critically, performance in limited viewing trials was better when preceded by a 15 second preview of the room without a designated target. The results indicate that the perception of distance is powerfully shaped by memory from prior visual experience with the scene. A theoretical framework for the dynamic perception of distance is presented. PMID:24099588

Angular declination and the dynamic perception of egocentric distance.

PubMed

Gajewski, Daniel A; Philbeck, John W; Wirtz, Philip W; Chichka, David

2014-02-01

The extraction of the distance between an object and an observer is fast when angular declination is informative, as it is with targets placed on the ground. To what extent does angular declination drive performance when viewing time is limited? Participants judged target distances in a real-world environment with viewing durations ranging from 36-220 ms. An important role for angular declination was supported by experiments showing that the cue provides information about egocentric distance even on the very first glimpse, and that it supports a sensitive response to distance in the absence of other useful cues. Performance was better at 220-ms viewing durations than for briefer glimpses, suggesting that the perception of distance is dynamic even within the time frame of a typical eye fixation. Critically, performance in limited viewing trials was better when preceded by a 15-s preview of the room without a designated target. The results indicate that the perception of distance is powerfully shaped by memory from prior visual experience with the scene. A theoretical framework for the dynamic perception of distance is presented. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Visual attention in egocentric field-of-view using RGB-D data

NASA Astrophysics Data System (ADS)

Olesova, Veronika; Benesova, Wanda; Polatsek, Patrik

2017-03-01

Most of the existing solutions predicting visual attention focus solely on referenced 2D images and disregard any depth information. This aspect has always represented a weak point since the depth is an inseparable part of the biological vision. This paper presents a novel method of saliency map generation based on results of our experiments with egocentric visual attention and investigation of its correlation with perceived depth. We propose a model to predict the attention using superpixel representation with an assumption that contrast objects are usually salient and have a sparser spatial distribution of superpixels than their background. To incorporate depth information into this model, we propose three different depth techniques. The evaluation is done on our new RGB-D dataset created by SMI eye-tracker glasses and KinectV2 device.

A social network analysis of alcohol-impaired drivers in Maryland : an egocentric approach.

DOT National Transportation Integrated Search

2011-04-01

This study examined the personal, household, and social structural attributes of alcoholimpaired : drivers in Maryland. The study used an egocentric approach of social network : analysis. This approach concentrated on specific actors (alcohol-impaire...

The Rorschach Egocentricity Index in subjects with intellectual disability: a study on the incidence of different psychological pathologies.

PubMed

Colucci, G; Pellicciotta, A; Buono, S; Di Nuovo, S F

1998-10-01

The aims of the present research were to assess the level of self-concern in people with intellectual disability using the Rorschach Egocentricity Index, to correlate the Index with other Rorschach and IQ variables, and to study the effect of associated psychological pathology. The Rorschach Inkblot Test and the Wechsler Intelligence Scale were administered to a group of 75 subjects with intellectual disability, aged between 18 and 38 years, who were divided into subgroups according to their additional diagnosis (i.e. personality disorders, psychosis and depression). A fourth subgroup was composed of people with intellectual disability but without other pathologies. The Egocentricity Index was very low in the subjects with intellectual disability and differences were a result of the effects of additional psychological pathologies. The meaning of the measurement of egocentricity in people with intellectual disability is discussed.

Intrinsic motivations drive learning of eye movements: an experiment with human adults.

PubMed

Caligiore, Daniele; Mustile, Magda; Cipriani, Daniele; Redgrave, Peter; Triesch, Jochen; De Marsico, Maria; Baldassarre, Gianluca

2015-01-01

Intrinsic motivations drive the acquisition of knowledge and skills on the basis of novel or surprising stimuli or the pleasure to learn new skills. In so doing, they are different from extrinsic motivations that are mainly linked to drives that promote survival and reproduction. Intrinsic motivations have been implicitly exploited in several psychological experiments but, due to the lack of proper paradigms, they are rarely a direct subject of investigation. This article investigates how different intrinsic motivation mechanisms can support the learning of visual skills, such as "foveate a particular object in space", using a gaze contingency paradigm. In the experiment participants could freely foveate objects shown in a computer screen. Foveating each of two "button" pictures caused different effects: one caused the appearance of a simple image (blue rectangle) in unexpected positions, while the other evoked the appearance of an always-novel picture (objects or animals). The experiment studied how two possible intrinsic motivation mechanisms might guide learning to foveate one or the other button picture. One mechanism is based on the sudden, surprising appearance of a familiar image at unpredicted locations, and a second one is based on the content novelty of the images. The results show the comparative effectiveness of the mechanism based on image novelty, whereas they do not support the operation of the mechanism based on the surprising location of the image appearance. Interestingly, these results were also obtained with participants that, according to a post experiment questionnaire, had not understood the functions of the different buttons suggesting that novelty-based intrinsic motivation mechanisms might operate even at an unconscious level.

Intrinsic Motivations Drive Learning of Eye Movements: An Experiment with Human Adults

PubMed Central

Caligiore, Daniele; Mustile, Magda; Cipriani, Daniele; Redgrave, Peter; Triesch, Jochen; De Marsico, Maria; Baldassarre, Gianluca

2015-01-01

Intrinsic motivations drive the acquisition of knowledge and skills on the basis of novel or surprising stimuli or the pleasure to learn new skills. In so doing, they are different from extrinsic motivations that are mainly linked to drives that promote survival and reproduction. Intrinsic motivations have been implicitly exploited in several psychological experiments but, due to the lack of proper paradigms, they are rarely a direct subject of investigation. This article investigates how different intrinsic motivation mechanisms can support the learning of visual skills, such as “foveate a particular object in space”, using a gaze contingency paradigm. In the experiment participants could freely foveate objects shown in a computer screen. Foveating each of two “button” pictures caused different effects: one caused the appearance of a simple image (blue rectangle) in unexpected positions, while the other evoked the appearance of an always-novel picture (objects or animals). The experiment studied how two possible intrinsic motivation mechanisms might guide learning to foveate one or the other button picture. One mechanism is based on the sudden, surprising appearance of a familiar image at unpredicted locations, and a second one is based on the content novelty of the images. The results show the comparative effectiveness of the mechanism based on image novelty, whereas they do not support the operation of the mechanism based on the surprising location of the image appearance. Interestingly, these results were also obtained with participants that, according to a post experiment questionnaire, had not understood the functions of the different buttons suggesting that novelty-based intrinsic motivation mechanisms might operate even at an unconscious level. PMID:25775248

Children's Visual Processing of Egocentric Cues in Action Planning for Reach

ERIC Educational Resources Information Center

Cordova, Alberto; Gabbard, Carl

2011-01-01

In this study the authors examined children's ability to code visual information into an egocentric frame of reference for planning reach movements. Children and adults estimated reach distance via motor imagery in immediate and response-delay conditions. Actual maximum reach was compared to estimates in multiple locations in peripersonal and…

Construction and reliability of the Japanese version of the Adolescent Egocentrism-Sociocentrism (AES) scale and its preliminary application in the Japanese university students.

PubMed

Yamamoto, Mayumi; Tomotake, Masahito; Ohmori, Tetsuro

2008-08-01

In recent years, the problem of interpersonal relationships has been reported to be associated with various adolescent psychiatric problems. Egocentrism is one factor related to the problem of interpersonal relationships. The Adolescent Egocentrism-Sociocentrism (AES) scale is used to assess egocentrism in Western countries, but no such scale has been developed in Japan. The purpose of our current study was to develop the Japanese version of the AES scale and investigate the relationship between the egocentrism assessed by the AES scale and the self-consciousness assessed by the Japanese version of the self-consciousness scale. The original version of the AES scale was first translated into Japanese using the forward-backward method and examined for factorial reliability and validity. The results demonstrated that the Japanese version of the AES scale shows adequate factorial reliability and validity, but different from the original version the "egocentrism personal fable" subscale which measures the feeling that oneself is special and unique was not extracted in the Japanese version. We found a moderate correlation between the non-social focuses of the AES scale and the public self-consciousness subscale of the self-consciousness scale. This correlation suggests that a strong attention of others' view on oneself results in the avoidance of others. The Japanese version of the AES scale can examine egocentrism adequately together with sociocentrism and non-social focuses. As this scale is self-reporting and easy to complete, it may have practical utility in a clinical setting.

Lateralization of Egocentric and Allocentric Spatial Processing after Parietal Brain Lesions

ERIC Educational Resources Information Center

Iachini, Tina; Ruggiero, Gennaro; Conson, Massimiliano; Trojano, Luigi

2009-01-01

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted…

Spatial midsession reversal learning in rats: Effects of egocentric Cue use and memory.

PubMed

Rayburn-Reeves, Rebecca M; Moore, Mary K; Smith, Thea E; Crafton, Daniel A; Marden, Kelly L

2018-07-01

The midsession reversal task has been used to investigate behavioral flexibility and cue use in non-human animals, with results indicating differences in the degree of control by environmental cues across species. For example, time-based control has been found in rats only when tested in a T-maze apparatus and under specific conditions in which position and orientation (i.e., egocentric) cues during the intertrial interval could not be used to aid performance. Other research in an operant setting has shown that rats often produce minimal errors around the reversal location, demonstrating response patterns similar to patterns exhibited by humans and primates in this task. The current study aimed to reduce, but not eliminate, the ability for rats to utilize egocentric cues by placing the response levers on the opposite wall of the chamber in relation to the pellet dispenser. Results showed that rats made minimal errors prior to the reversal, suggesting time-based cues were not controlling responses, and that they switched to the second correct stimulus within a few trials after the reversal event. Video recordings also revealed highly structured patterns of behavior by the majority of rats, which often differed depending on which response was reinforced. We interpret these findings as evidence that rats are adept at utilizing their own egocentric cues and that these cues, along with memory for the recent response-reinforcement contingencies, aid in maximizing reinforcement over the session. Copyright © 2018 Elsevier B.V. All rights reserved.

Spatial vision within egocentric and exocentric frames of reference

NASA Technical Reports Server (NTRS)

Howard, Ian P.

1989-01-01

The extent to which perceptual judgements within egocentric and exocentric frames of reference are subject to illusory disturbances and long term modifications is discussed. It is argued that well known spatial illusions, such as the oculogyral illusion and induced visual motion have usually been discussed without proper attention being paid to the frame of reference within which they occur, and that this has led to the construction of inadequate theories and inappropriate procedures for testing them.

Cognitive Development, Egocentrism, Self-Esteem, and Adolescent Contraceptive Knowledge, Attitudes, and Behavior.

ERIC Educational Resources Information Center

Holmbeck, Grayson N.; And Others

1994-01-01

Cognitive development, egocentrism, and self-esteem were examined in relation to contraceptive knowledge, attitudes, and behavior for 300 high school and first-year college students. Adolescents with higher cognitive development and self-esteem scores had more knowledge about sexuality and contraception and were more likely to use contraceptives.…

Thinking Allowed: Use of Egocentric Speech after Acquired Brain Injury (ABI)

ERIC Educational Resources Information Center

Rees, Sian A.; Skidmore, David

2011-01-01

This paper explores the use of thinking aloud made by young people who have sustained a severe acquired brain injury (ABI). The phenomenon is compared with the concepts of egocentric speech and inner speech before the form of thinking aloud by pupils with ABI is examined. It is suggested that by using thinking aloud, this group of pupils is able…

Flexible egocentricity: Asymmetric switch costs on a perspective-taking task.

PubMed

Samuel, Steven; Roehr-Brackin, Karen; Jelbert, Sarah; Clayton, Nicola S

2018-04-26

We gave 40 participants a task in which they needed to select target objects from an array according to the instructions of either an informed director (who shared their perspective of the array) or an ignorant director (whose view of the array was restricted due to barriers). Importantly, sometimes only one of the directors was visible, and on some trials when both directors were present, participants were required to switch between perspectives. We found that participants were faster to select items from the informed director's perspective than the ignorant director's perspective, but that they slowed when there was a visible but inactive second director. Crucially, relative to nonswitch trials where the same perspective was taken twice consecutively, participants exhibited a significant cost of switching between perspectives when returning to take their own perspective, but not when switching to the other point of view. We interpret these results as evidence that participants inhibit their more salient perspective in order to adopt another's, and then incur an asymmetric switch cost as a result. This suggests that although we are egocentric by default, our egocentricity is effectively, albeit temporarily, eliminated if we have just adopted an alternative frame of reference. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Mobile Phone Assessment in Egocentric Networks: A Pilot Study on Gay Men and Their Peers

PubMed Central

Comulada, W. Scott

2015-01-01

Mobile phone-based data collection encompasses the richness of social network research. Both individual-level and network-level measures can be recorded. For example, health-related behaviors can be reported via mobile assessment. Social interactions can be assessed by phone-log data. Yet the potential of mobile phone data collection has largely been untapped. This is especially true of egocentric studies in public health settings where mobile phones can enhance both data collection and intervention delivery, e.g. mobile users can video chat with counselors. This is due in part to privacy issues and other barriers that are more difficult to address outside of academic settings where most mobile research to date has taken place. In this article, we aim to inform a broader discussion on mobile research. In particular, benefits and challenges to mobile phone-based data collection are highlighted through our mobile phone-based pilot study that was conducted on egocentric networks of 12 gay men (n = 44 total participants). HIV-transmission and general health behaviors were reported through a mobile phone-based daily assessment that was administered through study participants’ own mobile phones. Phone log information was collected from gay men with Android phones. Benefits and challenges to mobile implementation are discussed, along with the application of multi-level models to the type of longitudinal egocentric data that we collected. PMID:25844003

Mobile Phone Assessment in Egocentric Networks: A Pilot Study on Gay Men and Their Peers.

PubMed

Comulada, W Scott

2014-12-01

Mobile phone-based data collection encompasses the richness of social network research. Both individual-level and network-level measures can be recorded. For example, health-related behaviors can be reported via mobile assessment. Social interactions can be assessed by phone-log data. Yet the potential of mobile phone data collection has largely been untapped. This is especially true of egocentric studies in public health settings where mobile phones can enhance both data collection and intervention delivery, e.g. mobile users can video chat with counselors. This is due in part to privacy issues and other barriers that are more difficult to address outside of academic settings where most mobile research to date has taken place. In this article, we aim to inform a broader discussion on mobile research. In particular, benefits and challenges to mobile phone-based data collection are highlighted through our mobile phone-based pilot study that was conducted on egocentric networks of 12 gay men (n = 44 total participants). HIV-transmission and general health behaviors were reported through a mobile phone-based daily assessment that was administered through study participants' own mobile phones. Phone log information was collected from gay men with Android phones. Benefits and challenges to mobile implementation are discussed, along with the application of multi-level models to the type of longitudinal egocentric data that we collected.

Egocentric pattern projection: how implicit personality theories recapitulate the geography of the self.

PubMed

Critcher, Clayton R; Dunning, David

2009-07-01

Five studies demonstrated egocentric pattern projection, in that the implicit personality theories (IPTs) that participants held about other people tended to recapitulate the terrain of their own personality. To the extent that participants believed they possessed 2 traits to a similar degree within themselves, they tended, through their judgments of others and estimates of population parameters, to claim that the 2 traits were positively correlated in other people; and if they believed they possessed 2 traits to a dissimilar degree within themselves, they tended to claim that the 2 traits were negatively correlated in other people. Further evidence showed that information about the self plays a causal role in the construction of implicit theories, making a unique contribution to the shape of IPTs over and above that of information about another person. The relevance of these data for recent controversies over egocentric social judgment is discussed. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

The role of egocentric and allocentric abilities in Alzheimer's disease: a systematic review.

PubMed

Serino, Silvia; Cipresso, Pietro; Morganti, Francesca; Riva, Giuseppe

2014-07-01

A great effort has been made to identify crucial cognitive markers that can be used to characterize the cognitive profile of Alzheimer's disease (AD). Because topographical disorientation is one of the earliest clinical manifestation of AD, an increasing number of studies have investigated the spatial deficits in this clinical population. In this systematic review, we specifically focused on experimental studies investigating allocentric and egocentric deficits to understand which spatial cognitive processes are differentially impaired in the different stages of the disease. First, our results highlighted that spatial deficits appear in the earliest stages of the disease. Second, a need for a more ecological assessment of spatial functions will be presented. Third, our analysis suggested that a prevalence of allocentric impairment exists. Specifically, two selected studies underlined that a more specific impairment is found in the translation between the egocentric and allocentric representations. In this perspective, the implications for future research and neurorehabilitative interventions will be discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

How Flexible is the Use of Egocentric Versus Allocentric Frame of Reference in the Williams Syndrome Population?

PubMed

Heiz, J; Majerus, S; Barisnikov, K

2017-09-28

This study examined the spontaneous use of allocentric and egocentric frames of reference and their flexible use as a function of instructions. The computerized spatial reference task created by Heiz and Barisnikov (2015) was used. Participants had to choose a frame of reference according to three types of instructions: spontaneous, allocentric and egocentric. The performances of 16 Williams Syndrome participants between 10 and 41 years were compared to those of two control groups (chronological age and non-verbal intellectual ability). The majority of Williams Syndrome participants did not show a preference for a particular frame of reference. When explicitly inviting participants to use an allocentric frame of reference, all three groups showed an increased use of the allocentric frame of reference. At the same time, an important heterogeneity of type of frame of reference used by Williams Syndrome participants was observed. Results demonstrate that despite difficulties in the spontaneous use of allocentric and egocentric frames of reference, some Williams Syndrome participants show flexibility in the use of an allocentric frame of reference when an explicit instruction is provided. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cincinnati water maze: A review of the development, methods, and evidence as a test of egocentric learning and memory

PubMed Central

Vorhees, Charles V.; Williams, Michael T.

2016-01-01

Advantageous maneuvering through the environment to find food and avoid or escape danger is central to survival of most animal species. The ability to do so depends on learning and remembering different locations, especially home-base. This capacity is encoded in the brain by two systems: one using cues outside the organism (distal cues), allocentric navigation, and one using self-movement, internal cues (proximal cues), for egocentric navigation. Whereas allocentric navigation involves the hippocampus, entorhinal cortex, and surrounding structures, egocentric navigation involves the dorsal striatum and connected structures; in humans this system encodes routes and integrated paths and when over-learned, becomes procedural memory. Allocentric assessment methods have been extensively reviewed elsewhere. The purpose of this paper is to review one specific method for assessing egocentric, route-based navigation in rats: the Cincinnati Water Maze (CWM). The test is an asymmetric multiple-T maze arranged in such a way that rats must learn to find path openings along walls rather at ends in order to reach the goal. Failing to do this leads to cul-de-sacs and repeated errors. The task may be learned in the light or dark, but in the dark, wherein distal cues are eliminated, provides the best assessment of egocentric navigation. When used in conjunction with tests of other types of learning, such as allocentric navigation, the CWM provides a balanced approach to assessing the two major forms of navigational learning and memory found in mammals. PMID:27545092

Developmental Time Course of the Acquisition of Sequential Egocentric and Allocentric Navigation Strategies

ERIC Educational Resources Information Center

Bullens, Jessie; Igloi, Kinga; Berthoz, Alain; Postma, Albert; Rondi-Reig, Laure

2010-01-01

Navigation in a complex environment can rely on the use of different spatial strategies. We have focused on the employment of "allocentric" (i.e., encoding interrelationships among environmental cues, movements, and the location of the goal) and "sequential egocentric" (i.e., sequences of body turns associated with specific choice points)…

Egocentrism in Children: Its Generality and Correlates. Head Start Evaluation and Research Center.

ERIC Educational Resources Information Center

Shantz, Carolyn U.

The construct of egocentrism within Piaget's theory of intellectual development was evaluated as to its convergent, discriminant, and predictive validity within the concrete-operational stage. A total of eighty Negro children drawn from grades one through four in low and middle socioeconomic level schools, were tested individually on a total of…

Absolute and relative cues for the auditory perception of egocentric distance.

PubMed

Mershon, D H; Bowers, J N

1979-01-01

Three experiments were performed to examine the reverberation cue to egocentric auditory distance and to determine the extent to which such a cue could provide 'absolute', as contrasted with 'relative', information about distance. In experiment 1 independent groups of blindfolded observers (200 altogether) were presented with broadband noise from a speaker at one of five different distances (0.55 to 8 m) in a normal hard-walled room. Half of each group of observers were presented with the sound at 0 deg azimuth, followed (after a delay) by the identical sound at 90 deg azimuth. The order of presentation was reversed for the remaining observers. Perceived distance varied significantly as a function of the physical distance to the speaker, even for the first presentations. The change in the binaural information between the 0 deg and 90 deg presentations did not significantly modify the results. For both orientations, near distances were overestimated and far distances were underestimated. Experiment 2 and 3 were designed to evaluate how much prior auditory exposure to the laboratory environment was necessary. A 200 Hz square-wave signal was presented from one of three distances (1, 2, or 6 m) to observers who had either minimal room information or an exposure which included talking within the room. Perceived distance varied significantly with physical distance regardless to exposure condition.

Activity Recognition in Egocentric video using SVM, kNN and Combined SVMkNN Classifiers

NASA Astrophysics Data System (ADS)

Sanal Kumar, K. P.; Bhavani, R., Dr.

2017-08-01

Egocentric vision is a unique perspective in computer vision which is human centric. The recognition of egocentric actions is a challenging task which helps in assisting elderly people, disabled patients and so on. In this work, life logging activity videos are taken as input. There are 2 categories, first one is the top level and second one is second level. Here, the recognition is done using the features like Histogram of Oriented Gradients (HOG), Motion Boundary Histogram (MBH) and Trajectory. The features are fused together and it acts as a single feature. The extracted features are reduced using Principal Component Analysis (PCA). The features that are reduced are provided as input to the classifiers like Support Vector Machine (SVM), k nearest neighbor (kNN) and combined Support Vector Machine (SVM) and k Nearest Neighbor (kNN) (combined SVMkNN). These classifiers are evaluated and the combined SVMkNN provided better results than other classifiers in the literature.

Emotional Egocentricity Bias Across the Life-Span.

PubMed

Riva, Federica; Triscoli, Chantal; Lamm, Claus; Carnaghi, Andrea; Silani, Giorgia

2016-01-01

In our daily lives, we often have to quickly estimate the emotions of our conspecifics in order to have successful social interactions. While this estimation process seems quite easy when we are ourselves in a neutral or equivalent emotional state, it has recently been shown that in case of incongruent emotional states between ourselves and the others, our judgments can be biased. This phenomenon, introduced to the literature with the term Emotional Egocentricity Bias (EEB), has been found to occur in young adults and, to a greater extent, in children. However, how the EEB changes across the life-span from adolescence to old age has been largely unexplored. In this study, we recruited 114 female participants subdivided in four cohorts (adolescents, young adults, middle-aged adults, older adults) to examine EEB age-related changes. Participants were administered with a recently developed paradigm which, by making use of visuo-tactile stimulation that elicits conflicting feelings in paired participants, allows the valid and reliable exploration of the EEB. Results highlighted a U-shape relation between age and EEB, revealing enhanced emotional egocentricity in adolescents and older adults compared to young and middle-aged adults. These results are in line with the neuroscientific literature which has recently shown that overcoming the EEB is associated with a greater activation of a portion of the parietal lobe, namely the right Supramarginal Gyrus (rSMG). This is an area that reaches full maturation by the end of adolescence and goes through an early decay. Thus, the age-related changes of the EEB could be possibly due to the life-span development of the rSMG. This study is the first one to show the quadratic relation between age and the EEB and set a milestone for further research exploring the neural correlates of the life-span development of the EEB. Future studies are needed in order to generalize these results to the male population and to explore gender

The two-visual-systems hypothesis and the perspectival features of visual experience.

PubMed

Foley, Robert T; Whitwell, Robert L; Goodale, Melvyn A

2015-09-01

Some critics of the two-visual-systems hypothesis (TVSH) argue that it is incompatible with the fundamentally egocentric nature of visual experience (what we call the 'perspectival account'). The TVSH proposes that the ventral stream, which delivers up our visual experience of the world, works in an allocentric frame of reference, whereas the dorsal stream, which mediates the visual control of action, uses egocentric frames of reference. Given that the TVSH is also committed to the claim that dorsal-stream processing does not contribute to the contents of visual experience, it has been argued that the TVSH cannot account for the egocentric features of our visual experience. This argument, however, rests on a misunderstanding about how the operations mediating action and the operations mediating perception are specified in the TVSH. In this article, we emphasize the importance of the 'outputs' of the two-systems to the specification of their respective operations. We argue that once this point is appreciated, it becomes evident that the TVSH is entirely compatible with a perspectival account of visual experience. Copyright © 2015 Elsevier Inc. All rights reserved.

Allocentric but not egocentric visual memory difficulties in adults with ADHD may represent cognitive inefficiency.

PubMed

Brown, Franklin C; Roth, Robert M; Katz, Lynda J

2015-08-30

Attention Deficit Hyperactivity Disorder (ADHD) has often been conceptualized as arising executive dysfunctions (e.g., inattention, defective inhibition). However, recent studies suggested that cognitive inefficiency may underlie many ADHD symptoms, according to reaction time and processing speed abnormalities. This study explored whether a non-timed measure of cognitive inefficiency would also be abnormal. A sample of 23 ADHD subjects was compared to 23 controls on a test that included both egocentric and allocentric visual memory subtests. A factor analysis was used to determine which cognitive variables contributed to allocentric visual memory. The ADHD sample performed significantly lower on the allocentric but not egocentric conditions. Allocentric visual memory was not associated with timed, working memory, visual perception, or mental rotation variables. This paper concluded by discussing how these results supported a cognitive inefficiency explanation for some ADHD symptoms, and discussed future research directions. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Egocentric virtual maze learning in adult survivors of childhood abuse with dissociative disorders: evidence from functional magnetic resonance imaging.

PubMed

Weniger, Godehard; Siemerkus, Jakob; Barke, Antonia; Lange, Claudia; Ruhleder, Mirjana; Sachsse, Ulrich; Schmidt-Samoa, Carsten; Dechent, Peter; Irle, Eva

2013-05-30

Present neuroimaging findings suggest two subtypes of trauma response, one characterized predominantly by hyperarousal and intrusions, and the other primarily by dissociative symptoms. The neural underpinnings of these two subtypes need to be better defined. Fourteen women with childhood abuse and the current diagnosis of dissociative amnesia or dissociative identity disorder but without posttraumatic stress disorder (PTSD) and 14 matched healthy comparison subjects underwent functional magnetic resonance imaging (fMRI) while finding their way in a virtual maze. The virtual maze presented a first-person view (egocentric), lacked any topographical landmarks and could be learned only by using egocentric navigation strategies. Participants with dissociative disorders (DD) were not impaired in learning the virtual maze when compared with controls, and showed a similar, although weaker, pattern of activity changes during egocentric learning when compared with controls. Stronger dissociative disorder severity of participants with DD was related to better virtual maze performance, and to stronger activity increase within the cingulate gyrus and the precuneus. Our results add to the present knowledge of preserved attentional and visuospatial mnemonic functioning in individuals with DD. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Using Egocentric Networks to Illustrate Information Seeking and Sharing by Alfalfa Farmers in Wyoming

ERIC Educational Resources Information Center

Noy, Shiri; Jabbour, Randa

2017-01-01

We explored using farmers' egocentric (personal) networks to understand how they seek farming advice and how their advice networks map onto their friendship networks. We examined results from a survey of alfalfa farmers (n = 634) in Wyoming. Farmers reported seeking advice from neighbors and fellow farmers, and most indicated that these people are…

Egocentrism and Development of Students' Identity (On the Example of Studying of Future Teachers)

ERIC Educational Resources Information Center

Gromova, Chulpan R.; Alimbekov, Akmatali

2015-01-01

Relevance of the studied problem is that the nature of interrelation between an index of an egocentrism and characteristics of identity isn't studied. Secondly, special trainings of decentration for students--future teachers are not developed. The article is directed to study the structure of the first-third year students' identity, connection…

Believers' estimates of God's beliefs are more egocentric than estimates of other people's beliefs

PubMed Central

Epley, Nicholas; Converse, Benjamin A.; Delbosc, Alexa; Monteleone, George A.; Cacioppo, John T.

2009-01-01

People often reason egocentrically about others' beliefs, using their own beliefs as an inductive guide. Correlational, experimental, and neuroimaging evidence suggests that people may be even more egocentric when reasoning about a religious agent's beliefs (e.g., God). In both nationally representative and more local samples, people's own beliefs on important social and ethical issues were consistently correlated more strongly with estimates of God's beliefs than with estimates of other people's beliefs (Studies 1–4). Manipulating people's beliefs similarly influenced estimates of God's beliefs but did not as consistently influence estimates of other people's beliefs (Studies 5 and 6). A final neuroimaging study demonstrated a clear convergence in neural activity when reasoning about one's own beliefs and God's beliefs, but clear divergences when reasoning about another person's beliefs (Study 7). In particular, reasoning about God's beliefs activated areas associated with self-referential thinking more so than did reasoning about another person's beliefs. Believers commonly use inferences about God's beliefs as a moral compass, but that compass appears especially dependent on one's own existing beliefs. PMID:19955414

Origins of retinal intrinsic signals: a series of experiments on retinas of macaque monkeys.

PubMed

Tsunoda, Kazushige; Hanazono, Gen; Inomata, Koichi; Kazato, Yoko; Suzuki, Wataru; Tanifuji, Manabu

2009-07-01

Diffuse flash stimuli applied to the ocular fundus evoke light reflectance decreases of the fundus illuminated with infrared observation light. This phenomenon, which is independent of the photopigment bleaching observed as an increase in the reflectance of visible light, is called intrinsic signals. Intrinsic signals, in general, are stimulus-evoked light reflectance changes of neural tissues due to metabolic changes, and they have been extensively investigated in the cerebral cortex. This noninvasive objective technique of functional imaging has good potential as a tool for the early detection of retinal dysfunction. Once the signal properties were studied in detail, however, it became apparent that the intrinsic signals observed in the retina have uniquely interesting properties of their own due to the characteristic layered structure of the retina. Experiments on anesthetized macaque monkeys are reviewed, and the possible origins of the intrinsic signals of the retina are discussed.

Toroidal modeling of the n = 1 intrinsic error field correction experiments in EAST

NASA Astrophysics Data System (ADS)

Yang, Xu; Liu, Yueqiang; Sun, Youwen; Wang, Huihui; Gu, Shuai; Jia, Manni; Li, Li; Liu, Yue; Wang, Zhirui; Zhou, Lina

2018-05-01

The m/n = 2/1 resonant vacuum error field (EF) in the EAST tokamak experiments, inferred from the compass coil current amplitude and phase scan for mode locking, was found to depend on the parity between the upper and lower rows of the EF correction (EFC) coils (Wang et al 2016 Nucl. Fusion 56 066011). Here m and n are the poloidal and toroidal harmonic numbers in a torus, respectively. This experimental observation implies that the compass scan results cannot be simply interpreted as reflecting the true intrinsic EF. This work aims at understanding this puzzle, based on toroidal modeling of the EFC plasma discharge in EAST using the MARS-F code (Liu et al 2000 Phys. Plasmas 7 3681). By varying the amplitude and phase of the assumed n = 1 intrinsic vacuum EF with different poloidal spectra, and by computing the plasma response to the assumed EF, the compass scan predicted 2/1 EF, based on minimizing the computed resonant electromagnetic torque, can be made to match well with that of the EFC experiments using both even and odd parity coils. Moreover, the compass scan predicted vacuum EFs are found to be significantly differing from the true intrinsic EF used as input to the MARS-F code. While the puzzling result remains to be fully resolved, the results from this study offer an improved understanding of the EFC experiments and the compass scan technique for determining the intrinsic resonant EF.

A methodological approach to the analysis of egocentric social networks in public health research: a practical example.

PubMed

Djomba, Janet Klara; Zaletel-Kragelj, Lijana

2016-12-01

Research on social networks in public health focuses on how social structures and relationships influence health and health-related behaviour. While the sociocentric approach is used to study complete social networks, the egocentric approach is gaining popularity because of its focus on individuals, groups and communities. One of the participants of the healthy lifestyle health education workshop 'I'm moving', included in the study of social support for exercise was randomly selected. The participant was denoted as the ego and members of her/his social network as the alteri. Data were collected by personal interviews using a self-made questionnaire. Numerical methods and computer programmes for the analysis of social networks were used for the demonstration of analysis. The size, composition and structure of the egocentric social network were obtained by a numerical analysis. The analysis of composition included homophily and homogeneity. Moreover, the analysis of the structure included the degree of the egocentric network, the strength of the ego-alter ties and the average strength of ties. Visualisation of the network was performed by three freely available computer programmes, namely: Egonet.QF, E-net and Pajek. The computer programmes were described and compared by their usefulness. Both numerical analysis and visualisation have their benefits. The decision what approach to use is depending on the purpose of the social network analysis. While the numerical analysis can be used in large-scale population-based studies, visualisation of personal networks can help health professionals at creating, performing and evaluation of preventive programmes, especially if focused on behaviour change.

Mental "Space" Travel: Damage to Posterior Parietal Cortex Prevents Egocentric Navigation and Reexperiencing of Remote Spatial Memories

ERIC Educational Resources Information Center

Ciaramelli, Elisa; Rosenbaum, R. Shayna; Solcz, Stephanie; Levine, Brian; Moscovitch, Morris

2010-01-01

The ability to navigate in a familiar environment depends on both an intact mental representation of allocentric spatial information and the integrity of systems supporting complementary egocentric representations. Although the hippocampus has been implicated in learning new allocentric spatial information, converging evidence suggests that the…

Relationships among Dispositional Ability Conceptions, Intrinsic Motivation, Perceived Competence, Experience, Persistance, and Performance

ERIC Educational Resources Information Center

Li, Weidong; Lee, Amelia M.; Solmon, Melinda A.

2005-01-01

This study was designed to explore the relationships among individuals' dispositional ability conceptions, intrinsic motivation, experience, perceived competence, persistence, and performance. Participants practiced a novel task, completed surveys before instruction and after practicing the task, and completed a skill test. The results indicated…

A selective egocentric topographical working memory deficit in the early stages of Alzheimer's disease: a preliminary study.

PubMed

Bianchini, F; Di Vita, A; Palermo, L; Piccardi, L; Blundo, C; Guariglia, C

2014-12-01

The aim of this study was to determine whether an egocentric topographical working memory (WM) deficit is present in the early stages of Alzheimer's disease (AD) with respect to other forms of visuospatial WM. Further, we would investigate whether this deficit could be present in patients having AD without topographical disorientation (TD) signs in everyday life assessed through an informal interview to caregivers. Seven patients with AD and 20 healthy participants performed the Walking Corsi Test and the Corsi Block-Tapping Test. The former test requires memorizing a sequence of places by following a path and the latter is a well-known visuospatial memory task. Patients with AD also performed a verbal WM test to exclude the presence of general WM impairments. Preliminary results suggest that egocentric topographical WM is selectively impaired, with respect to visuospatial and verbal WM, even without TD suggesting an important role of this memory in the early stages of AD. © The Author(s) 2014.

Exploring the Experiences of Upper Elementary School Children Who Are Intrinsically Motivated to Seek Information

ERIC Educational Resources Information Center

Crow, Sherry R.

2011-01-01

This article describes research conducted to understand the experiences of children in order to inform school librarians' practice in fostering intrinsic motivation for information seeking. An inductive naturalistic approach was used to explore the following question: "What are the experiences in the lives of upper-elementary school children…

Comparison of (+)-methamphetamine, ±-methylenedioxymethamphetamine, (+)-amphetamine and ±-fenfluramine in rats on egocentric learning in the Cincinnati water maze.

PubMed

Vorhees, Charles V; He, Elizabeth; Skelton, Matthew R; Graham, Devon L; Schaefer, Tori L; Grace, Curtis E; Braun, Amanda A; Amos-Kroohs, Robyn; Williams, Michael T

2011-05-01

(+)-Methamphetamine (MA), (±)-3,4-methylenedioxymethamphetamine (MDMA), (+)-amphetamine (AMPH), and (±)-fenfluramine (FEN) are phenylethylamines with CNS effects. At higher doses, each induces protracted reductions in brain dopamine (DA) and/or serotonin. Chronic MA and MDMA users show persistent monoamine reductions and cognitive impairments. In rats, similar neurochemical effects can be induced, yet cognitive impairments have been difficult to demonstrate. We recently showed that rats treated on a single day with MA (10 mg/kg x 4 at 2 h intervals) exhibit impaired egocentric learning (Cincinnati water maze [CWM]) without affecting spatial learning (Morris water maze [MWM]) (Herring et al., [2008] Psychopharmacology (Berl) 199:637–650). Whether this effect is unique to MA or is a general characteristic of these drugs is unknown. Accordingly, this experiment compared these drugs on CWM performance. Drugs were given s.c. in four doses at 2 h intervals. MA doses were 10 or 12.5 mg/kg/dose, AMPH 25 mg/kg/dose (to match MA12.5-induced hyperthermia), MDMA 15 mg/kg/dose (previously established hyperthermia-inducing dose), and FEN 16.5 mg/kg/dose (equimolar to MA12.5). Two weeks later, rats were tested in the CWM (2 trials/day, 21 days). AMPH and MA (both doses) induced significant increases in CWM errors and latency to reach the goal with no differences in swim speed. MDMA and FEN did not significantly alter learning. Given that FEN selectively and MDMA preferentially affect serotonin whereas AMPH selectively and MA preferentially affect DA, the data suggest that egocentric learning may be predominantly dopaminergically mediated.

Object-based and egocentric mental rotation performance in older adults: the importance of gender differences and motor ability.

PubMed

Jansen, Petra; Kaltner, Sandra

2014-01-01

In this study, mental rotation performance was assessed in both an object-based task, human figures and letters as stimuli, and in an egocentric-based task, a human figure as a stimulus, in 60 older persons between 60 and 71 years old (30 women, 30 men). Additionally all participants completed three motor tests measuring balance and mobility. The results show that the reaction time was slower for letters than for both human figure tasks and the mental rotation speed was faster over all for egocentric mental rotation tasks. Gender differences were found in the accuracy measurement, favoring males, and were independent of stimulus type, kind of transformation, and angular disparity. Furthermore, a regression analysis showed that the accuracy rate for object-based transformations with body stimuli could be predicted by gender and balance ability. This study showed that the mental rotation performance in older adults depends on stimulus type, kind of transformation, and gender and that performance partially relates to motor ability.

Influence of galvanic vestibular stimulation on egocentric and object-based mental transformations.

PubMed

Lenggenhager, Bigna; Lopez, Christophe; Blanke, Olaf

2008-01-01

The vestibular system analyses angular and linear accelerations of the head that are important information for perceiving the location of one's own body in space. Vestibular stimulation and in particular galvanic vestibular stimulation (GVS) that allow a systematic modification of vestibular signals has so far mainly been used to investigate vestibular influence on sensori-motor integration in eye movements and postural control. Comparatively, only a few behavioural and imaging studies have investigated how cognition of space and body may depend on vestibular processing. This study was designed to differentiate the influence of left versus right anodal GVS compared to sham stimulation on object-based versus egocentric mental transformations. While GVS was applied, subjects made left-right judgments about pictures of a plant or a human body presented at different orientations in the roll plane. All subjects reported illusory sensations of body self-motion and/or visual field motion during GVS. Response times in the mental transformation task were increased during right but not left anodal GVS for the more difficult stimuli and the larger angles of rotation. Post-hoc analyses suggested that the interfering effect of right anodal GVS was only present in subjects who reported having imagined turning themselves to solve the mental transformation task (egocentric transformation) as compared to those subjects having imagined turning the picture in space (object-based mental transformation). We suggest that this effect relies on shared functional and cortical mechanisms in the posterior parietal cortex associated with both right anodal GVS and mental imagery.

The Experience of Creating Community: An Intrinsic Case Study of Four Midwestern Public School Choral Teachers

ERIC Educational Resources Information Center

Parker, Elizabeth Cassidy

2016-01-01

The purpose of this intrinsic case study was to explore four midwestern choral teachers' experiences of creating and sustaining community within their public school choirs. Research questions included (1) how choral teachers describe their experiences of creating choral communities, (2) how the teacher-student relationship is experienced, and (3)…

Linguistic asymmetry, egocentric anchoring, and sensory modality as factors for the observed association between time and space perception.

PubMed

Choy, Eunice E Hang; Cheung, Him

2017-11-01

Temporal and spatial representations have been consistently shown to be inextricably intertwined. However, the exact nature of time-space mapping remains unknown. On the one hand, the conceptual metaphor theory postulates unilateral, asymmetric mapping of time onto space, that is, time is perceived in spatial terms but the perception of space is relatively independent of time. On the other hand, a theory of magnitude assumes bilateral and symmetric interactions between temporal and spatial perceptions. In the present paper, we argue that the concepts of linguistic asymmetry, egocentric anchoring, and sensory modality provide potential explanations for why evidences favoring both asymmetry and symmetry have been obtained. We first examine the asymmetry model and suggest that language plays a critical role in it. Next, we discuss the symmetry model in relation to egocentric anchoring and sensory modality. We conclude that since these three factors may jointly account for some conflicting past results regarding the strength and directionality of time-space mapping, they should be taken into serious consideration in future test designs.

Use of exocentric and egocentric representations in the concurrent planning of sequential saccades.

PubMed

Sharika, K M; Ramakrishnan, Arjun; Murthy, Aditya

2014-11-26

The concurrent planning of sequential saccades offers a simple model to study the nature of visuomotor transformations since the second saccade vector needs to be remapped to foveate the second target following the first saccade. Remapping is thought to occur through egocentric mechanisms involving an efference copy of the first saccade that is available around the time of its onset. In contrast, an exocentric representation of the second target relative to the first target, if available, can be used to directly code the second saccade vector. While human volunteers performed a modified double-step task, we examined the role of exocentric encoding in concurrent saccade planning by shifting the first target location well before the efference copy could be used by the oculomotor system. The impact of the first target shift on concurrent processing was tested by examining the end-points of second saccades following a shift of the second target during the first saccade. The frequency of second saccades to the old versus new location of the second target, as well as the propagation of first saccade localization errors, both indices of concurrent processing, were found to be significantly reduced in trials with the first target shift compared to those without it. A similar decrease in concurrent processing was obtained when we shifted the first target but kept constant the second saccade vector. Overall, these results suggest that the brain can use relatively stable visual landmarks, independent of efference copy-based egocentric mechanisms, for concurrent planning of sequential saccades. Copyright © 2014 the authors 0270-6474/14/3416009-13$15.00/0.

tDCS combined with optokinetic drift reduces egocentric neglect in severely impaired post-acute patients.

PubMed

Turgut, Nergiz; Miranda, Marcela; Kastrup, Andreas; Eling, Paul; Hildebrandt, Helmut

2018-06-01

Visuospatial neglect is a disabling syndrome resulting in impaired activities of daily living and in longer durations of inpatient rehabilitation. Effective interventions to remediate neglect are still needed. The combination of tDCS and an optokinetic task might qualify as a treatment method. A total of 32 post-acute patients with left (n = 20) or right-sided neglect were allotted to an intervention or a control group (both groups n = 16). The intervention group received eight sessions of 1.5-2.0 mA parietal transcranial direct current stimulation (tDCS) during the performance of an optokinetic task distributed over two weeks. Additionally they received standard therapy for five hours per day. The control group received only the standard therapy. Patients were examined twice before (with 3-4 days between examinations) and twice after treatment (5-6 days between examinations). Compared to the control group and controlling for spontaneous remission, the intervention group improved on spontaneous body orientation and the Clock Drawing Test. Intragroup comparisons showed broad improvements on egocentric but not on allocentric symptoms only for the intervention group. A short additional application of tDCS during an optokinetic task led to improvements of severe neglect compared to a standard neurological early rehabilitation treatment. Improvements seem to concern primarily egocentric rather than allocentric neglect.

"Coveting thy neighbour's legs": a qualitative study of exercisers' experiences of intrinsic and extrinsic goal pursuit.

PubMed

Sebire, Simon J; Standage, Martyn; Gillison, Fiona B; Vansteenkiste, Maarten

2013-06-01

Goals are central to exercise motivation, although not all goals (e.g., health vs. appearance goals) are equally psychologically or behaviorally adaptive. Within goal content theory (Vansteenkiste, Niemiec, & Soenens, 2010), goals are adaptive to the extent to which they satisfy psychological needs for autonomy, competence, and relatedness. However, little is known about what exercisers pursuing different goals are feeling, doing, thinking, and paying attention to that may help to explain the association between goal contents and need satisfaction. Using semistructured interviews and interpretative phenomenological analysis, we explored experiences of exercise among 11 adult exercisers who reported pursuing either predominantly intrinsic or extrinsic goals. Four themes emerged: (a) observation of others and resulting emotions, (b) goal expectations and time perspective, (c) markers of progress and (d) reactions to (lack of) goal achievement. Intrinsic and extrinsic goal pursuers reported divergent experiences within these four domains. The findings illuminate potential mechanisms by which different goals may influence psychological and behavioral outcomes in the exercise context.

The developmental dynamics of behavioral growth processes in rodent egocentric and allocentric space.

PubMed

Golani, Ilan

2012-06-01

In this review I focus on how three methodological principles advocated by Philip Teitelbaum influenced my work to this day: that similar principles of organization should be looked for in ontogeny and recovery of function; that the order of emergence of behavioral components provides a view on the organization of that behavior; and that the components of behavior should be exhibited by the animal itself in relatively pure form. I start by showing how these principles influenced our common work on the developmental dynamics of rodent egocentric space, and then proceed to describe how these principles affected my work with Yoav Benjamini and others on the developmental dynamics of rodent allocentric space. We analyze issues traditionally addressed by physiological psychologists with methods borrowed from ethology, EW (Eshkol-Wachman) movement notation, dynamical systems and exploratory data analysis. Then we show how the natural origins of axes embodied by the behavior of the organism itself, are used by us as the origins of axes for the measurement of the developmental moment-by-moment dynamics of behavior. Using this methodology we expose similar principles of organization across situations, species and preparations, provide a developmental view on the organization of behavior, expose the natural components of behavior in relatively pure form, and reveal how low level primitives generate higher level constructs. Advances in tracking technology should allow us to study how movements in egocentric and allocentric spaces interlace. Tracking of multi-limb coordination, progress in online recording of neural activity in freely moving animals, and the unprecedented accumulation of genetically engineered mouse preparations makes the behavioral ground plan exposed in this review essential for a systematic study of the brain/behavior interface. Copyright © 2012 Elsevier B.V. All rights reserved.

Intrinsic and contextual features in object recognition.

PubMed

Schlangen, Derrick; Barenholtz, Elan

2015-01-28

The context in which an object is found can facilitate its recognition. Yet, it is not known how effective this contextual information is relative to the object's intrinsic visual features, such as color and shape. To address this, we performed four experiments using rendered scenes with novel objects. In each experiment, participants first performed a visual search task, searching for a uniquely shaped target object whose color and location within the scene was experimentally manipulated. We then tested participants' tendency to use their knowledge of the location and color information in an identification task when the objects' images were degraded due to blurring, thus eliminating the shape information. In Experiment 1, we found that, in the absence of any diagnostic intrinsic features, participants identified objects based purely on their locations within the scene. In Experiment 2, we found that participants combined an intrinsic feature, color, with contextual location in order to uniquely specify an object. In Experiment 3, we found that when an object's color and location information were in conflict, participants identified the object using both sources of information equally. Finally, in Experiment 4, we found that participants used whichever source of information-either color or location-was more statistically reliable in order to identify the target object. Overall, these experiments show that the context in which objects are found can play as important a role as intrinsic features in identifying the objects. © 2015 ARVO.

The effects of autonomy-supportive and controlling teaching behaviour in biology lessons with primary and secondary experiences on students' intrinsic motivation and flow-experience

NASA Astrophysics Data System (ADS)

Hofferber, Natalia; Basten, Melanie; Großmann, Nadine; Wilde, Matthias

2016-09-01

Self-Determination Theory and Flow Theory propose that perceived autonomy fosters the positive qualities of motivation and flow-experience. Autonomy-support can help to maintain students' motivation in very interesting learning activities and may lead to an increase in the positive qualities of motivation in less interesting learning activities. This paper investigates whether autonomy-supportive or controlling teaching behaviour influence students' motivation and flow-experience in biology class. In study 1, 158 students of grade six worked on the adaptations of Harvest Mice (Micromys minutus) with living animals. The 153 sixth graders of study 2 dealt with the same content but instead worked with short films on laptops. Previous studies have shown that students perceive film sequences as less interesting than working with living animals. Students' intrinsic motivation and flow-experience were measured at the end of the first and the third lesson. In study 1, autonomy-supportive teaching behaviour led to significant differences in students' intrinsic motivation and flow-experience when compared to controlling teaching behaviour. In study 2, motivation and flow-experience were not always in line with theory. The positive effects of autonomy-supportive and the non-beneficial effects of the controlling teaching behaviour seem to be dependent on the interestingness of the teaching material.

Injection Drug Users’ Involvement In Drug Economy: Dynamics of Sociometric and Egocentric Social Networks

PubMed Central

Yang, Cui; Latkin, Carl; Muth, Stephen Q.; Rudolph, Abby

2014-01-01

The purpose of this analysis was to examine the effect of social network cohesiveness on drug economy involvement, and to test whether this relationship is mediated by drug support network size in a sample of active injection drug users. Involvement in the drug economy was defined by self-report of participation in at least one of the following activities: selling drugs, holding drugs or money for drugs, providing street security for drug sellers, cutting/packaging/cooking drugs, selling or renting drug paraphernalia (e.g., pipes, tools, rigs), and injecting drugs in others’ veins. The sample consists of 273 active injection drug users in Baltimore, Maryland who reported having injected drugs in the last 6 months and were recruited through either street outreach or by their network members. Egocentric drug support networks were assessed through a social network inventory at baseline. Sociometric networks were built upon the linkages by selected matching characteristics, and k-plex rank was used to characterize the level of cohesiveness of the individual to others in the social network. Although no direct effect was observed, structural equation modeling indicated k-plex rank was indirectly associated with drug economy involvement through drug support network size. These findings suggest the effects of large-scale sociometric networks on injectors’ drug economy involvement may occur through their immediate egocentric networks. Future harm reduction programs for injection drug users (IDUs) should consider providing programs coupled with economic opportunities to those drug users within a cohesive network subgroup. Moreover, individuals with a high connectivity to others in their network may be optimal individuals to train for diffusing HIV prevention messages. PMID:25309015

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Ramírez García, D.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. Von; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Weber, M.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.

2018-02-01

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon (?), thoron (?) and krypton (?). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ˜ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode.

Simulations Meet Experiment to Reveal New Insights into DNA Intrinsic Mechanics

PubMed Central

Ben Imeddourene, Akli; Elbahnsi, Ahmad; Guéroult, Marc; Oguey, Christophe; Foloppe, Nicolas; Hartmann, Brigitte

2015-01-01

The accurate prediction of the structure and dynamics of DNA remains a major challenge in computational biology due to the dearth of precise experimental information on DNA free in solution and limitations in the DNA force-fields underpinning the simulations. A new generation of force-fields has been developed to better represent the sequence-dependent B-DNA intrinsic mechanics, in particular with respect to the BI ↔ BII backbone equilibrium, which is essential to understand the B-DNA properties. Here, the performance of MD simulations with the newly updated force-fields Parmbsc0εζOLI and CHARMM36 was tested against a large ensemble of recent NMR data collected on four DNA dodecamers involved in nucleosome positioning. We find impressive progress towards a coherent, realistic representation of B-DNA in solution, despite residual shortcomings. This improved representation allows new and deeper interpretation of the experimental observables, including regarding the behavior of facing phosphate groups in complementary dinucleotides, and their modulation by the sequence. It also provides the opportunity to extensively revisit and refine the coupling between backbone states and inter base pair parameters, which emerges as a common theme across all the complementary dinucleotides. In sum, the global agreement between simulations and experiment reveals new aspects of intrinsic DNA mechanics, a key component of DNA-protein recognition. PMID:26657165

Recollection and unitization in associating actors with extrinsic and intrinsic motions.

PubMed

Kersten, Alan W; Earles, Julie L; Berger, Johanna D

2015-04-01

Four experiments provide evidence for a distinction between 2 different kinds of motion representations. Extrinsic motions involve the path of an object with respect to an external frame of reference. Intrinsic motions involve the relative motions of the parts of an object. This research suggests that intrinsic motions are represented conjointly with information about the identities of the actors who perform them, whereas extrinsic motions are represented separately from identity information. Experiment 1 demonstrated that participants remembered which actor had performed a particular intrinsic motion better than they remembered which actor had performed a particular extrinsic motion. Experiment 2 replicated this effect with incidental encoding of actor information, suggesting that encoding intrinsic motions leads one to automatically encode identity information. The results of Experiments 3 and 4 were fit by Yonelinas's (1999) source-memory model to quantify the contributions of familiarity and recollection to memory for the actors who carried out the intrinsic and extrinsic motions. Successful performance with extrinsic motion items in Experiment 3 required participants to remember in which scene contexts an actor had appeared, whereas successful performance in Experiment 4 required participants to remember the exact path taken by an actor in each scene. In both experiments, discrimination of old and new combinations of actors and extrinsic motions relied strongly on recollection, suggesting independent but associated representations of actors and extrinsic motions. In contrast, participants discriminated old and new combinations of actors and intrinsic motions primarily on the basis of familiarity, suggesting unitized representations of actors and intrinsic motions. (c) 2015 APA, all rights reserved).

Egocentric Social Network Analysis of Pathological Gambling

PubMed Central

Meisel, Matthew K.; Clifton, Allan D.; MacKillop, James; Miller, Joshua D.; Campbell, W. Keith; Goodie, Adam S.

2012-01-01

Aims To apply social network analysis (SNA) to investigate whether frequency and severity of gambling problems were associated with different network characteristics among friends, family, and co-workers. is an innovative way to look at relationships among individuals; the current study was the first to our knowledge to apply SNA to gambling behaviors. Design Egocentric social network analysis was used to formally characterize the relationships between social network characteristics and gambling pathology. Setting Laboratory-based questionnaire and interview administration. Participants Forty frequent gamblers (22 non-pathological gamblers, 18 pathological gamblers) were recruited from the community. Findings The SNA revealed significant social network compositional differences between the two groups: pathological gamblers (PGs) had more gamblers, smokers, and drinkers in their social networks than did nonpathological gamblers (NPGs). PGs had more individuals in their network with whom they personally gambled, smoked, and drank with than those with who were NPG. Network ties were closer to individuals in their networks who gambled, smoked, and drank more frequently. Associations between gambling severity and structural network characteristics were not significant. Conclusions Pathological gambling is associated with compositional but not structural differences in social networks. Pathological gamblers differ from non-pathological gamblers in the number of gamblers, smokers, and drinkers in their social networks. Homophily within the networks also indicates that gamblers tend to be closer with other gamblers. This homophily may serve to reinforce addictive behaviors, and may suggest avenues for future study or intervention. PMID:23072641

Egocentric social network analysis of pathological gambling.

PubMed

Meisel, Matthew K; Clifton, Allan D; Mackillop, James; Miller, Joshua D; Campbell, W Keith; Goodie, Adam S

2013-03-01

To apply social network analysis (SNA) to investigate whether frequency and severity of gambling problems were associated with different network characteristics among friends, family and co-workers is an innovative way to look at relationships among individuals; the current study was the first, to our knowledge, to apply SNA to gambling behaviors. Egocentric social network analysis was used to characterize formally the relationships between social network characteristics and gambling pathology. Laboratory-based questionnaire and interview administration. Forty frequent gamblers (22 non-pathological gamblers, 18 pathological gamblers) were recruited from the community. The SNA revealed significant social network compositional differences between the two groups: pathological gamblers (PGs) had more gamblers, smokers and drinkers in their social networks than did non-pathological gamblers (NPGs). PGs had more individuals in their network with whom they personally gambled, smoked and drank than those with who were NPG. Network ties were closer to individuals in their networks who gambled, smoked and drank more frequently. Associations between gambling severity and structural network characteristics were not significant. Pathological gambling is associated with compositional but not structural differences in social networks. Pathological gamblers differ from non-pathological gamblers in the number of gamblers, smokers and drinkers in their social networks. Homophily within the networks also indicates that gamblers tend to be closer with other gamblers. This homophily may serve to reinforce addictive behaviors, and may suggest avenues for future study or intervention. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

Internal friction in an intrinsically disordered protein—Comparing Rouse-like models with experiments

NASA Astrophysics Data System (ADS)

Soranno, Andrea; Zosel, Franziska; Hofmann, Hagen

2018-03-01

Internal friction is frequently found in protein dynamics. Its molecular origin however is difficult to conceptualize. Even unfolded and intrinsically disordered polypeptide chains exhibit signs of internal friction despite their enormous solvent accessibility. Here, we compare four polymer theories of internal friction with experimental results on the intrinsically disordered protein ACTR (activator of thyroid hormone receptor). Using nanosecond fluorescence correlation spectroscopy combined with single-molecule Förster resonance energy transfer (smFRET), we determine the time scales of the diffusive chain dynamics of ACTR at different solvent viscosities and varying degrees of compaction. Despite pronounced differences between the theories, we find that all models can capture the experimental viscosity-dependence of the chain relaxation time. In contrast, the observed slowdown upon chain collapse of ACTR is not captured by any of the theories and a mechanistic link between chain dimension and internal friction is still missing, implying that the current theories are incomplete. In addition, a discrepancy between early results on homopolymer solutions and recent single-molecule experiments on unfolded and disordered proteins suggests that internal friction is likely to be a composite phenomenon caused by a variety of processes.

Internal friction in an intrinsically disordered protein-Comparing Rouse-like models with experiments.

PubMed

Soranno, Andrea; Zosel, Franziska; Hofmann, Hagen

2018-03-28

Internal friction is frequently found in protein dynamics. Its molecular origin however is difficult to conceptualize. Even unfolded and intrinsically disordered polypeptide chains exhibit signs of internal friction despite their enormous solvent accessibility. Here, we compare four polymer theories of internal friction with experimental results on the intrinsically disordered protein ACTR (activator of thyroid hormone receptor). Using nanosecond fluorescence correlation spectroscopy combined with single-molecule Förster resonance energy transfer (smFRET), we determine the time scales of the diffusive chain dynamics of ACTR at different solvent viscosities and varying degrees of compaction. Despite pronounced differences between the theories, we find that all models can capture the experimental viscosity-dependence of the chain relaxation time. In contrast, the observed slowdown upon chain collapse of ACTR is not captured by any of the theories and a mechanistic link between chain dimension and internal friction is still missing, implying that the current theories are incomplete. In addition, a discrepancy between early results on homopolymer solutions and recent single-molecule experiments on unfolded and disordered proteins suggests that internal friction is likely to be a composite phenomenon caused by a variety of processes.

The impact of egocentric vs. allocentric agency attributions on the neural bases of reasoning about social rules.

PubMed

Canessa, Nicola; Pantaleo, Giuseppe; Crespi, Chiara; Gorini, Alessandra; Cappa, Stefano F

2014-09-18

We used the "standard" and "switched" social contract versions of the Wason Selection-task to investigate the neural bases of human reasoning about social rules. Both these versions typically elicit the deontically correct answer, i.e. the proper identification of the violations of a conditional obligation. Only in the standard version of the task, however, this response corresponds to the logically correct one. We took advantage of this differential adherence to logical vs. deontical accuracy to test the different predictions of logic rule-based vs. visuospatial accounts of inferential abilities in 14 participants who solved the standard and switched versions of the Selection-task during functional-Magnetic-Resonance-Imaging. Both versions activated the well known left fronto-parietal network of deductive reasoning. The standard version additionally recruited the medial parietal and right inferior parietal cortex, previously associated with mental imagery and with the adoption of egocentric vs. allocentric spatial reference frames. These results suggest that visuospatial processes encoding one's own subjective experience in social interactions may support and shape the interpretation of deductive arguments and/or the resulting inferences, thus contributing to elicit content effects in human reasoning. Copyright © 2014 Elsevier B.V. All rights reserved.

Expectation affects verbal judgments but not reaches to visually perceived egocentric distances.

PubMed

Pagano, Christopher C; Isenhower, Robert W

2008-04-01

Two response measures for reporting visually perceived egocentric distances-verbal judgments and blind manual reaches-were compared using a within-trial methodology. The expected range of possible target distances was manipulated by instructing the subjects that the targets would be between .50 and 1.00 of their maximum arm reach in one session and between .25 and .90 in another session. The actual range of target distances was always .50-.90. Verbal responses varied as a function of the range of expected distances, whereas simultaneous reaches remained unaffected. These results suggest that verbal responses are subject to a cognitive influence that does not affect actions. It is suggested that action responses are indicative of absolute perception, whereas cognitive responses may reflect only relative perception. The results also indicate that the dependant variable utilized for the study of depth perception will influence the obtained results.

Similarities and differences between the brain networks underlying allocentric and egocentric spatial learning in rat revealed by cytochrome oxidase histochemistry.

PubMed

Rubio, S; Begega, A; Méndez, M; Méndez-López, M; Arias, J L

2012-10-25

The involvement of different brain regions in place- and response-learning was examined using a water cross-maze. Rats were trained to find the goal from the initial arm by turning left at the choice point (egocentric strategy) or by using environmental cues (allocentric strategy). Although different strategies were required, the same maze and learning conditions were used. Using cytochrome oxidase histochemistry as a marker of cellular activity, the function of the 13 diverse cortical and subcortical regions was assessed in rats performing these two tasks. Our results show that allocentric learning depends on the recruitment of a large functional network, which includes the hippocampal CA3, dentate gyrus, medial mammillary nucleus and supramammillary nucleus. Along with the striatum, these last three structures are also related to egocentric spatial learning. The present study provides evidence for the contribution of these regions to spatial navigation and supports a possible functional interaction between the two memory systems, as their structural convergence may facilitate functional cooperation in the behaviours guided by more than one strategy. In summary, it can be argued that spatial learning is based on dynamic functional systems in which the interaction of brain regions is modulated by task requirements. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Does displayed enthusiasm favour recall, intrinsic motivation and time estimation?

PubMed

Moè, Angelica

2016-11-01

Displayed enthusiasm has been shown to relate to intrinsic motivation, vitality, and positive affect, but its effects on recall performance and time estimation have not yet been explored. This research aimed at studying the effects of a delivery style characterised by High Enthusiasm (HE) on recall, time estimation, and intrinsic motivation. In line with previous studies, effects on intrinsic motivation were expected. In addition, higher recall and lower time estimations were hypothesised. In two experiments, participants assigned to a HE condition or to a normal reading control condition listened to a narrative and to a descriptive passage. Then, they were asked to rate perceived time, enthusiasm, pleasure, interest, enjoyment and curiosity, before writing a free recall. Experiment 1 showed that in the HE condition, participants recalled more, were more intrinsically motivated, and expressed lower time estimations compared to the control condition. Experiment 2 confirmed the positive effects of HE reading compared to normal reading, using different passages and a larger sample.

Scalability, Timing, and System Design Issues for Intrinsic Evolvable Hardware

NASA Technical Reports Server (NTRS)

Hereford, James; Gwaltney, David

2004-01-01

In this paper we address several issues pertinent to intrinsic evolvable hardware (EHW). The first issue is scalability; namely, how the design space scales as the programming string for the programmable device gets longer. We develop a model for population size and the number of generations as a function of the programming string length, L, and show that the number of circuit evaluations is an O(L2) process. We compare our model to several successful intrinsic EHW experiments and discuss the many implications of our model. The second issue that we address is the timing of intrinsic EHW experiments. We show that the processing time is a small part of the overall time to derive or evolve a circuit and that major improvements in processor speed alone will have only a minimal impact on improving the scalability of intrinsic EHW. The third issue we consider is the system-level design of intrinsic EHW experiments. We review what other researchers have done to break the scalability barrier and contend that the type of reconfigurable platform and the evolutionary algorithm are tied together and impose limits on each other.

Dominance dynamics of competition between intrinsic and extrinsic grouping cues.

PubMed

Luna, Dolores; Villalba-García, Cristina; Montoro, Pedro R; Hinojosa, José A

2016-10-01

In the present study we examined the dominance dynamics of perceptual grouping cues. We used a paradigm in which participants selectively attended to perceptual groups based on several grouping cues in different blocks of trials. In each block, single and competing grouping cues were presented under different exposure durations (50, 150 or 350ms). Using this procedure, intrinsic vs. intrinsic cues (i.e. proximity and shape similarity) were compared in Experiment 1; extrinsic vs. extrinsic cues (i.e. common region and connectedness) in Experiment 2; and intrinsic vs. extrinsic cues (i.e. common region and shape similarity) in Experiment 3. The results showed that in Experiment 1, no dominance of any grouping cue was found: shape similarity and proximity grouping cues showed similar reaction times (RTs) and interference effects. In contrast, in Experiments 2 and 3, common region dominated processing: (i) RTs to common region were shorter than those to connectedness (Exp. 2) or shape similarity (Exp. 3); and (ii) when the grouping cues competed, common region interfered with connectedness (Exp. 2) and shape similarity (Exp. 3) more than vice versa. The results showed that the exposure duration of stimuli only affected the connectedness grouping cue. An important result of our experiments indicates that when two grouping cues compete, both the non-attended intrinsic cue in Experiment 1, and the non-dominant extrinsic cue in Experiments 2 and 3, are still perceived and they are not completely lost. Copyright © 2016 Elsevier B.V. All rights reserved.

Local Intrinsic Dimension Estimation by Generalized Linear Modeling.

PubMed

Hino, Hideitsu; Fujiki, Jun; Akaho, Shotaro; Murata, Noboru

2017-07-01

We propose a method for intrinsic dimension estimation. By fitting the power of distance from an inspection point and the number of samples included inside a ball with a radius equal to the distance, to a regression model, we estimate the goodness of fit. Then, by using the maximum likelihood method, we estimate the local intrinsic dimension around the inspection point. The proposed method is shown to be comparable to conventional methods in global intrinsic dimension estimation experiments. Furthermore, we experimentally show that the proposed method outperforms a conventional local dimension estimation method.

Intrinsic honesty and the prevalence of rule violations across societies.

PubMed

Gächter, Simon; Schulz, Jonathan F

2016-03-24

Deception is common in nature and humans are no exception. Modern societies have created institutions to control cheating, but many situations remain where only intrinsic honesty keeps people from cheating and violating rules. Psychological, sociological and economic theories suggest causal pathways to explain how the prevalence of rule violations in people's social environment, such as corruption, tax evasion or political fraud, can compromise individual intrinsic honesty. Here we present cross-societal experiments from 23 countries around the world that demonstrate a robust link between the prevalence of rule violations and intrinsic honesty. We developed an index of the 'prevalence of rule violations' (PRV) based on country-level data from the year 2003 of corruption, tax evasion and fraudulent politics. We measured intrinsic honesty in an anonymous die-rolling experiment. We conducted the experiments with 2,568 young participants (students) who, due to their young age in 2003, could not have influenced PRV in 2003. We find individual intrinsic honesty is stronger in the subject pools of low PRV countries than those of high PRV countries. The details of lying patterns support psychological theories of honesty. The results are consistent with theories of the cultural co-evolution of institutions and values, and show that weak institutions and cultural legacies that generate rule violations not only have direct adverse economic consequences, but might also impair individual intrinsic honesty that is crucial for the smooth functioning of society.

Intrinsic Honesty and the Prevalence of Rule Violations across Societies

PubMed Central

Gächter, Simon; Schulz, Jonathan F.

2016-01-01

Deception is common in nature and humans are no exception1. Modern societies have created institutions to control cheating, but many situations remain where only intrinsic honesty keeps people from cheating and violating rules. Psychological2, sociological3 and economic theories4 suggest causal pathways about how the prevalence of rule violations in people's social environment such as corruption, tax evasion, or political fraud can compromise individual intrinsic honesty. Here, we present cross-societal experiments from 23 countries around the world, which demonstrate a robust link between the prevalence of rule violations and intrinsic honesty. We developed an index of the Prevalence of Rule Violations (PRV) based on country-level data of corruption, tax evasion, and fraudulent politics. We measured intrinsic honesty in an anonymous die-rolling experiment.5 We conducted the experiments at least eight years after the measurement of PRV with 2568 young participants (students) who could not influence PRV. We find individual intrinsic honesty is stronger in the subject pools of low PRV countries than those of high PRV countries. The details of lying patterns support psychological theories of honesty.6,7 The results are consistent with theories of the cultural co-evolution of institutions and values8 and show that weak institutions and cultural legacies9-11 that generate rule violations not only have direct adverse economic consequences but might also impair individual intrinsic honesty that is crucial for the smooth functioning of society. PMID:26958830

Identifying the neural substrates of intrinsic motivation during task performance.

PubMed

Lee, Woogul; Reeve, Johnmarshall

2017-10-01

Intrinsic motivation is the inherent tendency to seek out novelty and challenge, to explore and investigate, and to stretch and extend one's capacities. When people imagine performing intrinsically motivating tasks, they show heightened anterior insular cortex (AIC) activity. To fully explain the neural system of intrinsic motivation, however, requires assessing neural activity while people actually perform intrinsically motivating tasks (i.e., while answering curiosity-inducing questions or solving competence-enabling anagrams). Using event-related functional magnetic resonance imaging, we found that the neural system of intrinsic motivation involves not only AIC activity, but also striatum activity and, further, AIC-striatum functional interactions. These findings suggest that subjective feelings of intrinsic satisfaction (associated with AIC activations), reward processing (associated with striatum activations), and their interactions underlie the actual experience of intrinsic motivation. These neural findings are consistent with the conceptualization of intrinsic motivation as the pursuit and satisfaction of subjective feelings (interest and enjoyment) as intrinsic rewards.

Language supports young children’s use of spatial relations to remember locations

PubMed Central

Miller, Hilary E.; Patterson, Rebecca; Simmering, Vanessa R.

2016-01-01

Two experiments investigated the role of language in children’s spatial recall performance. In particular, we assessed whether selecting an intrinsic reference frame could be improved through verbal encoding. Selecting an intrinsic reference frame requires remembering locations relative to nearby objects independent of one’s body (egocentric) or distal environmental (allocentric) cues, and does not reliably occur in children under 5 years of age (Nardini, Burgess, Breckenridge, & Atkinson, 2006). The current studies tested the relation between spatial language and 4-year-olds’ selection of an intrinsic reference frame in spatial recall. Experiment 1 showed that providing 4-year-olds with location-descriptive cues during (Exp. 1a) or before (Exp. 1b) the recall task improved performance both overall and specifically on trials relying most on an intrinsic reference frame. Additionally, children’s recall performance was predicted by their verbal descriptions of the task space (Exp. 1a control condition). Non-verbally highlighting relations among objects during the recall task (Exp. 2) supported children’s performance relative to the control condition, but significantly less than the location-descriptive cues. These results suggest that the ability to verbally represent relations is a potential mechanism that could account for developmental changes in the selection of an intrinsic reference frame during spatial recall. PMID:26896902

Language supports young children's use of spatial relations to remember locations.

PubMed

Miller, Hilary E; Patterson, Rebecca; Simmering, Vanessa R

2016-05-01

Two experiments investigated the role of language in children's spatial recall performance. In particular, we assessed whether selecting an intrinsic reference frame could be improved through verbal encoding. Selecting an intrinsic reference frame requires remembering locations relative to nearby objects independent of one's body (egocentric) or distal environmental (allocentric) cues, and does not reliably occur in children under 5 years of age (Nardini, Burgess, Breckenridge, & Atkinson, 2006). The current studies tested the relation between spatial language and 4-year-olds' selection of an intrinsic reference frame in spatial recall. Experiment 1 showed that providing 4-year-olds with location-descriptive cues during (Exp. 1a) or before (Exp. 1b) the recall task improved performance both overall and specifically on trials relying most on an intrinsic reference frame. Additionally, children's recall performance was predicted by their verbal descriptions of the task space (Exp. 1a control condition). Non-verbally highlighting relations among objects during the recall task (Exp. 2) supported children's performance relative to the control condition, but significantly less than the location-descriptive cues. These results suggest that the ability to verbally represent relations is a potential mechanism that could account for developmental changes in the selection of an intrinsic reference frame during spatial recall. Copyright © 2016 Elsevier B.V. All rights reserved.

Angular scale expansion theory and the misperception of egocentric distance in locomotor space.

PubMed

Durgin, Frank H

Perception is crucial for the control of action, but perception need not be scaled accurately to produce accurate actions. This paper reviews evidence for an elegant new theory of locomotor space perception that is based on the dense coding of angular declination so that action control may be guided by richer feedback. The theory accounts for why so much direct-estimation data suggests that egocentric distance is underestimated despite the fact that action measures have been interpreted as indicating accurate perception. Actions are calibrated to the perceived scale of space and thus action measures are typically unable to distinguish systematic (e.g., linearly scaled) misperception from accurate perception. Whereas subjective reports of the scaling of linear extent are difficult to evaluate in absolute terms, study of the scaling of perceived angles (which exist in a known scale, delimited by vertical and horizontal) provides new evidence regarding the perceptual scaling of locomotor space.

Conceptualizing Geosexual Archetypes: Mapping the Sexual Travels and Egocentric Sexual Networks of Gay and Bisexual Men in Toronto, Canada.

PubMed

Gesink, Dionne; Wang, Susan; Guimond, Tim; Kimura, Lauren; Connell, James; Salway, Travis; Gilbert, Mark; Mishra, Sharmistha; Tan, Darrell; Burchell, Ann N; Brennan, David J; Logie, Carmen H; Grace, Daniel

2018-06-01

There are complex, synergistic, and persistent sexually transmitted infection (STI) epidemics affecting gay, bisexual and other men who have sex with men (gbMSM) in every major urban centre across North America. We explored the spatial architecture of egocentric sexual networks for gbMSM in Toronto, Canada. Our integrative mixed methods study included in-depth interviews with 31 gbMSM between May and July 2016. During interviews, participants mapped their egocentric sexual network for the preceding 3 months geographically. At the end, a self-administered survey was used to collect sociodemographic characteristics, online technology use, and STI testing and history. We identified 6 geosexual archetypes: hosters, house-callers, privates, rovers, travellers, and geoflexibles. Hosters always, or almost always (≥80%), hosted sex at their home. House-callers always, or almost always (≥80%), had sex at their partner's home. Rovers always or almost always (≥80%) had sex at public venues (eg, bath houses, sex clubs) and other public spaces (eg, parks, cruising sites). Privates had sex in private-their own home or their partner's (part hoster, part house-caller). Travellers had sex away from their home, either at a partner's home or some other venue or public space (part house-caller, part rover). Geoflexibles had sex in a variety of locations-their home, their partner's home, or public venues. All hosters and rovers, and to a lesser extent, geoflexibles, reported a history of syphilis and human immunodeficiency virus. Prioritizing interventions to hosters, rovers, and geoflexibles may have an important impact on reducing STI transmission.

Prevalence of Principles of Piaget’s Theory Among 4-7-year-old Children and their Correlation with IQ

PubMed Central

Marwaha, Sugandha; Vashist, Binny

2017-01-01

Introduction Cognitive development is a major area of human development and was extensively studied by Jean Piaget. He proposed that the development of intellectual abilities occurs in a series of relatively distinct stages and that a child’s way of thinking and viewing the world is different at different stages. Aim To assess Piaget’s principles of the intuitive stage of preoperational period among 4-7-year-old children relative to their Intelligence quotient (IQ). Materials and Methods Various characteristics as described by Jean Piaget specific for the age group of 4-7 years along with those of the previous (preconceptual stage of preoperational period) and successive periods (concrete operations) were analysed using various experiments in 300 children. These characteristics included the concepts of perceptual and cognitive egocentrism, centration and reversibility. IQ of the children was measured using Seguin form board test. Inferential statistics were performed using Chi-square test and Kruskal Wallis test. The level of statistical significance was set at 0.05. Results The prevalence of perceptual and cognitive egocentrism was 10.7% and 31.7% based on the experiments and 33% based on the interview question. Centration was present in 96.3% of the children. About 99% children lacked the concept of reversibility according to the clay experiment while 97.7% possessed this concept according to the interview question. The mean IQ score of children who possessed perceptual egocentrism, cognitive egocentrism and egocentrism in dental setting was significantly higher than those who lacked these characteristics. Conclusion Perceptual egocentrism had almost disappeared and prevalence of cognitive egocentrism decreased with increase in age. Centration and lack of reversibility were appreciated in most of the children. There was a gradual reduction in the prevalence of these characters with increasing age. Mean IQ score of children who possessed perceptual egocentrism

Prevalence of Principles of Piaget's Theory Among 4-7-year-old Children and their Correlation with IQ.

PubMed

Marwaha, Sugandha; Goswami, Mousumi; Vashist, Binny

2017-08-01

Cognitive development is a major area of human development and was extensively studied by Jean Piaget. He proposed that the development of intellectual abilities occurs in a series of relatively distinct stages and that a child's way of thinking and viewing the world is different at different stages. To assess Piaget's principles of the intuitive stage of preoperational period among 4-7-year-old children relative to their Intelligence quotient (IQ). Various characteristics as described by Jean Piaget specific for the age group of 4-7 years along with those of the previous (preconceptual stage of preoperational period) and successive periods (concrete operations) were analysed using various experiments in 300 children. These characteristics included the concepts of perceptual and cognitive egocentrism, centration and reversibility. IQ of the children was measured using Seguin form board test. Inferential statistics were performed using Chi-square test and Kruskal Wallis test. The level of statistical significance was set at 0.05. The prevalence of perceptual and cognitive egocentrism was 10.7% and 31.7% based on the experiments and 33% based on the interview question. Centration was present in 96.3% of the children. About 99% children lacked the concept of reversibility according to the clay experiment while 97.7% possessed this concept according to the interview question. The mean IQ score of children who possessed perceptual egocentrism, cognitive egocentrism and egocentrism in dental setting was significantly higher than those who lacked these characteristics. Perceptual egocentrism had almost disappeared and prevalence of cognitive egocentrism decreased with increase in age. Centration and lack of reversibility were appreciated in most of the children. There was a gradual reduction in the prevalence of these characters with increasing age. Mean IQ score of children who possessed perceptual egocentrism, cognitive egocentrism and egocentrism in dental setting was

Coach autonomy support, basic need satisfaction, and intrinsic motivation of paralympic athletes.

PubMed

Banack, Hailey R; Sabiston, Catherine M; Bloom, Gordon A

2011-12-01

The purpose of the present study, grounded in self-determination theory, was to explore the relationship between Paralympic athletes' perceptions of autonomy-supportive coach behavior basic psychological needs, and intrinsic motivation to know, accomplish, and experience stimulation. One hundred thirteen Canadian Paralympic athletes completed an online survey, consisting of measures of coach autonomy support; of perceptions of autonomy, competence, and relatedness; and of intrinsic motivation. Perceived coach autonomy support was a predictor of athletes' perceptions of autonomy and relatedness. Perceived competence was a significant predictor of all three forms of intrinsic motivation, while perceived autonomy was a significant predictor of intrinsic motivation to accomplish and experience stimulation. The results highlight the important relationship between coach behavior and athlete motivation in disability sport.

Cholinesterase inhibitors modify the activity of intrinsic cardiac neurons.

PubMed

Darvesh, Sultan; Arora, Rakesh C; Martin, Earl; Magee, David; Hopkins, David A; Armour, J Andrew

2004-08-01

Cholinesterase inhibitors used to treat the symptoms of Alzheimer's disease (AD) inhibit both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), albeit to different degrees. Because central and peripheral neurons, including intrinsic cardiac neurons located on the surface of the mammalian heart, express both BuChE and AChE, we studied spontaneously active intrinsic cardiac neurons in the pig as a model to assess the effects of inhibition of AChE compared to BuChE. Neuroanatomical experiments showed that some porcine intrinsic cardiac neurons expressed AChE and/or BuChE. Enzyme kinetic experiments with cholinesterase inhibitors, namely, donepezil, galantamine, (+/-) huperzine A, metrifonate, rivastigmine, and tetrahydroaminoacridine, demonstrated that these compounds differentially inhibited porcine AChE and BuChE. Donepezil and (+/-) huperzine A were better reversible inhibitors of AChE, and galantamine equally inhibited both the enzymes. Tetrahydroaminoacridine was a better reversible inhibitor of BuChE. Rivastigmine caused more rapid inactivation of BuChE as compared to AChE. Neurophysiological studies showed that acetylcholine and butyrylcholine increase or decrease the spontaneous activity of the intrinsic cardiac neurons. Donepezil, galantamine, (+/-) huperzine A, and tetrahydroaminoacridine changed spontaneous neuronal activity by about 30-35 impulses per minute, while rivastigmine changed it by approximately 100 impulses per minute. It is concluded that (i) inhibition of AChE and BuChE directly affects the porcine intrinsic cardiac nervous system, (ii) the intrinsic cardiac nervous system represents a suitable model for examining the effects of cholinesterase inhibitors on mammalian neurons in vivo, and (iii) the activity of intrinsic cardiac neurons may be affected by pharmacological agents that inhibit cholinesterases.

Human phoneme recognition depending on speech-intrinsic variability.

PubMed

Meyer, Bernd T; Jürgens, Tim; Wesker, Thorsten; Brand, Thomas; Kollmeier, Birger

2010-11-01

The influence of different sources of speech-intrinsic variation (speaking rate, effort, style and dialect or accent) on human speech perception was investigated. In listening experiments with 16 listeners, confusions of consonant-vowel-consonant (CVC) and vowel-consonant-vowel (VCV) sounds in speech-weighted noise were analyzed. Experiments were based on the OLLO logatome speech database, which was designed for a man-machine comparison. It contains utterances spoken by 50 speakers from five dialect/accent regions and covers several intrinsic variations. By comparing results depending on intrinsic and extrinsic variations (i.e., different levels of masking noise), the degradation induced by variabilities can be expressed in terms of the SNR. The spectral level distance between the respective speech segment and the long-term spectrum of the masking noise was found to be a good predictor for recognition rates, while phoneme confusions were influenced by the distance to spectrally close phonemes. An analysis based on transmitted information of articulatory features showed that voicing and manner of articulation are comparatively robust cues in the presence of intrinsic variations, whereas the coding of place is more degraded. The database and detailed results have been made available for comparisons between human speech recognition (HSR) and automatic speech recognizers (ASR).

Conceptualizing Geosexual Archetypes: Mapping the Sexual Travels and Egocentric Sexual Networks of Gay and Bisexual Men in Toronto, Canada

PubMed Central

Gesink, Dionne; Wang, Susan; Guimond, Tim; Kimura, Lauren; Connell, James; Salway, Travis; Gilbert, Mark; Mishra, Sharmistha; Tan, Darrell; Burchell, Ann N.; Brennan, David J.; Logie, Carmen H.; Grace, Daniel

2018-01-01

Background There are complex, synergistic, and persistent sexually transmitted infection (STI) epidemics affecting gay, bisexual and other men who have sex with men (gbMSM) in every major urban centre across North America. We explored the spatial architecture of egocentric sexual networks for gbMSM in Toronto, Canada. Methods Our integrative mixed methods study included in-depth interviews with 31 gbMSM between May and July 2016. During interviews, participants mapped their egocentric sexual network for the preceding 3 months geographically. At the end, a self-administered survey was used to collect sociodemographic characteristics, online technology use, and STI testing and history. Results We identified 6 geosexual archetypes: hosters, house-callers, privates, rovers, travellers, and geoflexibles. Hosters always, or almost always (≥80%), hosted sex at their home. House-callers always, or almost always (≥80%), had sex at their partner’s home. Rovers always or almost always (≥80%) had sex at public venues (eg, bath houses, sex clubs) and other public spaces (eg, parks, cruising sites). Privates had sex in private—their own home or their partner's (part hoster, part house-caller). Travellers had sex away from their home, either at a partner’s home or some other venue or public space (part house-caller, part rover). Geoflexibles had sex in a variety of locations—their home, their partner’s home, or public venues. All hosters and rovers, and to a lesser extent, geoflexibles, reported a history of syphilis and human immunodeficiency virus. Conclusions Prioritizing interventions to hosters, rovers, and geoflexibles may have an important impact on reducing STI transmission. PMID:29465690

It's about time: Earlier rewards increase intrinsic motivation.

PubMed

Woolley, Kaitlin; Fishbach, Ayelet

2018-06-01

Can immediate (vs. delayed) rewards increase intrinsic motivation? Prior research compared the presence versus absence of rewards. By contrast, this research compared immediate versus delayed rewards, predicting that more immediate rewards increase intrinsic motivation by creating a perceptual fusion between the activity and its goal (i.e., the reward). In support of the hypothesis, framing a reward from watching a news program as more immediate (vs. delayed) increased intrinsic motivation to watch the program (Study 1), and receiving more immediate bonus (vs. delayed, Study 2; and vs. delayed and no bonus, Study 3) increased intrinsic motivation in an experimental task. The effect of reward timing was mediated by the strength of the association between an activity and a reward, and was specific to intrinsic (vs. extrinsic) motivation-immediacy influenced the positive experience of an activity, but not perceived outcome importance (Study 4). In addition, the effect of the timing of rewards was independent of the effect of the magnitude of the rewards (Study 5). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Species-specific preferences of German recreational anglers for freshwater fishing experiences, with emphasis on the intrinsic utilities of fish stocking and wild fishes.

PubMed

Arlinghaus, R; Beardmore, B; Riepe, C; Meyerhoff, J; Pagel, T

2014-12-01

To answer the question, whether anglers have an intrinsic preference for stocking or a preference for catch outcomes (e.g. catch rates) believed to be maintained by stocking, a discrete choice experiment was conducted among a sample of anglers (n = 1335) in Lower Saxony, Germany. After controlling for catch aspects of the fishing experience, no significant influence of two stocking attributes (stocking frequency and composition of the catch in terms of wild v. hatchery fishes) on the utility gained from fishing was found for any of the freshwater species that were studied. It was concluded that the previously documented large appreciation of fish stocking by anglers may be indicative of an underlying preference for sufficiently high catches rather than reflect an intrinsic preference for stocking or the catching of wild fishes per se. © 2014 The Fisheries Society of the British Isles.

Modeling heterogeneous responsiveness of intrinsic apoptosis pathway

PubMed Central

2013-01-01

molecular numbers. Furthermore, the extrinsic noise represented by random variations of two key apoptotic proteins, namely Cytochrome C and inhibitor of apoptosis proteins (IAP), is modeled separately or in combination with intrinsic noise. The resultant stochasticity in the timing of intrinsic apoptosis response shows that the fluctuating protein variations can induce cell-to-cell stochastic variability at a quantitative level agreeing with experiments. Finally, simulations illustrate that the mean abundance of fluctuating IAP protein is positively correlated with the degree of cellular stochasticity of the intrinsic apoptosis pathway. Conclusions Our theoretical and computational study shows that the pronounced non-genetic heterogeneity in intrinsic apoptosis responses among individual cells plausibly arises from extrinsic rather than intrinsic origin of fluctuations. In addition, it predicts that the IAP protein could serve as a potential therapeutic target for suppression of the cell-to-cell variation in the intrinsic apoptosis responsiveness. PMID:23875784

Predictors of Adolescent Female Decision Making Regarding Contraceptive Usage.

ERIC Educational Resources Information Center

Green, Vicki; And Others

1992-01-01

Examined relationship of cognitive capacity, cognitive egocentrism, and experience factors to decision making in contraceptive use. Findings from 50 sexually active, unmarried female adolescents revealed that cognitive capacity and cognitive egocentrism variables, not experience with contraceptives, were significantly related to, and predictive…

Age-related differences in function and structure of rSMG and reduced functional connectivity with DLPFC explains heightened emotional egocentricity bias in childhood.

PubMed

Steinbeis, Nikolaus; Bernhardt, Boris C; Singer, Tania

2015-02-01

Humans often judge others egocentrically, assuming that they feel or think similarly to themselves. Emotional egocentricity bias (EEB) occurs in situations when others feel differently to oneself. Using a novel paradigm, we investigated the neurocognitive mechanisms underlying the developmental capacity to overcome such EEB in children compared with adults. We showed that children display a stronger EEB than adults and that this correlates with reduced activation in right supramarginal gyrus (rSMG) as well as reduced coupling between rSMG and left dorsolateral prefrontal cortex (lDLPFC) in children compared with adults. Crucially, functional recruitment of rSMG was associated with age-related differences in cortical thickness of this region. Although in adults the mere presence of emotional conflict occurs between self and other recruited rSMG, rSMG-lDLPFC coupling was only observed when implementing empathic judgements. Finally, resting state analyses comparing connectivity patterns of rSMG with that of right temporoparietal junction suggested a unique role of rSMG for self-other distinction in the emotional domain for adults as well as for children. Thus, children's difficulties in overcoming EEB may be due to late maturation of regions distinguishing between conflicting socio-affective information and relaying this information to regions necessary for implementing accurate judgments. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Longitudinal relaxation properties of 1HN and 1Hα determined by direct-detected 13C NMR experiments to study intrinsically disordered proteins (IDPs)

NASA Astrophysics Data System (ADS)

Hošek, Tomáš; Gil-Caballero, Sergi; Pierattelli, Roberta; Brutscher, Bernhard; Felli, Isabella C.

2015-05-01

Intrinsically disordered proteins (IDPs) are functional proteins containing large fragments characterized by high local mobility. Bioinformatic studies have suggested that a significant fraction (more than 30%) of eukaryotic proteins has disordered regions of more than 50 amino acids in length. Hence, NMR methods for the characterization of local compactness and solvent accessibility in such highly disordered proteins are of high importance. Among the available approaches, the HET-SOFAST/BEST experiments (Schanda et al., 2006, Rennella et al., 2014) provide semi-quantitative information by monitoring longitudinal 1H relaxation of amide protons under different initial conditions. However, when approaching physiological sample conditions, the potential of these amide 1H detected experiments is reduced due to rapid amide proton solvent exchange. 13C direct detection methods therefore provide a valuable alternative thanks to a higher chemical shift dispersion and their intrinsic insensitivity toward solvent exchange. Here we present two sets of 13C-detected experiments, which indirectly measure 1HN and 1Hα inversion recovery profiles. The experiments consist of an initial spin inversion-recovery block optimized for selective manipulation of different types of proton spins followed by a CON read-out scheme. The proposed experiments were tested on human α-synuclein and ubiquitin, two representative examples of unfolded and folded proteins.

Intrinsic and Extrinsic Motivation Among Adolescent Ten-Pin Bowlers in Kuala Lumpur, Malaysia

PubMed Central

Teo, Eng-Wah; Khoo, Selina; Wong, Rebecca; Wee, Eng-Hoe; Lim, Boon-Hooi; Rengasamy, Shabesan Sit

2015-01-01

Motivation has long been associated with sports engagement. However, to date no research has been performed to understand the domain of motivation among ten-pin bowlers. The purpose of this study was to investigate different types of motivation (i.e., intrinsic vs. extrinsic) based on self-determination theory from the perspective of gender and the bowler type (competitive vs. casual). A total of 240 bowlers (104 male, 136 female; 152 competitive, 88 casual) with a mean age of 16.61 ± 0.78 years were recruited in Kuala Lumpur. The Sport Motivation Scale, a 28-item self-report questionnaire measuring seven subscales (i.e., intrinsic motivation to know, intrinsic motivation to accomplish, intrinsic motivation to experience stimulation, extrinsic motivation to identify regulation, extrinsic motivation for introjection regulation, extrinsic motivation to external regulation, and amotivation) was administered. Results showed significant differences (t=10.43, df=239, p=0.01) between total scores of intrinsic and extrinsic motivation among ten-pin bowlers. There were significant gender differences with respect to intrinsic motivation to know, intrinsic motivation to accomplish, intrinsic motivation to experience stimulation, and extrinsic motivation to identify regulation. However, no significant bowler type differences were found for either the intrinsic (t=−1.15, df=238, p=0.25) or extrinsic (t=−0.51, df=238, p=0.61) motivation dimensions. In conclusion, our study demonstrated substantial intrinsic motivation for gender effects, but no bowler type effects among adolescent ten-pin bowlers. PMID:25964827

Intrinsic and extrinsic motivation among adolescent ten-pin bowlers in kuala lumpur, malaysia.

PubMed

Teo, Eng-Wah; Khoo, Selina; Wong, Rebecca; Wee, Eng-Hoe; Lim, Boon-Hooi; Rengasamy, Shabesan Sit

2015-03-29

Motivation has long been associated with sports engagement. However, to date no research has been performed to understand the domain of motivation among ten-pin bowlers. The purpose of this study was to investigate different types of motivation (i.e., intrinsic vs. extrinsic) based on self-determination theory from the perspective of gender and the bowler type (competitive vs. casual). A total of 240 bowlers (104 male, 136 female; 152 competitive, 88 casual) with a mean age of 16.61 ± 0.78 years were recruited in Kuala Lumpur. The Sport Motivation Scale, a 28-item self-report questionnaire measuring seven subscales (i.e., intrinsic motivation to know, intrinsic motivation to accomplish, intrinsic motivation to experience stimulation, extrinsic motivation to identify regulation, extrinsic motivation for introjection regulation, extrinsic motivation to external regulation, and amotivation) was administered. Results showed significant differences (t=10.43, df=239, p=0.01) between total scores of intrinsic and extrinsic motivation among ten-pin bowlers. There were significant gender differences with respect to intrinsic motivation to know, intrinsic motivation to accomplish, intrinsic motivation to experience stimulation, and extrinsic motivation to identify regulation. However, no significant bowler type differences were found for either the intrinsic (t=-1.15, df=238, p=0.25) or extrinsic (t=-0.51, df=238, p=0.61) motivation dimensions. In conclusion, our study demonstrated substantial intrinsic motivation for gender effects, but no bowler type effects among adolescent ten-pin bowlers.

Intrinsic Factors Affecting Overseas Student Teaching

ERIC Educational Resources Information Center

Firmin, Michael W.; MacKay, Brenda B.; Firmin, Ruth L.

2007-01-01

We conducted a qualitative research study involving 13 undergraduate students who completed their student-teaching in overseas contexts. Participants completed two waves of interviews immediately after returning to campus from their multicultural experiences. Three intrinsic factors were found to have the greatest impact on students' overseas…

Organisational Learning and Employees' Intrinsic Motivation

ERIC Educational Resources Information Center

Remedios, Richard; Boreham, Nick

2004-01-01

This study examined the effects of organisational learning initiatives on employee motivation. Four initiatives consistent with theories of organisational learning were a priori ranked in terms of concepts that underpin intrinsic-motivation theory. Eighteen employees in a UK petrochemical company were interviewed to ascertain their experiences of…

Learning to learn – intrinsic plasticity as a metaplasticity mechanism for memory formation

PubMed Central

Sehgal, Megha; Song, Chenghui; Ehlers, Vanessa L.; Moyer, James R.

2013-01-01

“Use it or lose it” is a popular adage often associated with use-dependent enhancement of cognitive abilities. Much research has focused on understanding exactly how the brain changes as a function of experience. Such experience-dependent plasticity involves both structural and functional alterations that contribute to adaptive behaviors, such as learning and memory, as well as maladaptive behaviors, including anxiety disorders, phobias, and posttraumatic stress disorder. With the advancing age of our population, understanding how use-dependent plasticity changes across the lifespan may also help to promote healthy brain aging. A common misconception is that such experience-dependent plasticity (e.g., associative learning) is synonymous with synaptic plasticity. Other forms of plasticity also play a critical role in shaping adaptive changes within the nervous system, including intrinsic plasticity – a change in the intrinsic excitability of a neuron. Intrinsic plasticity can result from a change in the number, distribution or activity of various ion channels located throughout the neuron. Here, we review evidence that intrinsic plasticity is an important and evolutionarily conserved neural correlate of learning. Intrinsic plasticity acts as a metaplasticity mechanism by lowering the threshold for synaptic changes. Thus, learning-related intrinsic changes can facilitate future synaptic plasticity and learning. Such intrinsic changes can impact the allocation of a memory trace within a brain structure, and when compromised, can contribute to cognitive decline during the aging process. This unique role of intrinsic excitability can provide insight into how memories are formed and, more interestingly, how neurons that participate in a memory trace are selected. Most importantly, modulation of intrinsic excitability can allow for regulation of learning ability – this can prevent or provide treatment for cognitive decline not only in patients with clinical

Effect of q-profile structure on intrinsic torque reversals

NASA Astrophysics Data System (ADS)

Lu, Zhixin

2014-10-01

Intrinsic toroidal rotation plays an important role in mitigating macroinstability and regulating turbulent transport in ITER, where neutral beams are not sufficient to provide the requisite torque. Recent experiments on C-Mod with LHCD observed rotation reversal related to a change in the q profile. In this work, we focus on understanding the physics of intrinsic rotation reversals in LHCD plasmas, using nonlinear, global gyro-kinetic simulations and analysis of mode structure and spectrum symmetry breaking. The sensitive dependence of turbulent residual stress on magnetic shear is identified and characterized. The basic residual stress is non-vanishing when the k-parallel spectrum symmetry is broken, e.g., by E × B shear induced radial shift, non-uniformity in turbulence intensity, etc.. It is found that at low magnetic shear, the poloidal harmonics can shift strongly in the radial direction, as a feature of non-local effects, due to radial propagation and amplitude variation of the mode. This new symmetry breaking mechanism leads to a change in the sign of spectrum averaged parallel wave vector and thus the direction of intrinsic torque. Theoretical study shows that the competition between magnetic drift and ion kinetic effects determines the non-local effects and the structure of the asymmetry. Specifically, it is found that the direction of the intrinsic torque changes from counter- to co-current in the core, when magnetic shear decreases through a critical value. A critical shear ŝR = 0 . 2 ~ 0 . 5 for reversal of CTEM-induced intrinsic torque found by simulation is consistent with that from the LHCD C-Mod reversal experiments. In addition, simulations indicate ŝR = 1 ~ 2 for the reversal of ITG-induced torque, a prediction which can be tested by experiments. This work is supported by CER and CMTFO, UCSD and U.S. DOE-PPPL Contract DE-AC02-09CH11466.

Moral Distress, Workplace Health, and Intrinsic Harm.

PubMed

Weber, Elijah

2016-05-01

Moral distress is now being recognized as a frequent experience for many health care providers, and there's good evidence that it has a negative impact on the health care work environment. However, contemporary discussions of moral distress have several problems. First, they tend to rely on inadequate characterizations of moral distress. As a result, subsequent investigations regarding the frequency and consequences of moral distress often proceed without a clear understanding of the phenomenon being discussed, and thereby risk substantially misrepresenting the nature, frequency, and possible consequences of moral distress. These discussions also minimize the intrinsically harmful aspects of moral distress. This is a serious omission. Moral distress doesn't just have a negative impact on the health care work environment; it also directly harms the one who experiences it. In this paper, I claim that these problems can be addressed by first clarifying our understanding of moral distress, and then identifying what makes moral distress intrinsically harmful. I begin by identifying three common mistakes that characterizations of moral distress tend to make, and explaining why these mistakes are problematic. Next, I offer an account of moral distress that avoids these mistakes. Then, I defend the claim that moral distress is intrinsically harmful to the subject who experiences it. I conclude by explaining how acknowledging this aspect of moral distress should reshape our discussions about how best to deal with this phenomenon. © 2015 John Wiley & Sons Ltd.

Quantifying Intrinsic and Extrinsic Variability in Stochastic Gene Expression Models

PubMed Central

Singh, Abhyudai; Soltani, Mohammad

2013-01-01

Genetically identical cell populations exhibit considerable intercellular variation in the level of a given protein or mRNA. Both intrinsic and extrinsic sources of noise drive this variability in gene expression. More specifically, extrinsic noise is the expression variability that arises from cell-to-cell differences in cell-specific factors such as enzyme levels, cell size and cell cycle stage. In contrast, intrinsic noise is the expression variability that is not accounted for by extrinsic noise, and typically arises from the inherent stochastic nature of biochemical processes. Two-color reporter experiments are employed to decompose expression variability into its intrinsic and extrinsic noise components. Analytical formulas for intrinsic and extrinsic noise are derived for a class of stochastic gene expression models, where variations in cell-specific factors cause fluctuations in model parameters, in particular, transcription and/or translation rate fluctuations. Assuming mRNA production occurs in random bursts, transcription rate is represented by either the burst frequency (how often the bursts occur) or the burst size (number of mRNAs produced in each burst). Our analysis shows that fluctuations in the transcription burst frequency enhance extrinsic noise but do not affect the intrinsic noise. On the contrary, fluctuations in the transcription burst size or mRNA translation rate dramatically increase both intrinsic and extrinsic noise components. Interestingly, simultaneous fluctuations in transcription and translation rates arising from randomness in ATP abundance can decrease intrinsic noise measured in a two-color reporter assay. Finally, we discuss how these formulas can be combined with single-cell gene expression data from two-color reporter experiments for estimating model parameters. PMID:24391934

Quantifying intrinsic and extrinsic variability in stochastic gene expression models.

PubMed

Singh, Abhyudai; Soltani, Mohammad

2013-01-01

Genetically identical cell populations exhibit considerable intercellular variation in the level of a given protein or mRNA. Both intrinsic and extrinsic sources of noise drive this variability in gene expression. More specifically, extrinsic noise is the expression variability that arises from cell-to-cell differences in cell-specific factors such as enzyme levels, cell size and cell cycle stage. In contrast, intrinsic noise is the expression variability that is not accounted for by extrinsic noise, and typically arises from the inherent stochastic nature of biochemical processes. Two-color reporter experiments are employed to decompose expression variability into its intrinsic and extrinsic noise components. Analytical formulas for intrinsic and extrinsic noise are derived for a class of stochastic gene expression models, where variations in cell-specific factors cause fluctuations in model parameters, in particular, transcription and/or translation rate fluctuations. Assuming mRNA production occurs in random bursts, transcription rate is represented by either the burst frequency (how often the bursts occur) or the burst size (number of mRNAs produced in each burst). Our analysis shows that fluctuations in the transcription burst frequency enhance extrinsic noise but do not affect the intrinsic noise. On the contrary, fluctuations in the transcription burst size or mRNA translation rate dramatically increase both intrinsic and extrinsic noise components. Interestingly, simultaneous fluctuations in transcription and translation rates arising from randomness in ATP abundance can decrease intrinsic noise measured in a two-color reporter assay. Finally, we discuss how these formulas can be combined with single-cell gene expression data from two-color reporter experiments for estimating model parameters.

Flow for Exercise Adherence: Testing an Intrinsic Model of Health Behavior

ERIC Educational Resources Information Center

Petosa, R. Lingyak; Holtz, Brian

2013-01-01

Background: Health behavior theory generally does not include intrinsic motivation as a determinate of health practices. Purpose: The purpose of this study was to test the flow theory of exercise adherence. Flow theory posits that exercise can be intrinsically rewarding if the experiences of self/time transcendence and control/mastery are achieved…

Selective Disclosure of HIV Status in Egocentric Support Networks of People Living with HIV/AIDS

PubMed Central

Zang, Chunpeng; He, Xin

2014-01-01

The objective of this study was to investigate HIV disclosure activities in social support networks of people living with HIV/AIDS (PLWHAs). An egocentric network study was conducted in Nanning, China. A sample of 147 PLWHAs (egos) nominated 922 network members (alters) who would provide egos with social support. All egos disclosed their HIV status to at least one alter in their support networks and 26.5 % disclosed to all alters. Among network alters, 95.7 % of spouse alters, 59.9 % of other family member alters, and 29.7 % of friend alters were aware of egos’ HIV status. PLWHA egos were more likely to disclose their HIV status to their spouse and other family members, frequently-contacted alters, and alters who provided more social support. In addition, older egos and unmarried egos were more likely to disclose their HIV status. The findings indicate that network-based HIV intervention programs should take into consideration selective disclosure in social networks. PMID:24996393

Intrinsic factor

MedlinePlus

Intrinsic factor is a protein that helps your intestines absorb vitamin B12. It is made by cells in the ... Intrinsic factor is a protein that helps your body absorb vitamin B12. Vitamin B12 is needed for red blood ...

Does an Oblique/Slanted Perspective during Virtual Navigation Engage Both Egocentric and Allocentric Brain Strategies?

PubMed Central

Barra, Julien; Laou, Laetitia; Poline, Jean-Baptiste; Lebihan, Denis; Berthoz, Alain

2012-01-01

Perspective (route or survey) during the encoding of spatial information can influence recall and navigation performance. In our experiment we investigated a third type of perspective, which is a slanted view. This slanted perspective is a compromise between route and survey perspectives, offering both information about landmarks as in route perspective and geometric information as in survey perspective. We hypothesized that the use of slanted perspective would allow the brain to use either egocentric or allocentric strategies during storage and recall. Twenty-six subjects were scanned (3-Tesla fMRI) during the encoding of a path (40-s navigation movie within a virtual city). They were given the task of encoding a segment of travel in the virtual city and of subsequent shortcut-finding for each perspective: route, slanted and survey. The analysis of the behavioral data revealed that perspective influenced response accuracy, with significantly more correct responses for slanted and survey perspectives than for route perspective. Comparisons of brain activation with route, slanted, and survey perspectives suggested that slanted and survey perspectives share common brain activity in the left lingual and fusiform gyri and lead to very similar behavioral performance. Slanted perspective was also associated with similar activation to route perspective during encoding in the right middle occipital gyrus. Furthermore, slanted perspective induced intermediate patterns of activation (in between route and survey) in some brain areas, such as the right lingual and fusiform gyri. Our results suggest that the slanted perspective may be considered as a hybrid perspective. This result offers the first empirical support for the choice to present the slanted perspective in many navigational aids. PMID:23209583

Spatial Updating of Environments Described in Texts

ERIC Educational Resources Information Center

Avraamides, Marios N.

2003-01-01

People update egocentric spatial relations in an effortless and on-line manner when they move in the environment, but not when they only imagine themselves moving. In contrast to previous studies, the present experiments examined egocentric updating with spatial scenes that were encoded linguistically instead of perceived directly. Experiment 1…

Informationally administered reward enhances intrinsic motivation in schizophrenia.

PubMed

Lee, Hyeon-Seung; Jang, Seon-Kyeong; Lee, Ga-Young; Park, Seon-Cheol; Medalia, Alice; Choi, Kee-Hong

2017-10-01

Even when individuals with schizophrenia have an intact ability to enjoy rewarding moments, the means to assist them to translate rewarding experiences into goal-directed behaviors is unclear. The present study sought to determine whether informationally administered rewards enhance intrinsic motivation to foster goal-directed behaviors in individuals with schizophrenia (SZ) and healthy controls (HCs). Eighty-four participants (SZ=43, HCs=41) were randomly assigned to conditions involving either a performance-contingent reward with an informationally administered reward or a task-contingent reward with no feedback. Participants were asked to play two cognitive games of equalized difficulty. Accuracy, self-reported intrinsic motivation, free-choice intrinsic motivation (i.e., game play during a free-choice observation period), and perceived competency were measured. Intrinsic motivation and perceived competency in the cognitive games were similar between the two participant groups. The informationally administered reward significantly enhanced self-reported intrinsic motivation and perceived competency in both the groups. The likelihood that individuals with schizophrenia would play the game during the free-choice observation period was four times greater in the informationally administered reward condition than that in the no-feedback condition. Our findings suggest that, in the context of cognitive remediation, individuals with schizophrenia would benefit from informationally administered rewards. Copyright © 2017 Elsevier B.V. All rights reserved.

Sex Differences, Positive Feedback and Intrinsic Motivation.

ERIC Educational Resources Information Center

Deci, Edward L.; And Others

The paper presents two experiments which test the "change in feelings of competence and self-determination" proposition of cognitive evaluation theory. This proposition states that when a person receives feedback about his performance on an intrinsically motivated activity this information will affect his sense of competence and…

Influence of Intrinsic Colloid Formation on Migration of Cerium through Fractured Carbonate Rock.

PubMed

Tran, Emily L; Klein-BenDavid, Ofra; Teutsch, Nadya; Weisbrod, Noam

2015-11-17

Migration of colloids may facilitate the transport of radionuclides leaked from near surface waste sites and geological repositories. Intrinsic colloids are favorably formed by precipitation with carbonates in bicarbonate-rich environments, and their migration may be enhanced through fractured bedrock. The mobility of Ce(III) as an intrinsic colloid was studied in an artificial rainwater solution through a natural discrete chalk fracture. The results indicate that at variable injection concentrations (between 1 and 30 mg/L), nearly all of the recovered Ce takes the form of an intrinsic colloid of >0.45 μm diameter, including in those experiments in which the inlet solution was first filtered via 0.45 μm. In all experiments, these intrinsic colloids reached their maximum relative concentrations prior to that of the Br conservative tracer. Total Ce recovery from experiments using 0.45 μm filtered inlet solutions was only about 0.1%, and colloids of >0.45 μm constituted the majority of recovered Ce. About 1% of Ce was recovered when colloids of >0.45 μm were injected, indicating the enhanced mobility and recovery of Ce in the presence of bicarbonate.

Intrinsic Patterns of Human Activity

NASA Astrophysics Data System (ADS)

Hu, Kun; Ivanov, Plamen Ch.; Chen, Zhi; Hilton, Michael; Stanley, H. Eugene; Shea, Steven

2003-03-01

Activity is one of the defining features of life. Control of human activity is complex, being influenced by many factors both extrinsic and intrinsic to the body. The most obvious extrinsic factors that affect activity are the daily schedule of planned events, such as work and recreation, as well as reactions to unforeseen or random events. These extrinsic factors may account for the apparently random fluctuations in human motion observed over short time scales. The most obvious intrinsic factors are the body clocks including the circadian pacemaker that influences our sleep/wake cycle and ultradian oscillators with shorter time scales [2, 3]. These intrinsic rhythms may account for the underlying regularity in average activity level over longer periods of up to 24 h. Here we ask if the known extrinsic and intrinsic factors fully account for all complex features observed in recordings of human activity. To this end, we measure activity over two weeks from forearm motion in subjects undergoing their regular daily routine. Utilizing concepts from statistical physics, we demonstrate that during wakefulness human activity possesses previously unrecognized complex dynamic patterns. These patterns of activity are characterized by robust fractal and nonlinear dynamics including a universal probability distribution and long-range power-law correlations that are stable over a wide range of time scales (from minutes to hours). Surprisingly, we find that these dynamic patterns are unaffected by changes in the average activity level that occur within individual subjects throughout the day and on different days of the week, and between subjects. Moreover, we find that these patterns persist when the same subjects undergo time-isolation laboratory experiments designed to account for the phase of the circadian pacemaker, and control the known extrinsic factors by restricting behaviors and manipulating scheduled events including the sleep/wake cycle. We attribute these newly

Intrinsic Motivation.

ERIC Educational Resources Information Center

Deci, Edward L.

The paper draws together a wide variety of research which relates to the topic of intrinsic motivation; intrinsically motivated activities are defined as those which a person does for no apparent reward except the activity itself or the feelings which result from the activity. Most of this research was not originally reported within the framework…

Four-Year-Olds Use a Mixture of Spatial Reference Frames

PubMed Central

Negen, James; Nardini, Marko

2015-01-01

Keeping track of unseen objects is an important spatial skill. In order to do this, people must situate the object in terms of different frames of reference, including body position (egocentric frame of reference), landmarks in the surrounding environment (extrinsic frame reference), or other attached features (intrinsic frame of reference). Nardini et al. hid a toy in one of 12 cups in front of children, turned the array when they were not looking, and then asked them to point to the cup with the toy. This forced children to use the intrinsic frame (information about the array of cups) to locate the hidden toy. Three-year-olds made systematic errors by using the wrong frame of reference, 4-year-olds were at chance, and only 5- and 6-year-olds were successful. Can we better understand the developmental change that takes place at four years? This paper uses a modelling approach to re-examine the data and distinguish three possible strategies that could lead to the previous results at four years: (1) Children were choosing cups randomly, (2) Children were pointing between the egocentric/extrinsic-cued location and the correct target, and (3) Children were pointing near the egocentric/extrinsic-cued location on some trials and near the target on the rest. Results heavily favor the last possibility: 4-year-olds were not just guessing or trying to combine the available frames of reference. They were using the intrinsic frame on some trials, but not doing so consistently. These insights suggest that accounts of improving spatial performance at 4 years need to explain why there is a mixture of responses. Further application of the selected model also suggests that children become both more reliant on the correct frame and more accurate with any chosen frame as they mature. PMID:26133990

Genetically increased cell-intrinsic excitability enhances neuronal integration into adult brain circuits

PubMed Central

Lin, Chia-Wei; Sim, Shuyin; Ainsworth, Alice; Okada, Masayoshi; Kelsch, Wolfgang; Lois, Carlos

2009-01-01

New neurons are added to the adult brain throughout life, but only half ultimately integrate into existing circuits. Sensory experience is an important regulator of the selection of new neurons but it remains unknown whether experience provides specific patterns of synaptic input, or simply a minimum level of overall membrane depolarization critical for integration. To investigate this issue, we genetically modified intrinsic electrical properties of adult-generated neurons in the mammalian olfactory bulb. First, we observed that suppressing levels of cell-intrinsic neuronal activity via expression of ESKir2.1 potassium channels decreases, whereas enhancing activity via expression of NaChBac sodium channels increases survival of new neurons. Neither of these modulations affects synaptic formation. Furthermore, even when neurons are induced to fire dramatically altered patterns of action potentials, increased levels of cell-intrinsic activity completely blocks cell death triggered by NMDA receptor deletion. These findings demonstrate that overall levels of cell-intrinsic activity govern survival of new neurons and precise firing patterns are not essential for neuronal integration into existing brain circuits. PMID:20152111

A Tale of Three Cities: Fostering Intrinsic Motivation for Information Seeking in Children of Diverse Cultures

ERIC Educational Resources Information Center

Crow, Sherry R.; Kastello, Lisa

2017-01-01

The purpose of the research was to increase understanding of the experiences in the lives of upper elementary-aged students that foster an intrinsic motivation to seek information, as well as to compare and contrast the experiences of intrinsically motivated students from an individualist culture (Colorado Springs, Colorado, U.S.), a collectivist…

Egocentric framing - one way people may fail in a switch dilemma: evidence from excessive lane switching.

PubMed

Navon, David; Kaplan, Todd R; Kasten, Ronen

2013-11-01

To study switching behavior, an experiment mimicking the state of a driver on the road was conducted. In each trial participants were given a chance to switch lanes. Despite the fact that lane switching had no sound rational basis, participants often switched lanes when the speed of driving in their lane on the previous trial was relatively slow. That tendency was discerned even when switching behavior had been sparsely reinforced, and was especially marked in almost a third of the participants, who manifested it consistently. The findings illustrate a type of behavior occurring in various contexts (e.g., stocks held in a portfolio, conduct pertinent for residual life expectancy, supermarket queues). We argue that this behavior may be due to a fallacy reminiscent of that arising in the well-known "envelopes problem", in which each of two players holds a sum of money of which she knows nothing about except that it is either half or twice the amount held by the other player. Players may be paradoxically tempted to exchange assets, since an exchange fallaciously appears to always yield an expected value greater than whatever is regarded as the player's present assets. We argue that the fallacy is due to egocentrically framing the problem as if the "amount I have" is definite, albeit unspecified, and shows that framing the paradox acentrically instead eliminates the incentive to exchange assets. A possible psychological source for the human disposition to frame problems in a way that inflates expected gain is discussed. Finally, a heuristic meant to avert the source of the fallacy is proposed. © 2013.

Identifying intrinsic constituents of focus through ``imitation via restoration.''

NASA Astrophysics Data System (ADS)

Xu, Yi; Xu, Ching X.; Sun, Xuejing

2003-04-01

In this study we test the hypothesis that although certain parts of an observed intonation may seem dispensable in perception tests, they nevertheless are consistently produced by speakers. We refer to all consistently produced parts of an intonation as its ``intrinsic constituents.'' To identify the intrinsic constituents, we developed an experimental paradigm called ``imitation via restoration.'' In this paradigm, the intonation under scrutiny is first recorded by a native speaker. Then words carrying a potential constituent of the intonation are replaced by a loud noise. During the experiment, the sentence containing the replacement noise is presented to the subjects together with the text. The subjects' task is to repeat the sentence in exactly the same way as they hear it. The consistency with which subjects restore the missing parts of the target intonation would therefore provide a reasonable indication as to which of them are truly intrinsic to the intonation. Our first such experiment was conducted on determining whether focus consists of only on-focus pitch range expansion or it also involves obligatory post-focus pitch range suppression. Eight native speakers of Beijing Mandarin participated as subjects. Preliminary results have provided supporting evidence for the dual-component hypothesis.

Investigation of intrinsic toroidal rotation scaling in KSTAR

NASA Astrophysics Data System (ADS)

Yoo, J. W.; Lee, S. G.; Ko, S. H.; Seol, J.; Lee, H. H.; Kim, J. H.

2017-07-01

The behaviors of an intrinsic toroidal rotation without any external momentum sources are investigated in KSTAR. In these experiments, pure ohmic discharges with a wide range of plasma parameters are carefully selected and analyzed to speculate an unrevealed origin of toroidal rotation excluding any unnecessary heating sources, magnetic perturbations, and strong magneto-hydrodynamic activities. The measured core toroidal rotation in KSTAR is mostly in the counter-current direction and its magnitude strongly depends on the ion temperature divided by plasma current (Ti/IP). Especially the core toroidal rotation in the steady-state is well fitted by Ti/IP scaling with a slope of ˜-23, and the possible explanation of the scaling is compared with various candidates. As a result, the calculated offset rotation could not explain the measured core toroidal rotation since KSTAR has an extremely low intrinsic error field. For the stability conditions for ion and electron turbulences, it is hard to determine a dominant turbulence mode in this study. In addition, the intrinsic toroidal rotation level in ITER is estimated based on the KSTAR scaling since the intrinsic rotation plays an important role in stabilizing resistive wall modes for future reference.

Motor Memory Is Encoded as a Gain-Field Combination of Intrinsic and Extrinsic Action Representations

PubMed Central

Brayanov, Jordan B.; Press, Daniel Z.; Smith, Maurice A.

2013-01-01

Actions can be planned in either an intrinsic (body-based) reference frame or an extrinsic (world-based) frame, and understanding how the internal representations associated with these frames contribute to the learning of motor actions is a key issue in motor control. We studied the internal representation of this learning in human subjects by analyzing generalization patterns across an array of different movement directions and workspaces after training a visuomotor rotation in a single movement direction in one workspace. This provided a dense sampling of the generalization function across intrinsic and extrinsic reference frames, which allowed us to dissociate intrinsic and extrinsic representations and determine the manner in which they contributed to the motor memory for a trained action. A first experiment showed that the generalization pattern reflected a memory that was intermediate between intrinsic and extrinsic representations. A second experiment showed that this intermediate representation could not arise from separate intrinsic and extrinsic learning. Instead, we find that the representation of learning is based on a gain-field combination of local representations in intrinsic and extrinsic coordinates. This gain-field representation generalizes between actions by effectively computing similarity based on the (Mahalanobis) distance across intrinsic and extrinsic coordinates and is in line with neural recordings showing mixed intrinsic-extrinsic representations in motor and parietal cortices. PMID:23100418

Motor memory is encoded as a gain-field combination of intrinsic and extrinsic action representations.

PubMed

Brayanov, Jordan B; Press, Daniel Z; Smith, Maurice A

2012-10-24

Actions can be planned in either an intrinsic (body-based) reference frame or an extrinsic (world-based) frame, and understanding how the internal representations associated with these frames contribute to the learning of motor actions is a key issue in motor control. We studied the internal representation of this learning in human subjects by analyzing generalization patterns across an array of different movement directions and workspaces after training a visuomotor rotation in a single movement direction in one workspace. This provided a dense sampling of the generalization function across intrinsic and extrinsic reference frames, which allowed us to dissociate intrinsic and extrinsic representations and determine the manner in which they contributed to the motor memory for a trained action. A first experiment showed that the generalization pattern reflected a memory that was intermediate between intrinsic and extrinsic representations. A second experiment showed that this intermediate representation could not arise from separate intrinsic and extrinsic learning. Instead, we find that the representation of learning is based on a gain-field combination of local representations in intrinsic and extrinsic coordinates. This gain-field representation generalizes between actions by effectively computing similarity based on the (Mahalanobis) distance across intrinsic and extrinsic coordinates and is in line with neural recordings showing mixed intrinsic-extrinsic representations in motor and parietal cortices.

Re-thinking the role of the dorsal striatum in egocentric/response strategy.

PubMed

Botreau, Fanny; Gisquet-Verrier, Pascale

2010-01-01

Rats trained in a dual-solution cross-maze task, which can be solved by place and response strategies, predominantly used a response strategy after extensive training. This paper examines the involvement of the medial and lateral dorsal striatum (mDS and lDS) in the choice of these strategies after partial and extensive training. Our results show that rats with lDS and mDS lesions used mainly a response strategy from the early phase of training. We replicated these unexpected data in rats with lDS lesions and confirmed their tendency to use the response strategy in a modified cross-maze task. When trained in a dual-solution water-maze task, however, control and lesioned rats consistently used a place strategy, demonstrating that lDS and mDS lesioned rats can use a place strategy and that the shift towards a response strategy did not systematically result from extensive training. The present data did not show any clear dissociation between the mDS and lDS in dual solution tasks. They further indicate that the dorsal striatum seems to determine the strategies adopted in a particular context but cannot be considered as a neural support for the response memory system. Accordingly, the role of the lateral and medial part of the dorsal striatum in egocentric/response memory should be reconsidered.

Color and context: an ERP study on intrinsic and extrinsic feature binding in episodic memory.

PubMed

Ecker, Ullrich K H; Zimmer, Hubert D; Groh-Bordin, Christian

2007-09-01

Episodic memory for intrinsic item and extrinsic context information is postulated to rely on two distinct types of representation: object and episodic tokens. These provide the basis for familiarity and recollection, respectively. Electrophysiological indices of these processes (ERP old-new effects) were used together with behavioral data to test these assumptions. We manipulated an intrinsic object feature (color; Experiment 1) and a contextual feature (background; Experiments 1 and 2). In an inclusion task (Experiment 1), the study-test manipulation of color affected object recognition performance and modulated ERP old-new effects associated with both familiarity and recollection. In contrast, a contextual manipulation had no effect, although both intrinsic and extrinsic information was available in a direct feature (source memory) test. When made task relevant (exclusion task; Experiment 2), however, context affected the ERP recollection effect, while still leaving the ERP familiarity effect uninfluenced. We conclude that intrinsic features bound in object tokens are involuntarily processed during object recognition, thus influencing familiarity, whereas context features bound in episodic tokens are voluntarily accessed, exclusively influencing recollection. Figures depicting all the electrodes analyzed are available in an online supplement at www.psychonomic.org/archive.

Decoherence: Intrinsic, Extrinsic, and Environmental

NASA Astrophysics Data System (ADS)

Stamp, Philip

2012-02-01

Environmental decoherence times have been difficult to predict in solid-state systems. In spin systems, environmental decoherence is predicted to arise from nuclear spins, spin-phonon interactions, and long-range dipolar interactions [1]. Recent experiments have confirmed these predictions quantitatively in crystals of Fe8 molecules [2]. Coherent spin dynamics was observed over macroscopic volumes, with a decoherence Q-factor Qφ= 1.5 x10^6 (the upper predicted limit in this system being Qφ= 6 x10^7). Decoherence from dipolar interactions is particularly complex, and depends on the shape and the quantum state of the system. No extrinsic ``noise'' decoherence was observed. The generalization to quantum dot and superconducting qubit systems is also discussed. We then discuss searches for ``intrinsic'' decoherence [3,4], coming from non-linear corrections to quantum mechanics. Particular attention is paid to condensed matter tests of such intrinsic decoherence, in hybrid spin/optomechanical systems, and to ways of distinguishing intrinsic decoherence from environmental and extrinsic decoherence sources. [4pt] [1] Morello, A. Stamp, P. C. E. & Tupitsyn, Phys. Rev. Lett. 97, 207206 (2006).[0pt] [2] S. Takahashi et al., Nature 476, 76 (2011).[0pt] [3] Stamp, P. C. E., Stud. Hist. Phil. Mod. Phys. 37, 467 (2006). [0pt] [4] Stamp, P.C.E., Phil. Trans. Roy. Soc. A (to be published)

Binding of intrinsic and extrinsic features in working memory.

PubMed

Ecker, Ullrich K H; Maybery, Murray; Zimmer, Hubert D

2013-02-01

There is ongoing debate concerning the mechanisms of feature binding in working memory. In particular, there is controversy regarding the extent to which these binding processes are automatic. The present article demonstrates that binding mechanisms differ depending on whether the to-be-integrated features are perceived as forming a coherent object. We presented a series of experiments that investigated the binding of color and shape, whereby color was either an intrinsic feature of the shape or an extrinsic feature of the shape's background. Results show that intrinsic color affected shape recognition, even when it was incidentally studied and irrelevant for the recognition task. In contrast, extrinsic color did not affect shape recognition, even when the association of color and shape was encoded and retrievable on demand. This strongly suggests that binding of intrinsic intra-item information but not extrinsic contextual information is obligatory in visual working memory. We highlight links to perception as well as implicit and explicit long-term memory, which suggest that the intrinsic-extrinsic dimension is a principle relevant to multiple domains of human cognition. 2013 APA, all rights reserved

Intrinsic and extrinsic mortality reunited.

PubMed

Koopman, Jacob J E; Wensink, Maarten J; Rozing, Maarten P; van Bodegom, David; Westendorp, Rudi G J

2015-07-01

Intrinsic and extrinsic mortality are often separated in order to understand and measure aging. Intrinsic mortality is assumed to be a result of aging and to increase over age, whereas extrinsic mortality is assumed to be a result of environmental hazards and be constant over age. However, allegedly intrinsic and extrinsic mortality have an exponentially increasing age pattern in common. Theories of aging assert that a combination of intrinsic and extrinsic stressors underlies the increasing risk of death. Epidemiological and biological data support that the control of intrinsic as well as extrinsic stressors can alleviate the aging process. We argue that aging and death can be better explained by the interaction of intrinsic and extrinsic stressors than by classifying mortality itself as being either intrinsic or extrinsic. Recognition of the tight interaction between intrinsic and extrinsic stressors in the causation of aging leads to the recognition that aging is not inevitable, but malleable through the environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of Temperature on the Histotripsy Intrinsic Threshold for Cavitation.

PubMed

Vlaisavljevich, Eli; Xu, Zhen; Maxwell, Adam; Mancia, Lauren; Zhang, Xi; Lin, Kuang-Wei; Duryea, Alexander; Sukovich, Jonathan; Hall, Tim; Johnsen, Eric; Cain, Charles

2016-05-10

Histotripsy is an ultrasound ablation method that depends on the initiation of a dense cavitation bubble cloud to fractionate soft tissue. Previous work has demonstrated that a cavitation cloud can be formed by a single acoustic pulse with one high amplitude negative cycle, when the negative pressure amplitude exceeds a threshold intrinsic to the medium. The intrinsic thresholds in soft tissues and tissue phantoms that are water-based are similar to the intrinsic threshold of water over an experimentally verified frequency range of 0.3-3 MHz. Previous work studying the histotripsy intrinsic threshold has been limited to experiments performed at room temperature (~20°C). In this study, we investigate the effects of temperature on the histotripsy intrinsic threshold in water, which is essential to accurately predict the intrinsic thresholds expected over the full range of in vivo therapeutic temperatures. Based on previous work studying the histotripsy intrinsic threshold and classical nucleation theory, we hypothesize that the intrinsic threshold will decrease with increasing temperature. To test this hypothesis, the intrinsic threshold in water was investigated both experimentally and theoretically. The probability of generating cavitation bubbles was measured by applying a single pulse with one high amplitude negative cycle at 1 MHz to distilled, degassed water at temperatures ranging from 10°C-90°C. Cavitation was detected and characterized by passive cavitation detection and high-speed photography, from which the probability of cavitation was measured vs. pressure amplitude. The results indicate that the intrinsic threshold (the negative pressure at which the cavitation probability=0.5) significantly decreases with increasing temperature, showing a nearly linear decreasing trend from 29.8±0.4 MPa at 10˚C to 14.9±1.4 MPa at 90˚C. Overall, the results of this study support our hypothesis that the intrinsic threshold is highly dependent upon the temperature

Effects of Temperature on the Histotripsy Intrinsic Threshold for Cavitation

PubMed Central

Vlaisavljevich, Eli; Xu, Zhen; Maxwell, Adam; Mancia, Lauren; Zhang, Xi; Lin, Kuang-Wei; Duryea, Alexander; Sukovich, Jonathan; Hall, Tim; Johnsen, Eric; Cain, Charles

2018-01-01

Histotripsy is an ultrasound ablation method that depends on the initiation of a dense cavitation bubble cloud to fractionate soft tissue. Previous work has demonstrated that a cavitation cloud can be formed by a single acoustic pulse with one high amplitude negative cycle, when the negative pressure amplitude exceeds a threshold intrinsic to the medium. The intrinsic thresholds in soft tissues and tissue phantoms that are water-based are similar to the intrinsic threshold of water over an experimentally verified frequency range of 0.3–3 MHz. Previous work studying the histotripsy intrinsic threshold has been limited to experiments performed at room temperature (~ 20°C). In this study, we investigate the effects of temperature on the histotripsy intrinsic threshold in water, which is essential to accurately predict the intrinsic thresholds expected over the full range of in vivo therapeutic temperatures. Based on previous work studying the histotripsy intrinsic threshold and classical nucleation theory, we hypothesize that the intrinsic threshold will decrease with increasing temperature. To test this hypothesis, the intrinsic threshold in water was investigated both experimentally and theoretically. The probability of generating cavitation bubbles was measured by applying a single pulse with one high amplitude negative cycle at 1 MHz to distilled, degassed water at temperatures ranging from 10°C–90°C. Cavitation was detected and characterized by passive cavitation detection and high-speed photography, from which the probability of cavitation was measured vs. pressure amplitude. The results indicate that the intrinsic threshold (the negative pressure at which the cavitation probability = 0.5) significantly decreases with increasing temperature, showing a nearly linear decreasing trend from 29.8±0.4 MPa at 10°C to 14.9±1.4 MPa at 90°C. Overall, the results of this study support our hypothesis that the intrinsic threshold is highly dependent upon the

Playwriting Pedagogy and the Myth of Intrinsic Creativity

ERIC Educational Resources Information Center

Gardiner, Paul

2016-01-01

Debates surrounding the teaching of playwriting are heavily influenced by theories of creativity. This article reports on research in Australian secondary schools that explored the student and teacher experiences of playwriting pedagogy. The findings of the research revealed that teaching was based on a belief in intrinsic creativity: that…

Tunneling time in attosecond experiments, intrinsic-type of time. Keldysh, and Mandelstam-Tamm time

NASA Astrophysics Data System (ADS)

Kullie, Ossama

2016-05-01

Tunneling time in attosecond and strong-field experiments is one of the most controversial issues in current research, because of its importance to the theory of time, the time operator and the time-energy uncertainty relation in quantum mechanics. In Kullie (2015 Phys. Rev. A 92 052118) we derived an estimation of the (real) tunneling time, which shows an excellent agreement with the time measured in attosecond experiments, our derivation is found by utilizing the time-energy uncertainty relation, and it represents a quantum clock. In this work, we show different aspects of the tunneling time in attosecond experiments, we discuss and compare the different views and approaches, which are used to calculate the tunneling time, i.e. Keldysh time (as a real or imaginary quantity), Mandelstam-Tamm time, the classical view of the time measurement and our tunneling time relation(s). We draw some conclusions concerning the validity and the relation between the different types of the tunneling time with the hope that they will help to answer the question put forward by Orlando et al (2014 J. Phys. B 47 204002, 2014 Phys. Rev. A 89 014102): tunneling time, what does it mean? However, as we will see, the important question is a more general one: how to understand the time and the measurement of the time of a quantum system? In respect to our result, the time in quantum mechanics can be, in more general fashion, classified in two types, intrinsic dynamically connected, and external dynamically not connected to the system, and consequently (perhaps only) classical Newtonian time remains as a parametric type of time.

Neural evidence for the intrinsic value of action as motivation for behavior.

PubMed

Miura, Naoki; Tanabe, Hiroki C; Sasaki, Akihiro T; Harada, Tokiko; Sadato, Norihiro

2017-06-03

The intrinsic value of an action refers to the inherent sense that experiencing a behavior is enjoyable even if it has no explicit outcome. Previous research has suggested that a common valuation mechanism within the reward network may be responsible for processing the intrinsic value of achieving both the outcome and external rewards. However, how the intrinsic value of action is neurally represented remains unknown. We hypothesized that the intrinsic value of action is determined by an action-outcome contingency indicating the behavior is controllable and that the outcome of the action can be evaluated by this feedback. Consequently, the reward network should be activated, reflecting the generation of the intrinsic value of action. To test this hypothesis, we conducted a functional magnetic resonance imaging (fMRI) investigation of a stopwatch game in which the action-outcome contingency was manipulated. This experiment involved 36 healthy volunteers and four versions of a stopwatch game that manipulated controllability (the feeling that participants were controlling the stopwatch themselves) and outcome (a signal allowing participants to see the result of their action). A free-choice experiment was administered after the fMRI to explore preference levels for each game. The results showed that the stopwatch game with the action-outcome contingency evoked a greater degree of enjoyment because the participants chose this condition over those that lacked such a contingency. The ventral striatum and midbrain were activated only when action-outcome contingency was present. Thus, the intrinsic value of action was represented by an increase in ventral striatal and midbrain activation. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Intrinsic uncoupling of mitochondrial proton pumps. 2. Modeling studies.

PubMed

Pietrobon, D; Zoratti, M; Azzone, G F; Caplan, S R

1986-02-25

The thermodynamic and kinetic properties associated with intrinsic uncoupling in a six-state model of a redox proton pump have been studied by computing the flow-force relations for different degrees of coupling. Analysis of these relations shows the regulatory influence of the thermodynamic forces on the extent and relative contributions of redox slip and proton slip. Inhibition has been introduced into the model in two different ways, corresponding to possible modes of action of experimental inhibitors. Experiments relating the rate of electron transfer to delta microH at static head upon progressive inhibition of the pumps have been simulated considering (1) the limiting case that the nonzero rate of electron transfer at static head is only due to intrinsic uncoupling (no leaks) and (2) the experimentally observed case that about 30% of the nonzero rate of electron transfer at static head is due to a constant proton leakage conductance in parallel with the pumps, the rest being due to intrinsic uncoupling. The same simulations have been performed for experiments in which the rate of electron transfer is varied by varying the substrate concentration rather than by using an inhibitor. The corresponding experimental results obtained by measuring delta microH and the rate of electron transfer at different succinate concentrations in rat liver mitochondria are presented. Comparison between simulated behavior and experimental results leads to the general conclusion that the typical relationship between rate of electron transfer and delta microH found in mitochondria at static head could certainly be a manifestation of some degree of intrinsic uncoupling in the redox proton pumps.(ABSTRACT TRUNCATED AT 250 WORDS)

Probing the Action of Chemical Denaturant on an Intrinsically Disordered Protein by Simulation and Experiment.

PubMed

Zheng, Wenwei; Borgia, Alessandro; Buholzer, Karin; Grishaev, Alexander; Schuler, Benjamin; Best, Robert B

2016-09-14

Chemical denaturants are the most commonly used agents for unfolding proteins and are thought to act by better solvating the unfolded state. Improved solvation is expected to lead to an expansion of unfolded chains with increasing denaturant concentration, providing a sensitive probe of the denaturant action. However, experiments have so far yielded qualitatively different results concerning the effects of chemical denaturation. Studies using Förster resonance energy transfer (FRET) and other methods found an increase in radius of gyration with denaturant concentration, but most small-angle X-ray scattering (SAXS) studies found no change. This discrepancy therefore challenges our understanding of denaturation mechanism and more generally the accuracy of these experiments as applied to unfolded or disordered proteins. Here, we use all-atom molecular simulations to investigate the effect of urea and guanidinium chloride on the structure of the intrinsically disordered protein ACTR, which can be studied by experiment over a wide range of denaturant concentration. Using unbiased molecular simulations with a carefully calibrated denaturant model, we find that the protein chain indeed swells with increasing denaturant concentration. This is due to the favorable association of urea or guanidinium chloride with the backbone of all residues and with the side-chains of almost all residues, with denaturant-water transfer free energies inferred from this association in reasonable accord with experimental estimates. Interactions of the denaturants with the backbone are dominated by hydrogen bonding, while interactions with side-chains include other contributions. By computing FRET efficiencies and SAXS intensities at each denaturant concentration, we show that the simulation trajectories are in accord with both experiments on this protein, demonstrating that there is no fundamental inconsistency between the two types of experiment. Agreement with experiment also supports the

Validation of theoretical models of intrinsic torque in DIII-D

NASA Astrophysics Data System (ADS)

Grierson, B. A.; Wang, W. X.; Battaglia, D. J.; Chrystal, C.; Solomon, W. M.; Degrassie, J. S.; Staebler, G. M.; Boedo, J. A.

2016-10-01

Plasma rotation experiments in DIII-D are validating models of main-ion intrinsic rotation by testing Reynolds stress induced toroidal flow in the plasma core and intrinsic rotation induced by ion orbit losses in the plasma edge. In the core of dominantly electron heated plasmas with Te=Ti, the main-ion intrinsic toroidal rotation undergoes a reversal that correlates with the critical gradient for ITG turbulence. Residual stress arising from zonal-flow ExB shear and turbulence intensity gradient produce residual stress and counter-current intrinsic torque, which is balanced by momentum diffusion, creating the hollow profile. Quantitative agreement is obtained for the first time between the measured main-ion toroidal rotation and the rotation profile predicted by nonlinear GTS gyrokinetic simulations. At the plasma boundary, new main-ion CER measurements show a co-current rotation layer and this is tested against ion orbit loss models as the source of bulk plasma rotation. Work supported by the US Department of Energy under DE-AC02-09CH11466 and DE-FC02-04ER54698.

Global gyrokinetic simulations of intrinsic rotation in ASDEX Upgrade Ohmic L-mode plasmas

NASA Astrophysics Data System (ADS)

Hornsby, W. A.; Angioni, C.; Lu, Z. X.; Fable, E.; Erofeev, I.; McDermott, R.; Medvedeva, A.; Lebschy, A.; Peeters, A. G.; The ASDEX Upgrade Team

2018-05-01

Non-linear, radially global, turbulence simulations of ASDEX Upgrade (AUG) plasmas are performed and the nonlinear generated intrinsic flow shows agreement with the intrinsic flow gradients measured in the core of Ohmic L-mode plasmas at nominal parameters. Simulations utilising the kinetic electron model show hollow intrinsic flow profiles as seen in a predominant number of experiments performed at similar plasma parameters. In addition, significantly larger flow gradients are seen than in a previous flux-tube analysis (Hornsby et al 2017 Nucl. Fusion 57 046008). Adiabatic electron model simulations can show a flow profile with opposing sign in the gradient with respect to a kinetic electron simulation, implying a reversal in the sign of the residual stress due to kinetic electrons. The shaping of the intrinsic flow is strongly determined by the density gradient profile. The sensitivity of the residual stress to variations in density profile curvature is calculated and seen to be significantly stronger than to neoclassical flows (Hornsby et al 2017 Nucl. Fusion 57 046008). This variation is strong enough on its own to explain the large variations in the intrinsic flow gradients seen in some AUG experiments. Analysis of the symmetry breaking properties of the turbulence shows that profile shearing is the dominant mechanism in producing a finite parallel wave-number, with turbulence gradient effects contributing a smaller portion of the parallel wave-vector.

Network stigma towards people living with HIV/AIDS and their caregivers: An egocentric network study.

PubMed

Wu, Fei; He, Xin; Guida, Jennifer; Xu, Yongfang; Liu, Hongjie

2015-10-01

HIV stigma occurs among peers in social networks. However, the features of social networks that drive HIV stigma are not well understood. The objective of this study is to investigate anticipated HIV stigma within the social networks of people living with HIV/AIDS (PLWHA) (N = 147) and the social networks of PLWHA's caregivers (N = 148). The egocentric social network data were collected in Guangxi, China. More than half of PLWHA (58%) and their caregivers (53%) anticipated HIV stigma from their network peers. Both PLWHA and their caregivers anticipated that spouses or other family members were less likely to stigmatise them, compared to friend peers or other relationships. Married network peers were believed to stigmatise caregivers more than unmarried peers. The association between frequent contacts and anticipated stigma was negative among caregivers. Being in a close relationship with PLWHA or caregivers (e.g., a spouse or other family member) was associated with less anticipated stigma. Lower network density was associated with higher anticipated stigma among PLWHA's alters, but not among caregivers' alters. Findings may shed light on innovative stigma reduction interventions at the social network level and therefore improve HIV/AIDS treatment utilisation.

Isolating Observer-Based Reference Directions in Human Spatial Memory: Head, Body, and the Self-to-Array Axis

ERIC Educational Resources Information Center

Waller, David; Lippa, Yvonne; Richardson, Adam

2008-01-01

Several lines of research have suggested the importance of egocentric reference systems for determining how the spatial properties of one's environment are mentally organized. Yet relatively little is known about the bases for egocentric reference systems in human spatial memory. In three experiments, we examine the relative importance of…

Transport of Intrinsic Plutonium Colloids in Saturated Porous Media

NASA Astrophysics Data System (ADS)

Zhou, D.; Abdel-Fattah, A.; Boukhalfa, H.; Ware, S. D.; Tarimala, S.; Keller, A. A.

2011-12-01

column at a flow rate of ~ 6 mL/hr. Despite that the Pu intrinsic colloids are positively charged while the alluvium grain surfaces are negatively charged under the current experimental conditions, about 30% of the Pu colloids population transported through the column and broke through earlier than trillium. Our previous experiments in the same column have shown a highly unretarded transport of the negatively charged pseudo Pu colloids (Pu sorbed onto smectite colloids) and complete retardation of the dissolved Pu. The enhanced transport of Pu colloids was explained by the effective pore volume concept. Combining the results of these two experiments, it is concluded that the intrinsic Pu colloids transported in the column by adsorbing onto the background clay colloids due to electrostatic repulsion.

Understanding and predicting profile structure and parametric scaling of intrinsic rotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, W. X.; Grierson, B. A.; Ethier, S.

2017-08-10

This study reports on a recent advance in developing physical understanding and a first-principles-based model for predicting intrinsic rotation profiles in magnetic fusion experiments. It is shown for the first time that turbulent fluctuation-driven residual stress (a non-diffusive component of momentum flux) along with diffusive momentum flux can account for both the shape and magnitude of the observed intrinsic toroidal rotation profile. Both the turbulence intensity gradient and zonal flow E×B shear are identified as major contributors to the generation of the k ∥-asymmetry needed for the residual stress generation. The model predictions of core rotation based on global gyrokineticmore » simulations agree well with the experimental measurements of main ion toroidal rotation for a set of DIII-D ECH discharges. The validated model is further used to investigate the characteristic dependence of residual stress and intrinsic rotation profile structure on the multi-dimensional parametric space covering the turbulence type, q-profile structure, and up-down asymmetry in magnetic geometry with the goal of developing the physics understanding needed for rotation profile control and optimization. It is shown that in the flat-q profile regime, intrinsic rotations driven by ITG and TEM turbulence are in the opposite direction (i.e., intrinsic rotation reverses). The predictive model also produces reversed intrinsic rotation for plasmas with weak and normal shear q-profiles.« less

Can nature make us more caring? Effects of immersion in nature on intrinsic aspirations and generosity.

PubMed

Weinstein, Netta; Przybylski, Andrew K; Ryan, Richard M

2009-10-01

Four studies examined the effects of nature on valuing intrinsic and extrinsic aspirations. Intrinsic aspirations reflected prosocial and other-focused value orientations, and extrinsic aspirations predicted self-focused value orientations. Participants immersed in natural environments reported higher valuing of intrinsic aspirations and lower valuing of extrinsic aspirations, whereas those immersed in non-natural environments reported increased valuing of extrinsic aspirations and no change of intrinsic aspirations. Three studies explored experiences of nature relatedness and autonomy as underlying mechanisms of these effects, showing that nature immersion elicited these processes whereas non-nature immersion thwarted them and that they in turn predicted higher intrinsic and lower extrinsic aspirations. Studies 3 and 4 also extended the paradigm by testing these effects on generous decision making indicative of valuing intrinsic versus extrinsic aspirations.

Extrinsic photoresponse enhancement under additional intrinsic photoexcitation in organic semiconductors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kounavis, P., E-mail: pkounavis@upatras.gr

2016-06-28

Dual light beam photoresponse experiments are employed to explore the photoresponse under simultaneous extrinsic and intrinsic photoexcitation of organic semiconductors. The photoresponse of a red modulated light extrinsic photoexcitation is found that can be significantly enhanced under an additional blue bias-light intrinsic photoexcitation in two terminal pentacene films on glass substrates. From the frequency resolved photoresponse, it is deduced that the phenomenon of photoresponse enhancement can be attributed to an increase in the extrinsic photogeneration rate of the red modulated light and/or an improvement of the drift velocity of carriers under an additional blue light intrinsic photoexcitation. The possible predominantmore » extrinsic photogeneration mechanism, which can be compatible with the observed dependence of the photoresponse enhancement on the frequency and on the light intensities of the red and blue light excitation, is the singlet exciton dissociation through electron transfer to acceptor-like traps. Moreover, an improvement in the drift velocity of carriers traversing grain boundaries with potential energy barriers, which may be reduced by trapping of minority carriers created from the intrinsic photoexcitation, may partly contribute to the photoresponse enhancement.« less

Genome-Wide Prediction of Intrinsic Disorder; Sequence Alignment of Intrinsically Disordered Proteins

ERIC Educational Resources Information Center

Midic, Uros

2012-01-01

Intrinsic disorder (ID) is defined as a lack of stable tertiary and/or secondary structure under physiological conditions in vitro. Intrinsically disordered proteins (IDPs) are highly abundant in nature. IDPs possess a number of crucial biological functions, being involved in regulation, recognition, signaling and control, e.g. their functional…

NMR based solvent exchange experiments to understand the conformational preference of intrinsically disordered proteins using FG-nucleoporin peptide as a model

PubMed Central

Heisel, Kurt A.; Krishnan, V. V.

2014-01-01

The conformational preference of a peptide with three phenylalanine-glycine (FG) repeats from the intrinsically disordered domain of nucleoporin 159 (nup159) from the yeast nucleopore complex (NPC) is studied. Conformational states of this FG-peptide in dimethyl sulfoxide (DMSO), a non-native solvent are first studied. A solvent exchange scheme is designed and performed to understand how the conformational preferences of the peptide are altered as the solvent shifts from DMSO to water. An ensemble of structures of a 19-residue peptide is determined based on 13Cα, 1Hα, and 1HN chemical shifts and with inter-proton distances. An experimental model is then presented where chemical shifts and amide-proton temperature dependence is probed at changing DMSO to water ratios. These co-solvent experiments provide evidence of a conformational change as the fraction of water increases by the stark change in the behavior of amide protons under varied temperature. This investigation provides a NMR based experimental method in the field of intrinsically disordered proteins to realize conformational transitions from a non-native set of structures (in DMSO) to a native set of disordered conformers (in water). PMID:24037535

Comparing Effects of Intrinsic and Extrinsic Social Values Between Younger and Older Employees.

PubMed

Yeung, Dannii Y; Fung, Helene H; Chan, Darius K-S

2016-08-17

Socioemotional selectivity theory proposes that older adults emphasize emotional goals and interpersonal closeness to a greater extent than do younger adults, suggesting that holding social work-related values (SWVs) may be beneficial to older employees. This project aimed at examining two dimensions of SWVs, intrinsic and extrinsic SWVs, and tested whether age and work situation would moderate their effects on self-rated job performance. A cross-sectional survey (Study 1, N = 357) and a 14-day experience sampling study (Study 2, N = 77) were conducted among Chinese managerial employees. Study 1 showed that the direct effect of intrinsic SWVs on self-rated job performance was stronger in older employees than in younger employees. Study 2 demonstrated that older employees who valued intrinsic SWVs while being in social situations performed much better than when they did not value intrinsic SWVs but being in social situations; however such positive effect was not shown in younger employees. Findings of this project reveal that the effect of SWVs varies across locus of effect (intrinsic versus extrinsic), age, and work situation. Among older employees, the positive effect of intrinsic SWVs is more crucial than that of extrinsic SWVs on self-rated job performance. Findings of this project imply that intrinsically rewarding incentives would be more effective in motivating older employees to reach peak performance.

Temperature Response of Emissivity in Intrinsic Silicon: A Selective Absorber for Solar Energy Harvesting

NASA Astrophysics Data System (ADS)

Heredia, Cristian Alonso

The National Academy of Engineers named affordable solar energy as one of the grand challenges for the twenty-first century. Even in sunniest U.S. locations, without subsidies, home generation is still cost prohibitive. To address the cost of solar energy, we investigated intrinsic silicon as a low emissivity selective absorber. We wanted to determine the emissivity of intrinsic silicon at elevated temperatures. At elevated temperatures, a selective absorber coupled to a heat engine could efficiently generate electrical power. Photothermal efficiency depends on the absorber's emissivity. I analyzed total hemispherical emissivity for graphite and intrinsic silicon using a thermal decay method inside a thermal isolation chamber. The results show low emissivity values for intrinsic silicon. Consequently, for temperatures less than 300 °C, intrinsic silicon has a small emissivity (0.16). This small value is in agreement with doped silicon experiments. However, unlike doped silicon, at elevated temperatures of 600 °C, intrinsic silicon emissivity values remain low (0.33). Our analysis suggests intrinsic silicon could convert more solar power into heat than an ideal blackbody. Specifically, the harvested heat could drive a heat engine for efficient power generation. Thus, a cost-effective electrical generating system can operate with a small land footprint using earth abundant silicon.

Viewpoint in the Visual-Spatial Modality: The Coordination of Spatial Perspective

PubMed Central

Pyers, Jennie E.; Perniss, Pamela; Emmorey, Karen

2015-01-01

Sign languages express viewpoint-dependent spatial relations (e.g., left, right) iconically but must conventionalize from whose viewpoint the spatial relation is being described, the signer's or the perceiver's. In Experiment 1, ASL signers and sign-naïve gesturers expressed viewpoint-dependent relations egocentrically, but only signers successfully interpreted the descriptions non-egocentrically, suggesting that viewpoint convergence in the visual modality emerges with language conventionalization. In Experiment 2, we observed that the cost of adopting a non-egocentric viewpoint was greater for producers than for perceivers, suggesting that sign languages have converged on the most cognitively efficient means of expressing left-right spatial relations. We suggest that non-linguistic cognitive factors such as visual perspective-taking and motor embodiment may constrain viewpoint convergence in the visual-spatial modality. PMID:26981027

Viewpoint in the Visual-Spatial Modality: The Coordination of Spatial Perspective.

PubMed

Pyers, Jennie E; Perniss, Pamela; Emmorey, Karen

2015-06-01

Sign languages express viewpoint-dependent spatial relations (e.g., left, right) iconically but must conventionalize from whose viewpoint the spatial relation is being described, the signer's or the perceiver's. In Experiment 1, ASL signers and sign-naïve gesturers expressed viewpoint-dependent relations egocentrically, but only signers successfully interpreted the descriptions non-egocentrically, suggesting that viewpoint convergence in the visual modality emerges with language conventionalization. In Experiment 2, we observed that the cost of adopting a non-egocentric viewpoint was greater for producers than for perceivers, suggesting that sign languages have converged on the most cognitively efficient means of expressing left-right spatial relations. We suggest that non-linguistic cognitive factors such as visual perspective-taking and motor embodiment may constrain viewpoint convergence in the visual-spatial modality.

Dissociable intrinsic functional networks support noun-object and verb-action processing.

PubMed

Yang, Huichao; Lin, Qixiang; Han, Zaizhu; Li, Hongyu; Song, Luping; Chen, Lingjuan; He, Yong; Bi, Yanchao

2017-12-01

The processing mechanism of verbs-actions and nouns-objects is a central topic of language research, with robust evidence for behavioral dissociation. The neural basis for these two major word and/or conceptual classes, however, remains controversial. Two experiments were conducted to study this question from the network perspective. Experiment 1 found that nodes of the same class, obtained through task-evoked brain imaging meta-analyses, were more strongly connected with each other than nodes of different classes during resting-state, forming segregated network modules. Experiment 2 examined the behavioral relevance of these intrinsic networks using data from 88 brain-damaged patients, finding that across patients the relative strength of functional connectivity of the two networks significantly correlated with the noun-object vs. verb-action relative behavioral performances. In summary, we found that verbs-actions and nouns-objects are supported by separable intrinsic functional networks and that the integrity of such networks accounts for the relative noun-object- and verb-action-selective deficits. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of professional culture on intrinsic motivation among physicians in an academic medical center.

PubMed

Janus, Katharina

2014-01-01

Today, most healthcare organizations aim to manage professionals' motivation through monetary incentives, such as pay for performance. However, addressing motivation extrinsically can involve negative effects, such as disturbed teamwork, gaming the system, and crowd-out of intrinsic motivation. To offset these side effects, it is crucial to support professionals' intrinsic motivation actively, which is largely determined by enjoyment- and obligation-based social norms that derive from professionals' culture. For this study, a professional culture questionnaire was designed and validated, the results of which uncovered three factors: relationship to work, relationship to colleagues, and relationship to organization. These factors served as independent variables for regression analyses. Second, Amabile's validated work preference inventory was used to measure intrinsic motivation as a dependent variable. The regression analysis was controlled for sex, age, and experience. The study revealed that relationship to work had the strongest (and a positive) impact on intrinsic motivation in general and on Amabile's intrinsic subscales, enjoyment and challenge. Relationship to organization had a negative impact on intrinsic motivation and both subscales, and relationship to colleagues showed a low positive significance for the intrinsic scale only. Healthcare organizations have mostly focused on targeting professionals' extrinsic motivation. However, managing dimensions of professional culture can help support professionals' intrinsic motivation without incurring the side effects of monetary incentives.

Dynamics of intrinsic axial flows in unsheared, uniform magnetic fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, J. C.; Diamond, P. H.; Xu, X. Q.

2016-05-15

A simple model for the generation and amplification of intrinsic axial flow in a linear device, controlled shear decorrelation experiment, is proposed. This model proposes and builds upon a novel dynamical symmetry breaking mechanism, using a simple theory of drift wave turbulence in the presence of axial flow shear. This mechanism does not require complex magnetic field structure, such as shear, and thus is also applicable to intrinsic rotation generation in tokamaks at weak or zero magnetic shear, as well as to linear devices. This mechanism is essentially the self-amplification of the mean axial flow profile, i.e., a modulational instability.more » Hence, the flow development is a form of negative viscosity phenomenon. Unlike conventional mechanisms where the residual stress produces an intrinsic torque, in this dynamical symmetry breaking scheme, the residual stress induces a negative increment to the ambient turbulent viscosity. The axial flow shear is then amplified by this negative viscosity increment. The resulting mean axial flow profile is calculated and discussed by analogy with the problem of turbulent pipe flow. For tokamaks, the negative viscosity is not needed to generate intrinsic rotation. However, toroidal rotation profile gradient is enhanced by the negative increment in turbulent viscosity.« less

Depression, Smoking, and Ego-Centric Social Network Characteristics in Ohio Appalachian Women

PubMed Central

Lam, Jeffrey; Lu, Bo; Doogan, Nate; Thomson, Tiffany; Ferketich, Amy; Paskett, Electra D.; Wewers, Mary Ellen

2017-01-01

Depression is a serious, costly, and debilitating disorder that is understudied in rural women. Studies show that depression is associated with low social integration and support, but few studies investigate the relationship between depression and social network characteristics. This study examined the associations among women from three Ohio Appalachian counties enrolled in a health study, which aimed to collect information for a future social network smoking cessation intervention. An address-based sampling method was used to randomly select and recruit 404 women. A cross-sectional survey and interview were used to collect information about demographic, psychosocial, behavioral factors, and ego-centric social network characteristics, which are variables derived from an individual (ego) and her first degree contacts (alters). The CES-D scale assessed depressive symptoms. A multivariable logistic regression analysis described the association between these factors and participants with depression (defined as CES-D≥16). Higher network density, or greater number of relationships among alters divided by the total amount of alters, reduced the risk for depression (OR = 0.84, 95% confidence interval [CI] 0.73–0.95). Additionally, women with a high percentage of smoking alters were at greater risk for depression (OR = 1.19, 95% CI 1.02–1.39). Other factors associated with risk for depression included perceived stress score (OR = 1.34, 95% CI 1.24–1.45), loneliness score (OR = 1.37, 95% CI 1.05–1.80), and days with poor physical health (OR = 1.06, 95% CI 1.02–1.11). Findings suggest that psychosocial factors and social networks should be considered when addressing depression in clinical practice. PMID:29081878

Depression, Smoking, and Ego-Centric Social Network Characteristics in Ohio Appalachian Women.

PubMed

Lam, Jeffrey; Lu, Bo; Doogan, Nate; Thomson, Tiffany; Ferketich, Amy; Paskett, Electra D; Wewers, Mary Ellen

2017-01-01

Depression is a serious, costly, and debilitating disorder that is understudied in rural women. Studies show that depression is associated with low social integration and support, but few studies investigate the relationship between depression and social network characteristics. This study examined the associations among women from three Ohio Appalachian counties enrolled in a health study, which aimed to collect information for a future social network smoking cessation intervention. An address-based sampling method was used to randomly select and recruit 404 women. A cross-sectional survey and interview were used to collect information about demographic, psychosocial, behavioral factors, and ego-centric social network characteristics, which are variables derived from an individual (ego) and her first degree contacts (alters). The CES-D scale assessed depressive symptoms. A multivariable logistic regression analysis described the association between these factors and participants with depression (defined as CES-D≥16). Higher network density, or greater number of relationships among alters divided by the total amount of alters, reduced the risk for depression (OR = 0.84, 95% confidence interval [CI] 0.73-0.95). Additionally, women with a high percentage of smoking alters were at greater risk for depression (OR = 1.19, 95% CI 1.02-1.39). Other factors associated with risk for depression included perceived stress score (OR = 1.34, 95% CI 1.24-1.45), loneliness score (OR = 1.37, 95% CI 1.05-1.80), and days with poor physical health (OR = 1.06, 95% CI 1.02-1.11). Findings suggest that psychosocial factors and social networks should be considered when addressing depression in clinical practice.

Finding intrinsic rewards by embodied evolution and constrained reinforcement learning.

PubMed

Uchibe, Eiji; Doya, Kenji

2008-12-01

Understanding the design principle of reward functions is a substantial challenge both in artificial intelligence and neuroscience. Successful acquisition of a task usually requires not only rewards for goals, but also for intermediate states to promote effective exploration. This paper proposes a method for designing 'intrinsic' rewards of autonomous agents by combining constrained policy gradient reinforcement learning and embodied evolution. To validate the method, we use Cyber Rodent robots, in which collision avoidance, recharging from battery packs, and 'mating' by software reproduction are three major 'extrinsic' rewards. We show in hardware experiments that the robots can find appropriate 'intrinsic' rewards for the vision of battery packs and other robots to promote approach behaviors.

Intrinsic and Extrinsic Motivation for Smoking Cessation.

ERIC Educational Resources Information Center

Curry, Susan; And Others

1990-01-01

Evaluated intrinsic-extrinsic model of motivation for smoking cessation using two samples (Ns=1,217 and 151) of smokers. Analysis on Reasons for Quitting scale supported intrinsic-extrinsic motivation distinction, defining four-factor model with two intrinsic and two extrinsic dimensions. Found that smokers with higher levels of intrinsic relative…

The Visual System's Intrinsic Bias and Knowledge of Size Mediate Perceived Size and Location in the Dark

ERIC Educational Resources Information Center

Zhou, Liu; He, Zijiang J.; Ooi, Teng Leng

2013-01-01

Dimly lit targets in the dark are perceived as located about an implicit slanted surface that delineates the visual system's intrinsic bias (Ooi, Wu, & He, 2001). If the intrinsic bias reflects the internal model of visual space--as proposed here--its influence should extend beyond target localization. Our first 2 experiments demonstrated that…

Metacognitive Monitoring and Dementia: How Intrinsic and Extrinsic Cues Influence Judgments of Learning in People with Alzheimer’s disease

PubMed Central

Thomas, Ayanna K.; Lee, Meeyeon; Balota, David A.

2014-01-01

Objective The present research compared metamemorial monitoring processes among younger adults, non-demented older adults, and older adults diagnosed with early stage Dementia of the Alzheimer’s Type (DAT). Method In three experiments we examined the influence of intrinsic and extrinsic cues on Judgment of Learning (JOL) accuracy. Changes in association strength between cue-target word pairs served as our intrinsic manipulation in Experiments 1 and 2. Changes in encoding orientation served as our extrinsic manipulation in Experiment 3. Results Across all experiments we found that young adults, non-demented older adults, and individuals in the early stages of DAT effectively used intrinsic and extrinsic factors to guide JOL predictions. Conclusions We conclude that while certain aspects of metacognition may be impaired in both the normal and demented older populations, these groups remain able to use theory-based processing, or general knowledge about how memory works, to make metamemory monitoring predictions. PMID:23876118

Intrinsic Orbital Angular Momentum States of Neutrons

NASA Astrophysics Data System (ADS)

Cappelletti, Ronald L.; Jach, Terrence; Vinson, John

2018-03-01

It has been shown that single-particle wave functions, of both photons and electrons, can be created with a phase vortex, i.e., an intrinsic orbital angular momentum (OAM). A recent experiment has claimed similar success using neutrons [C. W. Clark et al., Nature, 525, 504 (2015), 10.1038/nature15265]. We show that their results are insufficient to unambiguously demonstrate OAM, and they can be fully explained as phase contrast interference patterns. Furthermore, given the small transverse coherence length of the neutrons in the original experiment, the probability that any neutron was placed in an OAM state is vanishingly small. We highlight the importance of the relative size of the coherence length, which presents a unique challenge for neutron experiments compared to electron or photon work, and we suggest improvements for the creation of neutron OAM states.

A case study of the intrinsic bioremediation of petroleum hydrocarbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barker, G.W.; Raterman, K.T.; Fisher, J.B.

1995-12-31

Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe{sup 3+} reduction, and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from themore » gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe{sup 3+} reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.« less

Intrinsic motivation and learning in a schizophrenia spectrum sample.

PubMed

Choi, Jimmy; Medalia, Alice

2010-05-01

A motivation is a telling hallmark of negative symptomatology in schizophrenia, and it impacts nearly every facet of behavior, including inclination to attempt the difficult cognitive tasks involved in cognitive remediation therapy. Experiences of external reward, reinforcement, and hedonic anticipatory enjoyment are diminished in psychosis, so therapeutics which instead target intrinsic motivation for cognitive tasks may enhance task engagement, and subsequently, remediation outcome. We examined whether outpatients could attain benefits from an intrinsically motivating instructional approach which (a) presents learning materials in a meaningful game-like context, (b) personalizes elements of the learning materials into themes of high interest value, and (c) offers choices so patients can increase their control over the learning process. We directly compared one learning method that incorporated the motivational paradigm into an arithmetic learning program against another method that carefully manipulated out the motivational variables in the same learning program. Fifty-seven subjects with schizophrenia or schizoaffective disorder were randomly assigned to one of the two learning programs for 10 thirty-minute sessions while an intent-to-treat convenience subsample (n=15) was used to account for practice effect. Outcome measures were arithmetic learning, attention, motivation, self competency, and symptom severity. Results showed the motivational group (a) acquired more arithmetic skill, (b) possessed greater intrinsic motivation for the task, (c) reported greater feelings of self competency post-treatment, and (d) demonstrated better post-test attention. Interestingly, baseline perception of self competency was a significant predictor of post-test arithmetic scores. Results demonstrated that incorporating intrinsically motivating instructional techniques into a difficult cognitive task promoted greater learning of the material, higher levels of intrinsic

Intrinsic disorder in transcription factors†

PubMed Central

Liu, Jiangang; Perumal, Narayanan B.; Oldfield, Christopher J.; Su, Eric W.; Uversky, Vladimir N.; Dunker, A. Keith

2008-01-01

Intrinsic disorder (ID) is highly abundant in eukaryotes, which reflect the greater need for disorder-associated signaling and transcriptional regulation in nucleated cells. Although several well-characterized examples of intrinsically disordered proteins in transcriptional regulation have been reported, no systematic analysis has been reported so far. To test for a general prevalence of intrinsic disorder in transcriptional regulation, we used the Predictor Of Natural Disorder Regions (PONDR) to analyze the abundance of intrinsic disorder in three transcription factor datasets and two control sets. This analysis revealed that from 94.13% to 82.63% of transcription factors posses extended regions of intrinsic disorder, relative to 54.51% and 18.64% of the proteins in two control datasets, which indicates the significant prevalence of intrinsic disorder in transcription factors. This propensity of transcription factors for intrinsic disorder was confirmed by cumulative distribution function analysis and charge-hydropathy plots. The amino acid composition analysis showed that all three transcription factor datasets were substantially depleted in order-promoting residues, and significantly enriched in disorder-promoting residues. Our analysis of the distribution of disorder within the transcription factor datasets revealed that: (a) The AT-hooks and basic regions of transcription factor DNA-binding domains are highly disordered; (b) The degree of disorder in transcription factor activation regions is much higher than that in DNA-binding domains; (c) The degree of disorder is significantly higher in eukaryotic transcription factors than in prokaryotic transcription factors; (d) The level of α-MoRFs (molecular recognition feature) prediction is much higher in transcription factors. Overall, our data reflected the fact that the eukaryotes with well-developed gene transcription machinery require transcription factor flexibility to be more efficient. PMID:16734424

A meta-analytic review of experiments examining the effects of extrinsic rewards on intrinsic motivation.

PubMed

Deci, E L; Koestner, R; Ryan, R M

1999-11-01

A meta-analysis of 128 studies examined the effects of extrinsic rewards on intrinsic motivation. As predicted, engagement-contingent, completion-contingent, and performance-contingent rewards significantly undermined free-choice intrinsic motivation (d = -0.40, -0.36, and -0.28, respectively), as did all rewards, all tangible rewards, and all expected rewards. Engagement-contingent and completion-contingent rewards also significantly undermined self-reported interest (d = -0.15, and -0.17), as did all tangible rewards and all expected rewards. Positive feedback enhanced both free-choice behavior (d = 0.33) and self-reported interest (d = 0.31). Tangible rewards tended to be more detrimental for children than college students, and verbal rewards tended to be less enhancing for children than college students. The authors review 4 previous meta-analyses of this literature and detail how this study's methods, analyses, and results differed from the previous ones.

Miniaturized INtrinsic DISsolution Screening (MINDISS) assay for preformulation.

PubMed

Alsenz, Jochem; Haenel, Elisabeth; Anedda, Aline; Du Castel, Pauline; Cirelli, Giorgio

2016-05-25

This study describes a novel Miniaturized INtrinsic DISsolution Screening (MINDISS) assay for measuring disk intrinsic dissolution rates (DIDR). In MINDISS, compacted mini disks of drugs (2-5mg/disk) are prepared in custom made holders with a surface area of 3mm(2). Disks are immersed, pellet side down, into 0.35ml of appropriate dissolution media per well in 96-well microtiter plates, media are stirred and disk-holders are transferred to new wells after defined periods of time. After filtration, drug concentration in dissolution media is quantified by Ultra Performance Liquid Chromatography (UPLC) and solid state property of the disk is characterized by Raman spectroscopy. MINDISS was identified as an easy-to-use tool for rapid, parallel determination of DIDR of compounds that requires only small amounts of compound and of dissolution medium. Results obtained with marketed drugs in MINDISS correlate well with large scale DIDR methods and indicate that MINDISS can be used for (1) rank-ordering of compounds by intrinsic dissolution in late phase discovery and early development, (2) comparison of polymorphic forms and salts, (3) screening and selection of appropriate dissolution media, and (4) characterization of the intestinal release behavior of compounds along the gastro intestinal tract by changing biorelevant media during experiments. Copyright © 2015 Elsevier B.V. All rights reserved.

Dopamine modulates an intrinsic mGluR5-mediated depolarization underlying prefrontal persistent activity

PubMed Central

Sidiropoulou, Kyriaki; Lu, Fang-Min; Fowler, Melissa A.; Xiao, Rui; Phillips, Christopher; Ozkan, Emin D.; Zhu, Michael X.; White, Francis J.; Cooper, Donald C.

2009-01-01

Intrinsic properties of neurons that enable them to maintain depolarized, persistently activated states in the absence of sustained input are poorly understood. In short-term memory tasks, individual prefrontal cortical (PFC) neurons are capable of maintaining persistent action potential output during delay periods between informative cues and behavioral responses. Dopamine and drugs of abuse alter PFC function and working memory possibly by modulating intrinsic neuronal properties. Here we use patch-clamp recording of layer 5 PFC pyramidal neurons to identify an action potential burst-evoked intrinsic mGluR5-mediated postsynaptic depolarization that initiates an activated state. Depolarization occurs in the absence of recurrent synaptic activity and is reduced by a postsynaptic dopamine D1/5 receptor pathway. The depolarization is substantially diminished following behavioral sensitization to cocaine; moreover the D1/5 receptor modulation is lost. We propose the burst-evoked intrinsic depolarization to be a novel form of short-term cellular memory that is modulated by dopamine and cocaine experience. PMID:19169252

Molecular Dynamics Simulations of Intrinsically Disordered Proteins: Force Field Evaluation and Comparison with Experiment.

PubMed

Henriques, João; Cragnell, Carolina; Skepö, Marie

2015-07-14

An increasing number of studies using molecular dynamics (MD) simulations of unfolded and intrinsically disordered proteins (IDPs) suggest that current force fields sample conformations that are overly collapsed. Here, we study the applicability of several state-of-the-art MD force fields, of the AMBER and GROMOS variety, for the simulation of Histatin 5, a short (24 residues) cationic salivary IDP with antimicrobial and antifungal properties. The quality of the simulations is assessed in three complementary analyses: (i) protein shape and size comparison with recent experimental small-angle X-ray scattering data; (ii) secondary structure prediction; (iii) energy landscape exploration and conformational class analysis. Our results show that, indeed, standard force fields sample conformations that are too compact, being systematically unable to reproduce experimental evidence such as the scattering function, the shape of the protein as compared with the Kratky plot, and intrapeptide distances obtained through the pair distance distribution function, p(r). The consistency of this deviation suggests that the problem is not mainly due to protein-protein or water-water interactions, whose parametrization varies the most between force fields and water models. In fact, as originally proposed in [ Best et al. J. Chem. Theory Comput. 2014, 10, 5113 - 5124.], balanced protein-water interactions may be the key to solving this problem. Our simulations using this approach produce results in very good agreement with experiment.

Intrinsic Angular Momentum of Light.

ERIC Educational Resources Information Center

Santarelli, Vincent

1979-01-01

Derives a familiar torque-angular momentum theorem for the electromagnetic field, and includes the intrinsic torques exerted by the fields on the polarized medium. This inclusion leads to the expressions for the intrinsic angular momentum carried by the radiation traveling through a charge-free medium. (Author/MA)

Coach Autonomy Support, Basic Need Satisfaction, and Intrinsic Motivation of Paralympic Athletes

ERIC Educational Resources Information Center

Banack, Hailey R.; Sabiston, Catherine M.; Bloom, Gordon A.

2011-01-01

The purpose of the present study, grounded in self-determination theory, was to explore the relationship between Paralympic athletes' perceptions of autonomy-supportive coach behavior, basic psychological needs, and intrinsic motivation to know, accomplish, and experience stimulation. One hundred thirteen Canadian Paralympic athletes completed an…

In Search of the Neural Circuits of Intrinsic Motivation

PubMed Central

Kaplan, Frederic; Oudeyer, Pierre-Yves

2007-01-01

Children seem to acquire new know-how in a continuous and open-ended manner. In this paper, we hypothesize that an intrinsic motivation to progress in learning is at the origins of the remarkable structure of children's developmental trajectories. In this view, children engage in exploratory and playful activities for their own sake, not as steps toward other extrinsic goals. The central hypothesis of this paper is that intrinsically motivating activities correspond to expected decrease in prediction error. This motivation system pushes the infant to avoid both predictable and unpredictable situations in order to focus on the ones that are expected to maximize progress in learning. Based on a computational model and a series of robotic experiments, we show how this principle can lead to organized sequences of behavior of increasing complexity characteristic of several behavioral and developmental patterns observed in humans. We then discuss the putative circuitry underlying such an intrinsic motivation system in the brain and formulate two novel hypotheses. The first one is that tonic dopamine acts as a learning progress signal. The second is that this progress signal is directly computed through a hierarchy of microcortical circuits that act both as prediction and metaprediction systems. PMID:18982131

Incentives and intrinsic motivation in healthcare.

PubMed

Berdud, Mikel; Cabasés, Juan M; Nieto, Jorge

It has been established in the literature that workers within public organisations are intrinsically motivated. This paper is an empirical study of the healthcare sector using methods of qualitative analysis research, which aims to answer the following hypotheses: 1) doctors are intrinsically motivated; 2) economic incentives and control policies may undermine doctors' intrinsic motivation; and 3) well-designed incentives may encourage doctors' intrinsic motivation. We conducted semi-structured interviews à-la-Bewley with 16 doctors from Navarre's Healthcare Service (Servicio Navarro de Salud-Osasunbidea), Spain. The questions were based on current theories of intrinsic motivation and incentives to test the hypotheses. Interviewees were allowed to respond openly without time constraints. Relevant information was selected, quantified and analysed by using the qualitative concepts of saturation and codification. The results seem to confirm the hypotheses. Evidence supporting hypotheses 1 and 2 was gathered from all interviewees, as well as indications of the validity of hypothesis 3 based on interviewees' proposals of incentives. The conclusions could act as a guide to support the optimal design of incentive policies and schemes within health organisations when healthcare professionals are intrinsically motivated. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

The intrinsic resistome of bacterial pathogens

PubMed Central

Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B. Sanchez, Maria; Martinez, Jose L.

2013-01-01

Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice. PMID:23641241

The intrinsic resistome of bacterial pathogens.

PubMed

Olivares, Jorge; Bernardini, Alejandra; Garcia-Leon, Guillermo; Corona, Fernando; B Sanchez, Maria; Martinez, Jose L

2013-01-01

Intrinsically resistant bacteria have emerged as a relevant health problem in the last years. Those bacterial species, several of them with an environmental origin, present naturally low-level susceptibility to several drugs. It has been proposed that intrinsic resistance is mainly the consequence of the impermeability of cellular envelopes, the activity of multidrug efflux pumps or the lack of appropriate targets for a given family of drugs. However, recently published articles indicate that the characteristic phenotype of susceptibility to antibiotics of a given bacterial species depends on the concerted activity of several elements, what has been named as intrinsic resistome. These determinants comprise not just classical resistance genes. Other elements, several of them involved in basic bacterial metabolic processes, are of relevance for the intrinsic resistance of bacterial pathogens. In the present review we analyze recent publications on the intrinsic resistomes of Escherichia coli and Pseudomonas aeruginosa. We present as well information on the role that global regulators of bacterial metabolism, as Crc from P. aeruginosa, may have on modulating bacterial susceptibility to antibiotics. Finally, we discuss the possibility of searching inhibitors of the intrinsic resistome in the aim of improving the activity of drugs currently in use for clinical practice.

The Role of Intrinsic and Extrinsic Factors in Infant Night Waking

ERIC Educational Resources Information Center

Karraker, Katherine

2008-01-01

This literature review focuses on factors found to be associated with individual differences in infant night waking. Infant night waking that requires parent intervention to assist the infant to return to sleep is of special concern to parents because of the sleep deprivation and fragmentation that they experience. Both intrinsic and extrinsic…

Distinguishing intrinsic from extrinsic factors underlying firing rate saturation in human motor units

PubMed Central

Lester, Rosemary A.; Johns, Richard K.

2014-01-01

During voluntary contraction, firing rates of individual motor units (MUs) increase modestly over a narrow force range beyond which little additional increase in firing rate is seen. Such saturation of MU discharge may be a consequence of extrinsic factors that limit net synaptic excitation acting on motor neurons (MNs) or may be due to intrinsic properties of the MNs. Two sets of experiments involving recording of human biceps brachii MUs were carried out to evaluate saturation. In the first set, the extent of saturation was quantified for 136 low-threshold MUs during isometric ramp contractions. Firing rate-force data were best fit by a saturating function for 90% of MUs recorded with a maximum rate of 14.8 ± 2.0 impulses/s. In the second set of experiments, to distinguish extrinsic from intrinsic factors underlying saturation, we artificially augmented descending excitatory drive to biceps MNs by activation of muscle spindle afferents through tendon vibration. We examined the change in firing rate caused by tendon vibration in 96 MUs that were voluntarily activated at rates below and at saturation. Vibration had little effect on the discharge of MUs that were firing at saturation frequencies but strongly increased firing rates of the same units when active at lower frequencies. These results indicate that saturation is likely caused by intrinsic mechanisms that prevent further increases in firing rate in the presence of increasing synaptic excitation. Possible intrinsic cellular mechanisms that limit firing rates of motor units during voluntary effort are discussed. PMID:25475356

The Neuroscience of Growth Mindset and Intrinsic Motivation.

PubMed

Ng, Betsy

2018-01-26

Our actions can be triggered by intentions, incentives or intrinsic values. Recent neuroscientific research has yielded some results about the growth mindset and intrinsic motivation. With the advances in neuroscience and motivational studies, there is a global need to utilize this information to inform educational practice and research. Yet, little is known about the neuroscientific interplay between growth mindset and intrinsic motivation. This paper attempts to draw on the theories of growth mindset and intrinsic motivation, together with contemporary ideas in neuroscience, outline the potential for neuroscientific research in education. It aims to shed light on the relationship between growth mindset and intrinsic motivation in terms of supporting a growth mindset to facilitate intrinsic motivation through neural responses. Recent empirical research from the educational neuroscience perspective that provides insights into the interplay between growth mindset and intrinsic motivation will also be discussed.

Importance and challenges of measuring intrinsic foot muscle strength

PubMed Central

2012-01-01

Background Intrinsic foot muscle weakness has been implicated in a range of foot deformities and disorders. However, to establish a relationship between intrinsic muscle weakness and foot pathology, an objective measure of intrinsic muscle strength is needed. The aim of this review was to provide an overview of the anatomy and role of intrinsic foot muscles, implications of intrinsic weakness and evaluate the different methods used to measure intrinsic foot muscle strength. Method Literature was sourced from database searches of MEDLINE, PubMed, SCOPUS, Cochrane Library, PEDro and CINAHL up to June 2012. Results There is no widely accepted method of measuring intrinsic foot muscle strength. Methods to estimate toe flexor muscle strength include the paper grip test, plantar pressure, toe dynamometry, and the intrinsic positive test. Hand-held dynamometry has excellent interrater and intrarater reliability and limits toe curling, which is an action hypothesised to activate extrinsic toe flexor muscles. However, it is unclear whether any method can actually isolate intrinsic muscle strength. Also most methods measure only toe flexor strength and other actions such as toe extension and abduction have not been adequately assessed. Indirect methods to investigate intrinsic muscle structure and performance include CT, ultrasonography, MRI, EMG, and muscle biopsy. Indirect methods often discriminate between intrinsic and extrinsic muscles, but lack the ability to measure muscle force. Conclusions There are many challenges to accurately measure intrinsic muscle strength in isolation. Most studies have measured toe flexor strength as a surrogate measure of intrinsic muscle strength. Hand-held dynamometry appears to be a promising method of estimating intrinsic muscle strength. However, the contribution of extrinsic muscles cannot be excluded from toe flexor strength measurement. Future research should clarify the relative contribution of intrinsic and extrinsic muscles

Intrinsic fluorescence of protein in turbid media using empirical relation based on Monte Carlo lookup table

NASA Astrophysics Data System (ADS)

Einstein, Gnanatheepam; Udayakumar, Kanniyappan; Aruna, Prakasarao; Ganesan, Singaravelu

2017-03-01

Fluorescence of Protein has been widely used in diagnostic oncology for characterizing cellular metabolism. However, the intensity of fluorescence emission is affected due to the absorbers and scatterers in tissue, which may lead to error in estimating exact protein content in tissue. Extraction of intrinsic fluorescence from measured fluorescence has been achieved by different methods. Among them, Monte Carlo based method yields the highest accuracy for extracting intrinsic fluorescence. In this work, we have attempted to generate a lookup table for Monte Carlo simulation of fluorescence emission by protein. Furthermore, we fitted the generated lookup table using an empirical relation. The empirical relation between measured and intrinsic fluorescence is validated using tissue phantom experiments. The proposed relation can be used for estimating intrinsic fluorescence of protein for real-time diagnostic applications and thereby improving the clinical interpretation of fluorescence spectroscopic data.

Intrinsic delay of permeable base transistor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Wenchao; Guo, Jing; So, Franky

2014-07-28

Permeable base transistors (PBTs) fabricated by vacuum deposition or solution process have the advantages of easy fabrication and low power operation and are a promising device structure for flexible electronics. Intrinsic delay of PBT, which characterizes the speed of the transistor, is investigated by solving the three-dimensional Poisson equation and drift-diffusion equation self-consistently using finite element method. Decreasing the emitter thickness lowers the intrinsic delay by improving on-current, and a thinner base is also preferred for low intrinsic delay because of fewer carriers in the base region at off-state. The intrinsic delay exponentially decreases as the emitter contact Schottky barriermore » height decreases, and it linearly depends on the carrier mobility. With an optimized emitter contact barrier height and device geometry, a sub-nano-second intrinsic delay can be achieved with a carrier mobility of ∼10 cm{sup 2}/V/s obtainable in solution processed indium gallium zinc oxide, which indicates the potential of solution processed PBTs for GHz operations.« less

The Impact of Nonlinear Pedagogy on Physical Education Teacher Education Students' Intrinsic Motivation

ERIC Educational Resources Information Center

Moy, Brendan; Renshaw, Ian; Davids, Keith

2016-01-01

Background: Providing motivationally supportive physical education experiences for learners is crucial, since empirical evidence in sport and physical education research has associated intrinsic motivation with positive educational outcomes. Self-determination theory (SDT) provides a valuable framework for examining motivationally supportive…

The Neuroscience of Growth Mindset and Intrinsic Motivation

PubMed Central

Ng, Betsy

2018-01-01

Our actions can be triggered by intentions, incentives or intrinsic values. Recent neuroscientific research has yielded some results about the growth mindset and intrinsic motivation. With the advances in neuroscience and motivational studies, there is a global need to utilize this information to inform educational practice and research. Yet, little is known about the neuroscientific interplay between growth mindset and intrinsic motivation. This paper attempts to draw on the theories of growth mindset and intrinsic motivation, together with contemporary ideas in neuroscience, outline the potential for neuroscientific research in education. It aims to shed light on the relationship between growth mindset and intrinsic motivation in terms of supporting a growth mindset to facilitate intrinsic motivation through neural responses. Recent empirical research from the educational neuroscience perspective that provides insights into the interplay between growth mindset and intrinsic motivation will also be discussed. PMID:29373496

Intrinsic motivation, curiosity, and learning: Theory and applications in educational technologies.

PubMed

Oudeyer, P-Y; Gottlieb, J; Lopes, M

2016-01-01

This chapter studies the bidirectional causal interactions between curiosity and learning and discusses how understanding these interactions can be leveraged in educational technology applications. First, we review recent results showing how state curiosity, and more generally the experience of novelty and surprise, can enhance learning and memory retention. Then, we discuss how psychology and neuroscience have conceptualized curiosity and intrinsic motivation, studying how the brain can be intrinsically rewarded by novelty, complexity, or other measures of information. We explain how the framework of computational reinforcement learning can be used to model such mechanisms of curiosity. Then, we discuss the learning progress (LP) hypothesis, which posits a positive feedback loop between curiosity and learning. We outline experiments with robots that show how LP-driven attention and exploration can self-organize a developmental learning curriculum scaffolding efficient acquisition of multiple skills/tasks. Finally, we discuss recent work exploiting these conceptual and computational models in educational technologies, showing in particular how intelligent tutoring systems can be designed to foster curiosity and learning. © 2016 Elsevier B.V. All rights reserved.

Estimation of Time-Varying, Intrinsic and Reflex Dynamic Joint Stiffness during Movement. Application to the Ankle Joint

PubMed Central

Guarín, Diego L.; Kearney, Robert E.

2017-01-01

Dynamic joint stiffness determines the relation between joint position and torque, and plays a vital role in the control of posture and movement. Dynamic joint stiffness can be quantified during quasi-stationary conditions using disturbance experiments, where small position perturbations are applied to the joint and the torque response is recorded. Dynamic joint stiffness is composed of intrinsic and reflex mechanisms that act and change together, so that nonlinear, mathematical models and specialized system identification techniques are necessary to estimate their relative contributions to overall joint stiffness. Quasi-stationary experiments have demonstrated that dynamic joint stiffness is heavily modulated by joint position and voluntary torque. Consequently, during movement, when joint position and torque change rapidly, dynamic joint stiffness will be Time-Varying (TV). This paper introduces a new method to quantify the TV intrinsic and reflex components of dynamic joint stiffness during movement. The algorithm combines ensemble and deterministic approaches for estimation of TV systems; and uses a TV, parallel-cascade, nonlinear system identification technique to separate overall dynamic joint stiffness into intrinsic and reflex components from position and torque records. Simulation studies of a stiffness model, whose parameters varied with time as is expected during walking, demonstrated that the new algorithm accurately tracked the changes in dynamic joint stiffness using as little as 40 gait cycles. The method was also used to estimate the intrinsic and reflex dynamic ankle stiffness from an experiment with a healthy subject during which ankle movements were imposed while the subject maintained a constant muscle contraction. The method identified TV stiffness model parameters that predicted the measured torque very well, accounting for more than 95% of its variance. Moreover, both intrinsic and reflex dynamic stiffness were heavily modulated through the

Intrinsic rewards experienced by a group of dentists working with underserved populations.

PubMed

Gardner, S P; Roberts-Thomson, K F; Winning, T A; Peterson, R

2014-09-01

The aim of this study was to explore, using qualitative methods, the intrinsic reasons why dentists work with underserved groups. Minority and marginalized groups of Australians suffer a greater burden of dental disease than the general population due to disparities in accessing care. Recruitment and retention of dentists to care for underserved groups is problematic due to personal, professional and structural reasons. What drives dentists to work with underserved groups is not widely known. Sixteen dentists were recruited using 'snowball' purposeful sampling. Semi-structured in-depth interviews were conducted. Thematic analysis was conducted on the transcriptions to identify themes. Five key themes emerged: (1) 'tapped on the shoulder', being personally approached or invited; (2) 'dental school experience', the challenges faced as a student; (3) 'empathic concern', the non-judgemental expressions of care toward others; (4) 'resilience', the ability to bounce back after setbacks; (5) 'intrinsic reward', the personal gain and satisfaction received. This study focuses on the intrinsic rewards which were found to be simple, unexpected, and associated with relieving pain, community engagement and making a difference. Emphasizing personal fulfilment and intrinsic reward could be useful when promoting dentistry as a career and when encouraging graduates to consider working with disadvantaged groups. © 2014 Australian Dental Association.

The fragmented self: imbalance between intrinsic and extrinsic self-networks in psychotic disorders.

PubMed

Ebisch, Sjoerd J H; Aleman, André

2016-08-01

Self-disturbances are among the core features of schizophrenia and related psychotic disorders. The basic structure of the self could depend on the balance between intrinsic and extrinsic self-processing. We discuss studies on self-related processing in psychotic disorders that provide converging evidence for disrupted communication between neural networks subserving the so-called intrinsic self and extrinsic self. This disruption might be mainly caused by impaired integrity of key brain hubs. The intrinsic self has been associated with cortical midline structures involved in self-referential processing, autobiographical memory, and emotional evaluation. Additionally, we highlight central aspects of the extrinsic self in its interaction with the environment using sensorimotor networks, including self-experience in sensation and actions. A deficient relationship between these self-aspects because of disrupted between-network interactions offers a framework to explain core clinical features of psychotic disorders. In particular, we show how relative isolation and reduced modularity of networks subserving intrinsic and extrinsic self-processing might trigger the emergence of hallucinations and delusions, and why patients with psychosis typically have difficulties with self-other relationships and do not recognise mental problems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Self-handicapping and intrinsic motivation: buffering intrinsic motivation from the threat of failure.

PubMed

Deppe, R K; Harackiewicz, J M

1996-04-01

High and low self-handicappers (as measured by E. E. Jones & F. Rhodewalt's [1982] Self-Handicapping Scale) were asked to play a game of pinball (in a competitive or noncompetitive setting) after they had practices as much as they wanted on a related task (thus, not practicing could have served as a self-handicap). High self-handicappers who did not practice much became more involved in the game and subsequently reported enjoying the game more than high self-handicappers who practiced a lot. Furthermore, the effects on enjoyment were mediated by task involvement, suggesting that the protection afforded by self-handicapping affects intrinsic motivation by allowing the individual to become absorbed in the activity instead of focusing on performance concerns. Individuals who self-handicap may be providing themselves with the "breathing room" they need to become absorbed in an activity and to experience the activity as enjoyable.

Intrinsic Valuation of Information in Decision Making under Uncertainty

PubMed Central

Bode, Stefan; Brydevall, Maja; Murawski, Carsten

2016-01-01

In a dynamic world, an accurate model of the environment is vital for survival, and agents ought regularly to seek out new information with which to update their world models. This aspect of behaviour is not captured well by classical theories of decision making, and the cognitive mechanisms of information seeking are poorly understood. In particular, it is not known whether information is valued only for its instrumental use, or whether humans also assign it a non-instrumental intrinsic value. To address this question, the present study assessed preference for non-instrumental information among 80 healthy participants in two experiments. Participants performed a novel information preference task in which they could choose to pay a monetary cost to receive advance information about the outcome of a monetary lottery. Importantly, acquiring information did not alter lottery outcome probabilities. We found that participants were willing to incur considerable monetary costs to acquire payoff-irrelevant information about the lottery outcome. This behaviour was well explained by a computational cognitive model in which information preference resulted from aversion to temporally prolonged uncertainty. These results strongly suggest that humans assign an intrinsic value to information in a manner inconsistent with normative accounts of decision making under uncertainty. This intrinsic value may be associated with adaptive behaviour in real-world environments by producing a bias towards exploratory and information-seeking behaviour. PMID:27416034

Buried and accessible surface area control intrinsic protein flexibility.

PubMed

Marsh, Joseph A

2013-09-09

Proteins experience a wide variety of conformational dynamics that can be crucial for facilitating their diverse functions. How is the intrinsic flexibility required for these motions encoded in their three-dimensional structures? Here, the overall flexibility of a protein is demonstrated to be tightly coupled to the total amount of surface area buried within its fold. A simple proxy for this, the relative solvent-accessible surface area (Arel), therefore shows excellent agreement with independent measures of global protein flexibility derived from various experimental and computational methods. Application of Arel on a large scale demonstrates its utility by revealing unique sequence and structural properties associated with intrinsic flexibility. In particular, flexibility as measured by Arel shows little correspondence with intrinsic disorder, but instead tends to be associated with multiple domains and increased α-helical structure. Furthermore, the apparent flexibility of monomeric proteins is found to be useful for identifying quaternary-structure errors in published crystal structures. There is also a strong tendency for the crystal structures of more flexible proteins to be solved to lower resolutions. Finally, local solvent accessibility is shown to be a primary determinant of local residue flexibility. Overall, this work provides both fundamental mechanistic insight into the origin of protein flexibility and a simple, practical method for predicting flexibility from protein structures. © 2013 Elsevier Ltd. All rights reserved.

Serosorting and sexual risk for HIV infection at the ego-alter dyadic level: an egocentric sexual network study among MSM in Nigeria

PubMed Central

Rodriguez-Hart, Cristina; Liu, Hongjie; Nowak, Rebecca G.; Orazulike, Ifeanyi; Zorowitz, Sam; Crowell, Trevor A.; Baral, Stefan D.; Blattner, William; Charurat, Man

2017-01-01

The objective of this egocentric network study was to investigate engagement in serosorting by HIV status and risk for HIV between seroconcordant and serodiscordant ego-alter dyads. Respondent-driving sampling was used to recruit 433 Nigerian MSM from 2013-2014. Participant (ego) characteristics and that of five sex partners (alters) were collected. Seroconcordancy was assessed at the ego level and for each dyad. Among 433 egos, 18% were seroconcordant with all partners. Among 880 dyads where participants knew their HIV status, 226 (25.7%) were seroconcordant, with 11.7% of HIV positive dyads seroconcordant and 37.0% of HIV negative dyads seroconcordant. Seroconcordant dyads reported fewer casual sex partners, less partner concurrency, and partners who had ever injected drugs, but condom use did not differ significantly. Serosorting may be a viable risk reduction strategy among Nigerian MSM, but awareness of and communication about HIV status should be increased. Future studies should assess serosorting on a partner-by-partner basis. PMID:26910338

Experience of Presence in Virtual Environments

DTIC Science & Technology

2003-09-01

perceptual position (exocentric, egocentric) neurolinguistic programming (NLP) assessment. Performance measures: Selection of correct spear, accuracy...the future. Accordingly, the Institute for Defense Analyses (IDA) is undertaking an analysis program to determine whether current data are sufficient...Many groups are seeking a better understanding of presence. From its start, IDA’s program has included pulling together the results of these efforts to

Moral and Spiritual Education as an Intrinsic Part of the Curriculum

ERIC Educational Resources Information Center

Clifford, Philomena

2013-01-01

This paper reports on a case study undertaken within a small, rural primary school in the UK to explore the extent to which it was possible to run a moral and spiritual programme as an intrinsic and inclusive part of the curriculum based on the children's acquisition of virtues. The pupils were encouraged to build on their own experience and…

Electron cyclotron heating and core intrinsic rotation reversal in DIII-D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grassie, J. S. de, E-mail: degrassie@fusion.gat.com; Boedo, J. A.; Grierson, B. A.

2015-12-10

The effect of electron cyclotron heating (ECH) on the intrinsic rotation profile in DIII-D is shown experimentally. Former DIII-D experiments have shown that ECH tends to cause an interior reduction in the normally co-Ip directed intrinsic rotation profile, and this core rotation can be fully reversed to the opposite direction. This effect is due to a turbulent rearrangement of the interior rotation profile. Here, we show results that there is more than one mechanism causing this. We compare two low density L-mode discharges where the only operational difference is the location of the ECH deposition. At low ECH power, comparablemore » to the Ohmic power, the primary change is in the q-profile accompanied by a reversal of the core intrinsic rotation direction for the more off-axis deposition. The change in the shear of the q-profile fits well with a recent theoretical prediction for this rotation reversal. At higher ECH power, the primary change is in the core electron temperature, Te, accompanied by a hollowing of the rotation profile near the magnetic axis. This effect appears to be due to the change in electron collisionality, consistent with another theoretical, gyrokinetic prediction. The variety of phenomena that could allow ECH to modify the intrinsic rotation profile give some expectation that regions of large velocity shear in the interior could be generated, with the possibility of triggering internal transport barriers.« less

Defining intrinsic vs. extrinsic atopic dermatitis.

PubMed

Karimkhani, Chante; Silverberg, Jonathan I; Dellavalle, Robert P

2015-06-16

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin condition characterized by eczematous lesions, i.e. ill-demarcated erythematous patches and plaques. AD is commonly associated with elevated immunoglobulin E (IgE) and atopic disorders, such as asthma, hay fever, and food allergies. Rackemann and Mallory were some of the first to distinguish between asthma based on the presence ("extrinsic") or absence ("intrinsic") of allergy. This distinction has subsequently been applied to AD based on the presence ("extrinsic") or absence ("intrinsic") of increased IgE and atopic disease. Although the distinction between intrinsic and extrinsic AD is widely used, it remains controversial.

Intrinsic Tunneling in Phase Separated Manganites

NASA Astrophysics Data System (ADS)

Singh-Bhalla, G.; Selcuk, S.; Dhakal, T.; Biswas, A.; Hebard, A. F.

2009-02-01

We present evidence of direct electron tunneling across intrinsic insulating regions in submicrometer wide bridges of the phase-separated ferromagnet (La,Pr,Ca)MnO3. Upon cooling below the Curie temperature, a predominantly ferromagnetic supercooled state persists where tunneling across the intrinsic tunnel barriers (ITBs) results in metastable, temperature-independent, high-resistance plateaus over a large range of temperatures. Upon application of a magnetic field, our data reveal that the ITBs are extinguished resulting in sharp, colossal, low-field resistance drops. Our results compare well to theoretical predictions of magnetic domain walls coinciding with the intrinsic insulating phase.

Close games versus blowouts: Optimal challenge reinforces one's intrinsic motivation to win.

PubMed

Meng, Liang; Pei, Guanxiong; Zheng, Jiehui; Ma, Qingguo

2016-12-01

When immersed in intrinsically motivating activities, individuals actively seek optimal challenge, which generally brings the most satisfaction as they play hard and finally win. To better simulate real-life scenarios in the controlled laboratory setting, a two-player online StopWatch (SW) game was developed, whose format is similar to that of a badminton tournament. During the game, a male opponent played by a confederate ensured that the same-sex participant paired with him won both matches, one with a wide margin (the lack of challenge condition) and another with a narrow one (the optimal challenge condition). Electrophysiological data were recorded during the entire experiment. An enlarged Stimulus-preceding negativity (SPN) was observed in the optimal challenge condition, indicating a more concentrated anticipatory attention toward the feedback and a stronger intrinsic motivation during close games. Thus, this study provided original neural evidence for predictions of Self-determination theory (SDT) and Flow theory, and confirmed and emphasized the significant role of optimal challenge in promoting one's intrinsic motivation to win. Copyright © 2016 Elsevier B.V. All rights reserved.

Neuromodulation intrinsic to the central pattern generator for escape swimming in Tritonia.

PubMed

Katz, P S

1998-11-16

Extrinsic neuromodulatory inputs to central pattern generators (CPGs) can alter the properties and synaptic interactions of neurons in those circuits and thereby modify the output of the CPG. Recent work in a number of systems has now demonstrated that neurons intrinsic to CPG can also evoke neuromodulatory actions on other members of the CPG. Such "intrinsic neuromodulation" plays a role in controlling the CPG underlying the escape swim response of the nudibrach mollusc, Tritonia diomedea. The dorsal swim interneurons (DSIs) are a bilaterally represented set of three serotonergic neurons that participate in the generation of the rhythmic swim motor program. Serotonin released from these CPG neurons functions both as a fast neurotransmitter and as a slower neuromodulator. In its modulatory role, serotonin enhances the release of neurotransmitter from another CPG neuron, C2, and also increases C2 excitability by decreasing spike frequency adaptation. These neuromodulatory actions intrinsic to the CPG may be important for the initial self-configuration of the system into a function CPG and for experience-dependent changes in the output such as behavioral sensitization and habituation.

Intrinsic-extrinsic factors in sport motivation.

PubMed

Pedersen, Darhl M

2002-10-01

Participants were 83 students (36 men and 47 women). 10 intrinsic-extrinsic factors involved in sport motivation were obtained. The factors were generated from items obtained from the participants rather than items from the experimenter. This was done to avoid the possible influence of preconceptions on the part of the experimenter regarding what the final dimensions may be. Obtained motivational factors were Social Reinforcement, Fringe Benefits, Fame and Fortune, External Forces, Proving Oneself, Social Benefits, Mental Enrichment, Expression of Self, Sense of Accomplishment, and Self-enhancement. Each factor was referred to an intrinsic-extrinsic dimension to describe its relative position on that dimension. The order of the factors as listed indicates increasing intrinsic motivation. i.e., the first four factors were rated in the extrinsic range, whereas the remaining six were rated to be in the intrinsic range. Next, the participants rated the extent to which each of the various factors was involved in their decision to participate in sport activities. The pattern of use of the motivational factors was the same for both sexes except that men indicated greater use of the Fringe Benefits factor. Overall, the more intrinsic a sport motivation factor was rated, the more likely it was to be rated as a factor in actual sport participation.

Intrinsic Correlations for Flaring Blazars Detected by Fermi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fan, J. H.; Xiao, H. B.; Lin, C.

2017-02-01

Blazars are an extreme subclass of active galactic nuclei. Their rapid variability, luminous brightness, superluminal motion, and high and variable polarization are probably due to a beaming effect. However, this beaming factor (or Doppler factor) is very difficult to measure. Currently, a good way to estimate it is to use the timescale of their radio flares. In this Letter, we use multiwavelength data and Doppler factors reported in the literature for a sample of 86 flaring blazars detected by Fermi to compute their intrinsic multiwavelength data and intrinsic spectral energy distributions and investigate the correlations among observed and intrinsic data.more » Quite interestingly, intrinsic data show a positive correlation between luminosity and peak frequency, in contrast with the behavior of observed data, and a tighter correlation between γ -ray luminosity and the lower-energy ones. For flaring blazars detected by Fermi , we conclude that (1) observed emissions are strongly beamed; (2) the anti-correlation between luminosity and peak frequency from the observed data is an apparent result, the correlation between intrinsic data being positive; and (3) intrinsic γ -ray luminosity is strongly correlated with other intrinsic luminosities.« less

Motivating learning, performance, and persistence: the synergistic effects of intrinsic goal contents and autonomy-supportive contexts.

PubMed

Vansteenkiste, Maarten; Simons, Joke; Lens, Willy; Sheldon, Kennon M; Deci, Edward L

2004-08-01

Three field experiments with high school and college students tested the self-determination theory hypotheses that intrinsic (vs. extrinsic) goals and autonomy-supportive (vs. controlling) learning climates would improve students' learning, performance, and persistence. The learning of text material or physical exercises was framed in terms of intrinsic (community, personal growth, health) versus extrinsic (money, image) goals, which were presented in an autonomy-supportive versus controlling manner. Analyses of variance confirmed that both experimentally manipulated variables yielded main effects on depth of processing, test performance, and persistence (all ps <.001), and an interaction resulted in synergistically high deep processing and test performance (but not persistence) when both intrinsic goals and autonomy support were present. Effects were significantly mediated by autonomous motivation.

Demand characteristics and self-report measures of imaginary audience sensitivity: implications for interpreting age differences in adolescent egocentrism.

PubMed

Vartanian, L R; Powlishta, K K

2001-06-01

Self-consciousness during early adolescence has been explained as an outcome of adolescent egocentrism, in which adolescents create an imaginary audience (IA) of attentive, critical peers. The possibility that such self-consciousness might result from contact with peers who are more attentive and critical than those encountered during childhood or adulthood has not been considered. Study 1 tested whether young adults, who are not theoretically susceptible to IA, could be made to receive high scores on IA and self-consciousness measures by having them complete a procedure in 1 of 3 laboratory conditions-a critical audience, a noncritical audience, or no audience. However, participants in the critical-audience condition received significantly lower IA and self-consciousness scores than participants in the no-audience condition did. Study 2 tested whether the directions given to Study 1 participants might have been responsible for the unexpected findings. Results indicated that participants instructed to give mature-sounding responses received lower IA/self-consciousness scores than did those asked to report their honest opinions. Together, the results of Studies 1 and 2 indicated that survey measures of IA are subject to demand characteristics and highlighted the need to interpret with caution age differences in IA as traditionally assessed.

Auditory word recognition: extrinsic and intrinsic effects of word frequency.

PubMed

Connine, C M; Titone, D; Wang, J

1993-01-01

Two experiments investigated the influence of word frequency in a phoneme identification task. Speech voicing continua were constructed so that one endpoint was a high-frequency word and the other endpoint was a low-frequency word (e.g., best-pest). Experiment 1 demonstrated that ambiguous tokens were labeled such that a high-frequency word was formed (intrinsic frequency effect). Experiment 2 manipulated the frequency composition of the list (extrinsic frequency effect). A high-frequency list bias produced an exaggerated influence of frequency; a low-frequency list bias showed a reverse frequency effect. Reaction time effects were discussed in terms of activation and postaccess decision models of frequency coding. The results support a late use of frequency in auditory word recognition.

Reconstructed phase spaces of intrinsic mode functions. Application to postural stability analysis.

PubMed

Snoussi, Hichem; Amoud, Hassan; Doussot, Michel; Hewson, David; Duchêne, Jacques

2006-01-01

In this contribution, we propose an efficient nonlinear analysis method characterizing postural steadiness. The analyzed signal is the displacement of the centre of pressure (COP) collected from a force plate used for measuring postural sway. The proposed method consists of analyzing the nonlinear dynamics of the intrinsic mode functions (IMF) of the COP signal. The nonlinear properties are assessed through the reconstructed phase spaces of the different IMFs. This study shows some specific geometries of the attractors of some intrinsic modes. Moreover, the volume spanned by the geometric attractors in the reconstructed phase space represents an efficient indicator of the postural stability of the subject. Experiments results corroborate the effectiveness of the method to blindly discriminate young subjects, elderly subjects and subjects presenting a risk of falling.

Intrinsic Motivation: An Overlooked Component for Student Success

ERIC Educational Resources Information Center

Augustyniak, Robert A.; Ables, Adrienne Z.; Guilford, Philip; Lujan, Heidi L.; Cortright, Ronald N.; DiCarlo, Stephen E.

2016-01-01

Intrinsic motivation to learn involves engaging in learning opportunities because they are seen as enjoyable, interesting, or relevant to meeting one's core psychological needs. As a result, intrinsic motivation is associated with high levels of effort and task performance. Students with greater levels of intrinsic motivation demonstrate strong…

The value of nature: Economic, intrinsic, or both?

EPA Science Inventory

There has been a long standing argument that ecosystems have intrinsic value and therefore there is no need to put a price tag on Mother Nature. The concept of intrinsic value reflects the perspective that nature has value in its own right, independent of human uses. Intrinsic va...

The Impact of Teaching Strategies on Intrinsic Motivation.

ERIC Educational Resources Information Center

Bomia, Lisa; Beluzo, Lynne; Demeester, Debra; Elander, Keli; Johnson, Mary; Sheldon, Betty

This paper examines intrinsic motivation by reviewing various motivational theories and models and discussing whether research supports the hypothesis that teaching strategies can influence intrinsic motivation. Intrinsic motivation, also known as self-motivation, refers to influences that originate from within a person which cause a person to act…

The dark side of monetary incentive: how does extrinsic reward crowd out intrinsic motivation.

PubMed

Ma, Qingguo; Jin, Jia; Meng, Liang; Shen, Qiang

2014-02-12

It was widely believed that incentives could effectively enhance the motivation of both students and employees. However, psychologists reported that extrinsic reward actually could undermine individuals' intrinsic motivation to a given interesting task, which challenged viewpoints from traditional incentive theories. Numerous studies have been carried out to test and explain the undermining effect; however, the neural basis of this effect is still elusive. Here, we carried out an electrophysiological study with a simple but interesting stopwatch task to explore to what extent the performance-based monetary reward undermines individuals' intrinsic motivation toward the task. The electrophysiological data showed that the differentiated feedback-related negativity amplitude toward intrinsic success failure divergence was prominently reduced once the extrinsic reward was imposed beforehand. However, such a difference was not observed in the control group, in which no extrinsic reward was provided throughout the experiment. Furthermore, such a pattern was not observed for P300 amplitude. Therefore, the current results indicate that extrinsic reward demotivates the intrinsic response of individuals toward success-failure outcome, which was reflected in the corresponding reduced motivational-related differentiated feedback-related negativity, but not in amplitude of P300.

Field and laboratory evidence for intrinsic biodegradation of vinyl chloride contamination in a Fe(III)-reducing aquifer

USGS Publications Warehouse

Bradley, P.M.; Chapelle, F.H.; Wilson, J.T.

1998-01-01

Intrinsic bioremediation of chlorinated ethenes in anaerobic aquifers previously has not been considered feasible, due, in large part, to 1) the production of vinyl chloride during microbial reductive dechlorination of higher chlorinated contaminants and 2) the apparent poor biodegradability of vinyl chloride under anaerobic conditions. In this study, a combination of field geochemical analyses and laboratory radiotracer ([1,2-14C] vinyl chloride) experiments was utilized to assess the potential for intrinsic biodegradation of vinyl chloride contamination in an Fe(III)-reducing, anaerobic aquifer. Microcosm experiments conducted under Fe(III)-reducing conditions with material from the Fe(III)-reducing, chlorinated-ethene contaminated aquifer demonstrated significant oxidation of [1,2-14C] vinyl chloride to 14CO2 with no detectable production of ethene or other reductive dehalogenation products. Rates of degradation derived from the microcosm experiments (0.9-1.3% d-1) were consistent with field-estimated rates (0.03-0.2% d-1) of apparent vinyl chloride degradation. Field estimates of apparent vinyl chloride biodegradation were calculated using two distinct approaches; 1) a solute dispersion model and 2) a mass balance assessment. These findings demonstrate that degradation under Fe(III) reducing conditions can be an environmentally significant mechanism for intrinsic bioremediation of vinyl chloride in anaerobic ground-water systems.

Fitness costs of intrinsic competition in two egg parasitoids of a true bug.

PubMed

Cusumano, Antonino; Peri, Ezio; Boivin, Guy; Colazza, Stefano

2015-10-01

Intrinsic competition in insect parasitoids occurs when supernumerary larvae develop in the same host as consequence of multiple ovipositions by females of the same species (intra-specific competition) or by females of different species (inter-specific competition). Studies on intrinsic competition have mainly focused on understanding the factors that play a role in the outcome of competition, while fitness-related effects for the parasitoid surviving the competition have been poorly investigated, especially in egg parasitoids. Interestingly, even the winning parasitoid can experience fitness costs due to larval development in a host in which multiple factors have been injected by the ovipositing females or released by their larvae. In this paper we studied fitness-related traits associated with intra- and inter-specific competition between Trissolcus basalis (Wollaston) and Ooencyrtus telenomicida (Vassiliev), the main egg parasitoids associated with the southern green stink bug Nezara viridula (L.) in Italy. We investigated the impact of intrinsic competition for the surviving parasitoid in terms of body size, developmental time, number and size of oocytes. Our results indicated that T. basalis adults did not experience fitness-related costs when surviving intra-specific competition; however, adults were smaller, took longer to develop and females produced fewer oocytes after surviving inter-specific competition. A different outcome was found for O. telenomicida where the emerging females were smaller, produced fewer and smaller oocytes when suffering intra-specific competition whereas no fitness costs were found when adults survived inter-specific competition. These results support the hypothesis that the impact of intrinsic competition in egg parasitoids depends on the severity of the competitive interaction, as fitness costs were more pronounced when the surviving parasitoid interacted with the most detrimental competitor. Copyright © 2015 Elsevier Ltd. All

Intrinsic and extrinsic motivation for smoking cessation.

PubMed

Curry, S; Wagner, E H; Grothaus, L C

1990-06-01

An intrinsic-extrinsic model of motivation for smoking cessation was evaluated with 2 samples (ns = 1.217 and 151) of smokers who requested self-help materials for smoking cessation. Exploratory and confirmatory principal components analysis on a 36-item Reasons for Quitting (RFQ) scale supported the intrinsic-extrinsic motivation distinction. A 4-factor model, with 2 intrinsic dimensions (concerns about health and desire for self-control) and 2 extrinsic dimensions (immediate reinforcement and social influence), was defined by 20 of the 36 RFQ items. The 20-item measure demonstrated moderate to high levels of internal consistency and convergent and discriminant validity. Logistic regression analyses indicated that smokers with higher levels of intrinsic relative to extrinsic motivation were more likely to achieve abstinence from smoking.

Short-range correlations in carbon-12, oxygen-16, and neon-20: Intrinsic properties

NASA Technical Reports Server (NTRS)

Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

1972-01-01

The Brueckner-Hartree-Fock (BHF) method has been applied to nuclei whose intrinsic structure is nonspherical. Reaction matrix elements were calculated as functions of starting energy for the Hamada-Johnston interaction using the Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single particle energies, radii, and shape deformations of the intrinsic state, in ordinary as well as renormalized BHF, are discussed and compared with previous HF studies and with experiment when possible. Results are presented for C-12, 0-16 and Ne-20. It is found that the binding energies and radii are too small, but that separation energies are well reproduced when the renormalized theory is used.

Refining the intrinsic chimera flap: a review.

PubMed

Agarwal, Jayant P; Agarwal, Shailesh; Adler, Neta; Gottlieb, Lawrence J

2009-10-01

Reconstruction of complex tissue deficiencies in which each missing component is in a different spatial relationship to each other can be particularly challenging, especially in patients with limited recipient vessels. The chimera flap design is uniquely suited to reconstruct these deformities. Chimera flaps have been previously defined in many ways with 2 main categories: prefabricated or intrinsic. Herein we attempt to clarify the definition of a true intrinsic chimeric flap and provide examples of how these constructs provide a method for reconstruction of complex defects. The versatility of the intrinsic chimera flap and its procurement from 7 different vascular systems is described. A clarification of the definition of a true intrinsic chimera flap is described. In addition, construction of flaps from the lateral femoral circumflex, deep circumflex iliac, inferior gluteal, peroneal, subscapular, thoracodorsal, and radial arterial systems is described to showcase the versatility of these chimera flaps. A true intrinsic chimera flap must consist of more than a single tissue type. Each of the tissue components receives its blood flow from separate vascular branches or perforators that are connected to a single vascular source. These vascular branches must be of appropriate length to allow for insetting with 3-dimensional spatial freedom. There are a multitude of sites from which true intrinsic chimera flaps may be harvested.

Optimized up-down asymmetry to drive fast intrinsic rotation in tokamaks

NASA Astrophysics Data System (ADS)

Ball, Justin; Parra, Felix I.; Landreman, Matt; Barnes, Michael

2018-02-01

Breaking the up-down symmetry of the tokamak poloidal cross-section can significantly increase the spontaneous rotation due to turbulent momentum transport. In this work, we optimize the shape of flux surfaces with both tilted elongation and tilted triangularity in order to maximize this drive of intrinsic rotation. Nonlinear gyrokinetic simulations demonstrate that adding optimally-tilted triangularity can double the momentum transport of a tilted elliptical shape. This work indicates that tilting the elongation and triangularity in an ITER-like device can reduce the energy transport and drive intrinsic rotation with an Alfvén Mach number of roughly 1% . This rotation is four times larger than the rotation expected in ITER and is approximately what is needed to stabilize MHD instabilities. It is shown that this optimal shape can be created using the shaping coils of several present-day experiments.

The experience of returning to work.

PubMed

Jansson, Inger; Björklund, Anita

2007-01-01

The purpose of this qualitative study was to explore from an environmental perspective the experiences of returning to work of former unemployed sickness absentees. Five separate focus-group interviews were carried out with themes concerning different environmental areas. The findings showed that the participants in their process of being off work and then attempting returning to work experienced a personal transition manifesting itself as a negative self-image, change of life-rhythm and restrictions in their roles and activities. In their progression, the participants experienced a need for reorientation and expressed feelings of alienation, and for that reason felt need of support from a network, especially a professional one. Regarding attitudes in society, the participants reported experiences of social stigmatization, both in mass media and in their immediate social environment, and an increasing egocentricity among their fellow-workers. They perceived their progression back to work as a 'time quarantine' and as a long and destructive wait for support. The findings indicate that the phenomenon of 'returning to work' after unemployment and sick leave could not be reduced to a single issue. It should rather be seen as a dynamic problem with individual and structural, environmental aspects.

Intrinsic operators for the electromagnetic nuclear current

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Adam, Jr.; H. Arenhovel

1996-09-01

The intrinsic electromagnetic nuclear meson exchange charge and current operators arising from a separation of the center-of-mass motion are derived for a one-boson-exchange model for the nuclear interaction with scalar, pseudoscalar and vector meson exchange including leading order relativistic terms. Explicit expressions for the meson exchange operators corresponding to the different meson types are given in detail for a two-nucleon system. These intrinsic operators are to be evaluated between intrinsic wave functions in their center-of-mass frame.

The alphabet of intrinsic disorder

PubMed Central

Theillet, Francois-Xavier; Kalmar, Lajos; Tompa, Peter; Han, Kyou-Hoon; Selenko, Philipp; Dunker, A. Keith; Daughdrill, Gary W.; Uversky, Vladimir N

2013-01-01

A significant fraction of every proteome is occupied by biologically active proteins that do not form unique three-dimensional structures. These intrinsically disordered proteins (IDPs) and IDP regions (IDPRs) have essential biological functions and are characterized by extensive structural plasticity. Such structural and functional behavior is encoded in the amino acid sequences of IDPs/IDPRs, which are enriched in disorder-promoting residues and depleted in order-promoting residues. In fact, amino acid residues can be arranged according to their disorder-promoting tendency to form an alphabet of intrinsic disorder that defines the structural complexity and diversity of IDPs/IDPRs. This review is the first in a series of publications dedicated to the roles that different amino acid residues play in defining the phenomenon of protein intrinsic disorder. We start with proline because data suggests that of the 20 common amino acid residues, this one is the most disorder-promoting. PMID:28516008

Intrinsic time quantum geometrodynamics

NASA Astrophysics Data System (ADS)

Ita, Eyo Eyo; Soo, Chopin; Yu, Hoi-Lai

2015-08-01

Quantum geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl curvature hypothesis, and thermodynamic and gravitational "arrows of time" point in the same direction. Ricci scalar potential corresponding to Einstein's general relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of gravitation and quantum mechanics.

Intrinsic motivation as a mediator between metacognition deficits and impaired functioning in psychosis.

PubMed

Luther, Lauren; Firmin, Ruth L; Vohs, Jenifer L; Buck, Kelly D; Rand, Kevin L; Lysaker, Paul H

2016-09-01

Poor functioning has long been observed in individuals with psychosis. Recent studies have identified metacognition - one's ability to form complex ideas about oneself and others and to use that information to respond to psychological and social challenges-as being an important determinant of functioning. However, the exact process by which deficits in metacognition lead to impaired functioning remains unclear. This study first examined whether low intrinsic motivation, or the tendency to pursue novel experiences and to engage in self-improvement, mediates the relationship between deficits in metacognition and impaired functioning. We then examined whether intrinsic motivation significantly mediated the relationship when controlling for age, education, symptoms, executive functioning, and social cognition. Mediation models were examined in a cross-sectional data set. One hundred and seventy-five individuals with a psychotic disorder completed interview-based measures of metacognition, intrinsic motivation, symptoms, and functioning and performance-based measures of executive functioning and social cognition. Analyses revealed that intrinsic motivation mediated the relationship between metacognition deficits and impaired functioning (95% CI of indirect effect [0.12-0.43]), even after controlling for the aforesaid variables (95% CI of indirect effect [0.04-0.29]). Results suggest that intrinsic motivation may be a mechanism that underlies the link between deficits in metacognition and impaired functioning and indicate that metacognition and intrinsic motivation may be important treatment targets to improve functioning in individuals with psychosis. The findings of this study suggest that deficits in metacognition may indirectly lead to impaired functioning through their effect on intrinsic motivation in individuals with psychosis. Psychological treatments that target deficits in both metacognition and intrinsic motivation may help to alleviate impaired functioning in

Emergence and evolution of an interaction between intrinsically disordered proteins

PubMed Central

Hultqvist, Greta; Åberg, Emma; Camilloni, Carlo; Sundell, Gustav N; Andersson, Eva; Dogan, Jakob; Chi, Celestine N; Vendruscolo, Michele; Jemth, Per

2017-01-01

Protein-protein interactions involving intrinsically disordered proteins are important for cellular function and common in all organisms. However, it is not clear how such interactions emerge and evolve on a molecular level. We performed phylogenetic reconstruction, resurrection and biophysical characterization of two interacting disordered protein domains, CID and NCBD. CID appeared after the divergence of protostomes and deuterostomes 450–600 million years ago, while NCBD was present in the protostome/deuterostome ancestor. The most ancient CID/NCBD formed a relatively weak complex (Kd∼5 µM). At the time of the first vertebrate-specific whole genome duplication, the affinity had increased (Kd∼200 nM) and was maintained in further speciation. Experiments together with molecular modeling using NMR chemical shifts suggest that new interactions involving intrinsically disordered proteins may evolve via a low-affinity complex which is optimized by modulating direct interactions as well as dynamics, while tolerating several potentially disruptive mutations. DOI: http://dx.doi.org/10.7554/eLife.16059.001 PMID:28398197

Charge transport and intrinsic fluorescence in amyloid-like fibrils

PubMed Central

del Mercato, Loretta Laureana; Pompa, Pier Paolo; Maruccio, Giuseppe; Torre, Antonio Della; Sabella, Stefania; Tamburro, Antonio Mario; Cingolani, Roberto; Rinaldi, Ross

2007-01-01

The self-assembly of polypeptides into stable, conductive, and intrinsically fluorescent biomolecular nanowires is reported. We have studied the morphology and electrical conduction of fibrils made of an elastin-related polypeptide, poly(ValGlyGlyLeuGly). These amyloid-like nanofibrils, with a diameter ranging from 20 to 250 nm, result from self-assembly in aqueous solution at neutral pH. Their morphological properties and conductivity have been investigated by atomic force microscopy, scanning tunneling microscopy, and two-terminal transport experiments at the micro- and nanoscales. We demonstrate that the nanofibrils can sustain significant electrical conduction in the solid state at ambient conditions and have remarkable stability. We also show intrinsic blue-green fluorescence of the nanofibrils by confocal microscopy analyses. These results indicate that direct (label-free) excitation can be used to investigate the aggregation state or the polymorphism of amyloid-like fibrils (and possibly of other proteinaceous material) and open up interesting perspectives for the use of peptide-based nanowire structures, with tunable physical and chemical properties, for a wide range of nanobiotechnological and bioelectronic applications. PMID:17984067

Does Facebook promote self-interest? Enactment of indiscriminate one-to-many communication on online social networking sites decreases prosocial behavior.

PubMed

Chiou, Wen-Bin; Chen, Szu-Wei; Liao, Da-Chi

2014-02-01

Abstract Communication tools on social networking sites (SNSs) provide users with an efficient way to distribute information to the public and/or their friends simultaneously. In this article, we show that this kind of indiscriminate one-to-many (i.e., monologue) communication, in which the diverse interests of recipients are not considered, may induce a tendency toward egocentrism that interferes with other-oriented concerns, resulting in a reduced inclination to display prosocial behavior. In Experiment 1, participants induced to post a public communication subsequently allocated less money to anonymous strangers in the dictator game than did control participants. In Experiment 2, participants directing a post about participation in an experiment to their Facebook friends volunteered to help code fewer data sheets than did controls. Moreover, an egocentric state was shown to mediate the relationship between indiscriminate one-to-many communication and helping behavior. We provide the first demonstration that indiscriminate one-to-many communication on online social networks may be associated with a tendency toward self-interest. Our results suggest that the prevalence of monologue communication on SNSs may induce an egocentric tendency that undermines the likelihood of prosocial behavior.

The experience sampling method: Investigating students' affective experience

NASA Astrophysics Data System (ADS)

Nissen, Jayson M.; Stetzer, MacKenzie R.; Shemwell, Jonathan T.

2013-01-01

Improving non-cognitive outcomes such as attitudes, efficacy, and persistence in physics courses is an important goal of physics education. This investigation implemented an in-the-moment surveying technique called the Experience Sampling Method (ESM) [1] to measure students' affective experience in physics. Measurements included: self-efficacy, cognitive efficiency, activation, intrinsic motivation, and affect. Data are presented that show contrasts in students' experiences (e.g., in physics vs. non-physics courses).

Intrinsically motivated reinforcement learning for human-robot interaction in the real-world.

PubMed

Qureshi, Ahmed Hussain; Nakamura, Yutaka; Yoshikawa, Yuichiro; Ishiguro, Hiroshi

2018-03-26

For a natural social human-robot interaction, it is essential for a robot to learn the human-like social skills. However, learning such skills is notoriously hard due to the limited availability of direct instructions from people to teach a robot. In this paper, we propose an intrinsically motivated reinforcement learning framework in which an agent gets the intrinsic motivation-based rewards through the action-conditional predictive model. By using the proposed method, the robot learned the social skills from the human-robot interaction experiences gathered in the real uncontrolled environments. The results indicate that the robot not only acquired human-like social skills but also took more human-like decisions, on a test dataset, than a robot which received direct rewards for the task achievement. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ab initio study of intrinsic profiles of liquid metals and their reflectivity

NASA Astrophysics Data System (ADS)

del Rio, B. G.; Souto, J.; Alemany, M. M. G.; González, L. E.

2017-08-01

The free surfaces of liquid metals are known to exhibit a stratified profile that, in favourable cases, shows up in experiments as a peak in the ratio between the reflectivity function and that of an ideal step-like profile. This peak is located at a wave-vector related to the distance between the layers of the profile. In fact the surface roughness produced by thermally induced capillary waves causes a depletion of the previous so called intrinsic reflectivity by a damping factor that may hinder the observation of the peak. The behaviour of the intrinsic reflectivity below the layering peak is however far from being universal, with systems as Ga or In where the reflectiviy falls uniformly towards the q → 0 value, others like Sn or Bi where a shoulder appears at intermediate wavevectors, and others like Hg which show a minimum. We have performed extensive ab initio simulations of the free liquid surfaces of Bi, Pb and Hg, that yield direct information on the structure of the profiles and found that the macroscopic capillary wave theory usually employed in order to remove the capillary wave components fails badly in some cases for the typical sample sizes affordable in ab initio simulations. However, a microscopic method for the determination of the intrinsic profile is shown to be succesful in obtaining meaningful intrinsic profiles and corresponding reflectivities which reproduce correctly the qualitative behaviour observed experimentally.

Intrinsic neuromodulation: altering neuronal circuits from within.

PubMed

Katz, P S; Frost, W N

1996-02-01

There are two sources of neuromodulation for neuronal circuits: extrinsic inputs and intrinsic components of the circuits themselves. Extrinsic neuromodulation is known to be pervasive in nervous systems, but intrinsic neuromodulation is less recognized, despite the fact that it has now been demonstrated in sensory and neuromuscular circuits and in central pattern generators. By its nature, intrinsic neuromodulation produces local changes in neuronal computation, whereas extrinsic neuromodulation can cause global changes, often affecting many circuits simultaneously. Studies in a number of systems are defining the different properties of these two forms of neuromodulation.

Effective Replays and Summarization of Virtual Experiences

PubMed Central

Ponto, Kevin; Kohlmann, Joe; Gleicher, Michael

2012-01-01

Direct replays of the experience of a user in a virtual environment are difficult for others to watch due to unnatural camera motions. We present methods for replaying and summarizing these egocentric experiences that effectively communicate the users observations while reducing unwanted camera movements. Our approach summarizes the viewpoint path as a concise sequence of viewpoints that cover the same parts of the scene. The core of our approach is a novel content dependent metric that can be used to identify similarities between viewpoints. This enables viewpoints to be grouped by similar contextual view information and provides a means to generate novel viewpoints that can encapsulate a series of views. These resulting encapsulated viewpoints are used to synthesize new camera paths that convey the content of the original viewers experience. Projecting the initial movement of the user back on the scene can be used to convey the details of their observations, and the extracted viewpoints can serve as bookmarks for control or analysis. Finally we present performance analysis along with two forms of validation to test whether the extracted viewpoints are representative of the viewers original observations and to test for the overall effectiveness of the presented replay methods. PMID:22402688

Intrinsic hybrid modes in a corrugated conical horn

NASA Astrophysics Data System (ADS)

Dendane, A.; Arnold, J. M.

1988-08-01

Computational requirements for the generation of intrinsic modes in a nonseparable waveguide geometry requiring a full vector field description with anistropic impedance boundaries were derived. Good agreement is shown between computed and measured radiation patterns in copolar and crosspolar configurations. This agreement establishes that the intrinsic mode correctly accounts for the local normal mode conversion which takes place along the horn in a conventional mode coupling scheme, at least for cone semiangles up to 15 deg. The advantage of the intrinsic mode formulation over the conventional mode-coupling theory is that, to construct a single intrinsic mode throughout the horn, only one local normal mode field is required at each cross section, whereas mode conversion from the HE11 mode would require all the HE1n modes to be known at each cross section. The intrinsic mode accounts also for fields which would appear as backward modes in coupled-mode theory. A complete coupled-mode theory solution requires the inversion of a large matrix at each cross section, whereas the intrinsic mode can be constructed explicitly using a simple Fourier-like integral; the perturbation solution of Dragone (1977) is difficult to make rigorous.

Serosorting and Sexual Risk for HIV Infection at the Ego-Alter Dyadic Level: An Egocentric Sexual Network Study Among MSM in Nigeria.

PubMed

Rodriguez-Hart, Cristina; Liu, Hongjie; Nowak, Rebecca G; Orazulike, Ifeanyi; Zorowitz, Sam; Crowell, Trevor A; Baral, Stefan D; Blattner, William; Charurat, Man

2016-11-01

The objective of this egocentric network study was to investigate engagement in serosorting by HIV status and risk for HIV between seroconcordant and serodiscordant ego-alter dyads. Respondent-driving sampling was used to recruit 433 Nigerian men who have sex with men (MSM) from 2013 to 2014. Participant (ego) characteristics and that of five sex partners (alters) were collected. Seroconcordancy was assessed at the ego level and for each dyad. Among 433 egos, 18 % were seroconcordant with all partners. Among 880 dyads where participants knew their HIV status, 226 (25.7 %) were seroconcordant, with 11.7 % of HIV positive dyads seroconcordant and 37.0 % of HIV negative dyads seroconcordant. Seroconcordant dyads reported fewer casual sex partners, less partner concurrency, and partners who had ever injected drugs, but condom use did not differ significantly. Serosorting may be a viable risk reduction strategy among Nigerian MSM, but awareness of and communication about HIV status should be increased. Future studies should assess serosorting on a partner-by-partner basis.

Elements of the Competitive Situation That Affect Intrinsic Motivation.

ERIC Educational Resources Information Center

Reeve, Johnmarshall; Deci, Edward L.

1996-01-01

Explores the effects of three elements of the competitive situation (competitive set, competitive outcome, and interpersonal context) on intrinsic motivation in a sample of college students (n=100). Competitive outcome and interpersonal context affected intrinsic motivation: winning increased intrinsic motivation, while pressured interpersonal…

Extrinsic and Intrinsic Responses to Environmental Change: Insights from Terrestrial Paleoecological Archives

NASA Astrophysics Data System (ADS)

Seddon, A. W. R.; Mackay, A. W.

2015-12-01

Current understanding of ecological behaviour indicates that systems can experience sudden and abrupt changes in state, driven either by a large external change in environmental conditions (extrinsically forced), or the result of a set local feedbacks and site-specific interactions (intrinsically mediated responses). Responses mediated by intrinsic processes are notoriously diffi- cult to predict, they can occur as slow environmental variables gradually erode the resilience of the system eventually resulting in threshold transitions between alternative stable states. Finding ways to identify, model and predict such complex ecosystem behavior has been identified as a priority research challenge for both ecology and paleoecology. The paleoecological record can play a role in understanding the processes behind abrupt ecological change because it enables the reconstruction of processes occurring over decadal-centennial timescales or longer. Therefore, paleoecological data can be used to identify the existence of ecological thresholds and to investigate the environmental processes that can lead to loss of resilience and abrupt transitions between alternate states. In addition, incidences of abrupt vegetation changes in the past can serve as palaeoecological model systems; analogues of abrupt dynamics which can be used to test theories surrounding ecological responses to climate change. Here, I present examples from a range of terrestrial ecosystems (Holocene environmental changes from a coastal lagoon in the Galapagos Islands; Northern European vegetation changes since the last deglaciation; the North American hemlock decline) demonstrating evidence of abrupt ecosystem change. For each system I present a set of statistical techniques tailored to distin- guish between extrinsic versus intrinsically mediated ecological responses. Examples are provided from both single sites (i.e. landscape scale) and multiple sites (regional-continental scale). These techniques provide a

A J-modulated protonless NMR experiment characterizes the conformational ensemble of the intrinsically disordered protein WIP.

PubMed

Rozentur-Shkop, Eva; Goobes, Gil; Chill, Jordan H

2016-12-01

Intrinsically disordered proteins (IDPs) are multi-conformational polypeptides that lack a single stable three-dimensional structure. It has become increasingly clear that the versatile IDPs play key roles in a multitude of biological processes, and, given their flexible nature, NMR is a leading method to investigate IDP behavior on the molecular level. Here we present an IDP-tailored J-modulated experiment designed to monitor changes in the conformational ensemble characteristic of IDPs by accurately measuring backbone one- and two-bond J( 15 N, 13 Cα) couplings. This concept was realized using a unidirectional (H)NCO 13 C-detected experiment suitable for poor spectral dispersion and optimized for maximum coverage of amino acid types. To demonstrate the utility of this approach we applied it to the disordered actin-binding N-terminal domain of WASp interacting protein (WIP), a ubiquitous key modulator of cytoskeletal changes in a range of biological systems. One- and two-bond J( 15 N, 13 Cα) couplings were acquired for WIP residues 2-65 at various temperatures, and in denaturing and crowding environments. Under native conditions fitted J-couplings identified in the WIP conformational ensemble a propensity for extended conformation at residues 16-23 and 45-60, and a helical tendency at residues 28-42. These findings are consistent with a previous study of the based upon chemical shift and RDC data and confirm that the WIP 2-65 conformational ensemble is biased towards the structure assumed by this fragment in its actin-bound form. The effects of environmental changes upon this ensemble were readily apparent in the J-coupling data, which reflected a significant decrease in structural propensity at higher temperatures, in the presence of 8 M urea, and under the influence of a bacterial cell lysate. The latter suggests that crowding can cause protein unfolding through protein-protein interactions that stabilize the unfolded state. We conclude that J-couplings are a

Factors Influencing Intrinsic Motivation towards Physical Activity.

ERIC Educational Resources Information Center

Rutherford, William J.; And Others

1992-01-01

Study examined factors that influenced intrinsic motivation toward physical activity in 60 adult males who completed questionnaires and physical fitness tests. Results showed that performance information given immediately after task performance increased perceived competence and intrinsic motivation levels toward exercise of individuals with…

Intrinsic defects and spectral characteristics of SrZrO3 perovskite

NASA Astrophysics Data System (ADS)

Li, Zhenzhang; Duan, He; Jin, Yahong; Zhang, Shaoan; Lv, Yang; Xu, Qinfang; Hu, Yihua

2018-04-01

First-principles calculations and experiment analysis were performed to study the internal relation between seven types of intrinsic defects and the persistent luminescence in SrZrO3 host material. The calculation shows that rich zirconium defects have the low energy cost and thus are easy to form. Zr vacancies are too high energy to play any role in defect which is related luminescence phenomenon of SrZrO3 phosphor. However, oxygen vacancies stand out as a likely candidate, because it can yield two carrier reservoirs: a fully-occupied singlet electron's reservoir which lies above the valence band maximum, and an empty triply degenerate hole's reservoir which is just below the conduction band minimum. Sr vacancies are not directly relevant to the persistent luminescence due to its too shallow electron trap level. The characteristics of these defects are fully explained by the equilibrium properties of SrZrO3. An experimental study of the thermoluminescence glow for these defects is conducted and the calculation is consistent with the experimental results. A mechanism of the persistent luminescence for SrZrO3:Pr3+, Eu3+ is explained according to oxygen vacancies trap center. Findings of this study may serve as theoretical references for controlling intrinsic traps by more refined experiments.

Caught between a rock and a hard place: An intrinsic single case study of nurse researchers' experiences of the presence of a nursing research culture in clinical practice.

PubMed

Berthelsen, Connie Bøttcher; Hølge-Hazelton, Bibi

2018-04-01

To explore how nurse researchers in clinical positions experience the presence of a nursing research culture in clinical practice. Higher demands in the hospitals for increasing the quality of patient care engender a higher demand for the skills of health professionals and evidence-based practice. However, the utilisation of nursing research in clinical practice is still limited. Intrinsic single case study design underlined by a constructivist perspective. Data were produced through a focus group interview with seven nurse researchers employed in clinical practice in two university hospitals in Zealand, Denmark, to capture the intrinsic aspects of the concept of nursing research culture in the context of clinical practice. A thematic analysis was conducted based on Braun and Clarke's theoretical guideline. "Caught between a rock and a hard place" was constructed as the main theme describing how nurse researchers in clinical positions experience the presence of a nursing research culture in clinical practice. The main theme was supported by three subthemes: Minimal academic tradition affects nursing research; Minimal recognition from physicians affects nursing research; and Moving towards a research culture. The nurse researchers in this study did not experience the presence of a nursing research culture in clinical practice, however; they called for more attention on removing barriers against research utilisation, promotion of applied research and interdisciplinary research collaboration, and passionate management support. The results of this case study show the pressure which nurse researchers employed in clinical practice are exposed to, and give examples on how to accommodate the further development of a nursing research culture in clinical practice. © 2017 John Wiley & Sons Ltd.

Predicting Intrinsic Motivation

ERIC Educational Resources Information Center

Martens, Rob; Kirschner, Paul A.

2004-01-01

Intrinsic motivation can be predicted from participants' perceptions of the social environment and the task environment (Ryan & Deci, 2000)in terms of control, relatedness and competence. To determine the degree of independence of these factors 251 students in higher vocational education (physiotherapy and hotel management) indicated the…

Layout Geometry in the Selection of Intrinsic Frames of Reference from Multiple Viewpoints

ERIC Educational Resources Information Center

Mou, Weimin; Zhao, Mintao; McNamara, Timothy P.

2007-01-01

Four experiments investigated the roles of layout geometry in the selection of intrinsic frames of reference in spatial memory. Participants learned the locations of objects in a room from 2 or 3 viewing perspectives. One view corresponded to the axis of bilateral symmetry of the layout, and the other view(s) was (were) nonorthogonal to the axis…

Egocentric Network and Condom Use Among Mid-Age Female Sex Workers in China: A Multilevel Modeling Analysis.

PubMed

Liu, Hongjie

2016-04-01

The epidemics of sexually transmitted infections (STIs) have spread among older adults in the world, including China. This study addresses the deficiency of studies about the multiple contextual influences on condom use among mid-age female sex workers (FSWs) over 35 years old. A combination of an egocentric network design and multilevel modeling was used to investigate factors of condom use over mid-age FSWs (egos) particular relationships with sexual partners (alters). Of the 1245 mid-age FSWs interviewed, 73% (907) reported having at least one sexual partner who would provide social support to egos. This generated a total of 1300 ego-alter sex ties in egos' support networks. Condoms were consistently used among one-third of sex ties. At the ego level, condoms were more likely to be used consistently if egos received a middle school education or above, had stronger perceived behavioral control for condom use, or consistently used condoms with other sex clients who were not in their support networks. At the alter level, condoms were not consistently used over spousal ties compared to other ties. Condoms were less likely to be used among alters whom ego trusted and provided emotional support. Cross-level factors (egos' attitudes toward condom use and emotional support from alters) documented a significant positive interaction on consistent condom use. Given the low frequency of condom use, future interventions should focus on mid-age FSWs and their partners within and beyond their support networks.

Egocentric Network and Condom Use Among Mid-Age Female Sex Workers in China: A Multilevel Modeling Analysis

PubMed Central

2016-01-01

Abstract The epidemics of sexually transmitted infections (STIs) have spread among older adults in the world, including China. This study addresses the deficiency of studies about the multiple contextual influences on condom use among mid-age female sex workers (FSWs) over 35 years old. A combination of an egocentric network design and multilevel modeling was used to investigate factors of condom use over mid-age FSWs (egos) particular relationships with sexual partners (alters). Of the 1245 mid-age FSWs interviewed, 73% (907) reported having at least one sexual partner who would provide social support to egos. This generated a total of 1300 ego–alter sex ties in egos' support networks. Condoms were consistently used among one-third of sex ties. At the ego level, condoms were more likely to be used consistently if egos received a middle school education or above, had stronger perceived behavioral control for condom use, or consistently used condoms with other sex clients who were not in their support networks. At the alter level, condoms were not consistently used over spousal ties compared to other ties. Condoms were less likely to be used among alters whom ego trusted and provided emotional support. Cross-level factors (egos' attitudes toward condom use and emotional support from alters) documented a significant positive interaction on consistent condom use. Given the low frequency of condom use, future interventions should focus on mid-age FSWs and their partners within and beyond their support networks. PMID:27028182

Hidden Structural Codes in Protein Intrinsic Disorder.

PubMed

Borkosky, Silvia S; Camporeale, Gabriela; Chemes, Lucía B; Risso, Marikena; Noval, María Gabriela; Sánchez, Ignacio E; Alonso, Leonardo G; de Prat Gay, Gonzalo

2017-10-17

Intrinsic disorder is a major structural category in biology, accounting for more than 30% of coding regions across the domains of life, yet consists of conformational ensembles in equilibrium, a major challenge in protein chemistry. Anciently evolved papillomavirus genomes constitute an unparalleled case for sequence to structure-function correlation in cases in which there are no folded structures. E7, the major transforming oncoprotein of human papillomaviruses, is a paradigmatic example among the intrinsically disordered proteins. Analysis of a large number of sequences of the same viral protein allowed for the identification of a handful of residues with absolute conservation, scattered along the sequence of its N-terminal intrinsically disordered domain, which intriguingly are mostly leucine residues. Mutation of these led to a pronounced increase in both α-helix and β-sheet structural content, reflected by drastic effects on equilibrium propensities and oligomerization kinetics, and uncovers the existence of local structural elements that oppose canonical folding. These folding relays suggest the existence of yet undefined hidden structural codes behind intrinsic disorder in this model protein. Thus, evolution pinpoints conformational hot spots that could have not been identified by direct experimental methods for analyzing or perturbing the equilibrium of an intrinsically disordered protein ensemble.

On the correlation between ‘non-local’ effects and intrinsic rotation reversals in Alcator C-Mod

NASA Astrophysics Data System (ADS)

Rodriguez-Fernandez, P.; Rice, J. E.; Cao, N. M.; Creely, A. J.; Howard, N. T.; Hubbard, A. E.; Irby, J. H.; White, A. E.

2017-07-01

Contemporary predictive models for heat and particle transport in tokamak plasmas are based on the assumption that local fluxes can be described in terms of local plasma parameters, where electromagnetic drift-wave-type turbulence is driven by local gradients and results in cross-field transport. The question of whether or not transport could be dominated by non-local terms in certain circumstances is essential for our understanding of transport in magnetically confined plasmas, and critical for developing predictive models for future tokamaks, such as ITER. Perturbative transport experiments using cold-pulse injections at low density seem to challenge the local closure of anomalous transport: a rapid temperature increase in the core of the plasma following a sharp edge cooling is widely observed in tokamaks and helical devices. Past work in Ohmic plasmas in Alcator C-Mod and in ECH plasmas in KSTAR found that the temperature inversions disappear at higher densities, above the intrinsic toroidal rotation reversal density. These observations suggested that the so-called ‘non-local’ heat transport effects were related to the intrinsic rotation reversal, and therefore to changes in momentum transport. In this work, new experiments and analysis at Alcator C-Mod show that intrinsic rotation reversals and disappearance of temperature inversions are not concomitant in Ohmic plasmas at high plasma current and in ICRH L-modes. This new data set shows that the correlation between transient temperature inversions and intrinsic rotation reversals is not universal, suggesting that ‘non-local’ heat transport and momentum transport effects may be affected by different physical mechanisms.

Cell intrinsic control of axon regeneration

PubMed Central

Mar, Fernando M; Bonni, Azad; Sousa, Mónica M

2014-01-01

Although neurons execute a cell intrinsic program of axonal growth during development, following the establishment of connections, the developmental growth capacity declines. Besides environmental challenges, this switch largely accounts for the failure of adult central nervous system (CNS) axons to regenerate. Here, we discuss the cell intrinsic control of axon regeneration, including not only the regulation of transcriptional and epigenetic mechanisms, but also the modulation of local protein translation, retrograde and anterograde axonal transport, and microtubule dynamics. We further explore the causes underlying the failure of CNS neurons to mount a vigorous regenerative response, and the paradigms demonstrating the activation of cell intrinsic axon growth programs. Finally, we present potential mechanisms to support axon regeneration, as these may represent future therapeutic approaches to promote recovery following CNS injury and disease. PMID:24531721

QT Adaptation and Intrinsic QT Variability in Congenital Long QT Syndrome.

PubMed

Seethala, Srikanth; Singh, Prabhpreet; Shusterman, Vladimir; Ribe, Margareth; Haugaa, Kristina H; Němec, Jan

2015-12-16

Increased variability of QT interval (QTV) has been linked to arrhythmias in animal experiments and multiple clinical situations. Congenital long QT syndrome (LQTS), a pure repolarization disease, may provide important information on the relationship between delayed repolarization and QTV. Twenty-four-hour Holter monitor tracings from 78 genotyped congenital LQTS patients (52 females; 51 LQT1, 23 LQT2, 2 LQT5, 2 JLN, 27 symptomatic; age, 35.2±12.3 years) were evaluated with computer-assisted annotation of RR and QT intervals. Several models of RR-QT relationship were tested in all patients. A model assuming exponential decrease of past RR interval contributions to QT duration with 60-second time constant provided the best data fit. This model was used to calculate QTc and residual "intrinsic" QTV, which cannot be explained by heart rate change. The intrinsic QTV was higher in patients with long QTc (r=0.68; P<10(-4)), and in LQT2 than in LQT1/5 patients (5.65±1.28 vs 4.46±0.82; P<0.0002). Both QTc and intrinsic QTV were similar in symptomatic and asymptomatic patients (467±52 vs 459±53 ms and 5.10±1.19 vs 4.74±1.09, respectively). In LQTS patients, QT interval adaptation to heart rate changes occurs with time constant ≈60 seconds, similar to results reported in control subjects. Intrinsic QTV correlates with the degree of repolarization delay and might reflect action potential instability observed in animal models of LQTS. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Intrinsic motivation and sportsmanship: mediating role of interpersonal relationships.

PubMed

Núñez, Juan L; Martín-Albo, José; Navarro, José G; Sánchez, Juana M; González-Cutre, David

2009-06-01

This study analyzed the mediating role of interpersonal relations between intrinsic motivation and sportsmanship. Athletes (98 men, 97 women), ages 11 to 43 years, completed measures of intrinsic motivation toward sports, self-concept of social and family relations, and sportsmanship orientation. A structural equation model indicated that self-concept of interpersonal relations mediated the relation between intrinsic motivation and sportsmanship. Also, intrinsic motivation was directly and positively associated with self-concept of interpersonal relations, which, in turn, was positively and significantly related to sportsmanship. Variances explained by self-concept of interpersonal relations and by sportsmanship were 32 and 56%, respectively. The motivational interaction between the context of interpersonal relations and the sports context proposed in the hierarchical model of intrinsic and extrinsic motivation was discussed.

The intrinsic three-dimensional shape of galactic bars

NASA Astrophysics Data System (ADS)

Méndez-Abreu, J.; Costantin, L.; Aguerri, J. A. L.; de Lorenzo-Cáceres, A.; Corsini, E. M.

2018-06-01

We present the first statistical study on the intrinsic three-dimensional (3D) shape of a sample of 83 galactic bars extracted from the CALIFA survey. We use the galaXYZ code to derive the bar intrinsic shape with a statistical approach. The method uses only the geometric information (ellipticities and position angles) of bars and discs obtained from a multi-component photometric decomposition of the galaxy surface-brightness distributions. We find that bars are predominantly prolate-triaxial ellipsoids (68%), with a small fraction of oblate-triaxial ellipsoids (32%). The typical flattening (intrinsic C/A semiaxis ratio) of the bars in our sample is 0.34, which matches well the typical intrinsic flattening of stellar discs at these galaxy masses. We demonstrate that, for prolate-triaxial bars, the intrinsic shape of bars depends on the galaxy Hubble type and stellar mass (bars in massive S0 galaxies are thicker and more circular than those in less massive spirals). The bar intrinsic shape correlates with bulge, disc, and bar parameters. In particular with the bulge-to-total (B/T) luminosity ratio, disc g - r color, and central surface brightness of the bar, confirming the tight link between bars and their host galaxies. Combining the probability distributions of the intrinsic shape of bulges and bars in our sample we show that 52% (16%) of bulges are thicker (flatter) than the surrounding bar at 1σ level. We suggest that these percentages might be representative of the fraction of classical and disc-like bulges in our sample, respectively.

Evolution of intrinsic disorder in eukaryotic proteins.

PubMed

Ahrens, Joseph B; Nunez-Castilla, Janelle; Siltberg-Liberles, Jessica

2017-09-01

Conformational flexibility conferred though regions of intrinsic structural disorder allows proteins to behave as dynamic molecules. While it is well-known that intrinsically disordered regions can undergo disorder-to-order transitions in real-time as part of their function, we also are beginning to learn more about the dynamics of disorder-to-order transitions along evolutionary time-scales. Intrinsically disordered regions endow proteins with functional promiscuity, which is further enhanced by the ability of some of these regions to undergo real-time disorder-to-order transitions. Disorder content affects gene retention after whole genome duplication, but it is not necessarily conserved. Altered patterns of disorder resulting from evolutionary disorder-to-order transitions indicate that disorder evolves to modify function through refining stability, regulation, and interactions. Here, we review the evolution of intrinsically disordered regions in eukaryotic proteins. We discuss the interplay between secondary structure and disorder on evolutionary time-scales, the importance of disorder for eukaryotic proteome expansion and functional divergence, and the evolutionary dynamics of disorder.

Intrinsic and induced isoproturon catabolic activity in dissimilar soils and soils under dissimilar land use.

PubMed

Reid, Brian J; Papanikolaou, Niki D; Wilcox, Ronah K

2005-02-01

The catabolic activity with respect to the systemic herbicide isoproturon was determined in soil samples by (14)C-radiorespirometry. The first experiment assessed levels of intrinsic catabolic activity in soil samples that represented three dissimilar soil series under arable cultivation. Results showed average extents of isoproturon mineralisation (after 240 h assay time) in the three soil series to be low. A second experiment assessed the impact of addition of isoproturon (0.05 microg kg(-1)) into these soils on the levels of catabolic activity following 28 days of incubation. Increased catabolic activity was observed in all three soils. A third experiment assessed levels of intrinsic catabolic activity in soil samples representing a single soil series managed under either conventional agricultural practice (including the use of isoproturon) or organic farming practice (with no use of isoproturon). Results showed higher (and more consistent) levels of isoproturon mineralisation in the soil samples collected from conventional land use. The final experiment assessed the impact of isoproturon addition on the levels of inducible catabolic activity in these soils. The results showed no significant difference in the case of the conventional farm soil samples while the induction of catabolic activity in the organic farm soil samples was significant.

The Information-Seeking Behavior of Intrinsically Motivated Elementary School Children of a Collectivist Culture

ERIC Educational Resources Information Center

Crow, Sherry R.

2015-01-01

This study, conducted in June 2014 in Kampala, Uganda, is a follow-up to a similar study conducted in Colorado Springs, Colorado, in 2008. The basic research question addressed is: "What are the experiences in the lives of upper elementary-aged Ugandan children that foster an intrinsic motivation to seek information?" A secondary…

Intrinsic material properties of cortical bone.

PubMed

Lopez Franco, Gloria E; Blank, Robert D; Akhter, Mohammed P

2011-01-01

The G171V mutation (high bone mass, HBM) is autosomal dominant and is responsible for high bone mass in humans. Transgenic HBM mice in which the human LRP5 G171V gene is inserted also show a similar phenotype with greater bone mass and biomechanical performance than wild-type mice, as determined by whole bone testing. Whole bone mechanics, however, depend jointly on bone mass, architecture, and intrinsic bone tissue mechanical properties. To determine whether the HBM mutation affects tissue-level biomechanical performance, we performed nano-indentation testing of unembedded cortical bone from HBM mice and their nontransgenic (NTG) littermates. Femora from 17-week-old mice (female, 8 mice/genotype) were subjected to nano-indentation using a Triboscope (Hysitron, Minneapolis, MN, USA). For each femoral specimen, approximately 10 indentations were made on the midshaft anterior surface with a target force of either 3 or 9 mN at a constant loading rate of 400 mN/s. The load-displacement data from each test were used to calculate indentation modulus and hardness for bone tissue. The intrinsic material property that reflected the bone modulus was greater (48%) in the HBM as compared to the NTG mice. Our results of intrinsic properties are consistent with the published structural and material properties of the midshaft femur in HBM and NTG mice. The greater intrinsic modulus in HBM reflects greater bone mineral content as compared to NTG (wild-type, WT) mice. This study suggests that the greater intrinsic property of cortical bone is derived from the greater bone mineral content and BMD, resulting in greater bone strength in HBM as compared to NTG (WT) mice.

Intrinsic Brightness Temperatures of AGN Jets

NASA Astrophysics Data System (ADS)

Homan, D. C.; Kovalev, Y. Y.; Lister, M. L.; Ros, E.; Kellermann, K. I.; Cohen, M. H.; Vermeulen, R. C.; Zensus, J. A.; Kadler, M.

2006-05-01

We present a new method for studying the intrinsic brightness temperatures of the parsec-scale jet cores of active galactic nuclei (AGNs). Our method uses observed superluminal motions and observed brightness temperatures for a large sample of AGNs to constrain the characteristic intrinsic brightness temperature of the sample as a whole. To study changes in intrinsic brightness temperature, we assume that the Doppler factors of individual jets are constant in time, as justified by their relatively small changes in observed flux density. We find that in their median-low brightness temperature state, the sources in our sample have a narrow range of intrinsic brightness temperatures centered on a characteristic temperature, Tint~=3×1010 K, which is close to the value expected for equipartition, when the energy in the radiating particles equals the energy stored in the magnetic fields. However, in their maximum brightness state, we find that sources in our sample have a characteristic intrinsic brightness temperature greater than 2×1011 K, which is well in excess of the equipartition temperature. In this state, we estimate that the energy in radiating particles exceeds the energy in the magnetic field by a factor of ~105. We suggest that the excess of particle energy when sources are in their maximum brightness state is due to injection or acceleration of particles at the base of the jet. Our results suggest that the common method of estimating jet Doppler factors by using a single measurement of observed brightness temperature, the assumption of equipartition, or both may lead to large scatter or systematic errors in the derived values.

Quantifying the topography of the intrinsic energy landscape of flexible biomolecular recognition

PubMed Central

Chu, Xiakun; Gan, Linfeng; Wang, Erkang; Wang, Jin

2013-01-01

Biomolecular functions are determined by their interactions with other molecules. Biomolecular recognition is often flexible and associated with large conformational changes involving both binding and folding. However, the global and physical understanding for the process is still challenging. Here, we quantified the intrinsic energy landscapes of flexible biomolecular recognition in terms of binding–folding dynamics for 15 homodimers by exploring the underlying density of states, using a structure-based model both with and without considering energetic roughness. By quantifying three individual effective intrinsic energy landscapes (one for interfacial binding, two for monomeric folding), the association mechanisms for flexible recognition of 15 homodimers can be classified into two-state cooperative “coupled binding–folding” and three-state noncooperative “folding prior to binding” scenarios. We found that the association mechanism of flexible biomolecular recognition relies on the interplay between the underlying effective intrinsic binding and folding energy landscapes. By quantifying the whole global intrinsic binding–folding energy landscapes, we found strong correlations between the landscape topography measure Λ (dimensionless ratio of energy gap versus roughness modulated by the configurational entropy) and the ratio of the thermodynamic stable temperature versus trapping temperature, as well as between Λ and binding kinetics. Therefore, the global energy landscape topography determines the binding–folding thermodynamics and kinetics, crucial for the feasibility and efficiency of realizing biomolecular function. We also found “U-shape” temperature-dependent kinetic behavior and a dynamical cross-over temperature for dividing exponential and nonexponential kinetics for two-state homodimers. Our study provides a unique way to bridge the gap between theory and experiments. PMID:23754431

Photovoltaic device comprising compositionally graded intrinsic photoactive layer

DOEpatents

Hoffbauer, Mark A; Williamson, Todd L

2013-04-30

Photovoltaic devices and methods of making photovoltaic devices comprising at least one compositionally graded photoactive layer, said method comprising providing a substrate; growing onto the substrate a uniform intrinsic photoactive layer having one surface disposed upon the substrate and an opposing second surface, said intrinsic photoactive layer consisting essentially of In.sub.1-xA.sub.xN,; wherein: i. 0.ltoreq.x.ltoreq.1; ii. A is gallium, aluminum, or combinations thereof; and iii. x is at least 0 on one surface of the intrinsic photoactive layer and is compositionally graded throughout the layer to reach a value of 1 or less on the opposing second surface of the layer; wherein said intrinsic photoactive layer is isothermally grown by means of energetic neutral atom beam lithography and epitaxy at a temperature of 600.degree. C. or less using neutral nitrogen atoms having a kinetic energy of from about 1.0 eV to about 5.0 eV, and wherein the intrinsic photoactive layer is grown at a rate of from about 5 nm/min to about 100 nm/min.

Uncoupled poroelastic and intrinsic viscoelastic dissipation in cartilage.

PubMed

Han, Guebum; Hess, Cole; Eriten, Melih; Henak, Corinne R

2018-04-26

This paper studies uncoupled poroelastic (flow-dependent) and intrinsic viscoelastic (flow-independent) energy dissipation mechanisms via their dependence on characteristic lengths to understand the root of cartilage's broadband dissipation behavior. Phase shift and dynamic modulus were measured from dynamic microindentation tests conducted on hydrated cartilage at different contact radii, as well as on dehydrated cartilage. Cartilage weight and thickness were recorded during dehydration. Phase shifts revealed poroelastic- and viscoelastic-dominant dissipation regimes in hydrated cartilage. Specifically, phase shift at a relatively small radius was governed by poroviscoelasticity, while phase shift at a relatively large radius was dominantly governed by intrinsic viscoelasticity. The uncoupled dissipation mechanisms demonstrated that intrinsic viscoelastic dissipation provided sustained broadband dissipation for all length scales, and additional poroelastic dissipation increased total dissipation at small length scales. Dehydration decreased intrinsic viscoelastic dissipation of cartilage. The findings demonstrated a possibility to measure poroelastic and intrinsic viscoelastic properties of cartilage at similar microscale lengths. Also they encouraged development of broadband cartilage like-dampers and provided important design parameters to maximize their performance. Copyright © 2018 Elsevier Ltd. All rights reserved.

Global Conformational Selection and Local Induced Fit for the Recognition between Intrinsic Disordered p53 and CBP

PubMed Central

Yu, Qingfen; Ye, Wei; Wang, Wei; Chen, Hai-Feng

2013-01-01

The transactivation domain (TAD) of tumor suppressor p53 can bind with the nuclear coactivator binding domain (NCBD) of cyclic-AMP response element binding protein (CBP) and activate transcription. NMR experiments demonstrate that both apo-NCBD and TAD are intrinsic disordered and bound NCBD/TAD undergoes a transition to well folded. The recognition mechanism between intrinsic disordered proteins is still hotly debated. Molecular dynamics (MD) simulations in explicit solvent are used to study the recognition mechanism between intrinsic disordered TAD and NCBD. The average RMSD values between bound and corresponding apo states and Kolmogorov-Smirnov P test analysis indicate that TAD and NCBD may follow an induced fit mechanism. Quantitative analysis indicates there is also a global conformational selection. In summary, the recognition of TAD and NCBD might obey a local induced fit and global conformational selection. These conclusions are further supported by high-temperature unbinding kinetics and room temperature landscape analysis. These methods can be used to study the recognition mechanism of other intrinsic disordered proteins. PMID:23555731

Intrinsic connectivity of neural networks in the awake rabbit.

PubMed

Schroeder, Matthew P; Weiss, Craig; Procissi, Daniel; Disterhoft, John F; Wang, Lei

2016-04-01

The way in which the brain is functionally connected into different networks has emerged as an important research topic in order to understand normal neural processing and signaling. Since some experimental manipulations are difficult or unethical to perform in humans, animal models are better suited to investigate this topic. Rabbits are a species that can undergo MRI scanning in an awake and conscious state with minimal preparation and habituation. In this study, we characterized the intrinsic functional networks of the resting New Zealand White rabbit brain using BOLD fMRI data. Group independent component analysis revealed seven networks similar to those previously found in humans, non-human primates and/or rodents including the hippocampus, default mode, cerebellum, thalamus, and visual, somatosensory, and parietal cortices. For the first time, the intrinsic functional networks of the resting rabbit brain have been elucidated demonstrating the rabbit's applicability as a translational animal model. Without the confounding effects of anesthetics or sedatives, future experiments may employ rabbits to understand changes in neural connectivity and brain functioning as a result of experimental manipulation (e.g., temporary or permanent network disruption, learning-related changes, and drug administration). Copyright © 2016 Elsevier Inc. All rights reserved.

Intrinsic and Extrinsic Neuromodulation of Olfactory Processing

PubMed Central

Lizbinski, Kristyn M.; Dacks, Andrew M.

2018-01-01

Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a “memory” by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform. PMID:29375314

Intrinsic and Extrinsic Neuromodulation of Olfactory Processing.

PubMed

Lizbinski, Kristyn M; Dacks, Andrew M

2017-01-01

Neuromodulation is a ubiquitous feature of neural systems, allowing flexible, context specific control over network dynamics. Neuromodulation was first described in invertebrate motor systems and early work established a basic dichotomy for neuromodulation as having either an intrinsic origin (i.e., neurons that participate in network coding) or an extrinsic origin (i.e., neurons from independent networks). In this conceptual dichotomy, intrinsic sources of neuromodulation provide a "memory" by adjusting network dynamics based upon previous and ongoing activation of the network itself, while extrinsic neuromodulators provide the context of ongoing activity of other neural networks. Although this dichotomy has been thoroughly considered in motor systems, it has received far less attention in sensory systems. In this review, we discuss intrinsic and extrinsic modulation in the context of olfactory processing in invertebrate and vertebrate model systems. We begin by discussing presynaptic modulation of olfactory sensory neurons by local interneurons (LNs) as a mechanism for gain control based on ongoing network activation. We then discuss the cell-class specific effects of serotonergic centrifugal neurons on olfactory processing. Finally, we briefly discuss the integration of intrinsic and extrinsic neuromodulation (metamodulation) as an effective mechanism for exerting global control over olfactory network dynamics. The heterogeneous nature of neuromodulation is a recurring theme throughout this review as the effects of both intrinsic and extrinsic modulation are generally non-uniform.

Measuring Intrinsic Curvature of Space with Electromagnetism

NASA Astrophysics Data System (ADS)

Mabin, Mason; Becker, Maria; Batelaan, Herman

2016-10-01

The concept of curved space is not readily observable in everyday life. The educational movie "Sphereland" attempts to illuminate the idea. The main character, a hexagon, has to go to great lengths to prove that her world is in fact curved. We present an experiment that demonstrates a new way to determine if a two-dimensional surface, the 2-sphere, is curved. The behavior of an electric field, placed on a spherical surface, is shown to be related to the intrinsic Gaussian curvature. This approach allows students to gain some understanding of Einstein's theory of general relativity, which relates the curvature of spacetime to the presence of mass and energy. Additionally, an opportunity is provided to investigate the dimensionality of Gauss's law.

Intrinsic pro-angiogenic status of cystic fibrosis airway epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verhaeghe, Catherine; Tabruyn, Sebastien P.; Oury, Cecile

Cystic fibrosis is a common genetic disorder characterized by a severe lung inflammation and fibrosis leading to the patient's death. Enhanced angiogenesis in cystic fibrosis (CF) tissue has been suggested, probably caused by the process of inflammation, as similarly described in asthma and chronic bronchitis. The present study demonstrates an intrinsic pro-angiogenic status of cystic fibrosis airway epithelial cells. Microarray experiments showed that CF airway epithelial cells expressed several angiogenic factors such as VEGF-A, VEGF-C, bFGF, and PLGF at higher levels than control cells. These data were confirmed by real-time quantitative PCR and, at the protein level, by ELISA. Conditionedmore » media of these cystic fibrosis cells were able to induce proliferation, migration and sprouting of cultured primary endothelial cells. This report describes for the first time that cystic fibrosis epithelial cells have an intrinsic angiogenic activity. Since excess of angiogenesis is correlated with more severe pulmonary disease, our results could lead to the development of new therapeutic applications.« less

Is color an intrinsic property of object representation?

PubMed

Naor-Raz, Galit; Tarr, Michael J; Kersten, Daniel

2003-01-01

The role of color in object representation was examined by using a variation of the Stroop paradigm in which observers named the displayed colors of objects or words. In experiment 1, colors of color-diagnostic objects were manipulated to be either typical or atypical of the object (eg a yellow banana versus a purple banana). A Stroop-like effect was obtained, with faster color-naming times for the typical as compared to the atypical condition. In experiment 2, naming colors on words specifying these same color-diagnostic objects reversed this pattern, with the typical condition producing longer response times than the atypical condition. In experiment 3, a blocked condition design that used the same words and colors as experiment 2 produced the standard Stroop-like facilitation for the typical condition. These results indicate that color is an intrinsic property of an object's representation at multiple levels. In experiment 4, we examined the specific level(s) at which color-shape associations arise by following the tasks used in experiments 1 and 2 with a lexical-decision task in which some items were conceptually related to items shown during color naming (eg banana/monkey). Priming for these associates was observed following color naming of words, but not pictures, providing further evidence that the color-shape associations responsible for the differing effects obtained in experiments 1 and 2 are due to the automatic activation of color-shape associations at different levels of representation.

Intrinsic resonances and AC-dipole simulations of 3He in the AGS Booster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hock, Kiel; Meot, Francois; Huang, Haixin

Polarized 3He collisions are part of future RHIC physics programs and of the eRHIC project. The anomalous magnetic moment of 3He (G=-4.184) is roughly three times greater than that of protons (G=1.793), a polarized species that is already used at the Collider-Accelerator complex at BNL. Because of the higher anomolous magnetic moment and possibly injecting into the AGS at rigidities beyond 7 T • m, 3He may have to cross depolarizing intrinsic resonances while accelerating in the Booster. To overcome these strong intrinsic resonances we look to an AC-dipole, which will need to be installed in the Booster. An AC-dipolemore » is a magnet that induces large betatron oscillations which forces the entire bunch to experience a stronger resonance and induce a spin flip of all particles. An artificial intrinsic resonance is created, with close proximity to the original intrinsic resonance, which requires simulations to gauge what magnet strength is required. Simulations have been performed using zgoubi regarding the resonances 0 + v y, 12 - v y, and 6 + v y and show that the AC-dipole is effective at overcoming these resonances. Benefits of avoiding the 0 + v y and crossing the 12 - v y and 6 + v y in the Booster presents the advantage of allowing injection above the 0 + v y in the AGS and minimizes the orbit distortions from the snakes.« less

Prediction of Intrinsic Cesium Desorption from Na-Smectite in Mixed Cation Solutions.

PubMed

Fukushi, Keisuke; Fukiage, Tomo

2015-09-01

Quantitative understanding of the stability of sorbed radionuclides in smectite is necessary to assess the performance of engineering barriers used for nuclear waste disposal. Our previous study demonstrated that the spatial organization of the smectite platelets triggered by the divalent cations led to the apparent fixation of intrinsic Cs in smectite, because some Cs is retained inside the formed tactoids. Natural water is usually a mixture of Na(+) and divalent cations (Ca(2+) and Mg(2+)). This study therefore investigated the desorption behavior of intrinsic Cs in Na-smecite in mixed Na(+)-divalent cation solutions under widely various cation concentrations using batch experiments, grain size measurements, and cation exchange modeling (CEM). Results show that increased Na(+) concentrations facilitate Cs desorption because Na(+) serves as the dispersion agent. A linear relation was obtained between the logarithm of the Na(+) fraction and the accessible Cs fraction in smectite. That relation enables the prediction of accessible Cs fraction as a function of solution cationic compositions. The corrected CEM considering the effects of the spatial organization suggests that the stability of intrinsic Cs in the smectite is governed by the Na(+) concentration, and suggests that it is almost independent of the concentrations of divalent cations in natural water.

Separating intrinsic from extrinsic fluctuations in dynamic biological systems

PubMed Central

Paulsson, Johan

2011-01-01

From molecules in cells to organisms in ecosystems, biological populations fluctuate due to the intrinsic randomness of individual events and the extrinsic influence of changing environments. The combined effect is often too complex for effective analysis, and many studies therefore make simplifying assumptions, for example ignoring either intrinsic or extrinsic effects to reduce the number of model assumptions. Here we mathematically demonstrate how two identical and independent reporters embedded in a shared fluctuating environment can be used to identify intrinsic and extrinsic noise terms, but also how these contributions are qualitatively and quantitatively different from what has been previously reported. Furthermore, we show for which classes of biological systems the noise contributions identified by dual-reporter methods correspond to the noise contributions predicted by correct stochastic models of either intrinsic or extrinsic mechanisms. We find that for broad classes of systems, the extrinsic noise from the dual-reporter method can be rigorously analyzed using models that ignore intrinsic stochasticity. In contrast, the intrinsic noise can be rigorously analyzed using models that ignore extrinsic stochasticity only under very special conditions that rarely hold in biology. Testing whether the conditions are met is rarely possible and the dual-reporter method may thus produce flawed conclusions about the properties of the system, particularly about the intrinsic noise. Our results contribute toward establishing a rigorous framework to analyze dynamically fluctuating biological systems. PMID:21730172

Separating intrinsic from extrinsic fluctuations in dynamic biological systems.

PubMed

Hilfinger, Andreas; Paulsson, Johan

2011-07-19

From molecules in cells to organisms in ecosystems, biological populations fluctuate due to the intrinsic randomness of individual events and the extrinsic influence of changing environments. The combined effect is often too complex for effective analysis, and many studies therefore make simplifying assumptions, for example ignoring either intrinsic or extrinsic effects to reduce the number of model assumptions. Here we mathematically demonstrate how two identical and independent reporters embedded in a shared fluctuating environment can be used to identify intrinsic and extrinsic noise terms, but also how these contributions are qualitatively and quantitatively different from what has been previously reported. Furthermore, we show for which classes of biological systems the noise contributions identified by dual-reporter methods correspond to the noise contributions predicted by correct stochastic models of either intrinsic or extrinsic mechanisms. We find that for broad classes of systems, the extrinsic noise from the dual-reporter method can be rigorously analyzed using models that ignore intrinsic stochasticity. In contrast, the intrinsic noise can be rigorously analyzed using models that ignore extrinsic stochasticity only under very special conditions that rarely hold in biology. Testing whether the conditions are met is rarely possible and the dual-reporter method may thus produce flawed conclusions about the properties of the system, particularly about the intrinsic noise. Our results contribute toward establishing a rigorous framework to analyze dynamically fluctuating biological systems.

Thin film solar cell including a spatially modulated intrinsic layer

DOEpatents

Guha, Subhendu; Yang, Chi-Chung; Ovshinsky, Stanford R.

1989-03-28

One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. The band gap of the intrinsic layer is always less than the band gap of the doped layers. The gradation of the intrinsic layer is effected such that the open circuit voltage and/or the fill factor of the one or plural solar cell structure is enhanced.

Imitating intrinsic alignments: a bias to the CMB lensing-galaxy shape cross-correlation power spectrum induced by the large-scale structure bispectrum

NASA Astrophysics Data System (ADS)

Merkel, Philipp M.; Schäfer, Björn Malte

2017-10-01

Cross-correlating the lensing signals of galaxies and comic microwave background (CMB) fluctuations is expected to provide valuable cosmological information. In particular, it may help tighten constraints on parameters describing the properties of intrinsically aligned galaxies at high redshift. To access the information conveyed by the cross-correlation signal, its accurate theoretical description is required. We compute the bias to CMB lensing-galaxy shape cross-correlation measurements induced by non-linear structure growth. Using tree-level perturbation theory for the large-scale structure bispectrum, we find that the bias is negative on most angular scales, therefore mimicking the signal of intrinsic alignments. Combining Euclid-like galaxy lensing data with a CMB experiment comparable to the Planck satellite mission, the bias becomes significant only on smallest scales (ℓ ≳ 2500). For improved CMB observations, however, the corrections amount to 10-15 per cent of the CMB lensing-intrinsic alignment signal over a wide multipole range (10 ≲ ℓ ≲ 2000). Accordingly, the power spectrum bias, if uncorrected, translates into 2σ and 3σ errors in the determination of the intrinsic alignment amplitude in the case of CMB stage III and stage IV experiments, respectively.

Flexible spatial perspective-taking: conversational partners weigh multiple cues in collaborative tasks.

PubMed

Galati, Alexia; Avraamides, Marios N

2013-01-01

Research on spatial perspective-taking often focuses on the cognitive processes of isolated individuals as they adopt or maintain imagined perspectives. Collaborative studies of spatial perspective-taking typically examine speakers' linguistic choices, while overlooking their underlying processes and representations. We review evidence from two collaborative experiments that examine the contribution of social and representational cues to spatial perspective choices in both language and the organization of spatial memory. Across experiments, speakers organized their memory representations according to the convergence of various cues. When layouts were randomly configured and did not afford intrinsic cues, speakers encoded their partner's viewpoint in memory, if available, but did not use it as an organizing direction. On the other hand, when the layout afforded an intrinsic structure, speakers organized their spatial memories according to the person-centered perspective reinforced by the layout's structure. Similarly, in descriptions, speakers considered multiple cues whether available a priori or at the interaction. They used partner-centered expressions more frequently (e.g., "to your right") when the partner's viewpoint was misaligned by a small offset or coincided with the layout's structure. Conversely, they used egocentric expressions more frequently when their own viewpoint coincided with the intrinsic structure or when the partner was misaligned by a computationally difficult, oblique offset. Based on these findings we advocate for a framework for flexible perspective-taking: people weigh multiple cues (including social ones) to make attributions about the relative difficulty of perspective-taking for each partner, and adapt behavior to minimize their collective effort. This framework is not specialized for spatial reasoning but instead emerges from the same principles and memory-depended processes that govern perspective-taking in non-spatial tasks.

Disclosing information about the self is intrinsically rewarding

PubMed Central

Tamir, Diana I.; Mitchell, Jason P.

2012-01-01

Humans devote 30–40% of speech output solely to informing others of their own subjective experiences. What drives this propensity for disclosure? Here, we test recent theories that individuals place high subjective value on opportunities to communicate their thoughts and feelings to others and that doing so engages neural and cognitive mechanisms associated with reward. Five studies provided support for this hypothesis. Self-disclosure was strongly associated with increased activation in brain regions that form the mesolimbic dopamine system, including the nucleus accumbens and ventral tegmental area. Moreover, individuals were willing to forgo money to disclose about the self. Two additional studies demonstrated that these effects stemmed from the independent value that individuals placed on self-referential thought and on simply sharing information with others. Together, these findings suggest that the human tendency to convey information about personal experience may arise from the intrinsic value associated with self-disclosure. PMID:22566617

The alphabet of intrinsic disorder

PubMed Central

Uversky, Vladimir N

2013-01-01

The ability of a protein to fold into unique functional state or to stay intrinsically disordered is encoded in its amino acid sequence. Both ordered and intrinsically disordered proteins (IDPs) are natural polypeptides that use the same arsenal of 20 proteinogenic amino acid residues as their major building blocks. The exceptional structural plasticity of IDPs, their capability to exist as heterogeneous structural ensembles and their wide array of important disorder-based biological functions that complements functional repertoire of ordered proteins are all rooted within the peculiar differential usage of these building blocks by ordered proteins and IDPs. In fact, some residues (so-called disorder-promoting residues) are noticeably more common in IDPs than in sequences of ordered proteins, which, in their turn, are enriched in several order-promoting residues. Furthermore, residues can be arranged according to their “disorder promoting potencies,” which are evaluated based on the relative abundances of various amino acids in ordered and disordered proteins. This review continues a series of publications on the roles of different amino acids in defining the phenomenon of protein intrinsic disorder and concerns glutamic acid, which is the second most disorder-promoting residue. PMID:28516010

A study of intrinsic statistical variation for low-energy nuclear recoils in liquid xenon detector for dark matter searches

NASA Astrophysics Data System (ADS)

Wang, Lu; Wei, Wenzhao; Mei, Dongming; Cubed Collaboration

2015-10-01

Noble liquid xenon experiments, such as XENON100, LUX, XENON 1-Ton, and LZ are large dark matter experiments directly searches for weakly interacting massive particles (WIMPs). One of the most important features is to discriminate nuclear recoils from electronic recoils. Detector response is generally calibrated with different radioactive sources including 83mKr, tritiated methane, 241AmBe, 252Cf, and DD-neutrons. The electronic recoil and nuclear recoil bands have been determined by these calibrations. However, the width of nuclear recoil band needs to be fully understood. We derive a theoretical model to understand the correlation of the width of nuclear recoil band and intrinsic statistical variation. In addition, we conduct experiments to validate the theoretical model. In this paper, we present the study of intrinsic statistical variation contributing to the width of nuclear recoil band. DE-FG02-10ER46709 and the state of South Dakota.

Is Seismically Determined Q an Intrinsic Material Property?

NASA Astrophysics Data System (ADS)

Langston, C. A.

2003-12-01

The seismic quality factor, Q, has a well-defined physical meaning as an intrinsic material property associated with a visco-elastic or a non-linear stress-strain constitutive relation for a material. Measurement of Q from seismic waves, however, involves interpreting seismic wave amplitude and phase as deviations from some ideal elastic wave propagation model. Thus, assumptions in the elastic wave propagation model become the basis for attributing anelastic properties to the earth continuum. Scientifically, the resulting Q model derived from seismic data is no more than a hypothesis that needs to be verified by other independent experiments concerning the continuum constitutive law and through careful examination of the truth of the assumptions in the wave propagation model. A case in point concerns the anelasticity of Mississippi embayment sediments in the central U.S. that has important implications for evaluation of earthquake strong ground motions. Previous body wave analyses using converted Sp phases have suggested that Qs is ~30 in the sediments based on simple ray theory assumptions. However, detailed modeling of 1D heterogeneity in the sediments shows that Qs cannot be resolved by the Sp data. An independent experiment concerning the amplitude decay of surface waves propagating in the sediments shows that Qs must be generally greater than 80 but is also subject to scattering attenuation. Apparent Q effects seen in direct P and S waves can also be produced by wave tunneling mechanisms in relatively simple 1D heterogeneity. Heterogeneity is a general geophysical attribute of the earth as shown by many high-resolution data sets and should be used as the first litmus test on assumptions made in seismic Q studies before a Q model can be interpreted as an intrinsic material property.

Exploring the link between intrinsic motivation and quality

NASA Astrophysics Data System (ADS)

Christy, Steven M.

1992-12-01

This thesis proposes that it is workers' intrinsic motivation that leads them to produce quality work. It reviews two different types of evidence- expert opinion and empirical studies--to attempt to evaluate a link between intrinsic motivation and work quality. The thesis reviews the works of Total Quality writers and behavioral scientists for any connection they might have made between intrinsic motivation and quality. The thesis then looks at the works of Deming and his followers in an attempt to establish a match between Deming's motivational assumptions and the four task rewards in the Thomas/Tymon model of intrinsic motivation: choice, competence, meaningfulness, and progress. Based upon this analysis, it is proposed that the four Thomas/Tymon task rewards are a promising theoretical foundation for explaining the motivational basis of quality for workers in Total Quality organizations.

What's in a name? Why these proteins are intrinsically disordered: Why these proteins are intrinsically disordered.

PubMed

Dunker, A Keith; Babu, M Madan; Barbar, Elisar; Blackledge, Martin; Bondos, Sarah E; Dosztányi, Zsuzsanna; Dyson, H Jane; Forman-Kay, Julie; Fuxreiter, Monika; Gsponer, Jörg; Han, Kyou-Hoon; Jones, David T; Longhi, Sonia; Metallo, Steven J; Nishikawa, Ken; Nussinov, Ruth; Obradovic, Zoran; Pappu, Rohit V; Rost, Burkhard; Selenko, Philipp; Subramaniam, Vinod; Sussman, Joel L; Tompa, Peter; Uversky, Vladimir N

2013-01-01

"What's in a name? That which we call a rose By any other name would smell as sweet." From "Romeo and Juliet", William Shakespeare (1594) This article opens a series of publications on disambiguation of the basic terms used in the field of intrinsically disordered proteins. We start from the beginning, namely from the explanation of what the expression "intrinsically disordered protein" actually means and why this particular term has been chosen as the common denominator for this class of proteins characterized by broad structural, dynamic and functional characteristics.

Personality traits associated with intrinsic academic motivation in medical students.

PubMed

Tanaka, Masaaki; Mizuno, Kei; Fukuda, Sanae; Tajima, Seiki; Watanabe, Yasuyoshi

2009-04-01

Motivation is one of the most important psychological concepts in education and is related to academic outcomes in medical students. In this study, the relationships between personality traits and intrinsic academic motivation were examined in medical students. The study group consisted of 119 Year 2 medical students at Osaka City University Graduate School of Medicine. They completed questionnaires dealing with intrinsic academic motivation (the Intrinsic Motivation Scale toward Learning) and personality (the Temperament and Character Inventory [TCI]). On simple regression analyses, the TCI dimensions of persistence, self-directedness, co-operativeness and self-transcendence were positively associated with intrinsic academic motivation. On multiple regression analysis adjusted for age and gender, the TCI dimensions of persistence, self-directedness and self-transcendence were positively associated with intrinsic academic motivation. The temperament dimension of persistence and the character dimensions of self-directedness and self-transcendence are associated with intrinsic academic motivation in medical students.

IceCube can constrain the intrinsic charm of the proton [IC at IC: IceCube can constrain the intrinsic charm of the proton

DOE PAGES

Laha, Ranjan; Brodsky, Stanley J.

2017-12-05

Here, the discovery of extraterrestrial neutrinos in the ~30 TeV–PeV energy range by IceCube provides new constraints on high energy astrophysics. An important background to the signal are the prompt neutrinos which originate from the decay of charm hadrons produced by high energy cosmic-ray particles interacting in the Earth’s atmosphere. It is conventional to use the calculations of charm hadroproduction using gluon splitting g → c¯c alone. However, QCD predicts an additional “intrinsic" component of the heavy quark distribution which arises from diagrams where heavy quarks are multiply connected to the proton’s valence quarks. We estimate the prompt neutrino spectrummore » due to intrinsic charm. We find that the atmospheric prompt neutrino flux from intrinsic charm is comparable to those calculated using QCD computations not including intrinsic charm, once we normalize the intrinsic charm differential cross sections to the ISR and the LEBC-MPS collaboration data. In the future, IceCube will constrain the intrinsic charm content of the proton and will contribute to one of the major questions in high energy physics phenomenology.« less

IceCube can constrain the intrinsic charm of the proton [IC at IC: IceCube can constrain the intrinsic charm of the proton

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laha, Ranjan; Brodsky, Stanley J.

Here, the discovery of extraterrestrial neutrinos in the ~30 TeV–PeV energy range by IceCube provides new constraints on high energy astrophysics. An important background to the signal are the prompt neutrinos which originate from the decay of charm hadrons produced by high energy cosmic-ray particles interacting in the Earth’s atmosphere. It is conventional to use the calculations of charm hadroproduction using gluon splitting g → c¯c alone. However, QCD predicts an additional “intrinsic" component of the heavy quark distribution which arises from diagrams where heavy quarks are multiply connected to the proton’s valence quarks. We estimate the prompt neutrino spectrummore » due to intrinsic charm. We find that the atmospheric prompt neutrino flux from intrinsic charm is comparable to those calculated using QCD computations not including intrinsic charm, once we normalize the intrinsic charm differential cross sections to the ISR and the LEBC-MPS collaboration data. In the future, IceCube will constrain the intrinsic charm content of the proton and will contribute to one of the major questions in high energy physics phenomenology.« less

Initiation Processes of the Tropical Intraseasonal Variability Simulated in an Aqua-Planet Experiment: What is the Intrinsic Mechanism for MJO Onset?

NASA Astrophysics Data System (ADS)

Takasuka, Daisuke; Satoh, Masaki; Miyakawa, Tomoki; Miura, Hiroaki

2018-04-01

To understand the intrinsic onset mechanism of the Madden-Julian Oscillation (MJO), we simulated a set of initiation processes of MJO-like disturbances in 10 year aqua-planet experiments using a global atmospheric model with a 56 km horizontal mesh and an explicit cloud scheme. Under a condition with a zonally nonuniform sea surface temperature (SST) in the tropics, we reproduced MJO-like disturbances over the western warm pool region. The lagged-composite analysis of detected MJO-like disturbances clarifies the time sequence of three-dimensional dynamic and moisture fields prior to the onset. We found that midtropospheric moistening, a condition that is favorable for deep convection, is particularly obvious in the initiation region 5-9 days before onset. The moistening is caused by two-dimensional horizontal advection due to cross-equatorial shallow circulations associated with mixed Rossby-gravity waves, as well as anomalous poleward flows of a negative Rossby response to suppressed convection. When the midtroposphere is sufficiently moistened, lower tropospheric signals of circumnavigating Kelvin waves trigger active convection. The surface latent heat flux (LHF) feedback contributes to the initial stages of convective organization, while the cloud-radiation feedback contributes to later stages. Sensitivity experiments suggest that circumnavigating Kelvin waves regulate the period of MJO-like disturbances because of efficient convective triggering and that the LHF feedback contributes to rapid convective organization. However, the experiments also reveal that both conditions are not necessary for the existence of MJO-like disturbances. Implications for the relevance of these mechanisms for MJO onset are also discussed.

The Complete Set of Genes Encoding Major Intrinsic Proteins in Arabidopsis Provides a Framework for a New Nomenclature for Major Intrinsic Proteins in Plants1

PubMed Central

Johanson, Urban; Karlsson, Maria; Johansson, Ingela; Gustavsson, Sofia; Sjövall, Sara; Fraysse, Laure; Weig, Alfons R.; Kjellbom, Per

2001-01-01

Major intrinsic proteins (MIPs) facilitate the passive transport of small polar molecules across membranes. MIPs constitute a very old family of proteins and different forms have been found in all kinds of living organisms, including bacteria, fungi, animals, and plants. In the genomic sequence of Arabidopsis, we have identified 35 different MIP-encoding genes. Based on sequence similarity, these 35 proteins are divided into four different subfamilies: plasma membrane intrinsic proteins, tonoplast intrinsic proteins, NOD26-like intrinsic proteins also called NOD26-like MIPs, and the recently discovered small basic intrinsic proteins. In Arabidopsis, there are 13 plasma membrane intrinsic proteins, 10 tonoplast intrinsic proteins, nine NOD26-like intrinsic proteins, and three small basic intrinsic proteins. The gene structure in general is conserved within each subfamily, although there is a tendency to lose introns. Based on phylogenetic comparisons of maize (Zea mays) and Arabidopsis MIPs (AtMIPs), it is argued that the general intron patterns in the subfamilies were formed before the split of monocotyledons and dicotyledons. Although the gene structure is unique for each subfamily, there is a common pattern in how transmembrane helices are encoded on the exons in three of the subfamilies. The nomenclature for plant MIPs varies widely between different species but also between subfamilies in the same species. Based on the phylogeny of all AtMIPs, a new and more consistent nomenclature is proposed. The complete set of AtMIPs, together with the new nomenclature, will facilitate the isolation, classification, and labeling of plant MIPs from other species. PMID:11500536

The SAMI Galaxy Survey: the intrinsic shape of kinematically selected galaxies

NASA Astrophysics Data System (ADS)

Foster, C.; van de Sande, J.; D'Eugenio, F.; Cortese, L.; McDermid, R. M.; Bland-Hawthorn, J.; Brough, S.; Bryant, J.; Croom, S. M.; Goodwin, M.; Konstantopoulos, I. S.; Lawrence, J.; López-Sánchez, Á. R.; Medling, A. M.; Owers, M. S.; Richards, S. N.; Scott, N.; Taranu, D. S.; Tonini, C.; Zafar, T.

2017-11-01

Using the stellar kinematic maps and ancillary imaging data from the Sydney AAO Multi Integral field (SAMI) Galaxy Survey, the intrinsic shape of kinematically selected samples of galaxies is inferred. We implement an efficient and optimized algorithm to fit the intrinsic shape of galaxies using an established method to simultaneously invert the distributions of apparent ellipticities and kinematic misalignments. The algorithm output compares favourably with previous studies of the intrinsic shape of galaxies based on imaging alone and our re-analysis of the ATLAS3D data. Our results indicate that most galaxies are oblate axisymmetric. We show empirically that the intrinsic shape of galaxies varies as a function of their rotational support as measured by the 'spin' parameter proxy λ _{R_e}. In particular, low-spin systems have a higher occurrence of triaxiality, while high-spin systems are more intrinsically flattened and axisymmetric. The intrinsic shape of galaxies is linked to their formation and merger histories. Galaxies with high-spin values have intrinsic shapes consistent with dissipational minor mergers, while the intrinsic shape of low-spin systems is consistent with dissipationless multimerger assembly histories. This range in assembly histories inferred from intrinsic shapes is broadly consistent with expectations from cosmological simulations.

Functional Anthology of Intrinsic Disorder. III. Ligands, Postranslational Modifications and Diseases Associated with Intrinsically Disordered Proteins

PubMed Central

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

2008-01-01

Currently, the understanding of the relationships between function, amino acid sequence and protein structure continues to represent one of the major challenges of the modern protein science. As much as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bioinformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200,000 proteins from Swiss-Prot database, each annotated with at least one of the 875 functional keywords was described in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Using this tool, we have found that out of the 711 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic

Can Burt's Theory of Structural Holes be Applied to Study Social Support Among Mid-Age Female Sex Workers? A Multi-Site Egocentric Network Study in China.

PubMed

Liu, Hongjie

2017-12-01

The epidemic of HIV/AIDS continues to spread among older adults and mid-age female sex workers (FSWs) over 35 years old. We used egocentric network data collected from three study sites in China to examine the applicability of Burt's Theory of Social Holes to study social support among mid-age FSWs. Using respondent-driven sampling, 1245 eligible mid-age FSWs were interviewed. Network structural holes were measured by network constraint and effective size. Three types of social networks were identified: family networks, workplace networks, and non-FSW networks. A larger effective size was significantly associated with a higher level of social support [regression coefficient (β) 5.43-10.59] across the three study samples. In contrast, a greater constraint was significantly associated with a lower level of social support (β -9.33 to -66.76). This study documents the applicability of the Theory of Structural Holes in studying network support among marginalized populations, such as FSWs.

Binding Mechanisms of Intrinsically Disordered Proteins: Theory, Simulation, and Experiment

PubMed Central

Mollica, Luca; Bessa, Luiza M.; Hanoulle, Xavier; Jensen, Malene Ringkjøbing; Blackledge, Martin; Schneider, Robert

2016-01-01

In recent years, protein science has been revolutionized by the discovery of intrinsically disordered proteins (IDPs). In contrast to the classical paradigm that a given protein sequence corresponds to a defined structure and an associated function, we now know that proteins can be functional in the absence of a stable three-dimensional structure. In many cases, disordered proteins or protein regions become structured, at least locally, upon interacting with their physiological partners. Many, sometimes conflicting, hypotheses have been put forward regarding the interaction mechanisms of IDPs and the potential advantages of disorder for protein-protein interactions. Whether disorder may increase, as proposed, e.g., in the “fly-casting” hypothesis, or decrease binding rates, increase or decrease binding specificity, or what role pre-formed structure might play in interactions involving IDPs (conformational selection vs. induced fit), are subjects of intense debate. Experimentally, these questions remain difficult to address. Here, we review experimental studies of binding mechanisms of IDPs using NMR spectroscopy and transient kinetic techniques, as well as the underlying theoretical concepts and numerical methods that can be applied to describe these interactions at the atomic level. The available literature suggests that the kinetic and thermodynamic parameters characterizing interactions involving IDPs can vary widely and that there may be no single common mechanism that can explain the different binding modes observed experimentally. Rather, disordered proteins appear to make combined use of features such as pre-formed structure and flexibility, depending on the individual system and the functional context. PMID:27668217

Youth fitness testing: the effect of percentile-based evaluative feedback on intrinsic motivation.

PubMed

Whitehead, J R; Corbin, C B

1991-06-01

This study was a test of Deci and Ryan's (1985) cognitive evaluation theory in a fitness testing situation. More specifically, it was a test of Proposition 2 of that theory, which posits that external events that increase or decrease perceived competence will increase or decrease intrinsic motivation. Seventh and eighth grade schoolchildren (N = 105) volunteered for an experiment that was ostensibly to collect data on a new youth fitness test (the Illinois Agility Run). After two untimed practice runs, a specially adapted version of the Intrinsic Motivation Inventory (IMI) was administered as a pretest of intrinsic motivation. Two weeks later when subjects ran again, they were apparently electronically timed. In reality, the subjects were given bogus feedback. Subjects in a positive feedback condition were told their scores were above the 80th percentile, while those in a negative feedback condition were told their scores were below the 20th percentile. Those in a control condition received no feedback. The IMI was again administered to the subjects after their runs. Multivariate and subsequent univariate tests were significant for all four subscale dependent variables (perceived interest-enjoyment, competence, effort, and pressure-tension). Positive feedback enhanced all aspects of intrinsic motivation, whereas negative feedback decreased them. In a further test of cognitive evaluation theory, path analysis results supported the prediction that perceived competence would mediate changes in the other IMI subscales. Taken together, these results clearly support cognitive evaluation theory and also may have important implications regarding motivation for those who administer youth fitness tests.

Lessons with Living Harvest Mice: An empirical study of their effects on intrinsic motivation and knowledge acquisition

NASA Astrophysics Data System (ADS)

Wilde, Matthias; Hußmann, Jona Samuel; Lorenzen, Simone; Meyer, Annika; Randler, Christoph

2012-12-01

The aim of this study was to evaluate the effects of living animals on pupils' intrinsic motivation and knowledge. Various studies from the late 1970s and 1980s stress the high effectiveness of authentic learning experiences in pupils' knowledge acquisition. However, there are only few current empirical studies on this topic. The research question of our study is to assess whether the use of living animals in the biology classroom supports intrinsic motivation and knowledge acquisition. In a pre-/post-test design, 185 fifth graders received two different treatments: the experimental group (N = 74) was taught with living harvest mice (Micromys minutus) and the control group (N = 111) received lessons with the same content which was presented in short film clips on laptop computers. Knowledge acquisition was assessed with open-ended and closed questions, while intrinsic motivation was tested with an adapted version of the Intrinsic Motivation Inventory (IMI). There were no differences in knowledge acquisition between the treatments. However, the results of the IMI showed significant differences in favour of the experimental group in interest/enjoyment, perceived competence, and perceived autonomy. Thus, living animals exert a positive influence on motivation.

Self-perception of intrinsic and extrinsic motivation.

PubMed

Calder, B J; Staw, B M

1975-04-01

Self-perception theory predicts that intrinsic and extrinsic motivation do not combine additively but rather interact. To test this predicted interaction, intrinsic and extrinsic motivation were both manipulated as independent variables. The results revealed a significant interaction for task satisfaction and a trend for the interaction on a behavioral measure. These results are discussed in terms of a general approach to the self-perception of motivation.

"I'm Just Going through the Motions": High-Stakes Accountability and Teachers' Access to Intrinsic Rewards

ERIC Educational Resources Information Center

Rooney, Erin

2015-01-01

This article explores teachers' experiences under high-stakes accountability and shows how the narrowing of curriculum depleted teachers' intrinsic work rewards. The article analyzes data from an ethnographic study of teachers' work in two high-poverty urban public schools. The study shows that as instructional mandates emphasized a narrowed…

Do people differentiate between intrinsic and extrinsic goals for physical activity?

PubMed

McLachlan, Sarah; Hagger, Martin S

2011-04-01

The distinction between intrinsic and extrinsic goals, and between goal pursuit for intrinsically and extrinsically motivated reasons, is a central premise of self-determination theory. Proponents of the theory have proposed that the pursuit of intrinsic goals and intrinsically motivated goal striving each predict adaptive psychological and behavioral outcomes relative to the pursuit of extrinsic goals and extrinsically motivated goal striving. Despite evidence to support these predictions, research has not explored whether individuals naturally differentiate between intrinsic and extrinsic goals. Two studies tested whether people make this differentiation when recalling goals for leisure-time physical activity. Using memory-recall methods, participants in Study 1 were asked to freely generate physical activity goals. A subsample (N = 43) was asked to code their freely generated goals as intrinsic or extrinsic. In Study 2, participants were asked to recall intrinsic and extrinsic goals after making a decision regarding their future physical activity. Results of these studies revealed that individuals' goal generation and recall exhibited significant clustering by goal type. Participants encountered some difficulties when explicitly coding goals. Findings support self-determination theory and indicate that individuals discriminate between intrinsic and extrinsic goals.

Relating specific emotions to intrinsic motivation: on the moderating role of positive and negative emotion differentiation.

PubMed

Vandercammen, Leen; Hofmans, Joeri; Theuns, Peter

2014-01-01

Despite the fact that studies on self-determination theory have traditionally disregarded the explicit role of emotions in the motivation eliciting process, research attention for the affective antecedents of motivation is growing. We add to this emerging research field by testing the moderating role of emotion differentiation -individual differences in the extent to which people can differentiate between specific emotions- on the relationship between twelve specific emotions and intrinsic motivation. To this end, we conducted a daily diary study (N = 72) and an experience sampling study (N = 34). Results showed that the relationship between enthusiasm, cheerfulness, optimism, contentedness, gloominess, miserableness, uneasiness (in both studies 1 and 2), calmness, relaxation, tenseness, depression, worry (only in Study 1) on one hand and intrinsic motivation on the other hand was moderated by positive emotion differentiation for the positive emotions and by negative emotion differentiation for the negative emotions. Altogether, these findings suggest that for people who are unable to distinguish between different specific positive emotions the relationship between those specific positive emotions and intrinsic motivation is stronger, whereas the relationship between specific negative emotions and intrinsic motivation is weaker for people who are able to distinguish between the different specific negative emotions. Theoretical and practical implications are discussed.

Relating Specific Emotions to Intrinsic Motivation: On the Moderating Role of Positive and Negative Emotion Differentiation

PubMed Central

Vandercammen, Leen; Hofmans, Joeri; Theuns, Peter

2014-01-01

Despite the fact that studies on self-determination theory have traditionally disregarded the explicit role of emotions in the motivation eliciting process, research attention for the affective antecedents of motivation is growing. We add to this emerging research field by testing the moderating role of emotion differentiation –individual differences in the extent to which people can differentiate between specific emotions– on the relationship between twelve specific emotions and intrinsic motivation. To this end, we conducted a daily diary study (N = 72) and an experience sampling study (N = 34). Results showed that the relationship between enthusiasm, cheerfulness, optimism, contentedness, gloominess, miserableness, uneasiness (in both studies 1 and 2), calmness, relaxation, tenseness, depression, worry (only in Study 1) on one hand and intrinsic motivation on the other hand was moderated by positive emotion differentiation for the positive emotions and by negative emotion differentiation for the negative emotions. Altogether, these findings suggest that for people who are unable to distinguish between different specific positive emotions the relationship between those specific positive emotions and intrinsic motivation is stronger, whereas the relationship between specific negative emotions and intrinsic motivation is weaker for people who are able to distinguish between the different specific negative emotions. Theoretical and practical implications are discussed. PMID:25517984

Self-Determination Theory: Intrinsic Motivation and Behavioral Change.

PubMed

Flannery, Marie

2017-03-01

Motivation is a central concept in behavioral change. This article reviews the self-determination theory with an emphasis on "intrinsic motivation," which is facilitated when three basic psychological needs (autonomy, competence, and relatedness) are met. Intrinsic motivation is associated with improved well-being and sustained behavioral change.

Tractography from HARDI using an Intrinsic Unscented Kalman Filter

PubMed Central

Cheng, Guang; Salehian, Hesamoddin; Forder, John R.; Vemuri, Baba C.

2014-01-01

A novel adaptation of the unscented Kalman filter (UKF) was recently introduced in literature for simultaneous multi-tensor estimation and fiber tractography from diffusion MRI. This technique has the advantage over other tractography methods in terms of computational efficiency, due to the fact that the UKF simultaneously estimates the diffusion tensors and propagates the most consistent direction to track along. This UKF and its variants reported later in literature however are not intrinsic to the space of diffusion tensors. Lack of this key property can possibly lead to inaccuracies in the multi-tensor estimation as well as in the tractography. In this paper, we propose a novel intrinsic unscented Kalman filter (IUKF) in the space of diffusion tensors which are symmetric positive definite matrices, that can be used for simultaneous recursive estimation of multi-tensors and propagation of directional information for use in fiber tractography from diffusion weighted MR data. In addition to being more accurate, IUKF retains all the advantages of UKF mentioned above. We demonstrate the accuracy and effectiveness of the proposed method via experiments publicly available phantom data from the fiber cup-challenge (MICCAI 2009) and diffusion weighted MR scans acquired from human brains and rat spinal cords. PMID:25203986

Volumes and intrinsic diameters of hypersurfaces

NASA Astrophysics Data System (ADS)

Paeng, Seong-Hun

2015-09-01

We estimate the volume and the intrinsic diameter of a hypersurface M with geometric information of a hypersurface which is parallel to M at distance T. It can be applied to the Riemannian Penrose inequality to obtain a lower bound of the total mass of a spacetime. Also it can be used to obtain upper bounds of the volume and the intrinsic diameter of the celestial r-sphere without a lower bound of the sectional curvature. We extend our results to metric-measure spaces by using the Bakry-Emery Ricci tensor.

Intraoperative intrinsic optical imaging of human somatosensory cortex during neurosurgical operations.

PubMed

Sato, Katsushige; Nariai, Tadashi; Momose-Sato, Yoko; Kamino, Kohtaro

2017-07-01

Intrinsic optical imaging as developed by Grinvald et al. is a powerful technique for monitoring neural function in the in vivo central nervous system. The advent of this dye-free imaging has also enabled us to monitor human brain function during neurosurgical operations. We briefly describe our own experience in functional mapping of the human somatosensory cortex, carried out using intraoperative optical imaging. The maps obtained demonstrate new additional evidence of a hierarchy for sensory response patterns in the human primary somatosensory cortex.

Extrinsic and intrinsic regulation of axon regeneration at a crossroads

PubMed Central

Kaplan, Andrew; Ong Tone, Stephan; Fournier, Alyson E.

2015-01-01

Repair of the injured spinal cord is a major challenge in medicine. The limited intrinsic regenerative response mounted by adult central nervous system (CNS) neurons is further hampered by astrogliosis, myelin debris and scar tissue that characterize the damaged CNS. Improved axon regeneration and recovery can be elicited by targeting extrinsic factors as well as by boosting neuron-intrinsic growth regulators. Our knowledge of the molecular basis of intrinsic and extrinsic regulators of regeneration has expanded rapidly, resulting in promising new targets to promote repair. Intriguingly certain neuron-intrinsic growth regulators are emerging as promising targets to both stimulate growth and relieve extrinsic inhibition of regeneration. This crossroads between the intrinsic and extrinsic aspects of spinal cord injury is a promising target for effective therapies for this unmet need. PMID:26136657

Extrinsic and intrinsic regulation of axon regeneration at a crossroads.

PubMed

Kaplan, Andrew; Ong Tone, Stephan; Fournier, Alyson E

2015-01-01

Repair of the injured spinal cord is a major challenge in medicine. The limited intrinsic regenerative response mounted by adult central nervous system (CNS) neurons is further hampered by astrogliosis, myelin debris and scar tissue that characterize the damaged CNS. Improved axon regeneration and recovery can be elicited by targeting extrinsic factors as well as by boosting neuron-intrinsic growth regulators. Our knowledge of the molecular basis of intrinsic and extrinsic regulators of regeneration has expanded rapidly, resulting in promising new targets to promote repair. Intriguingly certain neuron-intrinsic growth regulators are emerging as promising targets to both stimulate growth and relieve extrinsic inhibition of regeneration. This crossroads between the intrinsic and extrinsic aspects of spinal cord injury is a promising target for effective therapies for this unmet need.

Ethnic Stigma, Academic Anxiety, and Intrinsic Motivation in Middle Childhood

PubMed Central

Gillen-O’Neel, Cari; Ruble, Diane N.; Fuligni, Andrew J.

2011-01-01

Previous research addressing the dynamics of stigma and academics has focused on African-American adolescents and adults. The present study examined stigma awareness, academic anxiety, and intrinsic motivation among 451 young (ages 6–11) and diverse (African-American, Chinese, Dominican, Russian, and European-American) students. Results indicated that ethnic-minority children reported higher stigma awareness than European-American children. For all children, stigma awareness was associated with higher academic anxiety and lower intrinsic motivation. Despite these associations, ethnic-minority children reported higher levels of intrinsic motivation than their European-American peers. A significant portion of the higher intrinsic motivation among Dominican students was associated with their higher levels of school belonging, suggesting that supportive school environments may be important sources of intrinsic motivation among some ethnic-minority children. PMID:21883152

Intrinsic and extrinsic motivation for stereotypic and repetitive behavior.

PubMed

Joosten, Annette V; Bundy, Anita C; Einfeld, Stewart L

2009-03-01

This study provides evidence for intrinsic and extrinsic motivators for stereotypical and repetitive behavior in children with autism and intellectual disability and children with intellectual disability alone. We modified the Motivation Assessment Scale (MAS) (1988b); dividing it into intrinsic and extrinsic measures and adding items to assess anxiety as an intrinsic motivator. Rasch analysis of data from 279 MASs (74 children) revealed that the items formed two unidimensional scales. Anxiety was a more likely intrinsic motivator than sensory seeking for children with dual diagnoses; the reverse was true for children with intellectual disability only. Escape and gaining a tangible object were the most common extrinsic motivators for those with dual diagnoses and attention and escape for children with intellectual disability.

Optimal experience among teachers: new insights into the work paradox.

PubMed

Bassi, Marta; Delle Fave, Antonella

2012-01-01

Several studies highlighted that individuals perceive work as an opportunity for flow or optimal experience, but not as desirable and pleasant. This finding was defined as the work paradox. The present study addressed this issue among teachers from the perspective of self-determination theory, investigating work-related intrinsic and extrinsic motivation, as well as autonomous and controlled behavior regulation. In Study 1, 14 teachers were longitudinally monitored with Experience Sampling Method for one work week. In Study 2, 184 teachers were administered Flow Questionnaire and Work Preference Inventory, respectively investigating opportunities for optimal experience, and motivational orientations at work. Results showed that work-related optimal experiences were associated with both autonomous regulation and with controlled regulation. Moreover, teachers reported both intrinsic and extrinsic motivation at work, with a prevailing intrinsic orientation. Findings provide novel insights on the work paradox, and suggestions for teachers' well-being promotion.

Personalizing Sample Databases with Facebook Information to Increase Intrinsic Motivation

ERIC Educational Resources Information Center

Marzo, Asier; Ardaiz, Oscar; Sanz de Acedo, María Teresa; Sanz de Acedo, María Luisa

2017-01-01

Motivation is fundamental for students to achieve successful and complete learning. Motivation can be extrinsic, i.e., driven by external rewards, or intrinsic, i.e., driven by internal factors. Intrinsic motivation is the most effective and must be inspired by the task at hand. Here, a novel strategy is presented to increase intrinsic motivation…

IceCube can constrain the intrinsic charm of the proton

NASA Astrophysics Data System (ADS)

Laha, Ranjan; Brodsky, Stanley J.

2017-12-01

The discovery of extraterrestrial neutrinos in the ˜30 TeV - PeV energy range by IceCube provides new constraints on high energy astrophysics. An important background to the signal are the prompt neutrinos which originate from the decay of charm hadrons produced by high energy cosmic-ray particles interacting in the Earth's atmosphere. It is conventional to use the calculations of charm hadroproduction using gluon splitting g →c c ¯ alone. However, QCD predicts an additional "intrinsic" component of the heavy quark distribution which arises from diagrams where heavy quarks are multiply connected to the proton's valence quarks. We estimate the prompt neutrino spectrum due to intrinsic charm. We find that the atmospheric prompt neutrino flux from intrinsic charm is comparable to those calculated using QCD computations not including intrinsic charm, once we normalize the intrinsic charm differential cross sections to the ISR and the LEBC-MPS collaboration data. In the future, IceCube will constrain the intrinsic charm content of the proton and will contribute to one of the major questions in high energy physics phenomenology.

30 CFR 27.34 - Test for intrinsic safety.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Test for intrinsic safety. 27.34 Section 27.34 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.34 Test for intrinsic safety...

30 CFR 27.34 - Test for intrinsic safety.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Test for intrinsic safety. 27.34 Section 27.34 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test Requirements § 27.34 Test for intrinsic safety...

Intrinsic and Extrinsic Origins of the Polar Kerr Effect in a Chiral p-WAVE Superconductor

NASA Astrophysics Data System (ADS)

Goryo, Jun

Recently, the measurement of the polar Kerr effect (PKE) in the quasi two-dimensional superconductor Sr2RuO4, which is motivated to observe the chirality of px + ipy-wave pairing, has been reported. We clarify that the PKE has intrinsic and extrinsic (disorder-induced) origins. The extrinsic contribution would be dominant in the PKE experiment.

Changes in Intrinsic Motivation as a Function of Negative Feedback and Threats.

ERIC Educational Resources Information Center

Deci, Edward L.; Cascio, Wayne F.

Recent studies have demonstrated that external rewards can affect intrinsic motivation to perform an activity. Money tends to decrease intrinsic motivation, whereas positive verbal reinforcements tend to increase intrinsic motivation. This paper presents evidence that negative feedback and threats of punishment also decrease intrinsic motivation.…

Palatalization and Intrinsic Prosodic Vowel Features in Russian

ERIC Educational Resources Information Center

Ordin, Mikhail

2011-01-01

The presented study is aimed at investigating the interaction of palatalization and intrinsic prosodic features of the vowel in CVC (consonant+vowel+consonant) syllables in Russian. The universal nature of intrinsic prosodic vowel features was confirmed with the data from the Russian language. It was found that palatalization of the consonants…

Stepping into a Map: Initial Heading Direction Influences Spatial Memory Flexibility

ERIC Educational Resources Information Center

Gagnon, Stephanie A.; Brunyé, Tad T.; Gardony, Aaron; Noordzij, Matthijs L.; Mahoney, Caroline R.; Taylor, Holly A.

2014-01-01

Learning a novel environment involves integrating first-person perceptual and motoric experiences with developing knowledge about the overall structure of the surroundings. The present experiments provide insights into the parallel development of these egocentric and allocentric memories by intentionally conflicting body- and world-centered frames…

Ethnic stigma, academic anxiety, and intrinsic motivation in middle childhood.

PubMed

Gillen-O'Neel, Cari; Ruble, Diane N; Fuligni, Andrew J

2011-01-01

Previous research addressing the dynamics of stigma and academics has focused on African American adolescents and adults. The present study examined stigma awareness, academic anxiety, and intrinsic motivation among 451 young (ages 6-11) and diverse (African American, Chinese, Dominican, Russian, and European American) students. Results indicated that ethnic-minority children reported higher stigma awareness than European American children. For all children, stigma awareness was associated with higher academic anxiety and lower intrinsic motivation. Despite these associations, ethnic-minority children reported higher levels of intrinsic motivation than their European American peers. A significant portion of the higher intrinsic motivation among Dominican students was associated with their higher levels of school belonging, suggesting that supportive school environments may be important sources of intrinsic motivation among some ethnic-minority children. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

Intrinsic retrieval efficiency for quantum memories: A three-dimensional theory of light interaction with an atomic ensemble

NASA Astrophysics Data System (ADS)

Gujarati, Tanvi P.; Wu, Yukai; Duan, Luming

2018-03-01

Duan-Lukin-Cirac-Zoller quantum repeater protocol, which was proposed to realize long distance quantum communication, requires usage of quantum memories. Atomic ensembles interacting with optical beams based on off-resonant Raman scattering serve as convenient on-demand quantum memories. Here, a complete free space, three-dimensional theory of the associated read and write process for this quantum memory is worked out with the aim of understanding intrinsic retrieval efficiency. We develop a formalism to calculate the transverse mode structure for the signal and the idler photons and use the formalism to study the intrinsic retrieval efficiency under various configurations. The effects of atomic density fluctuations and atomic motion are incorporated by numerically simulating this system for a range of realistic experimental parameters. We obtain results that describe the variation in the intrinsic retrieval efficiency as a function of the memory storage time for skewed beam configuration at a finite temperature, which provides valuable information for optimization of the retrieval efficiency in experiments.

Gameplay as a source of intrinsic motivation in a randomized controlled trial of auditory training for tinnitus.

PubMed

Hoare, Derek J; Van Labeke, Nicolas; McCormack, Abby; Sereda, Magdalena; Smith, Sandra; Al Taher, Hala; Kowalkowski, Victoria L; Sharples, Mike; Hall, Deborah A

2014-01-01

Previous studies of frequency discrimination training (FDT) for tinnitus used repetitive task-based training programmes relying on extrinsic factors to motivate participation. Studies reported limited improvement in tinnitus symptoms. To evaluate FDT exploiting intrinsic motivations by integrating training with computer-gameplay. Sixty participants were randomly assigned to train on either a conventional task-based training, or one of two interactive game-based training platforms over six weeks. Outcomes included assessment of motivation, tinnitus handicap, and performance on tests of attention. Participants reported greater intrinsic motivation to train on the interactive game-based platforms, yet compliance of all three groups was similar (∼ 70%) and changes in self-reported tinnitus severity were not significant. There was no difference between groups in terms of change in tinnitus severity or performance on measures of attention. FDT can be integrated within an intrinsically motivating game. Whilst this may improve participant experience, in this instance it did not translate to additional compliance or therapeutic benefit. ClinicalTrials.gov NCT02095262.

Proteins contribute insignificantly to the intrinsic buffering capacity of yeast cytoplasm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poznanski, Jaroslaw; Szczesny, Pawel; Institute of Experimental Plant Biology and Biotechnology, Faculty of Biology, University of Warsaw, Warsaw

Highlights: Black-Right-Pointing-Pointer We predicted buffering capacity of yeast proteome from protein abundance data. Black-Right-Pointing-Pointer We measured total buffering capacity of yeast cytoplasm. Black-Right-Pointing-Pointer We showed that proteins contribute insignificantly to buffering capacity. -- Abstract: Intracellular pH is maintained by a combination of the passive buffering of cytoplasmic dissociable compounds and several active systems. Over the years, a large portion of and possibly most of the cell's intrinsic (i.e., passive non-bicarbonate) buffering effect was attributed to proteins, both in higher organisms and in yeast. This attribution was not surprising, given that the concentration of proteins with multiple protonable/deprotonable groups in themore » cell exceeds the concentration of free protons by a few orders of magnitude. Using data from both high-throughput experiments and in vitro laboratory experiments, we tested this concept. We assessed the buffering capacity of the yeast proteome using protein abundance data and compared it to our own titration of yeast cytoplasm. We showed that the protein contribution is less than 1% of the total intracellular buffering capacity. As confirmed with NMR measurements, inorganic phosphates play a crucial role in the process. These findings also shed a new light on the role of proteomes in maintaining intracellular pH. The contribution of proteins to the intrinsic buffering capacity is negligible, and proteins might act only as a recipient of signals for changes in pH.« less

Intrinsic phonon properties of double-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Tran, H. N.; Levshov, D. I.; Nguyen, V. C.; Paillet, M.; Arenal, R.; Than, X. T.; Zahab, A. A.; Yuzyuk, Y. I.; Phan, N. M.; Sauvajol, J.-L.; Michel, T.

2017-03-01

Double-walled carbon nanotubes (DWNT) are made of two concentric and weakly van der Waals coupled single-walled carbon nanotubes (SWNT). DWNTs are the simplest systems for studying the mechanical and electronic interactions between concentric carbon layers. In this paper we review recent results concerning the intrinsic features of phonons of DWNTs obtained from Raman experiments performed on index-identified DWNTs. The effect of the interlayer distance on the strength of the mechanical and electronic coupling between the layers, and thus on the frequencies of the Raman-active modes, namely the radial breathing-like modes (RBLMs) and G-modes, are evidenced and discussed. Invited talk at 8th International Workshop on Advanced Materials Science and Nanotechnology (IWAMSN2016), 8-12 November 2016, Ha Long City, Vietnam.

The Benefits of Mouse Keeping—an Empirical Study on Students' Flow and Intrinsic Motivation in Biology Lessons

NASA Astrophysics Data System (ADS)

Meyer, Annika; Klingenberg, Konstantin; Wilde, Matthias

2016-02-01

Contact with living animals is an exceptional possibility within biology education to facilitate an intense immersion into the study topic and even allow for a flow experience (Csikszentmihalyi 2000). Further, it might affect the perceptions of the students' basic needs for autonomy and competence and thereby their quality of motivation (Deci and Ryan 1985, 2002). Still, there is little empirical evidence about the duration of the exposure with living animals that is required. We investigated the students' flow experience, and the students' motivation, reported retrospectively in three different treatments: lessons involving short-term or long-term contact with living harvest mice and a control group without living animals. Our sample consisted of 156 fifth graders (10.76 years, SD = 0.513). The test instruments were adapted versions of the Flow Short Scale (FSS, Rheinberg et al. 2003) and of the Intrinsic Motivation Inventory (IMI, Ryan 1982). As expected, the control group produced significantly lower scores for both FSS and IMI. In addition, we found a significant difference between students with short-term versus long-term contact. Whereas the flow experience was indistinguishable for all pupils who had contact with living animals, those with long-term experience reported significantly higher intrinsic motivation.

Derivation of the extrinsic values of biological diversity from its intrinsic value and of both from the first principles of evolution.

PubMed

White, Peter S

2013-12-01

Conservation ethics have been based on 2 philosophical value systems: extrinsic value (defined broadly to include all values that derive from something external to the thing valued) and intrinsic value. Valuing biological diversity on the basis of an extrinsic value system is problematic because measurement is often difficult; extrinsic value changes as spatial or temporal scales change; extrinsic value differs on the basis of external factors; some species have trivial or negative extrinsic values; and extrinsic value varies across human cultures and societies and with such factors as socioeconomic conditions, individual experiences, and educational backgrounds. Valuing biological diversity on the basis of an intrinsic value system also poses challenges because intrinsic value can be seen as a disguised form of human extrinsic value; intrinsic value is initially ambiguous as to which objects or characteristics of biological diversity are to being valued; all aspects of biological diversity (e.g., species and ecosystems) are transitory; species and ecosystems are not static concrete entities; and intrinsic value of one species is often in conflict with the intrinsic value of other species. Extrinsic and intrinsic value systems share a common origin, such that extrinsic values are always derived from intrinsic value and life mutely expresses both intrinsic and extrinsic values-these are derived from and are products of biological evolution. Probing the values that underlie conservation helps the community clearly articulate its aims. Derivación de los Valores Extrínsecos de la Biodiversidad a Partir de sus Valores Intrínsecos y de Ambos a Partir de los Primeros Principios de la Evolución. © 2013 Society for Conservation Biology.

Intrinsic Peroxidase-like Activity of Ficin

NASA Astrophysics Data System (ADS)

Yang, Yufang; Shen, Dongjun; Long, Yijuan; Xie, Zhixiong; Zheng, Huzhi

2017-02-01

Ficin is classified as a sulfhydryl protease isolated from the latex of fig trees. In most cases, a particular enzyme fits a few types of substrate and catalyzes one type of reaction. In this investigation, we found sufficient proofs for the intrinsic peroxidase-like activity of ficin and designed experiments to examine its effectiveness in a variety of scenarios. Ficin can transform peroxidase substrates to colored products in the existence of H2O2. Our results also indicate that the active sites of peroxidase-like activity of ficin are different from that of protease, which reveals that one enzyme may catalyze more than one kind of substrate to perform different types of reactions. On the basis of these findings, H2O2 releasing from MCF-7 cells was detected successfully. Our findings support a wider application of ficin in biochemistry and open up the possibility of utilizing ficin as enzymatic mimics in biotechnology and environmental monitoring.

The Intrinsic Value of Nature and Moral Education

ERIC Educational Resources Information Center

Helton, William S.; Helton, Nicole D.

2007-01-01

Many environmental, humane and character educators try to foster a belief in the intrinsic value of nature and a respect for non-human life among students. Marangudakis argues that Christianity advocates anthropocentrism and opposes belief in the intrinsic value of nature. If Marangudakis is correct, then a goal of many environmental and humane…

Detecting early egocentric and allocentric impairments deficits in Alzheimer's disease: an experimental study with virtual reality.

PubMed

Serino, Silvia; Morganti, Francesca; Di Stefano, Fabio; Riva, Giuseppe

2015-01-01

Several studies have pointed out that egocentric and allocentric spatial impairments are one of the earliest manifestations of Alzheimer's Disease (AD). It is less clear how a break in the continuous interaction between these two representations may be a crucial marker to detect patients who are at risk to develop dementia. The main objective of this study is to compare the performances of participants suffering from amnestic mild cognitive impairment (aMCI group), patients with AD (AD group) and a control group (CG), using a virtual reality (VR)-based procedure for assessing the abilities in encoding, storing and syncing different spatial representations. In the first task, participants were required to indicate on a real map the position of the object they had memorized, while in the second task they were invited to retrieve its position from an empty version of the same virtual room, starting from a different position. The entire procedure was repeated across three different trials, depending on the object location in the encoding phase. Our finding showed that aMCI patients performed significantly more poorly in the third trial of the first task, showing a deficit in the ability to encode and store an allocentric viewpoint independent representation. On the other hand, AD patients performed significantly more poorly when compared to the CG in the second task, indicating a specific impairment in storing an allocentric viewpoint independent representation and then syncing it with the allocentric viewpoint dependent representation. Furthermore, data suggested that these impairments are not a product of generalized cognitive decline or of general decay in spatial abilities, but instead may reflect a selective deficit in the spatial organization Overall, these findings provide an initial insight into the cognitive underpinnings of amnestic impairment in aMCI and AD patient exploiting the potentiality of VR.

Turbulent diffusion with memories and intrinsic shear

NASA Technical Reports Server (NTRS)

Tchen, C. M.

1974-01-01

The first part of the present theory is devoted to the derivation of a Fokker-Planck equation. The eddies smaller than the hydrodynamic scale of the diffusion cloud form a diffusivity, while the inhomogeneous, bigger eddies give rise to a nonuniform migratory drift. This introduces an eddy-induced shear which reflects on the large-scale diffusion. The eddy-induced shear does not require the presence of a permanent wind shear and is intrinsic to the diffusion. Secondly, a transport theory of diffusivity is developed by the method of repeated-cascade and is based upon a relaxation of a chain of memories with decreasing information. The full range of diffusion consists of inertia, composite, and shear subranges, for which variance and eddy diffusivities are predicted. The coefficients are evaluated. Comparison with experiments in the upper atmosphere and oceans is made.

Intrinsic feature-based pose measurement for imaging motion compensation

DOEpatents

Baba, Justin S.; Goddard, Jr., James Samuel

2014-08-19

Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

Intrinsically bent DNA in replication origins and gene promoters.

PubMed

Gimenes, F; Takeda, K I; Fiorini, A; Gouveia, F S; Fernandez, M A

2008-06-24

Intrinsically bent DNA is an alternative conformation of the DNA molecule caused by the presence of dA/dT tracts, 2 to 6 bp long, in a helical turn phase DNA or with multiple intervals of 10 to 11 bp. Other than flexibility, intrinsic bending sites induce DNA curvature in particular chromosome regions such as replication origins and promoters. Intrinsically bent DNA sites are important in initiating DNA replication, and are sometimes found near to regions associated with the nuclear matrix. Many methods have been developed to localize bent sites, for example, circular permutation, computational analysis, and atomic force microscopy. This review discusses intrinsically bent DNA sites associated with replication origins and gene promoter regions in prokaryote and eukaryote cells. We also describe methods for identifying bent DNA sites for circular permutation and computational analysis.

Intrinsic Brain Connectivity in Fibromyalgia is Associated with Chronic Pain Intensity

PubMed Central

Napadow, Vitaly; LaCount, Lauren; Park, Kyungmo; As-Sanie, Suzie; Clauw, Daniel J; Harris, Richard E

2010-01-01

OBJECTIVE Fibromyalgia (FM) is considered to be the prototypical central chronic pain syndrome and is associated with widespread pain that fluctuates spontaneously. Multiple studies have demonstrated altered brain activity in these patients. Our objective was to investigate the degree of connectivity between multiple brain networks in FM, as well as how activity in these networks correlates with spontaneous pain. METHODS Resting functional magnetic resonance imaging (fMRI) data in FM patients (n=18) and age-matched healthy controls (HC, n=18) were analyzed using dual regression independent component analysis (ICA) - a data driven approach used to identify independent brain networks. We evaluated intrinsic, or resting, connectivity in multiple brain networks: the default mode network (DMN), the executive attention network (EAN), and the medial visual network (MVN), with the MVN serving as a negative control. Spontaneous pain levels were also covaried with intrinsic connectivity. RESULTS We found that FM patients had greater connectivity within the DMN and right EAN (rEAN; p<0.05, corrected), and greater connectivity between the DMN and the insular cortex – a brain region known to process evoked pain. Furthermore, greater spontaneous pain at the time of the scan correlated with greater intrinsic connectivity between the insula and both the DMN and rEAN (p<0.05, corrected). CONCLUSION Our findings indicate that resting brain activity within multiple networks is associated with spontaneous clinical pain in FM. These findings may also have broader implications for how subjective experiences such as pain arise from a complex interplay amongst multiple brain networks. PMID:20506181

Toward Modeling the Intrinsic Complexity of Test Problems

ERIC Educational Resources Information Center

Shoufan, Abdulhadi

2017-01-01

The concept of intrinsic complexity explains why different problems of the same type, tackled by the same problem solver, can require different times to solve and yield solutions of different quality. This paper proposes a general four-step approach that can be used to establish a model for the intrinsic complexity of a problem class in terms of…

Congenital hypertrophy of multiple intrinsic muscles of the foot.

PubMed

Shiraishi, Tomohiro; Park, Susam; Niu, Atushi; Hasegawa, Hiromi

2014-12-01

Congenital hypertrophy of a single intrinsic muscle of the foot is rare, and as far as we know, only six cases have been reported. We describe a case of congenital anomaly that showed hypertrophy of multiple intrinsic muscles of the foot; the affected muscles were all the intrinsic muscles of the foot except the extensor digitorum brevis or extensor hallucis. Other tissues such as adipose tissue, nervous tissue, or osseous tissue showed no abnormalities. To reduce the volume of the foot we removed parts of the enlarged muscles.

Creativity as Mediator for Intrinsic Motivation and Sales Performance

ERIC Educational Resources Information Center

Bodla, Mahmood A.; Naeem, Basharat

2014-01-01

Substantial theoretical and empirical literature indicates inconsistent performance implications of intrinsic motivation, suggesting the possibility of some explanatory mechanisms. However, little is known about the factors that might explain intrinsic motivation and sales force performance relation, particularly in highly competitive and…

The Emerging Neuroscience of Intrinsic Motivation: A New Frontier in Self-Determination Research

PubMed Central

Di Domenico, Stefano I.; Ryan, Richard M.

2017-01-01

Intrinsic motivation refers to people’s spontaneous tendencies to be curious and interested, to seek out challenges and to exercise and develop their skills and knowledge, even in the absence of operationally separable rewards. Over the past four decades, experimental and field research guided by self-determination theory (SDT; Ryan and Deci, 2017) has found intrinsic motivation to predict enhanced learning, performance, creativity, optimal development and psychological wellness. Only recently, however, have studies begun to examine the neurobiological substrates of intrinsic motivation. In the present article, we trace the history of intrinsic motivation research, compare and contrast intrinsic motivation to closely related topics (flow, curiosity, trait plasticity), link intrinsic motivation to key findings in the comparative affective neurosciences, and review burgeoning neuroscience research on intrinsic motivation. We review converging evidence suggesting that intrinsically motivated exploratory and mastery behaviors are phylogenetically ancient tendencies that are subserved by dopaminergic systems. Studies also suggest that intrinsic motivation is associated with patterns of activity across large-scale neural networks, namely, those that support salience detection, attentional control and self-referential cognition. We suggest novel research directions and offer recommendations for the application of neuroscience methods in the study of intrinsic motivation. PMID:28392765

The Emerging Neuroscience of Intrinsic Motivation: A New Frontier in Self-Determination Research.

PubMed

Di Domenico, Stefano I; Ryan, Richard M

2017-01-01

Intrinsic motivation refers to people's spontaneous tendencies to be curious and interested, to seek out challenges and to exercise and develop their skills and knowledge, even in the absence of operationally separable rewards. Over the past four decades, experimental and field research guided by self-determination theory (SDT; Ryan and Deci, 2017) has found intrinsic motivation to predict enhanced learning, performance, creativity, optimal development and psychological wellness. Only recently, however, have studies begun to examine the neurobiological substrates of intrinsic motivation. In the present article, we trace the history of intrinsic motivation research, compare and contrast intrinsic motivation to closely related topics (flow, curiosity, trait plasticity), link intrinsic motivation to key findings in the comparative affective neurosciences, and review burgeoning neuroscience research on intrinsic motivation. We review converging evidence suggesting that intrinsically motivated exploratory and mastery behaviors are phylogenetically ancient tendencies that are subserved by dopaminergic systems. Studies also suggest that intrinsic motivation is associated with patterns of activity across large-scale neural networks, namely, those that support salience detection, attentional control and self-referential cognition. We suggest novel research directions and offer recommendations for the application of neuroscience methods in the study of intrinsic motivation.

Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains

DOE PAGES

Kuang, Youdi; Lindsay, Lucas R.; Huang, Baoling

2015-01-01

High basal plane thermal conductivity k of multi-layer graphene makes it promising for thermal management applications. Here we examine the effects of tensile strain on thermal transport in this system. Using a first principles Boltzmann-Peierls equation for phonon transport approach, we calculate the room-temperature in-plane lattice k of multi-layer graphene (up to four layers) and graphite under different isotropic tensile strains. The calculated in-plane k of graphite, finite mono-layer graphene and 3-layer graphene agree well with previous experiments. The dimensional transitions of the intrinsic k and the extent of the diffusive transport regime from mono-layer graphene to graphite are presented.more » We find a peak enhancement of intrinsic k for multi-layer graphene and graphite with increasing strain and the largest enhancement amplitude is about 40%. In contrast the calculated intrinsic k with tensile strain decreases for diamond and diverges for graphene, we show that the competition between the decreased mode heat capacities and the increased lifetimes of flexural phonons with increasing strain contribute to this k behavior. Similar k behavior is observed for 2-layer hexagonal boron nitride systems, suggesting that it is an inherent thermal transport property in multi-layer systems assembled of purely two dimensional atomic layers. This study provides insights into engineering k of multi-layer graphene and boron nitride by strain and into the nature of thermal transport in quasi-two-dimensional and highly anisotropic systems.« less

The Roles for Prior Visual Experience and Age on the Extraction of Egocentric Distance.

PubMed

Wallin, Courtney P; Gajewski, Daniel A; Teplitz, Rebeca W; Mihelic Jaidzeka, Sandra; Philbeck, John W

2017-01-01

In a well-lit room, observers can generate well-constrained estimates of the distance to an object on the floor even with just a fleeting glimpse. Performance under these conditions is typically characterized by some underestimation but improves when observers have previewed the room. Such evidence suggests that information extracted from longer durations may be stored to contribute to the perception of distance at limited time frames. Here, we examined the possibility that this stored information is used differentially across age. Specifically, we posited that older adults would rely more than younger adults on information gathered and stored at longer glimpses to judge the distance of briefly glimpsed objects. We collected distance judgments from younger and older adults after brief target glimpses. Half of the participants were provided 20-s previews of the testing room in advance; the other half received no preview. Performance benefits were observed for all individuals with prior visual experience, and these were moderately more pronounced for the older adults. The results suggest that observers store contextual information gained from longer viewing durations to aid in the perception of distance at brief glimpses, and that this memory becomes more important with age. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Extrinsic and Intrinsic Motivation at 30: Unresolved Scientific Issues

ERIC Educational Resources Information Center

Reiss, Steven

2005-01-01

The undermining effect of extrinsic reward on intrinsic motivation remains unproven. The key unresolved issues are construct invalidity (all four definitions are unproved and two are illogical); measurement unreliability (the free-choice measure requires unreliable, subjective judgments to infer intrinsic motivation); inadequate experimental…

Clozapine and olanzapine but not risperidone impair the pre-frontal striatal system in relation to egocentric spatial orientation in a Y-maze.

PubMed

Castro, Cibele Canal; Dos Reis-Lunardelli, Eleonora Araujo; Schmidt, Werner J; Coitinho, Adriana Simon; Izquierdo, Iván

2007-11-01

Many studies indicate a dissociation between two forms of orientation: allocentric orientation, in which an organism orients on the basis of cues external to the organism, and egocentric spatial orientation (ESO) by which an organism orients on the basis of proprioceptive information. While allocentric orientation is mediated primarily by the hippocampus and its afferent and efferent connections, ESO is mediated by the prefronto-striatal system. Striatal lesions as well as classical neuroleptics, which block dopamine receptors, act through the prefronto-striatal system and impair ESO. The purpose of the present study was to determine the effects of the atypical antipsychotics clozapine, olanzapine and risperidone which are believed to exert its antipsychotic effects mainly by dopaminergic, cholinergic and serotonergic mechanisms. A delayed-two-alternative-choice-task, under conditions that required ESO and at the same time excluded allocentric spatial orientation was used. Clozapine and olanzapine treated rats made more errors than risperidone treated rats in the delayed alternation in comparison with the controls. Motor abilities were not impaired by any of the drugs. Thus, with regard to the delayed alternation requiring ESO, clozapine and olanzapine but not risperidone affects the prefronto-striatal system in a similar way as classical neuroleptics does.

Flexible spatial perspective-taking: conversational partners weigh multiple cues in collaborative tasks

PubMed Central

Galati, Alexia; Avraamides, Marios N.

2013-01-01

Research on spatial perspective-taking often focuses on the cognitive processes of isolated individuals as they adopt or maintain imagined perspectives. Collaborative studies of spatial perspective-taking typically examine speakers' linguistic choices, while overlooking their underlying processes and representations. We review evidence from two collaborative experiments that examine the contribution of social and representational cues to spatial perspective choices in both language and the organization of spatial memory. Across experiments, speakers organized their memory representations according to the convergence of various cues. When layouts were randomly configured and did not afford intrinsic cues, speakers encoded their partner's viewpoint in memory, if available, but did not use it as an organizing direction. On the other hand, when the layout afforded an intrinsic structure, speakers organized their spatial memories according to the person-centered perspective reinforced by the layout's structure. Similarly, in descriptions, speakers considered multiple cues whether available a priori or at the interaction. They used partner-centered expressions more frequently (e.g., “to your right”) when the partner's viewpoint was misaligned by a small offset or coincided with the layout's structure. Conversely, they used egocentric expressions more frequently when their own viewpoint coincided with the intrinsic structure or when the partner was misaligned by a computationally difficult, oblique offset. Based on these findings we advocate for a framework for flexible perspective-taking: people weigh multiple cues (including social ones) to make attributions about the relative difficulty of perspective-taking for each partner, and adapt behavior to minimize their collective effort. This framework is not specialized for spatial reasoning but instead emerges from the same principles and memory-depended processes that govern perspective-taking in non-spatial tasks

Direct measurement of the intrinsic ankle stiffness during standing.

PubMed

Vlutters, M; Boonstra, T A; Schouten, A C; van der Kooij, H

2015-05-01

Ankle stiffness contributes to standing balance, counteracting the destabilizing effect of gravity. The ankle stiffness together with the compliance between the foot and the support surface make up the ankle-foot stiffness, which is relevant to quiet standing. The contribution of the intrinsic ankle-foot stiffness to balance, and the ankle-foot stiffness amplitude dependency remain a topic of debate in the literature. We therefore developed an experimental protocol to directly measure the bilateral intrinsic ankle-foot stiffness during standing balance, and determine its amplitude dependency. By applying fast (40 ms) ramp-and-hold support surface rotations (0.005-0.08 rad) during standing, reflexive contributions could be excluded, and the amplitude dependency of the intrinsic ankle-foot stiffness was investigated. Results showed that reflexive activity could not have biased the torque used for estimating the intrinsic stiffness. Furthermore, subjects required less recovery action to restore balance after bilateral rotations in opposite directions compared to rotations in the same direction. The intrinsic ankle-foot stiffness appears insufficient to ensure balance, ranging from 0.93±0.09 to 0.44±0.06 (normalized to critical stiffness 'mgh'). This implies that changes in muscle activation are required to maintain balance. The non-linear stiffness decrease with increasing rotation amplitude supports the previous published research. With the proposed method reflexive effects can be ruled out from the measured torque without any model assumptions, allowing direct estimation of intrinsic stiffness during standing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functions of intrinsic disorder in transmembrane proteins.

PubMed

Kjaergaard, Magnus; Kragelund, Birthe B

2017-09-01

Intrinsic disorder is common in integral membrane proteins, particularly in the intracellular domains. Despite this observation, these domains are not always recognized as being disordered. In this review, we will discuss the biological functions of intrinsically disordered regions of membrane proteins, and address why the flexibility afforded by disorder is mechanistically important. Intrinsically disordered regions are present in many common classes of membrane proteins including ion channels and transporters; G-protein coupled receptors (GPCRs), receptor tyrosine kinases and cytokine receptors. The functions of the disordered regions are many and varied. We will discuss selected examples including: (1) Organization of receptors, kinases, phosphatases and second messenger sources into signaling complexes. (2) Modulation of the membrane-embedded domain function by ball-and-chain like mechanisms. (3) Trafficking of membrane proteins. (4) Transient membrane associations. (5) Post-translational modifications most notably phosphorylation and (6) disorder-linked isoform dependent function. We finish the review by discussing the future challenges facing the membrane protein community regarding protein disorder.

COMPENSATION FOR VARIABLE INTRINSIC NEURONAL EXCITABILITY BY CIRCUIT-SYNAPTIC INTERACTIONS

PubMed Central

Grashow, Rachel; Brookings, Ted; Marder, Eve

2010-01-01

Recent theoretical and experimental work indicates that neurons tune themselves to maintain target levels of excitation by modulating ion channel expression and synaptic strengths. As a result, functionally equivalent circuits can produce similar activity despite disparate underlying network and cellular properties. To experimentally test the extent to which synaptic and intrinsic conductances can produce target activity in the presence of variability in neuronal intrinsic properties, we used the dynamic clamp to create hybrid two-cell circuits built from four types of stomatogastric (STG) neurons coupled to the same model Morris-Lecar neuron by reciprocal inhibition. We measured six intrinsic properties (input resistance, minimum membrane potential, firing rate in response to +1nA of injected current, slope of the FI curve, spike height and spike voltage threshold) of Dorsal Gastric (DG), Gastric Mill (GM), Lateral Pyloric (LP) and Pyloric Dilator (PD) neurons from male crabs, Cancer borealis. The intrinsic properties varied two to seven-fold in each cell type. We coupled each biological neuron to the Morris-Lecar model with seven different values of inhibitory synaptic conductance, and also used the dynamic clamp to add seven different values of an artificial h-conductance, thus creating 49 different circuits for each biological neuron. Despite the variability in intrinsic excitability, networks formed from each neuron produced similar circuit performance at some values of synaptic and h-conductances. This work experimentally confirms results from previous modeling studies; tuning synaptic and intrinsic conductances can yield similar circuit output from neurons with variable intrinsic excitability. PMID:20610748

Intrinsic two-dimensional states on the pristine surface of tellurium

NASA Astrophysics Data System (ADS)

Li, Pengke; Appelbaum, Ian

2018-05-01

Atomic chains configured in a helical geometry have fascinating properties, including phases hosting localized bound states in their electronic structure. We show how the zero-dimensional state—bound to the edge of a single one-dimensional helical chain of tellurium atoms—evolves into two-dimensional bands on the c -axis surface of the three-dimensional trigonal bulk. We give an effective Hamiltonian description of its dispersion in k space by exploiting confinement to a virtual bilayer, and elaborate on the diminished role of spin-orbit coupling. These intrinsic gap-penetrating surface bands were neglected in the interpretation of seminal experiments, where two-dimensional transport was otherwise attributed to extrinsic accumulation layers.

Selection for intrinsic endurance modifies endocrine stress responsiveness

PubMed Central

Waters, R Parrish; Renner, Kenneth J; Summers, Cliff H; Watt, Michael L; Forster, Gina L; Koch, Lauren G; Britton, Steven L; Swallow, John G

2010-01-01

Physical exercise dampens an individual’s stress response and decreases symptoms of anxiety and depression disorders. While the extrinsic relationship of exercise and psychological state are established, their intrinsic relationship is unresolved. We investigated the potential intrinsic relationship of exercise with stress responsiveness using NIH rats bidirectionally selected for intrinsic endurance capacity. Selection resulted in two populations, one with high intrinsic endurance (high capacity runners; HCR) and one with low intrinsic endurance (low capacity runners; LCR). Animals from these populations were subjected to the elevated plus maze (EPM) and novel environment to assess levels of anxiety-like behavior, and to restraint stress to determine stress responsiveness. Pre-test plasma corticosterone levels and the response of plasma corticosterone to exposure to the EPM and restraint were analyzed using ELISA. A dexamethasone suppression test was performed to assess negative feedback tone of corticosterone release. Pre-test plasma corticosterone levels were similar between LCR and HCR, and these populations had similar behavioral and corticosterone responses to the EPM. Following restraint, HCR animals exhibited more anxiotypic behavior than LCR animals on the EPM, and exhibited an increase in plasma corticosterone following EPM and restraint that was not observed in LCR animals. HCR animals also exhibited more anxiotypic behavior in the novel environment compared to LCR animals. Plasma corticosterone levels were equally reduced in both populations following dexamethasone administration. Overall, our data suggest a positive genetic relationship between exercise endurance and stress responsiveness, which is at odds with the established extrinsic relationship of these traits. PMID:20682296

Mechanical signals at the base of a rat vibrissa: the effect of intrinsic vibrissa curvature and implications for tactile exploration

PubMed Central

Quist, Brian W.

2012-01-01

Rats actively tap and sweep their large mystacial vibrissae (whiskers) against objects to tactually explore their surroundings. When a vibrissa makes contact with an object, it bends, and this bending generates forces and bending moments at the vibrissa base. Researchers have only recently begun to quantify these mechanical variables. The present study quantifies the forces and bending moments at the vibrissa base with a quasi-static model of vibrissa deflection. The model was validated with experiments on real vibrissae. Initial simulations demonstrated that almost all vibrissa-object collisions during natural behavior will occur with the concave side of the vibrissa facing the object, and we therefore paid particular attention to the role of the vibrissa's intrinsic curvature in shaping the forces at the base. Both simulations and experiments showed that vibrissae with larger intrinsic curvatures will generate larger axial forces. Simulations also demonstrated that the range of forces and moments at the vibrissal base vary over approximately three orders of magnitude, depending on the location along the vibrissa at which object contact is made. Both simulations and experiments demonstrated that collisions in which the concave side of the vibrissa faces the object generate longer-duration contacts and larger net forces than collisions with the convex side. These results suggest that the orientation of the vibrissa's intrinsic curvature on the mystacial pad may increase forces during object contact and provide increased sensitivity to detailed surface features. PMID:22298834

What is Intrinsic Motivation? A Typology of Computational Approaches

PubMed Central

Oudeyer, Pierre-Yves; Kaplan, Frederic

2007-01-01

Intrinsic motivation, centrally involved in spontaneous exploration and curiosity, is a crucial concept in developmental psychology. It has been argued to be a crucial mechanism for open-ended cognitive development in humans, and as such has gathered a growing interest from developmental roboticists in the recent years. The goal of this paper is threefold. First, it provides a synthesis of the different approaches of intrinsic motivation in psychology. Second, by interpreting these approaches in a computational reinforcement learning framework, we argue that they are not operational and even sometimes inconsistent. Third, we set the ground for a systematic operational study of intrinsic motivation by presenting a formal typology of possible computational approaches. This typology is partly based on existing computational models, but also presents new ways of conceptualizing intrinsic motivation. We argue that this kind of computational typology might be useful for opening new avenues for research both in psychology and developmental robotics. PMID:18958277

Differential effects of non-informative vision and visual interference on haptic spatial processing

PubMed Central

van Rheede, Joram J.; Postma, Albert; Kappers, Astrid M. L.

2008-01-01

The primary purpose of this study was to examine the effects of non-informative vision and visual interference upon haptic spatial processing, which supposedly derives from an interaction between an allocentric and egocentric reference frame. To this end, a haptic parallelity task served as baseline to determine the participant-dependent biasing influence of the egocentric reference frame. As expected, large systematic participant-dependent deviations from veridicality were observed. In the second experiment we probed the effect of non-informative vision on the egocentric bias. Moreover, orienting mechanisms (gazing directions) were studied with respect to the presentation of haptic information in a specific hemispace. Non-informative vision proved to have a beneficial effect on haptic spatial processing. No effect of gazing direction or hemispace was observed. In the third experiment we investigated the effect of simultaneously presented interfering visual information on the haptic bias. Interfering visual information parametrically influenced haptic performance. The interplay of reference frames that subserves haptic spatial processing was found to be related to both the effects of non-informative vision and visual interference. These results suggest that spatial representations are influenced by direct cross-modal interactions; inter-participant differences in the haptic modality resulted in differential effects of the visual modality. PMID:18553074

Diffuse intrinsic pontine glioma in children and adolescents: a single-center experience.

PubMed

Vallero, Stefano Gabriele; Bertin, Daniele; Basso, Maria Eleonora; Pittana, Laura Stefania; Mussano, Anna; Fagioli, Franca

2014-06-01

Patients with diffuse intrinsic pontine glioma (DIPG) have a very poor prognosis. Only radiotherapy (XRT) has proven to be effective in delaying the disease progression. Several chemotherapy schedules have been applied so far, but none demonstrated significant improvements in progression and survival. We retrospectively analyzed the clinical data of children diagnosed with DIPG at our center (Pediatric Hospital "Regina Margherita," Turin, Italy) between 1999 and 2013. Progression-free survival (PFS) and overall survival (OS) were used to describe the outcomes. Twenty-four children were included in our report. Patients diagnosed before March 2003 (n = 12) were treated with XRT and vincristine (VCR); the remaining 12 patients received XRT and temozolomide (TMZ). Progression-free survival was 18.8 % at 1 year (SE = 7.6 %), while overall survival was 44.1 % at 1 year (SE = 9.9 %). Median PFS was 8.1 months, whereas median OS was 11.2 months. No statistically significant difference in PFS or OS was evidenced between the two treatment groups. Radiotherapy followed by VCR or TMZ allows obtaining results that are in line with previous reports, with no advantages over other similar treatment schedules. DIPGs are challenging tumors with a dismal outcome. Further research and newer therapies are urgently needed in order to achieve improvements in survival.

Functional anthology of intrinsic disorder. 3. Ligands, post-translational modifications, and diseases associated with intrinsically disordered proteins.

PubMed

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

2007-05-01

Currently, the understanding of the relationships between function, amino acid sequence, and protein structure continues to represent one of the major challenges of the modern protein science. As many as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bionformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200 000 proteins from the Swiss-Prot database, each annotated with at least one of the 875 functional keywords, was described in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V.N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Using this tool, we have found that out of the 710 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (see above). The second paper of the series was

Intrinsic and Extrinsic Motivation for Stereotypic and Repetitive Behavior

ERIC Educational Resources Information Center

Joosten, Annette V.; Bundy, Anita C.; Einfeld, Stewart L.

2009-01-01

This study provides evidence for intrinsic and extrinsic motivators for stereotypical and repetitive behavior in children with autism and intellectual disability and children with intellectual disability alone. We modified the Motivation Assessment Scale (MAS) (1988b); dividing it into intrinsic and extrinsic measures and adding items to assess…

College Student Intrinsic and/or Extrinsic Motivation and Learning.

ERIC Educational Resources Information Center

Lin, Yi-Guang; McKeachie, Wilbert J.

This paper investigates the joint effects of intrinsic and extrinsic goals on college students' learning in an introductory psychology course, a biology course, and several social science courses. The study questioned whether higher levels of motivation lead to better student performance. College students were surveyed using the Intrinsic Goal…

Gameplay as a Source of Intrinsic Motivation in a Randomized Controlled Trial of Auditory Training for Tinnitus

PubMed Central

Hoare, Derek J.; Van Labeke, Nicolas; McCormack, Abby; Sereda, Magdalena; Smith, Sandra; Taher, Hala Al; Kowalkowski, Victoria L.; Sharples, Mike; Hall, Deborah A.

2014-01-01

Background Previous studies of frequency discrimination training (FDT) for tinnitus used repetitive task-based training programmes relying on extrinsic factors to motivate participation. Studies reported limited improvement in tinnitus symptoms. Purpose To evaluate FDT exploiting intrinsic motivations by integrating training with computer-gameplay. Methods Sixty participants were randomly assigned to train on either a conventional task-based training, or one of two interactive game-based training platforms over six weeks. Outcomes included assessment of motivation, tinnitus handicap, and performance on tests of attention. Results Participants reported greater intrinsic motivation to train on the interactive game-based platforms, yet compliance of all three groups was similar (∼70%) and changes in self-reported tinnitus severity were not significant. There was no difference between groups in terms of change in tinnitus severity or performance on measures of attention. Conclusion FDT can be integrated within an intrinsically motivating game. Whilst this may improve participant experience, in this instance it did not translate to additional compliance or therapeutic benefit. Trial Registration ClinicalTrials.gov NCT02095262 PMID:25215617

Intrinsic cardiac nervous system in tachycardia induced heart failure.

PubMed

Arora, Rakesh C; Cardinal, Rene; Smith, Frank M; Ardell, Jeffrey L; Dell'Italia, Louis J; Armour, J Andrew

2003-11-01

The purpose of this study was to test the hypothesis that early-stage heart failure differentially affects the intrinsic cardiac nervous system's capacity to regulate cardiac function. After 2 wk of rapid ventricular pacing in nine anesthetized canines, cardiac and right atrial neuronal function were evaluated in situ in response to enhanced cardiac sensory inputs, stimulation of extracardiac autonomic efferent neuronal inputs, and close coronary arterial administration of neurochemicals that included nicotine. Right atrial neuronal intracellular electrophysiological properties were then evaluated in vitro in response to synaptic activation and nicotine. Intrinsic cardiac nicotine-sensitive, neuronally induced cardiac responses were also evaluated in eight sham-operated, unpaced animals. Two weeks of rapid ventricular pacing reduced the cardiac index by 54%. Intrinsic cardiac neurons of paced hearts maintained their cardiac mechano- and chemosensory transduction properties in vivo. They also responded normally to sympathetic and parasympathetic preganglionic efferent neuronal inputs, as well as to locally administered alpha-or beta-adrenergic agonists or angiotensin II. The dose of nicotine needed to modify intrinsic cardiac neurons was 50 times greater in failure compared with normal preparations. That dose failed to alter monitored cardiovascular indexes in failing preparations. Phasic and accommodating neurons identified in vitro displayed altered intracellular membrane properties compared with control, including decreased membrane resistance, indicative of reduced excitability. Early-stage heart failure differentially affects the intrinsic cardiac nervous system's capacity to regulate cardiodynamics. While maintaining its capacity to transduce cardiac mechano- and chemosensory inputs, as well as inputs from extracardiac autonomic efferent neurons, intrinsic cardiac nicotine-sensitive, local-circuit neurons differentially remodel such that their capacity to

Extrinsic and intrinsic blood supply to the optic chiasm.

PubMed

Salaud, Céline; Ploteau, Stéphane; Blery, Pauline; Pilet, Paul; Armstrong, Olivier; Hamel, Antoine

2018-04-01

Although there have been many studies of the arterial cerebral blood supply, only seven have described the optic chiasm (OC) blood supply and their results are contradictory. The aim of this study was to analyze the extrinsic and intrinsic OC blood supply on cadaveric specimens using dissections and microcomputer tomography (Micro-CT). Thirteen human specimens were dissected and the internal or common carotid arteries were injected with red latex, China Ink with gelatin or barium sulfate. Three Micro-CTs were obtained to reveal the intrinsic blood supply to the OC. The superior hypophyseal arteries (SupHypA) (13/13) and posterior communicating artery (PCoA) (12/13) supplied the pial network on the inferior side of the OC. The first segment of the anterior cerebral artery (ACA) (10/10), SupHypA (7/10), the anterior communicating artery (ACoA) (9/10), and PComA (1/10) supplied the pial network of its superior side. The intrinsic OC blood supply was divided into three networks (two lateral and one central). Capillaries entering the OC originated principally from the inferior pial network. The lateral network capillaries had the same orientation as the visual lateral pathways, but the central network was not correlated with the nasal fibers crossing into the OC. There was no anastomosis in the pial or intrinsic networks. Only SupHypA, PCoA, ACoA, and ACA were involved in the OC blood supply. Because there was no extrinsic or intrinsic anastomosis, all arteries should be preserved. Tumor compression of the inferior intrinsic arterial network could contribute to visual defects. Clin. Anat. 31:432-440, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Insulin aggregation tracked by its intrinsic TRES

NASA Astrophysics Data System (ADS)

Chung, Li Hung C.; Birch, David J. S.; Vyshemirsky, Vladislav; Ryadnov, Maxim G.; Rolinski, Olaf J.

2017-12-01

Time-resolved emission spectra (TRES) have been used to detect conformational changes of intrinsic tyrosines within bovine insulin at a physiological pH. The approach offers the ability to detect the initial stages of insulin aggregation at the molecular level. The data analysis has revealed the existence of at least three fluorescent species undergoing dielectric relaxation and significant spectral changes due to insulin aggregation. The results indicate the suitability of the intrinsic TRES approach for insulin studies and for monitoring its stability during storage and aggregation in insulin delivery devices.

Intrinsic instability of aberration-corrected electron microscopes.

PubMed

Schramm, S M; van der Molen, S J; Tromp, R M

2012-10-19

Aberration-corrected microscopes with subatomic resolution will impact broad areas of science and technology. However, the experimentally observed lifetime of the corrected state is just a few minutes. Here we show that the corrected state is intrinsically unstable; the higher its quality, the more unstable it is. Analyzing the contrast transfer function near optimum correction, we define an "instability budget" which allows a rational trade-off between resolution and stability. Unless control systems are developed to overcome these challenges, intrinsic instability poses a fundamental limit to the resolution practically achievable in the electron microscope.

Intrinsic brain connectivity in fibromyalgia is associated with chronic pain intensity.

PubMed

Napadow, Vitaly; LaCount, Lauren; Park, Kyungmo; As-Sanie, Sawsan; Clauw, Daniel J; Harris, Richard E

2010-08-01

Fibromyalgia (FM) is considered to be the prototypical central chronic pain syndrome and is associated with widespread pain that fluctuates spontaneously. Multiple studies have demonstrated altered brain activity in these patients. The objective of this study was to investigate the degree of connectivity between multiple brain networks in patients with FM, as well as how activity in these networks correlates with the level of spontaneous pain. Resting-state functional magnetic resonance imaging (FMRI) data from 18 patients with FM and 18 age-matched healthy control subjects were analyzed using dual-regression independent components analysis, which is a data-driven approach for the identification of independent brain networks. Intrinsic, or resting-state, connectivity was evaluated in multiple brain networks: the default mode network (DMN), the executive attention network (EAN), and the medial visual network (MVN), with the MVN serving as a negative control. Spontaneous pain levels were also analyzed for covariance with intrinsic connectivity. Patients with FM had greater connectivity within the DMN and right EAN (corrected P [P(corr)] < 0.05 versus controls), and greater connectivity between the DMN and the insular cortex, which is a brain region known to process evoked pain. Furthermore, greater intensity of spontaneous pain at the time of the FMRI scan correlated with greater intrinsic connectivity between the insula and both the DMN and right EAN (P(corr) < 0.05). These findings indicate that resting brain activity within multiple networks is associated with spontaneous clinical pain in patients with FM. These findings may also have broader implications for how subjective experiences such as pain arise from a complex interplay among multiple brain networks.

Do incentives undermine intrinsic motivation? Increases in intrinsic motivation within an incentive-based intervention for people living with HIV in Tanzania

PubMed Central

Dow, William H.; Njau, Prosper F.

2018-01-01

Background Cash and in-kind incentives can improve health outcomes in various settings; however, there is concern that incentives may ‘crowd out’ intrinsic motivation to engage in beneficial behaviors. We examined this hypothesis in a randomized trial of food and cash incentives for people living with HIV infection in Tanzania. Methods We analyzed data from 469 individuals randomized to one of three study arms: standard of care, short-term cash transfers, or short-term food assistance. Eligible participants were: 1) ≥18 years old; 2) HIV-infected; 3) food insecure; and 4) initiated antiretroviral therapy (ART) ≤90 days before the study. Food or cash transfers, valued at ~$11 per month and conditional on attending clinic visits, were provided for ≤6 months. Intrinsic motivation was measured at baseline, 6, and 12 months using the autonomous motivation section of the Treatment Self-Regulation Questionnaire (TSRQ). We compared the change in TSRQ score from baseline to 6 and 12 months and the change within study arms. Results The mean intrinsic motivation score was 2.79 at baseline (range: 1–3), 2.91 at 6 months (range: 1–3), and 2.95 at 12 months (range: 2–3), which was 6 months after the incentives had ended. Among all patients, the intrinsic motivation score increased by 0.13 points at 6 months (95% CI (0.09, 0.17), Cohen’s d = 0.29) and 0.19 points at 12 months (95% CI (0.14, 0.24), Cohen’s d = 0.49). Intrinsic motivation also increased within each study group at 6 months: 0.15 points in the food arm (95% CI (0.09, 0.21), Cohen’s d = 0.37), 0.11 points in the cash arm (95% CI (0.05, 0.18), Cohen’s d = 0.25), and 0.08 points in the comparison arm (95% CI (-0.03, 0.19), Cohen’s d = 0.21); findings were similar at 12 months. Increases in motivation were statistically similar between arms at 6 and 12 months. Conclusion Intrinsic motivation for ART adherence increased significantly both overall and within the food and cash incentive arms, even

Intrinsic and Extrinsic Motivations: Classic Definitions and New Directions.

PubMed

Ryan; Deci

2000-01-01

Intrinsic and extrinsic types of motivation have been widely studied, and the distinction between them has shed important light on both developmental and educational practices. In this review we revisit the classic definitions of intrinsic and extrinsic motivation in light of contemporary research and theory. Intrinsic motivation remains an important construct, reflecting the natural human propensity to learn and assimilate. However, extrinsic motivation is argued to vary considerably in its relative autonomy and thus can either reflect external control or true self-regulation. The relations of both classes of motives to basic human needs for autonomy, competence and relatedness are discussed. Copyright 2000 Academic Press.

Comment on 'Observation of intrinsic bistability in resonant-tunneling structures'

NASA Technical Reports Server (NTRS)

Sollner, T. C. L. G.

1987-01-01

It is suggested that the intrinsic bistability observed by Goldman et al. (1987) occurred not because of charging of the well, as is claimed, but because of oscillations in the negative-resistance region. A typical I-V curve for a double-barrier resonant-tunneling (DBRT) diode which is known to be oscillating is presented. In a reply to this comment, Goldman et al. show that the series resistance (of about 100 ohms) in Sollner's sample leads to extrinsic, rather than intrinsic, bistability. It is furthermore suggested that the mere presence of an oscillation does not in itself exclude intrinsic bistability in a DBRT structure. It is also noted that the intrinsic bistability and buildup of negative charge-space in a DBRT structure well has been demonstrated experimentally by Payling et al. (1987).

Lessons with Living Harvest Mice: An Empirical Study of Their Effects on Intrinsic Motivation and Knowledge Acquisition

ERIC Educational Resources Information Center

Wilde, Matthias; Hubmann, Jona Samuel; Lorenzen, Simone; Meyer, Annika; Randler, Christoph

2012-01-01

The aim of this study was to evaluate the effects of living animals on pupils' intrinsic motivation and knowledge. Various studies from the late 1970s and 1980s stress the high effectiveness of authentic learning experiences in pupils' knowledge acquisition. However, there are only few current empirical studies on this topic. The research question…

Detecting early egocentric and allocentric impairments deficits in Alzheimer’s disease: an experimental study with virtual reality

PubMed Central

Serino, Silvia; Morganti, Francesca; Di Stefano, Fabio; Riva, Giuseppe

2015-01-01

Several studies have pointed out that egocentric and allocentric spatial impairments are one of the earliest manifestations of Alzheimer’s Disease (AD). It is less clear how a break in the continuous interaction between these two representations may be a crucial marker to detect patients who are at risk to develop dementia. The main objective of this study is to compare the performances of participants suffering from amnestic mild cognitive impairment (aMCI group), patients with AD (AD group) and a control group (CG), using a virtual reality (VR)-based procedure for assessing the abilities in encoding, storing and syncing different spatial representations. In the first task, participants were required to indicate on a real map the position of the object they had memorized, while in the second task they were invited to retrieve its position from an empty version of the same virtual room, starting from a different position. The entire procedure was repeated across three different trials, depending on the object location in the encoding phase. Our finding showed that aMCI patients performed significantly more poorly in the third trial of the first task, showing a deficit in the ability to encode and store an allocentric viewpoint independent representation. On the other hand, AD patients performed significantly more poorly when compared to the CG in the second task, indicating a specific impairment in storing an allocentric viewpoint independent representation and then syncing it with the allocentric viewpoint dependent representation. Furthermore, data suggested that these impairments are not a product of generalized cognitive decline or of general decay in spatial abilities, but instead may reflect a selective deficit in the spatial organization Overall, these findings provide an initial insight into the cognitive underpinnings of amnestic impairment in aMCI and AD patient exploiting the potentiality of VR. PMID:26042034

Utilization of protein intrinsic disorder knowledge in structural proteomics

PubMed Central

Oldfield, Christopher J.; Xue, Bin; Van, Ya-Yue; Ulrich, Eldon L.; Markley, John L.; Dunker, A. Keith; Uversky, Vladimir N.

2014-01-01

Intrinsically disordered proteins (IDPs) and proteins with long disordered regions are highly abundant in various proteomes. Despite their lack of well-defined ordered structure, these proteins and regions are frequently involved in crucial biological processes. Although in recent years these proteins have attracted the attention of many researchers, IDPs represent a significant challenge for structural characterization since these proteins can impact many of the processes in the structure determination pipeline. Here we investigate the effects of IDPs on the structure determination process and the utility of disorder prediction in selecting and improving proteins for structural characterization. Examination of the extent of intrinsic disorder in existing crystal structures found that relatively few protein crystal structures contain extensive regions of intrinsic disorder. Although intrinsic disorder is not the only cause of crystallization failures and many structured proteins cannot be crystallized, filtering out highly disordered proteins from structure-determination target lists is still likely to be cost effective. Therefore it is desirable to avoid highly disordered proteins from structure-determination target lists and we show that disorder prediction can be applied effectively to enrich structure determination pipelines with proteins more likely to yield crystal structures. For structural investigation of specific proteins, disorder prediction can be used to improve targets for structure determination. Finally, a framework for considering intrinsic disorder in the structure determination pipeline is proposed. PMID:23232152

Effects of optical blur reduction on equivalent intrinsic blur.

PubMed

Kord Valeshabad, Ali; Wanek, Justin; McAnany, J Jason; Shahidi, Mahnaz

2015-04-01

To determine the effect of optical blur reduction on equivalent intrinsic blur, an estimate of the blur within the visual system, by comparing optical and equivalent intrinsic blur before and after adaptive optics (AO) correction of wavefront error. Twelve visually normal subjects (mean [±SD] age, 31 [±12] years) participated in this study. Equivalent intrinsic blur (σint) was derived using a previously described model. Optical blur (σopt) caused by high-order aberrations was quantified by Shack-Hartmann aberrometry and minimized using AO correction of wavefront error. σopt and σint were significantly reduced and visual acuity was significantly improved after AO correction (p ≤ 0.004). Reductions in σopt and σint were linearly dependent on the values before AO correction (r ≥ 0.94, p ≤ 0.002). The reduction in σint was greater than the reduction in σopt, although it was marginally significant (p = 0.05). σint after AO correlated significantly with σint before AO (r = 0.92, p < 0.001), and the two parameters were related linearly with a slope of 0.46. Reduction in equivalent intrinsic blur was greater than the reduction in optical blur after AO correction of wavefront error. This finding implies that visual acuity in subjects with high equivalent intrinsic blur can be improved beyond that expected from the reduction in optical blur alone.

Exploring the Role of Intrinsic Nodal Activation on the Spread of Influence in Complex Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Visweswara Sathanur, Arun; Halappanavar, Mahantesh; Shi, Yi

In many complex networked systems such as online social networks, at any given time, activity originates at certain nodes and subsequently spreads on the network through influence. To model the spread of influence in such a scenario, we consider the problem of identification of influential entities in a complex network when nodal activation can happen through two different mechanisms. The first mode of activation is due mechanisms intrinsic to the node. The second mechanism is through the influence of connected neighbors. In this work, we present a simple probabilistic formulation that models such self-evolving systems where information diffusion occurs primarilymore » because of the intrinsic activity of users and the spread of activity occurs due to influence. We provide an algorithm to mine for the influential seeds in such a scenario by modifying the well-known influence maximization framework with the independent cascade diffusion model. We provide small motivating examples to provide an intuitive understanding of the effect of including the intrinsic activation mechanism. We sketch a proof of the submodularity of the influence function under the new formulation and demonstrate the same with larger graphs. We then show by means of additional experiments on a real-world twitter dataset how the formulation can be applied to real-world social media datasets. Finally we derive a computationally efficient centrality metric that takes into account, both the mechanisms of activation and provides for an accurate as well as computationally efficient alternative approach to the problem of identifying influencers under intrinsic activation.« less

Intrinsic whole number bias in humans.

PubMed

Alonso-Díaz, Santiago; Piantadosi, Steven T; Hayden, Benjamin Y; Cantlon, Jessica F

2018-06-25

Humans have great difficulty comparing quotients including fractions, proportions, and probabilities and often erroneously isolate the whole numbers of the numerators and denominators to compare them. Some have argued that the whole number bias is a compensatory strategy to deal with difficult comparisons. We examined adult humans' preferences for gambles that differed only in numerosity, and not in factors that influence their expected value (probabilities and stakes). Subjects consistently preferred gambles with more winning balls to ones with fewer, even though the probabilities were mathematically identical, replicating prior results. In a second experiment, we found that subjects accurately represented the relative probabilities of the choice options during rapid nonverbal probability judgments but nonetheless showed biases based on whole numbers. We mathematically formalized and quantitatively evaluated cognitive rules based on existing hypotheses that attempt to explain subjects' whole number biases during quotient comparisons. The results show that the whole number bias is intrinsic to the way humans solve quotient comparisons rather than a compensatory strategy. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Challenges in Determining Intrinsic Viscosity Under Low Ionic Strength Solution Conditions.

PubMed

Pindrus, Mariya A; Shire, Steven J; Yadav, Sandeep; Kalonia, Devendra S

2017-04-01

To determine the intrinsic viscosity of several monoclonal antibodies (mAbs) under varying pH and ionic strength solution conditions. An online viscosity detector attached to HPLC (Viscotek®) was used to determine the intrinsic viscosity of mAbs. The Ross and Minton equation was used for viscosity prediction at high protein concentrations. Bulk viscosity was determined by a Cambridge viscometer. At 15 mM ionic strength, intrinsic viscosity of the mAbs determined by the single-point approach varied from 5.6 to 6.4 mL/g with changes in pH. High ionic strength did not significantly alter intrinsic viscosity, while a significant increase (up to 24.0 mL/g) was observed near zero mM. No difference in bulk viscosity of mAb3 was observed around pH 6 as a function of ionic strength. Data analysis revealed that near zero mM ionic strength limitations of the single-point technique result in erroneously high intrinsic viscosity. Intrinsic viscosity is a valuable tool that can be used to model baseline viscosity at higher protein concentrations. However, it is not predictive of solution non-ideality at higher protein concentrations. Furthermore, breakdown of numerous assumptions limits the applicability of experimental techniques near zero mM ionic strength conditions. For molecules and conditions studied, the single-point approach produced reliable intrinsic viscosity results at 15 mM. However, this approach must be used with caution near zero mM ionic strength. Data analysis can be used to reveal whether determined intrinsic viscosity is reliable or erroneously high.

Intrinsic motivation as a predictor of work outcome after vocational rehabilitation in schizophrenia.

PubMed

Saperstein, Alice M; Fiszdon, Joanna M; Bell, Morris D

2011-09-01

Intrinsic motivation is a construct commonly used in explaining goal-directed behavior. In people with schizophrenia, intrinsic motivation is usually subsumed as a feature of negative symptoms or underlying neurocognitive dysfunction. A growing literature reflects an interest in defining and measuring motivational impairment in schizophrenia and in delineating the specific role of intrinsic motivation as both an independent predictor and a mediator of psychosocial functioning. This cross-sectional study examined intrinsic motivation as a predictor of vocational outcomes for 145 individuals with schizophrenia and schizoaffective disorder participating in a 6-month work rehabilitation trial. Correlation and mediation analyses examined baseline intrinsic motivation and negative symptoms in relation to work hours and work performance. Data support a significant relationship between intrinsic motivation and negative symptoms and significant correlations with outcome variables, such that lower negative symptoms and greater intrinsic motivation were associated with better work functioning. Moreover, in this sample, intrinsic motivation fully mediated the relationships between negative symptoms, work productivity, and work performance. These results have significant implications on the design of work rehabilitation interventions for people with schizophrenia and support a role for targeting intrinsic motivation directly to influence vocational functioning. Future directions for research and intervention are discussed.

Intrinsic physiological properties of rat retinal ganglion cells with a comparative analysis.

PubMed

Wong, Raymond C S; Cloherty, Shaun L; Ibbotson, Michael R; O'Brien, Brendan J

2012-10-01

Mammalian retina contains 15-20 different retinal ganglion cell (RGC) types, each of which is responsible for encoding different aspects of the visual scene. The encoding is defined by a combination of RGC synaptic inputs, the neurotransmitter systems used, and their intrinsic physiological properties. Each cell's intrinsic properties are defined by its morphology and membrane characteristics, including the complement and localization of the ion channels expressed. In this study, we examined the hypothesis that the intrinsic properties of individual RGC types are conserved among mammalian species. To do so, we measured the intrinsic properties of 16 morphologically defined rat RGC types and compared these data with cat RGC types. Our data demonstrate that in the rat different morphologically defined RGC types have distinct patterns of intrinsic properties. Variation in these properties across cell types was comparable to that found for cat RGC types. When presumed morphological homologs in rat and cat retina were compared directly, some RGC types had very similar properties. The rat A2 cell exhibited patterns of intrinsic properties nearly identical to the cat alpha cell. In contrast, rat D2 cells (ON-OFF directionally selective) had a very different pattern of intrinsic properties than the cat iota cell. Our data suggest that the intrinsic properties of RGCs with similar morphology and suspected visual function may be subject to variation due to the behavioral needs of the species.

Social categories as markers of intrinsic interpersonal obligations.

PubMed

Rhodes, Marjorie; Chalik, Lisa

2013-06-01

Social categorization is an early-developing feature of human social cognition, yet the role that social categories play in children's understanding of and predictions about human behavior has been unclear. In the studies reported here, we tested whether a foundational functional role of social categories is to mark people as intrinsically obligated to one another (e.g., obligated to protect rather than harm). In three studies, children (aged 3-9, N = 124) viewed only within-category harm as violating intrinsic obligations; in contrast, they viewed between-category harm as violating extrinsic obligations defined by explicit rules. These data indicate that children view social categories as marking patterns of intrinsic interpersonal obligations, suggesting that a key function of social categories is to support inferences about how people will relate to members of their own and other groups.

The intrinsic shape of bulges in the CALIFA survey

NASA Astrophysics Data System (ADS)

Costantin, L.; Méndez-Abreu, J.; Corsini, E. M.; Eliche-Moral, M. C.; Tapia, T.; Morelli, L.; Dalla Bontà, E.; Pizzella, A.

2018-02-01

Context. The intrinsic shape of galactic bulges in nearby galaxies provides crucial information to separate bulge types. Aims: We aim to derive accurate constraints to the intrinsic shape of bulges to provide new clues on their formation mechanisms and set new limitations for future simulations. Methods: We retrieved the intrinsic shape of a sample of CALIFA bulges using a statistical approach. Taking advantage of GalMer numerical simulations of binary mergers we estimated the reliability of the procedure. Analyzing the i-band mock images of resulting lenticular remnants, we studied the intrinsic shape of their bulges at different galaxy inclinations. Finally, we introduced a new (B/A, C/A) diagram to analyze possible correlations between the intrinsic shape and the properties of bulges. Results: We tested the method on simulated lenticular remnants, finding that for galaxies with inclinations of 25° ≤ θ ≤ 65° we can safely derive the intrinsic shape of their bulges. We found that our CALIFA bulges tend to be nearly oblate systems (66%), with a smaller fraction of prolate spheroids (19%), and triaxial ellipsoids (15%). The majority of triaxial bulges are in barred galaxies (75%). Moreover, we found that bulges with low Sérsic indices or in galaxies with low bulge-to-total luminosity ratios form a heterogeneous class of objects; additionally, bulges in late-type galaxies or in less massive galaxies have no preference for being oblate, prolate, or triaxial. On the contrary, bulges with high Sérsic index, in early-type galaxies, or in more massive galaxies are mostly oblate systems. Conclusions: We concluded that various evolutionary pathways may coexist in galaxies, with merging events and dissipative collapse being the main mechanisms driving the formation of the most massive oblate bulges and bar evolution reshaping the less massive triaxial bulges.

How Important Is Intrinsic Spirituality in Depression Care?

PubMed Central

Cooper, Lisa A; Brown, Charlotte; Thi Vu, Hong; Ford, Daniel E; Powe, Neil R

2001-01-01

We used a cross-sectional survey to compare the views of African-American and white adult primary care patients (N = 76) regarding the importance of various aspects of depression care. Patients were asked to rate the importance of 126 aspects of depression care (derived from attitudinal domains identified in focus groups) on a 5-point Likert scale. The 30 most important items came from 9 domains: 1) health professionals' interpersonal skills, 2) primary care provider recognition of depression, 3) treatment effectiveness, 4) treatment problems, 5) patient understanding about treatment, 6) intrinsic spirituality, 7) financial access, 8) life experiences, and 9) social support. African-American and white patients rated most aspects of depression care as similarly important, except that the odds of rating spirituality as extremely important for depression care were 3 times higher for African Americans than the odds for whites. PMID:11556945

Semisupervised Support Vector Machines With Tangent Space Intrinsic Manifold Regularization.

PubMed

Sun, Shiliang; Xie, Xijiong

2016-09-01

Semisupervised learning has been an active research topic in machine learning and data mining. One main reason is that labeling examples is expensive and time-consuming, while there are large numbers of unlabeled examples available in many practical problems. So far, Laplacian regularization has been widely used in semisupervised learning. In this paper, we propose a new regularization method called tangent space intrinsic manifold regularization. It is intrinsic to data manifold and favors linear functions on the manifold. Fundamental elements involved in the formulation of the regularization are local tangent space representations, which are estimated by local principal component analysis, and the connections that relate adjacent tangent spaces. Simultaneously, we explore its application to semisupervised classification and propose two new learning algorithms called tangent space intrinsic manifold regularized support vector machines (TiSVMs) and tangent space intrinsic manifold regularized twin SVMs (TiTSVMs). They effectively integrate the tangent space intrinsic manifold regularization consideration. The optimization of TiSVMs can be solved by a standard quadratic programming, while the optimization of TiTSVMs can be solved by a pair of standard quadratic programmings. The experimental results of semisupervised classification problems show the effectiveness of the proposed semisupervised learning algorithms.

Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials.

PubMed

Jin, Jia; Yu, Liping; Ma, Qingguo

2015-01-01

Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.

Tai Chi Chuan optimizes the functional organization of the intrinsic human brain architecture in older adults

PubMed Central

Wei, Gao-Xia; Dong, Hao-Ming; Yang, Zhi; Luo, Jing; Zuo, Xi-Nian

2014-01-01

Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC experts had significantly greater and more experience-dependent functional homogeneity in the right post-central gyrus (PosCG) and less functional homogeneity in the left anterior cingulate cortex (ACC) and the right dorsal lateral prefrontal cortex. Increased functional homogeneity in the PosCG was correlated with TCC experience. Intriguingly, decreases in functional homogeneity (improved functional specialization) in the left ACC and increases in functional homogeneity (improved functional integration) in the right PosCG both predicted performance gains on attention network behavior tests. These findings provide evidence for the functional plasticity of the brain’s intrinsic architecture toward optimizing locally functional organization, with great implications for understanding the effects of TCC on cognition, behavior and health in aging population. PMID:24860494

Intrinsic motivation, neurocognition and psychosocial functioning in schizophrenia: testing mediator and moderator effects.

PubMed

Nakagami, Eri; Xie, Bin; Hoe, Maanse; Brekke, John S

2008-10-01

This study examined the nature of the relationships among neurocognition, intrinsic motivation, and psychosocial functioning for persons with schizophrenia. Hypotheses concerning both mediator and moderator mechanisms were tested. 120 individuals diagnosed with schizophrenia were recruited as they entered outpatient psychosocial rehabilitation programs. Measures of psychosocial functioning and intrinsic motivation were administered at baseline. Measures of neurocognition were administered at baseline by testers blind to scores on other study variables. Data were analyzed using latent construct modeling to test for mediator and moderator effects. There were strong bivariate relationships between neurocognition, intrinsic motivation, and psychosocial functioning. The results demonstrated that intrinsic motivation strongly mediated the relationship between neurocognition and psychosocial functioning. This mediation was evidenced by: (i) the direct path from neurocognition to functional outcome no longer being statistically significant after the introduction of motivation into the model, (ii) the statistical significance of the indirect path from neurocognition through motivation to functional outcome. There was no support for the two moderation hypotheses: the level of neurocognition did not influence the relationship between intrinsic motivation and psychosocial functioning, nor did the level of intrinsic motivation influence the relationship between neurocognition and psychosocial functioning. Neurocognition influences psychosocial functioning through its relationship with intrinsic motivation. Intrinsic motivation is a critical mechanism for explaining the relationship between neurocognition and psychosocial functioning. Implications for the theoretical understanding and psychosocial treatment of intrinsic motivation in schizophrenia are discussed.

BRIDGE21--Exploring the Potential to Foster Intrinsic Student Motivation through a Team-Based, Technology-Mediated Learning Model

ERIC Educational Resources Information Center

Lawlor, John; Marshall, Kevin; Tangney, Brendan

2016-01-01

It is generally accepted that intrinsic student motivation is a critical requirement for effective learning but formal learning in school places a huge reliance on extrinsic motivation to focus the learner. This reliance on extrinsic motivation is driven by the pressure on formal schooling to "deliver to the test." The experience of the…

Intrinsic incompatibilities evolving as a by-product of divergent ecological selection: Considering them in empirical studies on divergence with gene flow.

PubMed

Kulmuni, J; Westram, A M

2017-06-01

The possibility of intrinsic barriers to gene flow is often neglected in empirical research on local adaptation and speciation with gene flow, for example when interpreting patterns observed in genome scans. However, we draw attention to the fact that, even with gene flow, divergent ecological selection may generate intrinsic barriers involving both ecologically selected and other interacting loci. Mechanistically, the link between the two types of barriers may be generated by genes that have multiple functions (i.e., pleiotropy), and/or by gene interaction networks. Because most genes function in complex networks, and their evolution is not independent of other genes, changes evolving in response to ecological selection can generate intrinsic barriers as a by-product. A crucial question is to what extent such by-product barriers contribute to divergence and speciation-that is whether they stably reduce gene flow. We discuss under which conditions by-product barriers may increase isolation. However, we also highlight that, depending on the conditions (e.g., the amount of gene flow and the strength of selection acting on the intrinsic vs. the ecological barrier component), the intrinsic incompatibility may actually destabilize barriers to gene flow. In practice, intrinsic barriers generated as a by-product of divergent ecological selection may generate peaks in genome scans that cannot easily be interpreted. We argue that empirical studies on divergence with gene flow should consider the possibility of both ecological and intrinsic barriers. Future progress will likely come from work combining population genomic studies, experiments quantifying fitness and molecular studies on protein function and interactions. © 2017 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

The influence of visual and vestibular orientation cues in a clock reading task.

PubMed

Davidenko, Nicolas; Cheong, Yeram; Waterman, Amanda; Smith, Jacob; Anderson, Barrett; Harmon, Sarah

2018-05-23

We investigated how performance in the real-life perceptual task of analog clock reading is influenced by the clock's orientation with respect to egocentric, gravitational, and visual-environmental reference frames. In Experiment 1, we designed a simple clock-reading task and found that observers' reaction time to correctly tell the time depends systematically on the clock's orientation. In Experiment 2, we dissociated egocentric from environmental reference frames by having participants sit upright or lie sideways while performing the task. We found that both reference frames substantially contribute to response times in this task. In Experiment 3, we placed upright or rotated participants in an upright or rotated immersive virtual environment, which allowed us to further dissociate vestibular from visual cues to the environmental reference frame. We found evidence of environmental reference frame effects only when visual and vestibular cues were aligned. We discuss the implications for the design of remote and head-mounted displays. Copyright © 2018 Elsevier Inc. All rights reserved.

Anomalous Ion Heating, Intrinsic and Induced Rotation in the Pegasus Toroidal Experiment

NASA Astrophysics Data System (ADS)

Burke, M. G.; Barr, J. L.; Bongard, M. W.; Fonck, R. J.; Hinson, E. T.; Perry, J. M.; Redd, A. J.; Thome, K. E.

2014-10-01

Pegasus plasmas are initiated through either standard, MHD stable, inductive current drive or non-solenoidal local helicity injection (LHI) current drive with strong reconnection activity, providing a rich environment to study ion dynamics. During LHI discharges, a large amount of anomalous impurity ion heating has been observed, with Ti ~ 800 eV but Te < 100 eV. The ion heating is hypothesized to be a result of large-scale magnetic reconnection activity, as the amount of heating scales with increasing fluctuation amplitude of the dominant, edge localized, n = 1 MHD mode. Chordal Ti spatial profiles indicate centrally peaked temperatures, suggesting a region of good confinement near the plasma core surrounded by a stochastic region. LHI plasmas are observed to rotate, perhaps due to an inward radial current generated by the stochastization of the plasma edge by the injected current streams. H-mode plasmas are initiated using a combination of high-field side fueling and Ohmic current drive. This regime shows a significant increase in rotation shear compared to L-mode plasmas. In addition, these plasmas have been observed to rotate in the counter-Ip direction without any external momentum sources. The intrinsic rotation direction is consistent with predictions from the saturated Ohmic confinement regime. Work supported by US DOE Grant DE-FG02-96ER54375.

Effects of Optical Blur Reduction on Equivalent Intrinsic Blur

PubMed Central

Valeshabad, Ali Kord; Wanek, Justin; McAnany, J. Jason; Shahidi, Mahnaz

2015-01-01

Purpose To determine the effect of optical blur reduction on equivalent intrinsic blur, an estimate of the blur within the visual system, by comparing optical and equivalent intrinsic blur before and after adaptive optics (AO) correction of wavefront error. Methods Twelve visually normal individuals (age; 31 ± 12 years) participated in this study. Equivalent intrinsic blur (σint) was derived using a previously described model. Optical blur (σopt) due to high-order aberrations was quantified by Shack-Hartmann aberrometry and minimized using AO correction of wavefront error. Results σopt and σint were significantly reduced and visual acuity (VA) was significantly improved after AO correction (P ≤ 0.004). Reductions in σopt and σint were linearly dependent on the values before AO correction (r ≥ 0.94, P ≤ 0.002). The reduction in σint was greater than the reduction in σopt, although it was marginally significant (P = 0.05). σint after AO correlated significantly with σint before AO (r = 0.92, P < 0.001) and the two parameters were related linearly with a slope of 0.46. Conclusions Reduction in equivalent intrinsic blur was greater than the reduction in optical blur due to AO correction of wavefront error. This finding implies that VA in subjects with high equivalent intrinsic blur can be improved beyond that expected from the reduction in optical blur alone. PMID:25785538

The Intrinsic Value of Campus Maintenance.

ERIC Educational Resources Information Center

Yeatts, G. Dewey

2003-01-01

Discusses how an emphasis on student recruitment, combined with deferred maintenance backlogs and maintenance budget cuts, suggest that further study needs to be done on the intrinsic value of campus maintenance. (EV)

The role of intrinsic motivations in attention allocation and shifting

PubMed Central

Di Nocera, Dario; Finzi, Alberto; Rossi, Silvia; Staffa, Mariacarla

2014-01-01

The concepts of attention and intrinsic motivations are of great interest within adaptive robotic systems, and can be exploited in order to guide, activate, and coordinate multiple concurrent behaviors. Attention allocation strategies represent key capabilities of human beings, which are strictly connected with action selection and execution mechanisms, while intrinsic motivations directly affect the allocation of attentional resources. In this paper we propose a model of Reinforcement Learning (RL), where both these capabilities are involved. RL is deployed to learn how to allocate attentional resources in a behavior-based robotic system, while action selection is obtained as a side effect of the resulting motivated attentional behaviors. Moreover, the influence of intrinsic motivations in attention orientation is obtained by introducing rewards associated with curiosity drives. In this way, the learning process is affected not only by goal-specific rewards, but also by intrinsic motivations. PMID:24744746

Trapped electron mode turbulence driven intrinsic rotation in Tokamak plasmas.

PubMed

Wang, W X; Hahm, T S; Ethier, S; Zakharov, L E; Diamond, P H

2011-02-25

Progress from global gyrokinetic simulations in understanding the origin of intrinsic rotation in toroidal plasmas is reported. The turbulence-driven intrinsic torque associated with nonlinear residual stress generation due to zonal flow shear induced asymmetry in the parallel wave number spectrum is shown to scale close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing experimental empirical scalings of intrinsic rotation. The origin of current scaling is found to be enhanced k(∥) symmetry breaking induced by the increased radial variation of the safety factor as the current decreases. The intrinsic torque is proportional to the pressure gradient because both turbulence intensity and zonal flow shear, which are two key ingredients for driving residual stress, increase with turbulence drive, which is R/L(T(e)) and R/L(n(e)) for the trapped electron mode. © 2011 American Physical Society

Intrinsic Motivation in Physical Education

ERIC Educational Resources Information Center

Davies, Benjamin; Nambiar, Nathan; Hemphill, Caroline; Devietti, Elizabeth; Massengale, Alexandra; McCredie, Patrick

2015-01-01

This article describes ways in which educators can use Harter's perceived competence motivation theory, the achievement goal theory, and self-determination theory to develop students' intrinsic motivation to maintain physical fitness, as demonstrated by the Sound Body Sound Mind curriculum and proven effective by the 2013 University of…

Measure of synchrony in the activity of intrinsic cardiac neurons

PubMed Central

Longpré, Jean-Philippe; Salavatian, Siamak; Beaumont, Eric; Armour, J. Andrew; Ardell, Jeffrey L.; Jacquemet, Vincent

2014-01-01

Recent multielectrode array recordings in ganglionated plexi of canine atria have opened the way to the study of population dynamics of intrinsic cardiac neurons. These data provide critical insights into the role of local processing that these ganglia play in the regulation of cardiac function. Low firing rates, marked non-stationarity, interplay with the cardiovascular and pulmonary systems and artifacts generated by myocardial activity create new constraints not present in brain recordings for which almost all neuronal analysis techniques have been developed. We adapted and extended the jitter-based synchrony index (SI) to (1) provide a robust and computationally-efficient tool for assessing the level and statistical significance of SI between cardiac neurons, (2) estimate the bias on SI resulting from neuronal activity possibly hidden in myocardial artifacts, (3) quantify the synchrony or anti-synchrony between neuronal activity and the phase in the cardiac and respiratory cycles. The method was validated on firing time series from a total of 98 individual neurons identified in 8 dog experiments. SI ranged from −0.14 to 0.66, with 23 pairs of neurons with SI>0.1. The estimated bias due to artifacts was typically < 1%. Strongly cardiovascular- and pulmonary-related neurons (SI>0.5) were found. Results support the use of jitter-based synchrony index in the context of intrinsic cardiac neurons. PMID:24621585

Cell Type-specific Intrinsic Perithreshold Oscillations in Hippocampal GABAergic Interneurons.

PubMed

Kang, Young-Jin; Lewis, Hannah Elisabeth Smashey; Young, Mason William; Govindaiah, Gubbi; Greenfield, Lazar John; Garcia-Rill, Edgar; Lee, Sang-Hun

2018-04-15

The hippocampus plays a critical role in learning, memory, and spatial processing through coordinated network activity including theta and gamma oscillations. Recent evidence suggests that hippocampal subregions (e.g., CA1) can generate these oscillations at the network level, at least in part, through GABAergic interneurons. However, it is unclear whether specific GABAergic interneurons generate intrinsic theta and/or gamma oscillations at the single-cell level. Since major types of CA1 interneurons (i.e., parvalbumin-positive basket cells (PVBCs), cannabinoid type 1 receptor-positive basket cells (CB 1 BCs), Schaffer collateral-associated cells (SCAs), neurogliaform cells and ivy cells) are thought to play key roles in network theta and gamma oscillations in the hippocampus, we tested the hypothesis that these cells generate intrinsic perithreshold oscillations at the single-cell level. We performed whole-cell patch-clamp recordings from GABAergic interneurons in the CA1 region of the mouse hippocampus in the presence of synaptic blockers to identify intrinsic perithreshold membrane potential oscillations. The majority of PVBCs (83%), but not the other interneuron subtypes, produced intrinsic perithreshold gamma oscillations if the membrane potential remained above -45 mV. In contrast, CB 1 BCs, SCAs, neurogliaform cells, ivy cells, and the remaining PVBCs (17%) produced intrinsic theta, but not gamma, oscillations. These oscillations were prevented by blockers of persistent sodium current. These data demonstrate that the major types of hippocampal interneurons produce distinct frequency bands of intrinsic perithreshold membrane oscillations. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Intrinsic DNA curvature in trypanosomes.

PubMed

Smircich, Pablo; El-Sayed, Najib M; Garat, Beatriz

2017-11-09

Trypanosoma cruzi and Trypanosoma brucei are protozoan parasites causing Chagas disease and African sleeping sickness, displaying unique features of cellular and molecular biology. Remarkably, no canonical signals for RNA polymerase II promoters, which drive protein coding genes transcription, have been identified so far. The secondary structure of DNA has long been recognized as a signal in biological processes and more recently, its involvement in transcription initiation in Leishmania was proposed. In order to study whether this feature is conserved in trypanosomatids, we undertook a genome wide search for intrinsic DNA curvature in T. cruzi and T. brucei. Using a region integrated intrinsic curvature (RIIC) scoring that we previously developed, a non-random distribution of sequence-dependent curvature was observed. High RIIC scores were found to be significantly correlated with transcription start sites in T. cruzi, which have been mapped in divergent switch regions, whereas in T. brucei, the high RIIC scores correlated with sites that have been involved not only in RNA polymerase II initiation but also in termination. In addition, we observed regions with high RIIC score presenting in-phase tracts of Adenines, in the subtelomeric regions of the T. brucei chromosomes that harbor the variable surface glycoproteins genes. In both T. cruzi and T. brucei genomes, a link between DNA conformational signals and gene expression was found. High sequence dependent curvature is associated with transcriptional regulation regions. High intrinsic curvature also occurs at the T. brucei chromosome subtelomeric regions where the recombination processes involved in the evasion of the immune host system take place. These findings underscore the relevance of indirect DNA readout in these ancient eukaryotes.

Revealing the functional neuroanatomy of intrinsic alertness using fMRI: methodological peculiarities.

PubMed

Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander T; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

2011-01-01

Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that--as a methodological artifact--left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing the

Revealing the Functional Neuroanatomy of Intrinsic Alertness Using fMRI: Methodological Peculiarities

PubMed Central

Clemens, Benjamin; Zvyagintsev, Mikhail; Sack, Alexander; Heinecke, Armin; Willmes, Klaus; Sturm, Walter

2011-01-01

Clinical observations and neuroimaging data revealed a right-hemisphere fronto-parietal-thalamic-brainstem network for intrinsic alertness, and additional left fronto-parietal activity during phasic alertness. The primary objective of this fMRI study was to map the functional neuroanatomy of intrinsic alertness as precisely as possible in healthy participants, using a novel assessment paradigm already employed in clinical settings. Both the paradigm and the experimental design were optimized to specifically assess intrinsic alertness, while at the same time controlling for sensory-motor processing. The present results suggest that the processing of intrinsic alertness is accompanied by increased activity within the brainstem, thalamus, anterior cingulate gyrus, right insula, and right parietal cortex. Additionally, we found increased activation in the left hemisphere around the middle frontal gyrus (BA 9), the insula, the supplementary motor area, and the cerebellum. Our results further suggest that rather minute aspects of the experimental design may induce aspects of phasic alertness, which in turn might lead to additional brain activation in left-frontal areas not normally involved in intrinsic alertness. Accordingly, left BA 9 activation may be related to co-activation of the phasic alertness network due to the switch between rest and task conditions functioning as an external warning cue triggering the phasic alertness network. Furthermore, activation of the intrinsic alertness network during fixation blocks due to enhanced expectancy shortly before the switch to the task block might, when subtracted from the task block, lead to diminished activation in the typical right hemisphere intrinsic alertness network. Thus, we cautiously suggest that – as a methodological artifact – left frontal activations might show up due to phasic alertness involvement and intrinsic alertness activations might be weakened due to contrasting with fixation blocks, when assessing

Immediate and delayed recall of a small-scale spatial array.

PubMed

Tlauka, Michael; Donaldson, Phillip; Bonnar, Daniel

2015-01-01

The study examined people's spatial memory of a small-scale array of objects. Earlier work has primarily relied on short-retention intervals, and to date it is not known whether performance is affected by longer intervals between learning and recall. In the present investigation, university students studied seven target objects. Recall was tested immediately after learning and after an interval of seven days. Performance was found to be similar in the immediate and delayed conditions, and the results suggested that recall was facilitated by egocentric and intrinsic cues. The findings are discussed with reference to recent investigations that have shown task parameters can influence spatial recall.

Extrinsic and intrinsic motivation at 30: Unresolved scientific issues.

PubMed

Reiss, Steven

2005-01-01

The undermining effect of extrinsic reward on intrinsic motivation remains unproven. The key unresolved issues are construct invalidity (all four definitions are unproved and two are illogical); measurement unreliability (the free-choice measure requires unreliable, subjective judgments to infer intrinsic motivation); inadequate experimental controls (negative affect and novelty, not cognitive evaluation, may explain "undermining" effects); and biased metareviews (studies with possible floor effects excluded, but those with possible ceiling effects included). Perhaps the greatest error with the undermining theory, however, is that it does not adequately recognize the multifaceted nature of intrinsic motivation (Reiss, 2004a). Advice to limit the use of applied behavior analysis based on "hidden" undermining effects is ideologically inspired and is unsupported by credible scientific evidence.

The Dispositions of Elementary School Children of Individualistic and Collectivist Cultures Who Are Intrinsically Motivated to Seek Information

ERIC Educational Resources Information Center

Crow, Sherry R.; Kastello, Lisa

2016-01-01

This paper is based on two studies conducted in Colorado Springs, Colorado, in 2008 and in Kampala, Uganda, in 2014. The basic research question addressed in both studies was: "What are the experiences in the lives of upper elementary-aged children that foster an intrinsic motivation to seek information?" The secondary question was:…

Intrinsic motivation and amotivation in first episode and prolonged psychosis.

PubMed

Luther, Lauren; Lysaker, Paul H; Firmin, Ruth L; Breier, Alan; Vohs, Jenifer L

2015-12-01

The deleterious functional implications of motivation deficits in psychosis have generated interest in examining dimensions of the construct. However, there remains a paucity of data regarding whether dimensions of motivation differ over the course of psychosis. Therefore, this study examined two motivation dimensions, trait-like intrinsic motivation, and the negative symptom of amotivation, and tested the impact of illness phase on the 1) levels of these dimensions and 2) relationship between these dimensions. Participants with first episode psychosis (FEP; n=40) and prolonged psychosis (n=66) completed clinician-rated measures of intrinsic motivation and amotivation. Analyses revealed that when controlling for group differences in gender and education, the FEP group had significantly more intrinsic motivation and lower amotivation than the prolonged psychosis group. Moreover, intrinsic motivation was negatively correlated with amotivation in both FEP and prolonged psychosis, but the magnitude of the relationship did not statistically differ between groups. These findings suggest that motivation deficits are more severe later in the course of psychosis and that low intrinsic motivation may be partially independent of amotivation in both first episode and prolonged psychosis. Clinically, these results highlight the importance of targeting motivation in early intervention services. Copyright © 2015 Elsevier B.V. All rights reserved.

The effect of homework choices on achievement and intrinsic motivation

NASA Astrophysics Data System (ADS)

Christensen, Emily Fast

The purpose of this research was to test an intervention of choices in homework on the achievement and intrinsic motivation of seventh-grade science students at a middle school. The intervention was based on concepts from the cognitive evaluation theory of Edward L. Deci and Richard M. Ryan (1985). The subjects were sixteen heterogeneous classes of seventh-grade students, who were divided among four teachers. Two randomly chosen classes from each teacher received choices in their homework and the remaining two classes of each teacher received similar homework assignments without choices. Two hypotheses were developed for this study: (1) Seventh-grade science students given choices in their homework would show an increase in intrinsic motivation as measured on a motivation orientation measure, compared to students not given choices in their homework, and (2) Seventh-grade science students given choices in their homework would show an increase in achievement on an achievement measure, compared to students not given choices in their homework. Having choices in homework did not increase intrinsic motivation or achievement. However, students who did their homework did significantly better on the posttest, and students who were more intrinsically motivated did significantly better on the posttest. Just doing the homework was important for achievement, and intrinsic motivation was linked to achievement.

Recent Progress on Stretchable Electronic Devices with Intrinsically Stretchable Components.

PubMed

Trung, Tran Quang; Lee, Nae-Eung

2017-01-01

Stretchable electronic devices with intrinsically stretchable components have significant inherent advantages, including simple fabrication processes, a high integrity of the stacked layers, and low cost in comparison with stretchable electronic devices based on non-stretchable components. The research in this field has focused on developing new intrinsically stretchable components for conductors, semiconductors, and insulators. New methodologies and fabrication processes have been developed to fabricate stretchable devices with intrinsically stretchable components. The latest successful examples of stretchable conductors for applications in interconnections, electrodes, and piezoresistive devices are reviewed here. Stretchable conductors can be used for electrode or sensor applications depending on the electrical properties of the stretchable conductors under mechanical strain. A detailed overview of the recent progress in stretchable semiconductors, stretchable insulators, and other novel stretchable materials is also given, along with a discussion of the associated technological innovations and challenges. Stretchable electronic devices with intrinsically stretchable components such as field-effect transistors (FETs), photodetectors, light-emitting diodes (LEDs), electronic skins, and energy harvesters are also described and a new strategy for development of stretchable electronic devices is discussed. Conclusions and future prospects for the development of stretchable electronic devices with intrinsically stretchable components are discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phosphorothioate oligonucleotides inhibit the intrinsic tenase complex.

PubMed

Sheehan, J P; Lan, H C

1998-09-01

Systemic administration of ISIS 2302, a 20-mer antisense phosphorothioate oligonucleotide targeting human intercellular adhesion molecule-1 mRNA, causes prolongation of plasma clotting times in both monkey and human studies. The anticoagulant effects of ISIS 2302 were investigated with both in vitro coagulation assays in human plasma and purified enzyme systems. At high oligonucleotide plasma concentrations (>100 microgram/mL), prolongation of the prothrombin and thrombin times was observed. In a thrombin time assay using purified components, high concentrations of ISIS 2302 inhibited thrombin clotting activity both by stimulating inhibition by heparin cofactor II and directly competing with fibrinogen for binding to anion binding exosite I. In contrast, low concentrations of ISIS 2302 (<100 microgram/mL) showed a selective, linear prolongation of the activated partial thromboplastin time (PTT). The rate limiting effect of 50 microgram/mL ISIS 2302, which prolonged the PTT to 1.5 times control, was identified by sequential modification of the clotting assay. Delaying addition of oligonucleotide until after contact activation failed to correct prolongation of the PTT. The calcium-dependent steps of the intrinsic pathway were individually assessed by adding sufficient activated coagulation factor to correct the PTT in plasma deficient in that specific factor. Addition of factor XIa, IXa, VIIIa, or Va failed to correct the PTT in the presence of ISIS 2302. In contrast, 0.2 nmol/L factor Xa corrected prolongation of the PTT in factor X-deficient plasma with or without oligonucleotide present. ISIS 2302 (50 microgram/mL) did not prolong a modified Russel viper venom time, suggesting no significant inhibition of prothrombinase. Thus, 50 microgram/mL ISIS 2302 prolonged the PTT by selectively inhibiting intrinsic tenase activity. ISIS 2302 showed partial inhibition of intrinsic tenase activity (to approximately 35% of control) at clinically relevant oligonucleotide

Biophysical properties of intrinsically disordered p130Cas substrate domain--implication in mechanosensing.

PubMed

Hotta, Kinya; Ranganathan, Soumya; Liu, Ruchuan; Wu, Fei; Machiyama, Hiroaki; Gao, Rong; Hirata, Hiroaki; Soni, Neelesh; Ohe, Takashi; Hogue, Christopher W V; Madhusudhan, M S; Sawada, Yasuhiro

2014-04-01

Mechanical stretch-induced tyrosine phosphorylation in the proline-rich 306-residue substrate domain (CasSD) of p130Cas (or BCAR1) has eluded an experimentally validated structural understanding. Cellular p130Cas tyrosine phosphorylation is shown to function in areas without internal actomyosin contractility, sensing force at the leading edge of cell migration. Circular dichroism shows CasSD is intrinsically disordered with dominant polyproline type II conformations. Strongly conserved in placental mammals, the proline-rich sequence exhibits a pseudo-repeat unit with variation hotspots 2-9 residues before substrate tyrosine residues. Atomic-force microscopy pulling experiments show CasSD requires minimal extension force and exhibits infrequent, random regions of weak stability. Proteolysis, light scattering and ultracentrifugation results show that a monomeric intrinsically disordered form persists for CasSD in solution with an expanded hydrodynamic radius. All-atom 3D conformer sampling with the TraDES package yields ensembles in agreement with experiment when coil-biased sampling is used, matching the experimental radius of gyration. Increasing β-sampling propensities increases the number of prolate conformers. Combining the results, we conclude that CasSD has no stable compact structure and is unlikely to efficiently autoinhibit phosphorylation. Taking into consideration the structural propensity of CasSD and the fact that it is known to bind to LIM domains, we propose a model of how CasSD and LIM domain family of transcription factor proteins may function together to regulate phosphorylation of CasSD and effect machanosensing.

Not All Ideals are Equal: Intrinsic and Extrinsic Ideals in Relationships.

PubMed

Rodriguez, Lindsey M; Hadden, Benjamin W; Knee, C Raymond

2015-03-01

The ideal standards model suggests that greater consistency between ideal standards and actual perceptions of one's relationship predicts positive relationship evaluations; however, no research has evaluated whether this differs across types of ideals. A self-determination theory perspective was derived to test whether satisfaction of intrinsic ideals buffers the importance of extrinsic ideals. Participants (N=195) in committed relationships directly and indirectly reported the extent to which their partner met their ideal on two dimensions: intrinsic (e.g., warm, intimate) and extrinsic (e.g., attractive, successful). Relationship need fulfillment and relationship quality were also assessed. Hypotheses were largely supported, such that satisfaction of intrinsic ideals more strongly predicted relationship functioning, and satisfaction of intrinsic ideals buffered the relevance of extrinsic ideals for outcomes.

Not All Ideals are Equal: Intrinsic and Extrinsic Ideals in Relationships

PubMed Central

Rodriguez, Lindsey M.; Hadden, Benjamin W.; Knee, C. Raymond

2015-01-01

The ideal standards model suggests that greater consistency between ideal standards and actual perceptions of one’s relationship predicts positive relationship evaluations; however, no research has evaluated whether this differs across types of ideals. A self-determination theory perspective was derived to test whether satisfaction of intrinsic ideals buffers the importance of extrinsic ideals. Participants (N=195) in committed relationships directly and indirectly reported the extent to which their partner met their ideal on two dimensions: intrinsic (e.g., warm, intimate) and extrinsic (e.g., attractive, successful). Relationship need fulfillment and relationship quality were also assessed. Hypotheses were largely supported, such that satisfaction of intrinsic ideals more strongly predicted relationship functioning, and satisfaction of intrinsic ideals buffered the relevance of extrinsic ideals for outcomes. PMID:25821396

Intrinsic and extrinsic motives for originally following a sport team and team identification.

PubMed

Wann, D L; Ensor, C L; Bilyeu, J K

2001-10-01

Research indicates that both highly and lowly identified fans are more likely to be intrinsically than extrinsically motivated and that highly identified fans have a particularly strong inclination for intrinsic motivation. The current investigation was designed to extend this work by examining the relationship between level of identification and one's intrinsic and extrinsic motives for originally following a sport team. Preference for intrinsic motives for originally following a team should be highest among those high on team identification. 88 participants completed questionnaires containing the Sport Spectator Identification Scale and items assessing their intrinsic and extrinsic motives for originally identifying with a team. Analyses provided clear support for the hypotheses.

Intrinsic and extrinsic effects on image memorability.

PubMed

Bylinskii, Zoya; Isola, Phillip; Bainbridge, Constance; Torralba, Antonio; Oliva, Aude

2015-11-01

Previous studies have identified that images carry the attribute of memorability, a predictive value of whether a novel image will be later remembered or forgotten. Here we investigate the interplay between intrinsic and extrinsic factors that affect image memorability. First, we find that intrinsic differences in memorability exist at a finer-grained scale than previously documented. Second, we test two extrinsic factors: image context and observer behavior. Building on prior findings that images that are distinct with respect to their context are better remembered, we propose an information-theoretic model of image distinctiveness. Our model can automatically predict how changes in context change the memorability of natural images. In addition to context, we study a second extrinsic factor: where an observer looks while memorizing an image. It turns out that eye movements provide additional information that can predict whether or not an image will be remembered, on a trial-by-trial basis. Together, by considering both intrinsic and extrinsic effects on memorability, we arrive at a more complete and fine-grained model of image memorability than previously available. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intrinsic Viscosity of Dendrimers via Equilibrium Molecular Dynamics

NASA Astrophysics Data System (ADS)

Drew, Phil; Adolf, David

2004-03-01

Equilibrium molecular dynamics simulations of dendrimers in dilute solution have been performed using dl-poly. Analysis of the system stress tensor via the Green-Kubo formula produces the viscosity of the dendrimer solution which, when coupled with that of a solvent only system leads to the intrinsic viscosity of the dendrimer solute. Particular attention has been paid to error analysis as the auto-correlation of the stress tensor exhibits a long time tail, potentially leading to large uncertainties in the solution, and hence intrinsic, viscosities. In order to counter this effect and provide reliable statistical averaging, simulations have been run spanning very many times the longest system relaxation. Comparison is made to previous studies, using different techniques, which suggest a peak in the intrinsic viscosity of dendrimers at around generation four. Results are also presented from investigations in to the individual contributions to the system stress tensor from the solvent and the solute.

The Relations of Mothers' Controlling Vocalizations to Children's Intrinsic Motivation.

ERIC Educational Resources Information Center

Deci, Edward L.; And Others

1993-01-01

Coded maternal vocalizations during videotaped play sessions of mothers and their six- or seven-year-old children. Children's intrinsic motivation was assessed by observing children's play when they were alone in a room. Found a negative relationship between maternal controlling vocalizations and children's intrinsic motivation. (MM)

30 CFR 18.44 - Non-intrinsically safe battery-powered equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Non-intrinsically safe battery-powered... Construction and Design Requirements § 18.44 Non-intrinsically safe battery-powered equipment. (a) Battery-powered equipment shall use battery assemblies approved under Part 7 of this chapter, or battery...

30 CFR 18.44 - Non-intrinsically safe battery-powered equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Non-intrinsically safe battery-powered... Construction and Design Requirements § 18.44 Non-intrinsically safe battery-powered equipment. (a) Battery-powered equipment shall use battery assemblies approved under Part 7 of this chapter, or battery...

30 CFR 18.44 - Non-intrinsically safe battery-powered equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Non-intrinsically safe battery-powered... Construction and Design Requirements § 18.44 Non-intrinsically safe battery-powered equipment. (a) Battery-powered equipment shall use battery assemblies approved under Part 7 of this chapter, or battery...

30 CFR 18.44 - Non-intrinsically safe battery-powered equipment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Non-intrinsically safe battery-powered... Construction and Design Requirements § 18.44 Non-intrinsically safe battery-powered equipment. (a) Battery-powered equipment shall use battery assemblies approved under Part 7 of this chapter, or battery...

30 CFR 18.44 - Non-intrinsically safe battery-powered equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Non-intrinsically safe battery-powered... Construction and Design Requirements § 18.44 Non-intrinsically safe battery-powered equipment. (a) Battery-powered equipment shall use battery assemblies approved under Part 7 of this chapter, or battery...

Hot carrier-assisted intrinsic photoresponse in graphene.

PubMed

Gabor, Nathaniel M; Song, Justin C W; Ma, Qiong; Nair, Nityan L; Taychatanapat, Thiti; Watanabe, Kenji; Taniguchi, Takashi; Levitov, Leonid S; Jarillo-Herrero, Pablo

2011-11-04

We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation (of wavelength 850 nanometers) at the p-n interface leads to striking six-fold photovoltage patterns as a function of bottom- and top-gate voltages. These patterns, together with the measured spatial and density dependence of the photoresponse, provide strong evidence that nonlocal hot carrier transport, rather than the photovoltaic effect, dominates the intrinsic photoresponse in graphene. This regime, which features a long-lived and spatially distributed hot carrier population, may offer a path to hot carrier-assisted thermoelectric technologies for efficient solar energy harvesting.

Transfer of Learning Relates to Intrinsic Connectivity between Hippocampus, Ventromedial Prefrontal Cortex, and Large-Scale Networks

PubMed Central

Gerraty, Raphael T.; Davidow, Juliet Y.; Wimmer, G. Elliott; Kahn, Itamar

2014-01-01

An important aspect of adaptive learning is the ability to flexibly use past experiences to guide new decisions. When facing a new decision, some people automatically leverage previously learned associations, while others do not. This variability in transfer of learning across individuals has been demonstrated repeatedly and has important implications for understanding adaptive behavior, yet the source of these individual differences remains poorly understood. In particular, it is unknown why such variability in transfer emerges even among homogeneous groups of young healthy participants who do not vary on other learning-related measures. Here we hypothesized that individual differences in the transfer of learning could be related to relatively stable differences in intrinsic brain connectivity, which could constrain how individuals learn. To test this, we obtained a behavioral measure of memory-based transfer outside of the scanner and on a separate day acquired resting-state functional MRI images in 42 participants. We then analyzed connectivity across independent component analysis-derived brain networks during rest, and tested whether intrinsic connectivity in learning-related networks was associated with transfer. We found that individual differences in transfer were related to intrinsic connectivity between the hippocampus and the ventromedial prefrontal cortex, and between these regions and large-scale functional brain networks. Together, the findings demonstrate a novel role for intrinsic brain dynamics in flexible learning-guided behavior, both within a set of functionally specific regions known to be important for learning, as well as between these regions and the default and frontoparietal networks, which are thought to serve more general cognitive functions. PMID:25143610

Intrinsic thermodynamics of ethoxzolamide inhibitor binding to human carbonic anhydrase XIII

PubMed Central

2012-01-01

Background Human carbonic anhydrases (CAs) play crucial role in various physiological processes including carbon dioxide and hydrocarbon transport, acid homeostasis, biosynthetic reactions, and various pathological processes, especially tumor progression. Therefore, CAs are interesting targets for pharmaceutical research. The structure-activity relationships (SAR) of designed inhibitors require detailed thermodynamic and structural characterization of the binding reaction. Unfortunately, most publications list only the observed thermodynamic parameters that are significantly different from the intrinsic parameters. However, only intrinsic parameters could be used in the rational design and SAR of the novel compounds. Results Intrinsic binding parameters for several inhibitors, including ethoxzolamide, trifluoromethanesulfonamide, and acetazolamide, binding to recombinant human CA XIII isozyme were determined. The parameters were the intrinsic Gibbs free energy, enthalpy, entropy, and the heat capacity. They were determined by titration calorimetry and thermal shift assay in a wide pH and temperature range to dissect all linked protonation reaction contributions. Conclusions Precise determination of the inhibitor binding thermodynamics enabled correct intrinsic affinity and enthalpy ranking of the compounds and provided the means for SAR analysis of other rationally designed CA inhibitors. PMID:22676044

Digested disorder: Quarterly intrinsic disorder digest (January/February/March, 2013).

PubMed

Uversky, Vladimir N

2013-01-01

The current literature on intrinsically disordered proteins is blooming. A simple PubMed search for "intrinsically disordered protein OR natively unfolded protein" returns about 1,800 hits (as of June 17, 2013), with many papers published quite recently. To keep interested readers up to speed with this literature, we are starting a "Digested Disorder" project, which will encompass a series of reader's digest type of publications aiming at the objective representation of the research papers and reviews on intrinsically disordered proteins. The only two criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest covers papers published during the period of January, February and March of 2013. The papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings.

Functional Advantages of Conserved Intrinsic Disorder in RNA-Binding Proteins.

PubMed

Varadi, Mihaly; Zsolyomi, Fruzsina; Guharoy, Mainak; Tompa, Peter

2015-01-01

Proteins form large macromolecular assemblies with RNA that govern essential molecular processes. RNA-binding proteins have often been associated with conformational flexibility, yet the extent and functional implications of their intrinsic disorder have never been fully assessed. Here, through large-scale analysis of comprehensive protein sequence and structure datasets we demonstrate the prevalence of intrinsic structural disorder in RNA-binding proteins and domains. We addressed their functionality through a quantitative description of the evolutionary conservation of disordered segments involved in binding, and investigated the structural implications of flexibility in terms of conformational stability and interface formation. We conclude that the functional role of intrinsically disordered protein segments in RNA-binding is two-fold: first, these regions establish extended, conserved electrostatic interfaces with RNAs via induced fit. Second, conformational flexibility enables them to target different RNA partners, providing multi-functionality, while also ensuring specificity. These findings emphasize the functional importance of intrinsically disordered regions in RNA-binding proteins.

Intrinsically Disordered Energy Landscapes

PubMed Central

Chebaro, Yassmine; Ballard, Andrew J.; Chakraborty, Debayan; Wales, David J.

2015-01-01

Analysis of an intrinsically disordered protein (IDP) reveals an underlying multifunnel structure for the energy landscape. We suggest that such ‘intrinsically disordered’ landscapes, with a number of very different competing low-energy structures, are likely to characterise IDPs, and provide a useful way to address their properties. In particular, IDPs are present in many cellular protein interaction networks, and several questions arise regarding how they bind to partners. Are conformations resembling the bound structure selected for binding, or does further folding occur on binding the partner in a induced-fit fashion? We focus on the p53 upregulated modulator of apoptosis (PUMA) protein, which adopts an -helical conformation when bound to its partner, and is involved in the activation of apoptosis. Recent experimental evidence shows that folding is not necessary for binding, and supports an induced-fit mechanism. Using a variety of computational approaches we deduce the molecular mechanism behind the instability of the PUMA peptide as a helix in isolation. We find significant barriers between partially folded states and the helix. Our results show that the favoured conformations are molten-globule like, stabilised by charged and hydrophobic contacts, with structures resembling the bound state relatively unpopulated in equilibrium. PMID:25999294

Novel Intrinsic Ignition Method Measuring Local-Global Integration Characterizes Wakefulness and Deep Sleep.

PubMed

Deco, Gustavo; Tagliazucchi, Enzo; Laufs, Helmut; Sanjuán, Ana; Kringelbach, Morten L

2017-01-01

A precise definition of a brain state has proven elusive. Here, we introduce the novel local-global concept of intrinsic ignition characterizing the dynamical complexity of different brain states. Naturally occurring intrinsic ignition events reflect the capability of a given brain area to propagate neuronal activity to other regions, giving rise to different levels of integration. The ignitory capability of brain regions is computed by the elicited level of integration for each intrinsic ignition event in each brain region, averaged over all events. This intrinsic ignition method is shown to clearly distinguish human neuroimaging data of two fundamental brain states (wakefulness and deep sleep). Importantly, whole-brain computational modelling of this data shows that at the optimal working point is found where there is maximal variability of the intrinsic ignition across brain regions. Thus, combining whole brain models with intrinsic ignition can provide novel insights into underlying mechanisms of brain states.

Adolescents' Perceptions of Family Connectedness, Intrinsic Religiosity, and Depressed Mood

ERIC Educational Resources Information Center

Houltberg, Benjamin J.; Henry, Carolyn S.; Merten, Michael J.; Robinson, Linda C.

2011-01-01

Using a sample of 248 ninth and tenth grade students at public high schools, we examined adolescents' perceptions of family connectedness, intrinsic religiosity, and adolescents' gender in relation to depressed mood and whether intrinsic religiosity and gender moderated the association of aspects of family connectedness to adolescent depressed…

Beyond the Boost: Measuring the Intrinsic Dipole of the Cosmic Microwave Background Using the Spectral Distortions of the Monopole and Quadrupole.

PubMed

Yasini, Siavash; Pierpaoli, Elena

2017-12-01

We present a general framework for the accurate spectral modeling of the low multipoles of the cosmic microwave background (CMB) as observed in a boosted frame. In particular, we demonstrate how spectral measurements of the low multipoles can be used to separate the motion-induced dipole of the CMB from a possible intrinsic dipole component. In a moving frame, the leakage of an intrinsic dipole moment into the CMB monopole and quadrupole induces spectral distortions with distinct frequency functions that, respectively, peak at 337 and 276 GHz. The leakage into the quadrupole moment also induces a geometrical distortion to the spatial morphology of this mode. The combination of these effects can be used to lift the degeneracy between the motion-induced dipole and any intrinsic dipole that the CMB might possess. Assuming the current peculiar velocity measurements, the leakage of an intrinsic dipole with an amplitude of ΔT=30  μK into the monopole and quadrupole moments will be detectable by a PIXIE-like experiment at ∼40  nK (2.5σ) and ∼130  nK (11σ) level at their respective peak frequencies.

Quality of experience in real and virtual environments: some suggestions for the development of positive technologies.

PubMed

Gaggioli, Andrea

2012-01-01

What does one feel when one uses virtual reality? How does this experience differ from the experience associated with "real life" activities and situations? To answer these questions, we used the Experience Sampling Method (ESM), a procedure that allows researchers to investigate the daily fluctuations in the quality of experience through on-line self reports that participants fill out during daily life. The investigation consisted in one-week ESM observation (N = 42). During this week, participants underwent two virtual reality sessions: Immediately after the exposure to virtual environments, they were asked to complete a ESM report. For data analysis, experiential variables were aggregated into four dimensions: Mood, Engagement, Confidence, and Intrinsic Motivation Intrinsic Motivation. Findings showed that virtual experience is characterized by a specific configuration, which comprises significantly positive values for affective and cognitive components. In particular, positive scores of Mood suggest that participants perceived VR as an intrinsically pleasurable activity, while positive values of Engagement indicate that the use of VR and the experimental task provided valid opportunities for action and high skill investment. Furthermore, results showed that virtual experience is associated with Flow, a state of consciousness characterized by narrowed focus of attention, deep concentration, positive affect and intrinsic reward. Implications for VR research and practice are discussed.

The role of geographic and network factors in racial disparities in HIV among young men who have sex with men: An egocentric network study

PubMed Central

Mustanski, Brian; Birkett, Michelle; Kuhns, Lisa M.; Latkin, Carl A.; Muth, Stephen Q.

2014-01-01

The objective of this study was to characterize and compare individual and sexual network characteristics of Black, White, and Latino YMSM as potential drivers of racial disparities in HIV. Egocentric network interviews were conducted with 175 diverse YMSM who described 837 sex partners within 167 sexual-active egos. Sexual partner alter attributes were summarized by ego. Descriptives of ego demographics, sexual partner demographics, and network characteristics were calculated by race of the ego and compared. No racial differences were found in individual engagement in HIV risk behaviors or concurrent sexual partnership. Racial differences were found in partner characteristics, including female gender, non-gay sexual orientations, older age, and residence in a high HIV prevalence neighborhood. Racial differences in relationship characteristics included type of relationships (i.e., main partner) and strength of relationships. Network characteristics also showed differences, including sexual network density and assortativity by race. Most racial differences were in the direction of effects that would tend to increase HIV incidence among Black YMSM. These data suggest that racial disparities in HIV may be driven and/or maintained by a combination of racial differences in partner characteristics, assortativity by race, and increased sexual network density, rather than differences in individual’s HIV risk behaviors. PMID:25430501

The Role of Geographic and Network Factors in Racial Disparities in HIV Among Young Men Who have Sex with Men: An Egocentric Network Study.

PubMed

Mustanski, Brian; Birkett, Michelle; Kuhns, Lisa M; Latkin, Carl A; Muth, Stephen Q

2015-06-01

The objective of this study was to characterize and compare individual and sexual network characteristics of Black, White, and Latino young men who have sex with men (YMSM) as potential drivers of racial disparities in HIV. Egocentric network interviews were conducted with 175 diverse YMSM who described 837 sex partners within 167 sexual-active egos. Sexual partner alter attributes were summarized by ego. Descriptives of ego demographics, sexual partner demographics, and network characteristics were calculated by race of the ego and compared. No racial differences were found in individual engagement in HIV risk behaviors or concurrent sexual partnership. Racial differences were found in partner characteristics, including female gender, non-gay sexual orientations, older age, and residence in a high HIV prevalence neighborhood. Racial differences in relationship characteristics included type of relationships (i.e., main partner) and strength of relationships. Network characteristics also showed differences, including sexual network density and assortativity by race. Most racial differences were in the direction of effects that would tend to increase HIV incidence among Black YMSM. These data suggest that racial disparities in HIV may be driven and/or maintained by a combination of racial differences in partner characteristics, assortativity by race, and increased sexual network density, rather than differences in individual's HIV risk behaviors.

Intrinsic foot muscle volume in experienced runners with and without chronic plantar fasciitis.

PubMed

Cheung, R T H; Sze, L K Y; Mok, N W; Ng, G Y F

2016-09-01

Plantar fasciitis, a common injury in runners, has been speculated to be associated with weakness of the intrinsic foot muscles. A recent study reported that atrophy of the intrinsic forefoot muscles might contribute to plantar fasciitis by destabilizing the medial longitudinal arch. However, intrinsic foot muscle volume difference between individuals with plantar fasciitis and healthy counterparts remains unknown. This study examined the relationship of intrinsic foot muscle volume and incidence of plantar fasciitis. Case-control study. 20 experienced (≥5 years) runners were recruited. Ten of them had bilateral chronic (≥2 years) plantar fasciitis while the others were healthy characteristics-matched runners. Intrinsic muscle volumes of the participants' right foot were scanned with a 1.5T magnetic resonance system and segmented using established methods. Body-mass normalized intrinsic foot muscle volumes were compared between runners with and without chronic plantar fasciitis. There was significant greater rearfoot intrinsic muscle volume in healthy runners than runners with chronic plantar fasciitis (Cohen's d=1.13; p=0.023). A similar trend was also observed in the total intrinsic foot muscle volume but it did not reach a statistical significance (Cohen's d=0.92; p=0.056). Forefoot volume was similar between runners with and without plantar fasciitis. These results suggest that atrophy of intrinsic foot muscles may be associated with symptoms of plantar fasciitis in runners. These findings may provide useful information in rehabilitation strategies of chronic plantar fasciitis. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Dimensionless size scaling of intrinsic rotation in DIII-D

DOE PAGES

deGrassie, John S.; Solomon, Wayne M.; Rice, J. E.; ...

2016-08-01

A dimensionless empirical scaling for intrinsic toroidal rotation is given; M A ~β Nρ*, where M A is the toroidal velocity divided by the Alfvén velocity, β N the usual normalized β value, and ρ* is the ion gyroradius divided by the minor radius. This scaling describes well experimental data from DIII-D, and also some published data from C-Mod and JET. The velocity used in this scaling is in an outer location in minor radius, outside of the interior core and inside of the large gradient edge region in H-mode conditions. Furthermore, this scaling establishes the basic magnitude of themore » intrinsic toroidal rotation and its relation to the rich variety of rotation profiles that can be realized for intrinsic conditions is discussed.« less

Recombinant Intrinsically Disordered Proteins for NMR: Tips and Tricks.

PubMed

Calçada, Eduardo O; Korsak, Magdalena; Kozyreva, Tatiana

2015-01-01

The growing recognition of the several roles that intrinsically disordered proteins play in biology places an increasing importance on protein sample availability to allow the characterization of their structural and dynamic properties. The sample preparation is therefore the limiting step to allow any biophysical method being able to characterize the properties of an intrinsically disordered protein and to clarify the links between these properties and the associated biological functions. An increasing array of tools has been recruited to help prepare and characterize the structural and dynamic properties of disordered proteins. This chapter describes their sample preparation, covering the most common drawbacks/barriers usually found working in the laboratory bench. We want this chapter to be the bedside book of any scientist interested in preparing intrinsically disordered protein samples for further biophysical analysis.

Peer clustering of exercise and eating behaviours among young adults in Sweden: a cross-sectional study of egocentric network data.

PubMed

Barclay, Kieron J; Edling, Christofer; Rydgren, Jens

2013-08-28

Research suggests that the growing prevalence of obesity may be related to the influence of the health behaviours of peers. We look at clustering of exercise and eating behaviours amongst a previously unstudied group, young adults in Sweden. Previous research has mainly been conducted in the United States and Britain, countries that have relatively high rates of obesity. Using ego-alter dyads from the egocentric network data as the unit of analysis, we conduct logistic regressions to investigate the association between ego and alter exercise and eating behaviours. Respondents have a significantly greater probability of engaging in regular exercise and eating healthily if a nominated peer also does so. Furthermore, the degree to which this behavior is shared is modulated by the strength of the relationship between the two individuals, with a greater probability of engaging in these behaviours observed when the relationship with the nominated peer is strong relative to when the relationship is weak. However, we find that ego-alter homogeneity in terms of gender and migration status was not associated with a significantly greater probability of behaving in a similar manner to a nominated peer. Furthermore, the status of the nominated peer as a relative or not did not impact the probability that the ego would engage in similar health behaviours to that alter. We observe strong associations between ego and alter health behaviours for young adults, consistent with previous research. Although we cannot draw causal inferences, these results suggest that the health behaviours of an individual's peers may play a role in shaping their own health behaviours.

Remembering the real me: Nostalgia offers a window to the intrinsic self.

PubMed

Baldwin, Matthew; Biernat, Monica; Landau, Mark J

2015-01-01

Seven studies reveal that nostalgia, a sentimental affection for the past, offers a window to the intrinsic self-concept-who people think they truly are. In Study 1, state nostalgia was associated with higher authenticity and lower extrinsic self-focus (concern with meeting extrinsic value standards). In Study 2, experimentally primed nostalgia increased perceived authenticity of the past self, which in turn predicted reduced current extrinsic self-focus. Study 3 showed that nostalgia increased the accessibility of the intrinsic self-concept but not the everyday self-concept. Study 4 provided evidence for a moderator suggested by our theoretical analysis: Recalling a nostalgic event increased felt nostalgia and positive affect, but this effect was attenuated if participants were prompted to recognize external factors controlling their behavior during that event. Next we treated nostalgia as an outcome variable and a moderator to test whether nostalgia is triggered by, and buffers against, threats to the intrinsic self. Using a mediation approach, Study 5 showed that participants primed to feel blocked in intrinsic self-expression responded with increased nostalgia. In Study 6, intrinsic self-threat reduced intrinsic self-expression and subjective well-being for participants who were not given an opportunity to respond with nostalgia but not for participants who were allowed to reflect on a nostalgic memory. In line with the experimental findings, correlational data from Study 7 indicated that dispositional nostalgia positively predicted intrinsic self-expression and well-being. Understanding nostalgia as a window to the intrinsic self points to new directions for research on nostalgia's antecedents, moderators, and consequences for well-being. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Content of intrinsic disorder influences the outcome of cell-free protein synthesis.

PubMed

Tokmakov, Alexander A; Kurotani, Atsushi; Ikeda, Mariko; Terazawa, Yumiko; Shirouzu, Mikako; Stefanov, Vasily; Sakurai, Tetsuya; Yokoyama, Shigeyuki

2015-09-11

Cell-free protein synthesis is used to produce proteins with various structural traits. Recent bioinformatics analyses indicate that more than half of eukaryotic proteins possess long intrinsically disordered regions. However, no systematic study concerning the connection between intrinsic disorder and expression success of cell-free protein synthesis has been presented until now. To address this issue, we examined correlations of the experimentally observed cell-free protein expression yields with the contents of intrinsic disorder bioinformatically predicted in the expressed sequences. This analysis revealed strong relationships between intrinsic disorder and protein amenability to heterologous cell-free expression. On the one hand, elevated disorder content was associated with the increased ratio of soluble expression. On the other hand, overall propensity for detectable protein expression decreased with disorder content. We further demonstrated that these tendencies are rooted in some distinct features of intrinsically disordered regions, such as low hydrophobicity, elevated surface accessibility and high abundance of sequence motifs for proteolytic degradation, including sites of ubiquitination and PEST sequences. Our findings suggest that identification of intrinsically disordered regions in the expressed amino acid sequences can be of practical use for predicting expression success and optimizing cell-free protein synthesis.

Importance of Intrinsic and Instrumental Value of Education in Pakistan

ERIC Educational Resources Information Center

Kumar, Mahendar

2017-01-01

Normally, effectiveness of any object or thing is judged by two values; intrinsic and instrumental. To compare intrinsic value of education with instrumental value, this study has used the following variables: getting knowledge for its own sake, getting knowledge for social status, getting knowledge for job or business endeavor and getting…

Intrinsic rotation, hysteresis and back transition in reversed shear internal transport barriers

NASA Astrophysics Data System (ADS)

Kim, S. S.; Jhang, Hogun; Diamond, P. H.; Terzolo, L.; Yi, S.; Hahm, T. S.

2011-07-01

A study of intrinsic rotation and hysteresis in ion thermal internal transport barrier (ITB) is presented. Global flux-driven gyrofluid simulations are performed. It is found that significant co-current intrinsic rotation (0.1 <~ Mth <~ 0.2, where Mth is the thermal Mach number) can be produced in ITB plasmas. Exploration of the relationship between the intrinsic rotation and the ITB temperature gradient leads to a novel scaling of intrinsic rotation in ITB plasmas. Long time power ramp simulations with self-consistently evolving profiles clearly demonstrate the existence of hysteresis in reversed shear ITBs. It is shown that intrinsic rotation plays an important role in ITB dynamics and is responsible for determining unique properties of ITB hysteresis. A negative feedback mechanism based on destruction of E × B shear prevails in barrier back transition, triggered by an outward momentum transport event during the power ramp down.

Electronegativity and intrinsic disorder of preeclampsia-related proteins.

PubMed

Polanco, Carlos; Castañón-González, Jorge Alberto; Uversky, Vladimir N; Buhse, Thomas; Samaniego Mendoza, José Lino; Calva, Juan J

2017-01-01

Preeclampsia, hemorrhage, and infection are the leading causes of maternal death in underdeveloped countries. Since several proteins associated with preeclampsia are known, we conducted a computational study which evaluated the commonness and potential functionality of intrinsic disorder of these proteins and also made an attempt to characterize their origin. The origin of the preeclampsia-related proteins was assessed with a supervised technique, a Polarity Index Method (PIM), which evaluates the electronegativity of proteins based solely on their sequence. The commonness of intrinsic disorder was evaluated using several disorder predictors from the PONDR family, the charge-hydropathy plot (CH-plot) and cumulative distribution function (CDF) analyses, and using the MobiDB web-based tool, whereas potential functionality of intrinsic disorder was studied with the D2P2 resource and ANCHOR predictor of disorder-based binding sites, and the STRING tool was used to build the interactivity networks of the preeclampsia-related proteins. Peculiarities of the PIM-derived polar profile of the group of preeclampsia-related proteins were then compared with profiles of a group of lipoproteins, antimicrobial peptides, angiogenesis-related proteins, and the intrinsically disordered proteins. Our results showed a high graphical correlation between preeclampsia proteins, lipoproteins, and the angiogenesis proteins. We also showed that many preeclampsia-related proteins contain numerous functional disordered regions. Therefore, these bioinformatics results led us to assume that the preeclampsia proteins are highly associated with the lipoproteins group, and that some preeclampsia-related proteins contain significant amounts of functional disorders.

Predicting rotation for ITER via studies of intrinsic torque and momentum transport in DIII-D

DOE PAGES

Chrystal, C.; Grierson, B. A.; Staebler, G. M.; ...

2017-03-30

Here, experiments at the DIII-D tokamak have used dimensionless parameter scans to investigate the dependencies of intrinsic torque and momentum transport in order to inform a prediction of the rotation profile in ITER. Measurements of intrinsic torque profiles and momentum confinement time in dimensionless parameter scans of normalized gyroradius and collisionality are used to predict the amount of intrinsic rotation in the pedestal of ITER. Additional scans of T e/T i and safety factor are used to determine the accuracy of momentum flux predictions of the quasi-linear gyrokinetic code TGLF. In these scans, applications of modulated torque are used tomore » measure the incremental momentum diffusivity, and results are consistent with the E x B shear suppression of turbulent transport. These incremental transport measurements are also compared with the TGLF results. In order to form a prediction of the rotation profile for ITER, the pedestal prediction is used as a boundary condition to a simulation that uses TGLF to determine the transport in the core of the plasma. The predicted rotation is ≈20 krad/s in the core, lower than in many current tokamak operating scenarios. TGLF predictions show that this rotation is still significant enough to have a strong effect on confinement via E x B shear.« less

More than a bystander: the contributions of intrinsic skeletal muscle defects in motor neuron diseases

PubMed Central

Boyer, Justin G.; Ferrier, Andrew; Kothary, Rashmi

2013-01-01

Spinal muscular atrophy (SMA), amyotrophic lateral sclerosis (ALS), and spinal-bulbar muscular atrophy (SBMA) are devastating diseases characterized by the degeneration of motor neurons. Although the molecular causes underlying these diseases differ, recent findings have highlighted the contribution of intrinsic skeletal muscle defects in motor neuron diseases. The use of cell culture and animal models has led to the important finding that muscle defects occur prior to and independently of motor neuron degeneration in motor neuron diseases. In SMA for instance, the muscle specific requirements of the SMA disease-causing gene have been demonstrated by a series of genetic rescue experiments in SMA models. Conditional ALS mouse models expressing a muscle specific mutant SOD1 gene develop atrophy and muscle degeneration in the absence of motor neuron pathology. Treating SBMA mice by over-expressing IGF-1 in a skeletal muscle-specific manner attenuates disease severity and improves motor neuron pathology. In the present review, we provide an in depth description of muscle intrinsic defects, and discuss how they impact muscle function in these diseases. Furthermore, we discuss muscle-specific therapeutic strategies used to treat animal models of SMA, ALS, and SBMA. The study of intrinsic skeletal muscle defects is crucial for the understanding of the pathophysiology of these diseases and will open new therapeutic options for the treatment of motor neuron diseases. PMID:24391590

The Application of Piagetian Theory to Sexuality: A Preliminary Exploration

ERIC Educational Resources Information Center

Breese, Richard W.

1978-01-01

A dimension of sexuality is defined as a form of knowledge and is situated in Piaget's existing theory of cognitive development. Investigates whether sexual egocentrism is comparable to cognitive egocentrism at each stage of sexual development. Uses D. Elkind's (1967) explication of egocentrism and how it is overcome throughout the sexual stages.…

The More You Can Get the Better: Mentoring Constellations and Intrinsic Career Success

ERIC Educational Resources Information Center

van Emmerik, I. J. Jetty

2004-01-01

This study focused on the relationship between mentoring constellations and intrinsic career success. Hierarchical regression analyses on the data of 416 female and 594 male university members showed that mentoring was positively associated with intrinsic career success i.e., career satisfaction and intrinsic job satisfaction. Several…

Novel Intrinsic Ignition Method Measuring Local-Global Integration Characterizes Wakefulness and Deep Sleep

PubMed Central

Tagliazucchi, Enzo; Sanjuán, Ana

2017-01-01

Abstract A precise definition of a brain state has proven elusive. Here, we introduce the novel local-global concept of intrinsic ignition characterizing the dynamical complexity of different brain states. Naturally occurring intrinsic ignition events reflect the capability of a given brain area to propagate neuronal activity to other regions, giving rise to different levels of integration. The ignitory capability of brain regions is computed by the elicited level of integration for each intrinsic ignition event in each brain region, averaged over all events. This intrinsic ignition method is shown to clearly distinguish human neuroimaging data of two fundamental brain states (wakefulness and deep sleep). Importantly, whole-brain computational modelling of this data shows that at the optimal working point is found where there is maximal variability of the intrinsic ignition across brain regions. Thus, combining whole brain models with intrinsic ignition can provide novel insights into underlying mechanisms of brain states. PMID:28966977

INTRINSIC CURVATURE: A MARKER OF MILLIMETER-SCALE TANGENTIAL CORTICO-CORTICAL CONNECTIVITY?

PubMed Central

RONAN, LISA; PIENAAR, RUDOLPH; WILLIAMS, GUY; BULLMORE, ED; CROW, TIM J.; ROBERTS, NEIL; JONES, PETER B.; SUCKLING, JOHN; FLETCHER, PAUL C.

2012-01-01

In this paper, we draw a link between cortical intrinsic curvature and the distributions of tangential connection lengths. We suggest that differential rates of surface expansion not only lead to intrinsic curvature of the cortical sheet, but also to differential inter-neuronal spacing. We propose that there follows a consequential change in the profile of neuronal connections: specifically an enhancement of the tendency towards proportionately more short connections. Thus, the degree of cortical intrinsic curvature may have implications for short-range connectivity. PMID:21956929

Are There Intrinsically X-Ray Quiet Quasars

NASA Technical Reports Server (NTRS)

Gallagher, S. C.; Brandt, W. N.; Laor, A.; Elvis, Martin; Mathur, S.; Wills, Beverly J.; Iyomoto, N.; White, Nicholas (Technical Monitor)

2000-01-01

Recent ROSAT studies have identified a significant population of Active Galactic Nuclei (AGN) that are notably faint in soft X-rays relative to their optical fluxes. Are these AGN intrinsically X-ray weak or are they just highly absorbed? Brandt, Laor & Wills have systematically examined the optical and UV spectral properties of a well-defined sample of these soft X-ray weak (SXW) AGN drawn from the Boroson & Green sample of all the Palomar Green AGN 00 with z < 0.5. We present ASCA observations of three of these SXW AGN: PG 1011-040, PG 1535+547 (Mrk 486), and PG 2112+059. In general, our ASCA observations support the intrinsic absorption scenario for explaining soft X-ray weakness; both PG 1535+547 and PG 2112+059 show significant column densities (NH is approximately 10(exp 22) - 10(exp 23)/sq cm) of absorbing gas. Interestingly, PG 1011-040 shows no spectral evidence for X-ray absorption. The weak X-ray emission may result from very strong absorption of a partially covered source, or this AGN may be intrinsically X-ray weak. PG 2112+059 is a Broad Absorption Line (BAL) QSO, and we find it to have the highest X-ray flux known of this class. It shows a typical power-law X-ray continuum above 3 keV; this is the first direct evidence that BAL QSOs indeed have normal X-ray continua underlying their intrinsic absorption. Finally, marked variability between the ROSAT and ASCA observations of PG 1535+547 and PG 2112+059 suggests that the soft X-ray weak designation may be transient, and multi-epoch 0.1-10.0 KeV X-ray observations are required to constrain variability of the absorber and continuum.

Intrinsic coherence time of trions in monolayer MoSe2 measured via two-dimensional coherent spectroscopy

NASA Astrophysics Data System (ADS)

Titze, Michael; Li, Bo; Zhang, Xiang; Ajayan, Pulickel M.; Li, Hebin

2018-05-01

Quantum coherence and its dynamics in monolayer transition metal dichalcogenides (TMDs) are essential information to fully control valley pseudospin for valleytronics applications. Experimental understanding of coherence dephasing dynamics has been limited for excitons and largely unexplored for trions in monolayer TMDs. Here we use optical two-dimensional coherent spectroscopy to measure the trion coherence dephasing time in monolayer MoSe2 by analyzing the homogeneous linewidth. An intrinsic coherence time of 182 fs is extrapolated from the excitation density and temperature dependence measurement. The results show that trion-trion and trion-phonon interactions strongly affect the coherence dephasing time, while the intrinsic coherence time at zero excitation and zero temperature is primarily limited by the pure dephasing due to defect states. Our experiment also confirms optical two-dimensional coherent spectroscopy as a reliable technique for studying valley quantum dynamics in two-dimensional layered materials.

Skin electronics from scalable fabrication of an intrinsically stretchable transistor array.

PubMed

Wang, Sihong; Xu, Jie; Wang, Weichen; Wang, Ging-Ji Nathan; Rastak, Reza; Molina-Lopez, Francisco; Chung, Jong Won; Niu, Simiao; Feig, Vivian R; Lopez, Jeffery; Lei, Ting; Kwon, Soon-Ki; Kim, Yeongin; Foudeh, Amir M; Ehrlich, Anatol; Gasperini, Andrea; Yun, Youngjun; Murmann, Boris; Tok, Jeffery B-H; Bao, Zhenan

2018-03-01

Skin-like electronics that can adhere seamlessly to human skin or within the body are highly desirable for applications such as health monitoring, medical treatment, medical implants and biological studies, and for technologies that include human-machine interfaces, soft robotics and augmented reality. Rendering such electronics soft and stretchable-like human skin-would make them more comfortable to wear, and, through increased contact area, would greatly enhance the fidelity of signals acquired from the skin. Structural engineering of rigid inorganic and organic devices has enabled circuit-level stretchability, but this requires sophisticated fabrication techniques and usually suffers from reduced densities of devices within an array. We reasoned that the desired parameters, such as higher mechanical deformability and robustness, improved skin compatibility and higher device density, could be provided by using intrinsically stretchable polymer materials instead. However, the production of intrinsically stretchable materials and devices is still largely in its infancy: such materials have been reported, but functional, intrinsically stretchable electronics have yet to be demonstrated owing to the lack of a scalable fabrication technology. Here we describe a fabrication process that enables high yield and uniformity from a variety of intrinsically stretchable electronic polymers. We demonstrate an intrinsically stretchable polymer transistor array with an unprecedented device density of 347 transistors per square centimetre. The transistors have an average charge-carrier mobility comparable to that of amorphous silicon, varying only slightly (within one order of magnitude) when subjected to 100 per cent strain for 1,000 cycles, without current-voltage hysteresis. Our transistor arrays thus constitute intrinsically stretchable skin electronics, and include an active matrix for sensory arrays, as well as analogue and digital circuit elements. Our process offers a

Skin electronics from scalable fabrication of an intrinsically stretchable transistor array

NASA Astrophysics Data System (ADS)

Wang, Sihong; Xu, Jie; Wang, Weichen; Wang, Ging-Ji Nathan; Rastak, Reza; Molina-Lopez, Francisco; Chung, Jong Won; Niu, Simiao; Feig, Vivian R.; Lopez, Jeffery; Lei, Ting; Kwon, Soon-Ki; Kim, Yeongin; Foudeh, Amir M.; Ehrlich, Anatol; Gasperini, Andrea; Yun, Youngjun; Murmann, Boris; Tok, Jeffery B.-H.; Bao, Zhenan

2018-03-01

Skin-like electronics that can adhere seamlessly to human skin or within the body are highly desirable for applications such as health monitoring, medical treatment, medical implants and biological studies, and for technologies that include human-machine interfaces, soft robotics and augmented reality. Rendering such electronics soft and stretchable—like human skin—would make them more comfortable to wear, and, through increased contact area, would greatly enhance the fidelity of signals acquired from the skin. Structural engineering of rigid inorganic and organic devices has enabled circuit-level stretchability, but this requires sophisticated fabrication techniques and usually suffers from reduced densities of devices within an array. We reasoned that the desired parameters, such as higher mechanical deformability and robustness, improved skin compatibility and higher device density, could be provided by using intrinsically stretchable polymer materials instead. However, the production of intrinsically stretchable materials and devices is still largely in its infancy: such materials have been reported, but functional, intrinsically stretchable electronics have yet to be demonstrated owing to the lack of a scalable fabrication technology. Here we describe a fabrication process that enables high yield and uniformity from a variety of intrinsically stretchable electronic polymers. We demonstrate an intrinsically stretchable polymer transistor array with an unprecedented device density of 347 transistors per square centimetre. The transistors have an average charge-carrier mobility comparable to that of amorphous silicon, varying only slightly (within one order of magnitude) when subjected to 100 per cent strain for 1,000 cycles, without current-voltage hysteresis. Our transistor arrays thus constitute intrinsically stretchable skin electronics, and include an active matrix for sensory arrays, as well as analogue and digital circuit elements. Our process offers a

Defining the Intrinsic Cardiac Risks of Operations to Improve Preoperative Cardiac Risk Assessments.

PubMed

Liu, Jason B; Liu, Yaoming; Cohen, Mark E; Ko, Clifford Y; Sweitzer, Bobbie J

2018-02-01

Current preoperative cardiac risk stratification practices group operations into broad categories, which might inadequately consider the intrinsic cardiac risks of individual operations. We sought to define the intrinsic cardiac risks of individual operations and to demonstrate how grouping operations might lead to imprecise estimates of perioperative cardiac risk. Elective operations (based on Common Procedural Terminology codes) performed from January 1, 2010 to December 31, 2015 at hospitals participating in the American College of Surgeons National Surgical Quality Improvement Program were studied. A composite measure of perioperative adverse cardiac events was defined as either cardiac arrest requiring cardiopulmonary resuscitation or acute myocardial infarction. Operations' intrinsic cardiac risks were derived from mixed-effects models while controlling for patient mix. Resultant risks were sorted into low-, intermediate-, and high-risk categories, and the most commonly performed operations within each category were identified. Intrinsic operative risks were also examined using a representative grouping of operations to portray within-group variation. Sixty-six low, 30 intermediate, and 106 high intrinsic cardiac risk operations were identified. Excisional breast biopsy had the lowest intrinsic cardiac risk (overall rate, 0.01%; odds ratio, 0.11; 95% CI, 0.02 to 0.25) relative to the average, whereas aorto-bifemoral bypass grafting had the highest (overall rate, 4.1%; odds ratio, 6.61; 95% CI, 5.54 to 7.90). There was wide variation in the intrinsic cardiac risks of operations within the representative grouping (median odds ratio, 1.40; interquartile range, 0.88 to 2.17). A continuum of intrinsic cardiac risk exists among operations. Grouping operations into broad categories inadequately accounts for the intrinsic cardiac risk of individual operations.

Iron and intrinsic deep level states in Ga2O3

NASA Astrophysics Data System (ADS)

Ingebrigtsen, M. E.; Varley, J. B.; Kuznetsov, A. Yu.; Svensson, B. G.; Alfieri, G.; Mihaila, A.; Badstübner, U.; Vines, L.

2018-01-01

Using a combination of deep level transient spectroscopy, secondary ion mass spectrometry, proton irradiation, and hybrid functional calculations, we identify two similar deep levels that are associated with Fe impurities and intrinsic defects in bulk crystals and molecular beam epitaxy and hydride vapor phase epitaxi-grown epilayers of β-Ga2O3. First, our results indicate that FeGa, and not an intrinsic defect, acts as the deep acceptor responsible for the often dominating E2 level at ˜0.78 eV below the conduction band minimum. Second, by provoking additional intrinsic defect generation via proton irradiation, we identified the emergence of a new level, labeled as E2*, having the ionization energy very close to that of E2, but exhibiting an order of magnitude larger capture cross section. Importantly, the properties of E2* are found to be consistent with its intrinsic origin. As such, contradictory opinions of a long standing literature debate on either extrinsic or intrinsic origin of the deep acceptor in question converge accounting for possible contributions from E2 and E2* in different experimental conditions.

Adenovirus type 5 intrinsic adsorption rates measured by surface plasmon resonance.

PubMed

Roper, D Keith; Nakra, Shamit

2006-01-01

Intrinsic adsorption rates of whole adenovirus type 5 (Ad5) onto a diethylaminoethyl (DEAE) anion exchange surface are measured for the first time by surface plasmon resonance (SPR). Fitting SPR sensorgrams to a two-compartment mass transport reaction model distinguishes intrinsic adsorption rates from slow diffusive Ad5 mass transport. Ad5 is a widely used viral vector for gene therapy that binds electrostatically to surfaces of cells and synthetics such as membranes, chromatographic resins, and glass. Increasing NaCl concentration from 4.8 to 14.4mM shifts binding of whole Ad5 from diffusion control to a regime where both sorption and diffusion affect binding. Intrinsic adsorption rates for Ad5-DEAE interaction are 16 times faster than intrinsic adsorption rates for Ad5 fiber knob interacting with soluble extracellular domain of coxsackievirus adenovirus receptors (s-CAR).

Bimanual motor coordination controlled by cooperative interactions in intrinsic and extrinsic coordinates.

PubMed

Sakurada, Takeshi; Ito, Koji; Gomi, Hiroaki

2016-01-01

Although strong motor coordination in intrinsic muscle coordinates has frequently been reported for bimanual movements, coordination in extrinsic visual coordinates is also crucial in various bimanual tasks. To explore the bimanual coordination mechanisms in terms of the frame of reference, here we characterized implicit bilateral interactions in visuomotor tasks. Visual perturbations (finger-cursor gain change) were applied while participants performed a rhythmic tracking task with both index fingers under an in-phase or anti-phase relationship in extrinsic coordinates. When they corrected the right finger's amplitude, the left finger's amplitude unintentionally also changed [motor interference (MI)], despite the instruction to keep its amplitude constant. Notably, we observed two specificities: one was large MI and low relative-phase variability (PV) under the intrinsic in-phase condition, and the other was large MI and high PV under the extrinsic in-phase condition. Additionally, using a multiple-interaction model, we successfully decomposed MI into intrinsic components caused by motor correction and extrinsic components caused by visual-cursor mismatch of the right finger's movements. This analysis revealed that the central nervous system facilitates MI by combining intrinsic and extrinsic components in the condition with in-phases in both intrinsic and extrinsic coordinates, and that under-additivity of the effects is explained by the brain's preference for the intrinsic interaction over extrinsic interaction. In contrast, the PV was significantly correlated with the intrinsic component, suggesting that the intrinsic interaction dominantly contributed to bimanual movement stabilization. The inconsistent features of MI and PV suggest that the central nervous system regulates multiple levels of bilateral interactions for various bimanual tasks. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and

Changes in self-perceptions of competence and intrinsic motivation among elementary schoolchildren.

PubMed

Bouffard, Thérèse; Marcoux, Marie-France; Vezeau, Carole; Bordeleau, Luce

2003-06-01

Children's perceived competence and intrinsic motivation are assumed to be very high at the outset of schooling. However, how they change and how they relate to each other and to academic achievement across early schooling years remain open to question. This 3-year longitudinal study was aimed at examining the following questions. Do children's perceived competence and intrinsic motivation about reading and mathematics change across the first 3 years of schooling? Do their perceived competence and intrinsic motivation differ according to academic domains? Do their perceived competence and intrinsic motivation relate to their academic achievement in each academic domain? A total of 115 elementary schoolchildren (63 boys and 52 girls) were examined in first grade (mean age = 84,5 months, SD =.67) and for the next 2 years. Children responded to questionnaires about their perceived competence and intrinsic motivation in reading and mathematics. Year-end grades in these two subjects were used as a measure of performance. Changes in perceived competence and intrinsic motivation, and between-year intercorrelations, were observed to differ according to academic domains and gender. Intrinsic motivation did not make a significant contribution to academic achievement at either school grade or in any academic domain, whereas perceived competence was significantly related to achievement at each school grade in both reading and mathematics. Differences between boys and girls observed in this study were not linked to a specific domain and cannot be attributed to gender-role stereotypes. Girls appeared to be more precocious in differentiating their competence and intrinsic motivation according to academic domain, as well as in being able to process and integrate information about their ability from past performances in a domain to judge their competence in the same domain.

Resolving the SELEX--LHCb Double-Charm Baryon Conflict: The Impact of Intrinsic Heavy-Quark Hadroproduction and Supersymmetric Light-Front Holographic QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brodsky, Stanley

2017-01-01

In this paper we show that the intrinsic heavy-quark QCD mechanism for the hadroproduction of heavy hadrons at largemore » $$x_F$$ can resolve the apparent conflict between measurements of double-charm baryons by the SELEX fixed-target experiment and the LHCb experiment at the LHC collider. We show that both experiments are compatible, and that both results can be correct. The observed spectroscopy of double-charm hadrons is in agreement with the predictions of supersymmetric light front holographic QCD.« less

Integrating intrinsic mobility into unmanned ground vehicle systems

NASA Astrophysics Data System (ADS)

Brosinsky, Chris A.; Penzes, Steven G.; Buehler, Martin G.; Steeves, Carl

2001-09-01

The ability of an Unmanned Ground Vehicle (UGV) to successfully move about in its environment is enabled by the synergistic combination of perception, control and platform (mobility and utility). Vast effort is being expended on the former technologies but little demonstrable evidence has been produced to indicate that the latter (mobility/utility) has been considered as an integral part of the UGV systems level capability; a concept commonly referred to as intrinsic mobility. While past work described the rationale for hybrid locomotion, this paper aims to demonstrate that integrating intrinsic mobility into a UGV systems mobility element or 'vehicle' will be a key contributor to the magnitude of autonomy that the system can achieve. This paper serves to provide compelling evidence that 1) intrinsic mobility improvements provided by hybrid locomotion configurations offer the best generic mobility, that 2) strict attention must be placed on the optimization of both utility (inherent vehicle capabilities) and mobility and that 3) the establishment of measures of performance for unmanned vehicle mobility is an unmet and latent need.

Crude and intrinsic birth rates for Asian countries.

PubMed

Rele, J R

1978-01-01

An attempt to estimate birth rates for Asian countries. The main sources of information in developing countries has been census age-sex distribution, although inaccuracies in the basic data have made it difficult to reach a high degree of accuracy. Different methods bring widely varying results. The methodology presented here is based on the use of the conventional child-woman ratio from the census age-sex distribution, with a rough estimate of the expectation of life at birth. From the established relationships between child-woman ratio and the intrinsic birth rate of the nature y = a + bx + cx(2) at each level of life expectation, the intrinsic birth rate is first computed using coefficients already computed. The crude birth rate is obtained using the adjustment based on the census age-sex distribution. An advantage to this methodology is that the intrinsic birth rate, normally an involved computation, can be obtained relatively easily as a biproduct of the crude birth rates and the bases for the calculations for each of 33 Asian countries, in some cases over several time periods.

Pseudomonas aeruginosa reveals high intrinsic resistance to penem antibiotics: penem resistance mechanisms and their interplay.

PubMed

Okamoto, K; Gotoh, N; Nishino, T

2001-07-01

Pseudomonas aeruginosa exhibits high intrinsic resistance to penem antibiotics such as faropenem, ritipenem, AMA3176, sulopenem, Sch29482, and Sch34343. To investigate the mechanisms contributing to penem resistance, we used the laboratory strain PAO1 to construct a series of isogenic mutants with an impaired multidrug efflux system MexAB-OprM and/or impaired chromosomal AmpC beta-lactamase. The outer membrane barrier of PAO1 was partially eliminated by inducing the expression of the plasmid-encoded Escherichia coli major porin OmpF. Susceptibility tests using the mutants and the OmpF expression plasmid showed that MexAB-OprM and the outer membrane barrier, but not AmpC beta-lactamase, are the main mechanisms involved in the high intrinsic penem resistance of PAO1. However, reducing the high intrinsic penem resistance of PAO1 to the same level as that of penem-susceptible gram-negative bacteria such as E. coli required the loss of either both MexAB-OprM and AmpC beta-lactamase or both MexAB-OprM and the outer membrane barrier. Competition experiments for penicillin-binding proteins (PBPs) revealed that the affinity of PBP 1b and PBP 2 for faropenem were about 1.8- and 1.5-fold lower, than the respective affinity for imipenem. Loss of the outer membrane barrier, MexAB, and AmpC beta-lactamase increased the susceptibility of PAO1 to almost all penems tested compared to the susceptibility of the AmpC-deficient PAO1 mutants to imipenem. Thus, it is suggested that the high intrinsic penem resistance of P. aeruginosa is generated from the interplay among the outer membrane barrier, the active efflux system, and AmpC beta-lactamase but not from the lower affinity of PBPs for penems.