Telencephalic neural activation following passive avoidance learning in a terrestrial toad.

PubMed

Puddington, Martín M; Daneri, M Florencia; Papini, Mauricio R; Muzio, Rubén N

2016-12-15

The present study explores passive avoidance learning and its neural basis in toads (Rhinella arenarum). In Experiment 1, two groups of toads learned to move from a lighted compartment into a dark compartment. After responding, animals in the experimental condition were exposed to an 800-mM strongly hypertonic NaCl solution that leads to weight loss. Control animals received exposure to a 300-mM slightly hypertonic NaCl solution that leads to neither weight gain nor loss. After 10 daily acquisition trials, animals in the experimental group showed significantly longer latency to enter the dark compartment. Additionally, 10 daily trials in which both groups received the 300-mM NaCl solution after responding eliminated this group effect. Thus, experimental animals showed gradual acquisition and extinction of a passive avoidance respond. Experiment 2 replicated the gradual acquisition effect, but, after the last trial, animals were sacrificed and neural activation was assessed in five brain regions using AgNOR staining for nucleoli-an index of brain activity. Higher activation in the experimental animals, relative to controls, was observed in the amygdala and striatum. Group differences in two other regions, lateral pallium and septum, were borderline, but nonsignificant, whereas group differences in the medial pallium were nonsignificant. These preliminary results suggest that a striatal-amygdala activation could be a key component of the brain circuit controlling passive avoidance learning in amphibians. The results are discussed in relation to the results of analogous experiments with other vertebrates. Copyright © 2016 Elsevier B.V. All rights reserved.

Individual differences in sensitivity to reward and punishment and neural activity during reward and avoidance learning.

PubMed

Kim, Sang Hee; Yoon, HeungSik; Kim, Hackjin; Hamann, Stephan

2015-09-01

In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Seeing direct and averted gaze activates the approach-avoidance motivational brain systems.

PubMed

Hietanen, Jari K; Leppänen, Jukka M; Peltola, Mikko J; Linna-Aho, Kati; Ruuhiala, Heidi J

2008-01-01

Gaze direction is known to be an important factor in regulating social interaction. Recent evidence suggests that direct and averted gaze can signal the sender's motivational tendencies of approach and avoidance, respectively. We aimed at determining whether seeing another person's direct vs. averted gaze has an influence on the observer's neural approach-avoidance responses. We also examined whether it would make a difference if the participants were looking at the face of a real person or a picture. Measurements of hemispheric asymmetry in the frontal electroencephalographic activity indicated that another person's direct gaze elicited a relative left-sided frontal EEG activation (indicative of a tendency to approach), whereas averted gaze activated right-sided asymmetry (indicative of avoidance). Skin conductance responses were larger to faces than to control objects and to direct relative to averted gaze, indicating that faces, in general, and faces with direct gaze, in particular, elicited more intense autonomic activation and strength of the motivational tendencies than did control stimuli. Gaze direction also influenced subjective ratings of emotional arousal and valence. However, all these effects were observed only when participants were facing a real person, not when looking at a picture of a face. This finding was suggested to be due to the motivational responses to gaze direction being activated in the context of enhanced self-awareness by the presence of another person. The present results, thus, provide direct evidence that eye contact and gaze aversion between two persons influence the neural mechanisms regulating basic motivational-emotional responses and differentially activate the motivational approach-avoidance brain systems.

Neuroscience and approach/avoidance personality traits: a two stage (valuation-motivation) approach.

PubMed

Corr, Philip J; McNaughton, Neil

2012-11-01

Many personality theories link specific traits to the sensitivities of the neural systems that control approach and avoidance. But there is no consensus on the nature of these systems. Here we combine recent advances in economics and neuroscience to provide a more solid foundation for a neuroscience of approach/avoidance personality. We propose a two-stage integration of valuation (loss/gain) sensitivities with motivational (approach/avoidance/conflict) sensitivities. Our key conclusions are: (1) that valuation of appetitive and aversive events (e.g. gain and loss as studied by behavioural economists) is an independent perceptual input stage--with the economic phenomenon of loss aversion resulting from greater negative valuation sensitivity compared to positive valuation sensitivity; (2) that valuation of an appetitive stimulus then interacts with a contingency of presentation or omission to generate a motivational 'attractor' or 'repulsor', respectively (vice versa for an aversive stimulus); (3) the resultant behavioural tendencies to approach or avoid have distinct sensitivities to those of the valuation systems; (4) while attractors and repulsors can reinforce new responses they also, more usually, elicit innate or previously conditioned responses and so the perception/valuation-motivation/action complex is best characterised as acting as a 'reinforcer' not a 'reinforcement'; and (5) approach-avoidance conflict must be viewed as activating a third motivation system that is distinct from the basic approach and avoidance systems. We provide examples of methods of assessing each of the constructs within approach-avoidance theories and of linking these constructs to personality measures. We sketch a preliminary five-element reinforcer sensitivity theory (RST-5) as a first step in the integration of existing specific approach-avoidance theories into a coherent neuroscience of personality. Copyright © 2012 Elsevier Ltd. All rights reserved.

Multiantenna Relay Beamforming Design for QoS Discrimination in Two-Way Relay Networks

PubMed Central

Xiong, Ke; Zhang, Yu; Li, Dandan; Zhong, Zhangdui

2013-01-01

This paper investigates the relay beamforming design for quality of service (QoS) discrimination in two-way relay networks. The purpose is to keep legitimate two-way relay users exchange their information via a helping multiantenna relay with QoS guarantee while avoiding the exchanged information overhearing by unauthorized receiver. To this end, we propose a physical layer method, where the relay beamforming is jointly designed with artificial noise (AN) which is used to interfere in the unauthorized user's reception. We formulate the joint beamforming and AN (BFA) design into an optimization problem such that the received signal-to-interference-ratio (SINR) at the two legitimate users is over a predefined QoS threshold while limiting the received SINR at the unauthorized user which is under a certain secure threshold. The objective of the optimization problem is to seek the optimal AN and beamforming vectors to minimize the total power consumed by the relay node. Since the optimization problem is nonconvex, we solve it by using semidefinite program (SDP) relaxation. For comparison, we also study the optimal relay beamforming without using AN (BFO) under the same QoS discrimination constraints. Simulation results show that both the proposed BFA and BFO can achieve the QoS discrimination of the two-way transmission. However, the proposed BFA yields significant power savings and lower infeasible rates compared with the BFO method. PMID:24391459

FVCOM one-way and two-way nesting using ESMF: Development and validation

NASA Astrophysics Data System (ADS)

Qi, Jianhua; Chen, Changsheng; Beardsley, Robert C.

2018-04-01

Built on the Earth System Modeling Framework (ESMF), the one-way and two-way nesting methods were implemented into the unstructured-grid Finite-Volume Community Ocean Model (FVCOM). These methods help utilize the unstructured-grid multi-domain nesting of FVCOM with an aim at resolving the multi-scale physical and ecosystem processes. A detail of procedures on implementing FVCOM into ESMF was described. The experiments were made to validate and evaluate the performance of the nested-grid FVCOM system. The first was made for a wave-current interaction case with a two-domain nesting with an emphasis on qualifying a critical need of nesting to resolve a high-resolution feature near the coast and harbor with little loss in computational efficiency. The second was conducted for the pseudo river plume cases to examine the differences in the model-simulated salinity between one-way and two-way nesting approaches and evaluate the performance of mass conservative two-way nesting method. The third was carried out for the river plume case in the realistic geometric domain in Mass Bay, supporting the importance for having the two-way nesting for coastal-estuarine integrated modeling. The nesting method described in this paper has been used in the Northeast Coastal Ocean Forecast System (NECOFS)-a global-regional-coastal nesting FVCOM system that has been placed into the end-to-end forecast and hindcast operations since 2007.

Two-Way Immersion: A Key to Global Awareness.

ERIC Educational Resources Information Center

Howard, Elizabeth R.

2002-01-01

Describes the use of two-way immersion education to provide students with opportunities to understand and appreciate other countries and cultures. The main features of two-way immersion education are bilingual language instruction, cross-cultural understanding, and international exchanges. Includes case study of two-way immersion at the Alicia…

Comparative analysis of the performance of One-Way and Two-Way urban road networks

NASA Astrophysics Data System (ADS)

Gheorghe, Carmen

2017-10-01

The fact that the number of vehicles is increasing year after year represents a challenge in road traffic management because it is necessary to adjust the road traffic, in order to prevent any incidents, using mostly the same road infrastructure. At this moment one-way road network provides efficient traffic flow for vehicles but it is not ideal for pedestrians. Therefore, a proper solution must be found and applied when and where it is necessary. Replacing one-way road network with two-way road network may be a viable solution especially if in the area is high pedestrian traffic. The paper aims to highlight the influence of both, one-way and two-way urban road networks through an experimental research which was performed by using traffic data collected in the field. Each of the two scenarios analyzed were based on the same traffic data, the same geometrical conditions of the road (lane width, total road segment width, road slopes, total length of the road network) and also the same signaling conditions (signalised intersection or roundabout). The analysis which involves two-way scenario reveals changes in the performance parameters like delay average, stops average, delay stop average and vehicle speed average. Based on the values obtained, it was possible to perform a comparative analysis between the real, one-way, scenario and the theoretical, two-way, scenario.

Two-Way Bilingual Education and Latino Students

ERIC Educational Resources Information Center

Brooke-Garza, Elizabeth

2015-01-01

Two-way bilingual immersion (TWBI) programs have demonstrated great success in improving Latino English learners' educational outcomes. Nevertheless, TWBI classrooms are not immune to the greater power dynamics and influences of United States society. This Participatory Action Research study brought together eight two-way bilingual immersion…

Active avoidance learning requires prefrontal suppression of amygdala-mediated defensive reactions.

PubMed

Moscarello, Justin M; LeDoux, Joseph E

2013-02-27

Signaled active avoidance (AA) paradigms train subjects to prevent an aversive outcome by performing a learned behavior during the presentation of a conditioned cue. This complex form of conditioning involves pavlovian and instrumental components, which produce competing behavioral responses that must be reconciled for the subject to successfully avoid an aversive stimulus. In signaled AA paradigm for rat, we tested the hypothesis that the instrumental component of AA training recruits infralimbic prefrontal cortex (ilPFC) to inhibit central amygdala (CeA)-mediated Pavlovian reactions. Pretraining lesions of ilPFC increased conditioned freezing while causing a corresponding decrease in avoidance; lesions of CeA produced opposite effects, reducing freezing and facilitating avoidance behavior. Pharmacological inactivation experiments demonstrated that ilPFC is relevant to both acquisition and expression phases of AA learning. Inactivation experiments also revealed that AA produces an ilPFC-mediated diminution of pavlovian reactions that extends beyond the training context, even when the conditioned stimulus is presented in an environment that does not allow the avoidance response. Finally, injection of a protein synthesis inhibitor into either ilPFC or CeA impaired or facilitated AA, respectively, showing that avoidance training produces two opposing memory traces in these regions. These data support a model in which AA learning recruits ilPFC to inhibit CeA-mediated defense behaviors, leading to a robust suppression of freezing that generalizes across environments. Thus, ilPFC functions as an inhibitory interface, allowing instrumental control over an aversive outcome to attenuate the expression of freezing and other reactions to conditioned threat.

Two-way ANOVA Problems with Simple Numbers.

ERIC Educational Resources Information Center

Read, K. L. Q.; Shihab, L. H.

1998-01-01

Describes how to construct simple numerical examples in two-way ANOVAs, specifically randomized blocks, balanced two-way layouts, and Latin squares. Indicates that working through simple numerical problems is helpful to students meeting a technique for the first time and should be followed by computer-based analysis of larger, real datasets when…

Avoiding boredom: Caudate and insula activity reflects boredom-elicited purchase bias.

PubMed

Dal Mas, Dennis E; Wittmann, Bianca C

2017-07-01

People show a strong tendency to avoid boring situations, but the neural systems mediating this behavioural bias are yet unknown. We used functional magnetic resonance imaging (fMRI) to investigate how the anticipation of a boring task influences decisions to purchase entertainment. Participants accepted higher prices to avoid boredom compared to control tasks, and individual differences in boredom experience predicted the increase in price. This behavioural bias was associated with higher activity in the caudate nucleus during music purchases driven by boredom avoidance. Insula activation was increased during performance of the boring task and subsequently associated with individual differences in boredom-related decision making. These results identify a mechanism that drives decisions to avoid boring situations and potentially underlies consumer decisions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of interspecific interactions on avoidance response to contamination.

PubMed

Silva, Daniel C V R; Araújo, Cristiano V M; Marassi, Rodrigo J; Cardoso-Silva, Sheila; Neto, Morun B; Silva, Gilmar C; Ribeiro, Rui; Silva, Flávio T; Paiva, Teresa C B; Pompêo, Marcelo L M

2018-06-17

An increasing number of studies have shown the ability of organisms to escape from toxic effects due to contamination, by moving spatially towards less contaminated habitats. However, this issue has been investigated in monospecific scenarios, without considering possible interactions between species during the contamination avoidance process. It is widely known that the spatial distribution of one species can be affected by another one, in different ways. Therefore, the main question addressed in the present study was as follows: Might interspecific interaction between the freshwater fish Danio rerio (zebrafish) and Poecilia reticulata (guppy) change their behavior patterns in terms of avoidance in the presence of a copper gradient? Zebrafish and guppies exposed to a copper gradient were tested for avoidance responses in a free-choice, non-forced, static, multi-compartmented exposure system, using two distinct approaches: (1) monospecific tests, in which only one species was exposed to the copper gradient, at two different population densities; and (2) multispecific tests, in which both species were tested simultaneously. In the control (with no copper) monospecific tests, both species were randomly distributed; however, in the control multispecific test, P. reticulata tended to aggregate. In the monospecific tests with a copper gradient, both species avoided copper in a similar way, with AC 50 (concentration triggering avoidance in 50% of the exposed population) values between 15 and 18 μg·L -1 , irrespective of the population density. However, in the multispecific tests, P. reticulata displaced D. rerio to previously avoided copper levels, consequently increasing the AC 50 of D. rerio to 75 μg·L -1 . This study shows the importance of understanding the interactions among species in contaminated areas, and the way that one species can prevent the avoidance behavior of another. Copyright © 2018 Elsevier B.V. All rights reserved.

Temporary asphalt medians for two-lane, two-way operation.

DOT National Transportation Integrated Search

1989-01-01

A typical temporary asphalt median for two-lane, two-way operation is 12 to 18 in wide, 4 in high, is painted with yellow reflectorized paint, and has orange tubular markers with reflectorized white collars mounted at a spacing of about 50 ft. This h...

Context-dependent activation of reduced autobiographical memory specificity as an avoidant coping style.

PubMed

Debeer, Elise; Raes, Filip; Williams, J Mark G; Hermans, Dirk

2011-12-01

According to the affect-regulation hypothesis (Williams et al., 2007), reduced autobiographical memory specificity (rAMS) or overgeneral memory (OGM) might be considered a cognitive avoidance strategy; that is, people learn to avoid the emotionally painful consequences associated with the retrieval of specific negative memories. Based on this hypothesis, one would predict significant negative associations between AMS and avoidant coping. However, studies investigating this prediction have led to equivocal results. In the present study we tested a possible explanation for these contradictory findings. It was hypothesized that rAMS (in part) reflects an avoidant coping strategy, which might only become apparent under certain conditions, that is, conditions that signal the possibility of 'danger.' To test this hypothesis, we assessed AMS and behavioral avoidance but experimentally manipulated the instructions. In the neutral condition, two parallel versions of the Autobiographical Memory Test (AMT) were presented under neutral instructions. In the threat condition, the first AMT was presented under neutral instructions, while the second AMT was presented under 'threat instructions.' Results showed no significant correlations between avoidance and OGM under neutral conditions but significant and markedly stronger correlations under threat conditions, with more avoidance being associated with fewer specific and more categoric memories. In addition, high avoiders showed a stronger reduction in AMS in the threat condition as compared with the neutral condition, while low avoiders showed no such difference between conditions. The data confirm that OGM can be considered as part of a broader avoidant coping style. However, more importantly, they show that, at least in nonclinical individuals, the activation of this coping style may depend on the context. (c) 2011 APA, all rights reserved.

[Delayed reactions of active avoidance in white rats under conditions of an alternative choice].

PubMed

Ioseliani, T K; Sikharulidze, N I; Kadagishvili, A Ia; Mitashvili, E G

1995-01-01

It was shown that if the rats had been learned and then tested using conventional pain punishment of erroneous choice they were able to solve the problem of alternative choice only in the period of immediate action of conditioned stimuli. If the pain punishment for erroneously chosen compartment had not been applied in animal learning and testing, rats successfully solved the problem of alternative choice even after 5-second delay. Introduction of pain punishment led to the frustration of earlier elaborated delayed avoidance reactions. Analysis of the obtained results allows us to argue that the apparent incapability of white rats for solving the problems of delayed avoidance is caused by simultaneous action of two different mechanisms, i.e., those of the active and passive avoidance rather than short-term memory deficit.

Some implications of reciprocity for two-way clock synchronization

NASA Technical Reports Server (NTRS)

Jespersen, J. L.

1979-01-01

The difficulties related to propagation perturbances in one-way and two-way methods for the synchronization of remote clocks are defined, and a possible means of circumventing these problems in the two-way method is suggested. In the two-way method, if signals are launched from two sources, A and B, then the two signals arriving at A and B will be displaced in arrival time by an amount that is equal to the difference in launch times of the two signals. Thus, the only condition to comparing clocks is that the medium be isotropic. The practice implementation of this is explored theoretically, in some detail, with respect to the Loran-C navigation system.

Active avoidance requires inhibitory signaling in the rodent prelimbic prefrontal cortex

PubMed Central

Bravo-Rivera, Christian; Rodriguez-Romaguera, Jose; Pagan-Rivera, Pablo A; Burgos-Robles, Anthony; Roman-Ortiz, Ciorana; Quirk, Gregory J

2018-01-01

Much is known about the neural circuits of conditioned fear and its relevance to understanding anxiety disorders, but less is known about other anxiety-related behaviors such as active avoidance. Using a tone-signaled, platform-mediated avoidance task, we observed that pharmacological inactivation of the prelimbic prefrontal cortex (PL) delayed avoidance. Surprisingly, optogenetic silencing of PL glutamatergic neurons did not delay avoidance. Consistent with this, inhibitory but not excitatory responses of rostral PL neurons were associated with avoidance training. To test the importance of these inhibitory responses, we optogenetically stimulated PL neurons to counteract the tone-elicited reduction in firing rate. Photoactivation of rostral (but not caudal) PL neurons at 4 Hz impaired avoidance. These findings suggest that inhibitory responses of rostral PL neurons signal the avoidability of a potential threat and underscore the importance of designing behavioral optogenetic studies based on neuronal firing responses. PMID:29851381

Activation of β-adrenoceptor facilitates active avoidance learning through enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Lv, Jing; Feng, Hao; Chen, Ling; Wang, Wei-Yao; Yue, Xue-Ling; Jin, Qing-Hua

2017-10-18

Long-term potentiation (LTP) is widely accepted as the best studied model for neurophysiological mechanisms that could underlie learning and memory formation. Despite a number of studies indicating that β-adrenoceptors in the hippocampal dentate gyrus (DG) is involved in the modulation of learning and memory as well as LTP, few studies have used glutamate release as a visual indicator in awake animals to explore the role of β-adrenoceptors in learning-dependent LTP. Therefore, in the present study, the effects of propranolol (an antagonist of β-adrenoceptor) and isoproterenol (an agonist of β-adrenoceptor) on extracellular concentrations of glutamate and amplitudes of field excitatory postsynaptic potential were measured in the DG region during active avoidance learning in freely moving conscious rats. In the control group, the glutamate level in the DG was significantly increased during the acquisition of active avoidance behavior and returned to basal level following extinction training. In propranolol group, antagonism of β-adrenoceptors in the DG significantly reduced the change in glutamate level, and the acquisition of the active avoidance behavior was significantly inhibited. In contrast, the change in glutamate level was significantly enhanced by isoproterenol, and the acquisition of the active avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in glutamate level were accompanied by corresponding changes in field excitatory postsynaptic potential amplitude and active avoidance behavior. Our results suggest that activation of β-adrenoceptors in the hippocampal DG facilitates active avoidance learning by modulations of glutamate level and synaptic efficiency in rats.

Children's Avoidance of Interrupting Others' Activities in Requesting Help: Cultural Aspects of Considerateness.

PubMed

Ruvalcaba, Omar; Rogoff, Barbara; López, Angélica; Correa-Chávez, Maricela; Gutiérrez, Kris

2015-01-01

To be able to collaborate skillfully, people need to coordinate well with others, taking into account how their actions fit with those of their partners. This is a key aspect of an approach to learning called Learning by Observing and Pitching In, hypothesized to be common in many Indigenous-heritage communities of the Americas. This chapter considers cultural values that emphasize considerateness and awareness of how one's actions impact others such as the Mexican cultural value of respeto and cultural differences in children's efforts to avoid interrupting others' activity. US Mexican-heritage children showed more evidence of avoiding interrupting the ongoing activity of an adult when they requested help, compared with European American children from families with extensive schooling experience. Most of the Mexican-heritage children's requests for help that gave evidence of avoiding interruption were made nonverbally, which may facilitate unobtrusive requests. There were no significant differences among children from two US Mexican-heritage backgrounds varying in experience with Western schooling and likely experience with Indigenous-American practices, suggesting that the Mexican cultural value of respeto and associated considerateness is widespread even among US Mexican-heritage families with extensive experience with Western schooling and life in the United States. © 2015 Elsevier Inc. All rights reserved.

A Feasibility Study on Crash Avoidance at Four-Way Stop-Sign-Controlled Intersections Using Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Kim, Do Hyun; Choi, Kyoung Ho; Kim, Kyeong Tae; Li, Ki Joune

In this letter, we propose a novel approach using wireless sensor networks (WSNs) to enhance the safety and efficiency of four-way stop-sign-controlled (FWSC) intersections. The proposed algorithm provides right of way (RoW) and crash avoidance information by means of an intelligent WSN system. The system is composed of magnetic sensors, embedded in the center of a lane, with relay nodes and a base station placed on the side of the road. The experimental results show that the vehicle detection accuracy is over 99% and the sensor node battery life expectancy is over 3 years for traffic of 5, 800 vehicles per day. For the traffic application we consider, a strong effect is observed as the projected conflict rate was reduced by 72% compared to an FWSC intersection operated with only driver perception.

Big sagebrush response to one-way and two-way chaining in Southeastern Utah

Treesearch

John A. Fairchild; James N. Davis; Jack D. Brotherson

2005-01-01

A decadent, mixed stand of Wyoming big sagebrush, Artemisia tridentata wyomingensis, and mountain big sagebrush, Artemisia tridentata vaseyana, located north of Cisco, Utah, was subjected to one-way and two-way chaining treatments in November 1987. The effect of the treatments on plant community characteristics and shrub vigor was...

Successive and discrete spaced conditioning in active avoidance learning in young and aged zebrafish.

PubMed

Yang, Peng; Kajiwara, Riki; Tonoki, Ayako; Itoh, Motoyuki

2018-05-01

We designed an automated device to study active avoidance learning abilities of zebrafish. Open source tools were used for the device control, statistical computing, and graphic outputs of data. Using the system, we developed active avoidance tests to examine the effects of trial spacing and aging on learning. Seven-month-old fish showed stronger avoidance behavior as measured by color preference index with discrete spaced training as compared to successive spaced training. Fifteen-month-old fish showed a similar trend, but with reduced cognitive abilities compared with 7-month-old fish. Further, in 7-month-old fish, an increase in learning ability during trials was observed with discrete, but not successive, spaced training. In contrast, 15-month-old fish did not show increase in learning ability during trials. Therefore, these data suggest that discrete spacing is more effective for learning than successive spacing, with the zebrafish active avoidance paradigm, and that the time course analysis of active avoidance using discrete spaced training is useful to detect age-related learning impairment. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Coordinated Dynamic Behaviors for Multirobot Systems With Collision Avoidance.

PubMed

Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare

2017-12-01

In this paper, we propose a novel methodology for achieving complex dynamic behaviors in multirobot systems. In particular, we consider a multirobot system partitioned into two subgroups: 1) dependent and 2) independent robots. Independent robots are utilized as a control input, and their motion is controlled in such a way that the dependent robots solve a tracking problem, that is following arbitrarily defined setpoint trajectories, in a coordinated manner. The control strategy proposed in this paper explicitly addresses the collision avoidance problem, utilizing a null space-based behavioral approach: this leads to combining, in a non conflicting manner, the tracking control law with a collision avoidance strategy. The combination of these control actions allows the robots to execute their task in a safe way. Avoidance of collisions is formally proven in this paper, and the proposed methodology is validated by means of simulations and experiments on real robots.

Passive versus active hazard detection and avoidance systems

NASA Astrophysics Data System (ADS)

Neveu, D.; Mercier, G.; Hamel, J.-F.; Simard Bilodeau, V.; Woicke, S.; Alger, M.; Beaudette, D.

2015-06-01

Upcoming planetary exploration missions will require advanced guidance, navigation and control technologies to reach landing sites with high precision and safety. Various technologies are currently in development to meet that goal. Some technologies rely on passive sensors and benefit from the low mass and power of such solutions while others rely on active sensors and benefit from an improved robustness and accuracy. This paper presents two different hazard detection and avoidance (HDA) system design approaches. The first architecture relies only on a camera as the passive HDA sensor while the second relies, in addition, on a Lidar as the active HDA sensor. Both options use in common an innovative hazard map fusion algorithm aiming at identifying the safest landing locations. This paper presents the simulation tools and reports the closed-loop software simulation results obtained using each design option. The paper also reports the Monte Carlo simulation campaign that was used to assess the robustness of each design option. The performance of each design option is compared against each other in terms of performance criteria such as percentage of success, mean distance to nearest hazard, etc. The applicability of each design option to planetary exploration missions is also discussed.

Elevated amygdala activity during reappraisal anticipation predicts anxiety in avoidant personality disorder.

PubMed

Denny, Bryan T; Fan, Jin; Liu, Xun; Ochsner, Kevin N; Guerreri, Stephanie; Mayson, Sarah Jo; Rimsky, Liza; McMaster, Antonia; New, Antonia S; Goodman, Marianne; Siever, Larry J; Koenigsberg, Harold W

2015-02-01

Avoidant personality disorder is characterized by pervasive anxiety, fear of criticism, disapproval, and rejection, particularly in anticipation of exposure to social situations. An important but underexplored question concerns whether anxiety in avoidant patients is associated with an impaired ability to engage emotion regulatory strategies in anticipation of and during appraisal of negative social stimuli. We examined the use of an adaptive emotion regulation strategy, cognitive reappraisal, in avoidant patients. In addition to assessing individual differences in state and trait anxiety levels, self-reported affect as well as measures of neural activity were compared between 17 avoidant patients and 21 healthy control participants both in anticipation of and during performance of a reappraisal task. Avoidant patients showed greater state and trait-related anxiety relative to healthy participants. In addition, relative to healthy participants, avoidant patients showed pronounced amygdala hyper-reactivity during reappraisal anticipation, and this hyper-reactivity effect was positively associated with increasing self-reported anxiety levels. Our finding of exaggerated amygdala activity during reappraisal anticipation could reflect anxiety about the impending need to reappraise, anxiety about the certainty of an upcoming negative image, or anxiety relating to anticipated scrutiny of task responses by the experimenters. While we believe that all of these possibilities are consistent with the phenomenology of avoidant personality disorder, future research may clarify this ambiguity. These results suggest that amygdala reactivity in anticipation of receiving negative social information may represent a key component of the neural mechanisms underlying the heightened anxiety present in avoidant patients. Published by Elsevier B.V.

Avoided criticality and slow relaxation in frustrated two-dimensional models

DOE PAGES

Esterlis, Ilya; Kivelson, Steven A.; Tarjus, Gilles

2017-10-23

Here, frustration and the associated phenomenon of “avoided criticality” have been proposed as an explanation for the dramatic relaxation slowdown in glass-forming liquids. To test this, we have undertaken a Monte Carlo study of possibly the simplest such problem, the two-dimensional XY model with frustration corresponding to a small flux f per plaquette. At f = 0, there is a Berezinskii-Kosterlitz-Thouless transition at T*, but at any small but nonzero f, this transition is avoided and replaced (presumably) by a vortex-ordering transition at much lower temperatures. We thus have studied the evolution of the dynamics for small and moderate fmore » as the system is cooled from above T* to below. Although we do find strongly temperature-dependent slowing of the dynamics as T crosses T* and that simultaneously the dynamics becomes more complex, neither effect is anywhere nearly as dramatic as the corresponding phenomena in glass-forming liquids. At the very least, this implies that the properties of supercooled liquids must depend on more than frustration and the existence of an avoided transition.« less

Multiple Two-Way Time Message Exchange (TTME) Time Synchronization for Bridge Monitoring Wireless Sensor Networks

PubMed Central

Shi, Fanrong; Tuo, Xianguo; Yang, Simon X.; Li, Huailiang; Shi, Rui

2017-01-01

Wireless sensor networks (WSNs) have been widely used to collect valuable information in Structural Health Monitoring (SHM) of bridges, using various sensors, such as temperature, vibration and strain sensors. Since multiple sensors are distributed on the bridge, accurate time synchronization is very important for multi-sensor data fusion and information processing. Based on shape of the bridge, a spanning tree is employed to build linear topology WSNs and achieve time synchronization in this paper. Two-way time message exchange (TTME) and maximum likelihood estimation (MLE) are employed for clock offset estimation. Multiple TTMEs are proposed to obtain a subset of TTME observations. The time out restriction and retry mechanism are employed to avoid the estimation errors that are caused by continuous clock offset and software latencies. The simulation results show that the proposed algorithm could avoid the estimation errors caused by clock drift and minimize the estimation error due to the large random variable delay jitter. The proposed algorithm is an accurate and low complexity time synchronization algorithm for bridge health monitoring. PMID:28471418

Multiple Two-Way Time Message Exchange (TTME) Time Synchronization for Bridge Monitoring Wireless Sensor Networks.

PubMed

Shi, Fanrong; Tuo, Xianguo; Yang, Simon X; Li, Huailiang; Shi, Rui

2017-05-04

Wireless sensor networks (WSNs) have been widely used to collect valuable information in Structural Health Monitoring (SHM) of bridges, using various sensors, such as temperature, vibration and strain sensors. Since multiple sensors are distributed on the bridge, accurate time synchronization is very important for multi-sensor data fusion and information processing. Based on shape of the bridge, a spanning tree is employed to build linear topology WSNs and achieve time synchronization in this paper. Two-way time message exchange (TTME) and maximum likelihood estimation (MLE) are employed for clock offset estimation. Multiple TTMEs are proposed to obtain a subset of TTME observations. The time out restriction and retry mechanism are employed to avoid the estimation errors that are caused by continuous clock offset and software latencies. The simulation results show that the proposed algorithm could avoid the estimation errors caused by clock drift and minimize the estimation error due to the large random variable delay jitter. The proposed algorithm is an accurate and low complexity time synchronization algorithm for bridge health monitoring.

Allergen avoidance.

PubMed

Woodcock, A; Custovic, A

2000-12-09

Allergen exposure is a risk factor for sensitisation, prevalence and severity of allergic disease. Effective allergen avoidance strategies have been devised. The cost-benefit in public health terms should be established by prospective controlled studies that are under way around the world.

Development and validation of two measures of emotional contrast avoidance: The contrast avoidance questionnaires.

PubMed

Llera, Sandra J; Newman, Michelle G

2017-06-01

The Contrast Avoidance (CA) model (Newman & Llera, 2011) proposed that individuals with generalized anxiety disorder (GAD) fear sharp emotional shifts (or contrasts), such as the shift from a pleasant or neutral state to one of sudden distress following a negative event. Further, the model suggests that chronic worry is employed by those with GAD to sustain negative emotionality as a means to avoid sudden shifts into negativity. The model has received empirical support; however, no validated measure exists to assess CA tendencies. In this paper we developed and tested two measures of CA: one focusing on worry, and another examining broader mechanisms of CA that could be used test whether CA is applicable to other disorders. In Study 1, Part 1, we used 3 samples of participants (each N=410) to perform item reduction, exploratory factor analysis, and confirmatory factor analysis. In Study 1, Part 2, we performed tests of construct validity. In Study 2, we used a new sample (N=126) to determine test-retest reliability. All data point to the strong psychometric properties of the CA questionnaires and their relationship to GAD. Both measures distinguished between participants reporting clinical levels of GAD symptoms and nonanxious controls, demonstrating their utility as complementary measures of CA tendencies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trait Approach and Avoidance Motivation: Lateralized Neural Activity Associated with Executive Function

PubMed Central

Spielberg, Jeffrey M.; Miller, Gregory A.; Engels, Anna S.; Herrington, John D.; Sutton, Bradley P.; Banich, Marie T.; Heller, Wendy

2010-01-01

Motivation and executive function are both necessary for the completion of goal-directed behavior. Research investigating the manner in which these processes interact is beginning to emerge and has implicated middle frontal gyrus (MFG) as a site of interaction for relevant neural mechanisms. However, this research has focused on state motivation, and it has not examined functional lateralization. The present study examined the impact of trait levels of approach and avoidance motivation on neural processes associated with executive function. Functional magnetic resonance imaging was conducted while participants performed a color-word Stroop task. Analyses identified brain regions in which trait approach and avoidance motivation (measured by questionnaires) moderated activation associated with executive control. Approach was hypothesized to be associated with left-lateralized MFG activation, whereas avoidance was hypothesized to be associated with right-lateralized MFG activation. Results supported both hypotheses. Present findings implicate areas of middle frontal gyrus in top-down control to guide behavior in accordance with motivational goals. PMID:20728552

Two-way digital communications

NASA Astrophysics Data System (ADS)

Glenn, William E.; Daly, Ed

1996-03-01

The communications industry has been rapidly converting from analog to digital communications for audio, video, and data. The initial applications have been concentrating on point-to-multipoint transmission. Currently, a new revolution is occurring in which two-way point-to-point transmission is a rapidly growing market. The system designs for video compression developed for point-to-multipoint transmission are unsuitable for this new market as well as for satellite based video encoding. A new system developed by the Space Communications Technology Center has been designed to address both of these newer applications. An update on the system performance and design will be given.

Physical activity during work and leisure show contrasting associations with fear-avoidance beliefs: cross-sectional study among more than 10,000 wage earners of the general working population.

PubMed

Tribian, Annika; Vinstrup, Jonas; Sundstrup, Emil; Jay, Kenneth; Bös, Klaus; Andersen, Lars L

2018-01-26

The association between different types of physical activity and fear-avoidance beliefs remains unclear. This study investigates the association between work-related and leisure-time physical activity with fear-avoidance beliefs in the general working population. Currently employed wage earners (n=10,427) from the 2010 round of the Danish Work Environment Cohort Study replied to questions about work, lifestyle and health. General linear models controlling for lifestyle, psychosocial work factors, education, pain, medication-use and chronic diseases tested associations of work-related and leisure-time physical activity (explanatory variables) with fear-avoidance beliefs (outcome variable, scale 0-100). The level of fear-avoidance was 41.7 (SD 27.3), 38.0 (SD 26.9) and 54.3 (SD 27.7) among the general working population, a subgroup of pain-free individuals, and a subgroup with back disease, respectively. In the general working population, the level of fear-avoidance among those with low, moderate and high physical activity during leisure were 47 [95% confidence intervals (CI) 45-49], 44 (95% CI 42-46) and 43 (95% CI 41-45), and physical activity at work were 40 (95% CI 39-42), 44 (95% CI 42-46) and 49 (95% CI 48-51), respectively. Individuals with back disease and a high level of physical activity at work showed the overall highest level of fear-avoidance whereas pain-free individuals with a low level of physical activity at work showed the overall lowest level of fear-avoidance. Physical activity during work and leisure shows contrasting associations with fear-avoidance beliefs. While high physical activity during leisure is associated with lower levels, high physical activity at work is associated with higher levels of fear-avoidance. The present results may reflect some deeply rooted negative beliefs about pain and work in the population. On the societal level, campaigns may be a possible way forward as these have shown to improve beliefs about musculoskeletal

Two-Way Gene Interaction From Microarray Data Based on Correlation Methods.

PubMed

Alavi Majd, Hamid; Talebi, Atefeh; Gilany, Kambiz; Khayyer, Nasibeh

2016-06-01

Gene networks have generated a massive explosion in the development of high-throughput techniques for monitoring various aspects of gene activity. Networks offer a natural way to model interactions between genes, and extracting gene network information from high-throughput genomic data is an important and difficult task. The purpose of this study is to construct a two-way gene network based on parametric and nonparametric correlation coefficients. The first step in constructing a Gene Co-expression Network is to score all pairs of gene vectors. The second step is to select a score threshold and connect all gene pairs whose scores exceed this value. In the foundation-application study, we constructed two-way gene networks using nonparametric methods, such as Spearman's rank correlation coefficient and Blomqvist's measure, and compared them with Pearson's correlation coefficient. We surveyed six genes of venous thrombosis disease, made a matrix entry representing the score for the corresponding gene pair, and obtained two-way interactions using Pearson's correlation, Spearman's rank correlation, and Blomqvist's coefficient. Finally, these methods were compared with Cytoscape, based on BIND, and Gene Ontology, based on molecular function visual methods; R software version 3.2 and Bioconductor were used to perform these methods. Based on the Pearson and Spearman correlations, the results were the same and were confirmed by Cytoscape and GO visual methods; however, Blomqvist's coefficient was not confirmed by visual methods. Some results of the correlation coefficients are not the same with visualization. The reason may be due to the small number of data.

Two-Way Regularized Fuzzy Clustering of Multiple Correspondence Analysis.

PubMed

Kim, Sunmee; Choi, Ji Yeh; Hwang, Heungsun

2017-01-01

Multiple correspondence analysis (MCA) is a useful tool for investigating the interrelationships among dummy-coded categorical variables. MCA has been combined with clustering methods to examine whether there exist heterogeneous subclusters of a population, which exhibit cluster-level heterogeneity. These combined approaches aim to classify either observations only (one-way clustering of MCA) or both observations and variable categories (two-way clustering of MCA). The latter approach is favored because its solutions are easier to interpret by providing explicitly which subgroup of observations is associated with which subset of variable categories. Nonetheless, the two-way approach has been built on hard classification that assumes observations and/or variable categories to belong to only one cluster. To relax this assumption, we propose two-way fuzzy clustering of MCA. Specifically, we combine MCA with fuzzy k-means simultaneously to classify a subgroup of observations and a subset of variable categories into a common cluster, while allowing both observations and variable categories to belong partially to multiple clusters. Importantly, we adopt regularized fuzzy k-means, thereby enabling us to decide the degree of fuzziness in cluster memberships automatically. We evaluate the performance of the proposed approach through the analysis of simulated and real data, in comparison with existing two-way clustering approaches.

Dizocilpine (MK-801) impairs learning in the active place avoidance task but has no effect on the performance during task/context alternation.

PubMed

Vojtechova, Iveta; Petrasek, Tomas; Hatalova, Hana; Pistikova, Adela; Vales, Karel; Stuchlik, Ales

2016-05-15

The prevention of engram interference, pattern separation, flexibility, cognitive coordination and spatial navigation are usually studied separately at the behavioral level. Impairment in executive functions is often observed in patients suffering from schizophrenia. We have designed a protocol for assessing these functions all together as behavioral separation. This protocol is based on alternated or sequential training in two tasks testing different hippocampal functions (the Morris water maze and active place avoidance), and alternated or sequential training in two similar environments of the active place avoidance task. In Experiment 1, we tested, in adult rats, whether the performance in two different spatial tasks was affected by their order in sequential learning, or by their day-to-day alternation. In Experiment 2, rats learned to solve the active place avoidance task in two environments either alternately or sequentially. We found that rats are able to acquire both tasks and to discriminate both similar contexts without obvious problems regardless of the order or the alternation. We used two groups of rats, controls and a rat model of psychosis induced by a subchronic intraperitoneal application of 0.08mg/kg of dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors. Dizocilpine had no selective effect on parallel/sequential learning of tasks/contexts. However, it caused hyperlocomotion and a significant deficit in learning in the active place avoidance task regardless of the task alternation. Cognitive coordination tested by this task is probably more sensitive to dizocilpine than spatial orientation because no hyperactivity or learning impairment was observed in the Morris water maze. Copyright © 2016 Elsevier B.V. All rights reserved.

Collision avoidance for aircraft in abort landing

NASA Astrophysics Data System (ADS)

Mathwig, Jarret

We study the collision avoidance between two aircraft flying in the same vertical plane: a host aircraft on a glide path and an intruder aircraft on a horizontal trajectory below that of the host aircraft and heading in the opposite direction. Assuming that the intruder aircraft is uncooperative, the host aircraft executes an optimal abort landing maneuver: it applies maximum thrust setting and maximum angle of attack lifting the flight path over the original path, thereby increasing the timewise minimum distance between the two aircraft and, in this way, avoiding the potential collision. In the presence of weak constraints on the aircraft and/or the environment, the angle of attack must be brought to the maximum value and kept there until the maximin point is reached. On the other hand, in the presence of strong constraints on the aircraft and the environment, desaturation of the angle of attack might have to take place before the maximin point is reached. This thesis includes four parts. In the first part, after an introduction and review of the available literature, we reformulate and solve the one-subarc Chebyshev maximin problem as a two-subarc Bolza-Pontryagin problem in which the avoidance and the recovery maneuvers are treated simultaneously. In the second part, we develop a guidance scheme (gamma guidance) capable of approximating the optimal trajectory in real time. In the third part, we present the algorithms employed to solve the one-subarc and two-subarc problems. In the fourth part, we decompose the two-subarc Bolza-Pontryagin problem into two one-subarc problems: the avoidance problem and the recovery problem, to be solved in sequence; remarkably, for problems where the ratio of total maneuver time to avoidance time is sufficiently large (≥5), this simplified procedure predicts accurately the location of the maximin point as well as the maximin distance.

Effect of width and boundary conditions on meeting maneuvers on two-way separated cycle tracks.

PubMed

Garcia, Alfredo; Gomez, Fernando Agustin; Llorca, Carlos; Angel-Domenech, Antonio

2015-05-01

Cycle track design guidelines are rarely based on scientific studies. In the case of off-road two-way cycle tracks, a minimum width must facilitate both passing and meeting maneuvers, being meeting maneuvers the most frequent. This study developed a methodology to observe meeting maneuvers using an instrumented bicycle, equipped with video cameras, a GPS tracker, laser rangefinders and speed sensors. This bicycle collected data on six two-way cycle tracks ranging 1.3-2.15m width delimitated by different boundary conditions. The meeting maneuvers between the instrumented bicycle and every oncoming bicycle were characterized by the meeting clearance between the two bicycles, the speed of opposing bicycle and the reaction of the opposing rider: change in trajectory, stop pedaling or braking. The results showed that meeting clearance increased with the cycle track width and decreased if the cycle track had lateral obstacles, especially if they were higher than the bicycle handlebar. The speed of opposing bicycle shown the same tendency, although were more disperse. Opposing cyclists performed more reaction maneuvers on narrower cycle tracks and on cycle tracks with lateral obstacles to the handlebar height. Conclusions suggested avoiding cycle tracks narrower than 1.6m, as they present lower meeting clearances, lower bicycle speeds and frequent reaction maneuvers. Copyright © 2015 Elsevier Ltd. All rights reserved.

An investigation of two-way text messaging use with deaf students at the secondary level.

PubMed

Akamatsu, C Tane; Mayer, Connie; Farrelly, Shona

2006-01-01

Deaf and hard-of-hearing students are often delayed in developing their independent living skills because of parental restrictions on activities outside the home due to worries about their child's inability to communicate, their whereabouts, and their general safety. Recent accounts of the use of two-way text messagers suggests that, like electronic mail, distance communication problems that have long plagued deaf people may be ameliorated--by the use of such technology (M. R. Power & D. Power, 2004; S. S. Rhone & Cox News Service, 2002). This project was designed as an initial foray into investigating the use of two-way text messaging technology as a way of increasing the independence of deaf adolescents and reducing their parents' anxiety about their safety and responsibility. All the deaf and hard-of-hearing students in the deaf and hard-of-hearing programs at two urban high schools (ages 13-19), the staff of the deaf departments at these two schools, and the parents/guardians of the students participated in this study. Preuse surveys, postuse surveys, and monthly statistics on the number of times each pager was used enabled us to chart how often the participants used the technology. The data were used to identify concerns that parents have about student independence and safety, the extent to which deaf students engage in independent activities, and expectations surrounding how two-way text messaging use might increase independence and literacy skills. The data collected on this project to date confirm that two-way text messaging technology is indeed useful for deaf adolescents and helps alleviate some of the concerns that have kept them from developing independence as quickly or readily as their hearing peers. The potential policy implications for this research are discussed.

Trait approach and avoidance motivation: lateralized neural activity associated with executive function.

PubMed

Spielberg, Jeffrey M; Miller, Gregory A; Engels, Anna S; Herrington, John D; Sutton, Bradley P; Banich, Marie T; Heller, Wendy

2011-01-01

Motivation and executive function are both necessary for the completion of goal-directed behavior. Research investigating the manner in which these processes interact is beginning to emerge and has implicated middle frontal gyrus (MFG) as a site of interaction for relevant neural mechanisms. However, this research has focused on state motivation, and it has not examined functional lateralization. The present study examined the impact of trait levels of approach and avoidance motivation on neural processes associated with executive function. Functional magnetic resonance imaging was conducted while participants performed a color-word Stroop task. Analyses identified brain regions in which trait approach and avoidance motivation (measured by questionnaires) moderated activation associated with executive control. Approach was hypothesized to be associated with left-lateralized MFG activation, whereas avoidance was hypothesized to be associated with right-lateralized MFG activation. Results supported both hypotheses. Present findings implicate areas of middle frontal gyrus in top-down control to guide behavior in accordance with motivational goals. Copyright © 2010 Elsevier Inc. All rights reserved.

General immunity and superadditivity of two-way Gaussian quantum cryptography.

PubMed

Ottaviani, Carlo; Pirandola, Stefano

2016-03-01

We consider two-way continuous-variable quantum key distribution, studying its security against general eavesdropping strategies. Assuming the asymptotic limit of many signals exchanged, we prove that two-way Gaussian protocols are immune to coherent attacks. More precisely we show the general superadditivity of the two-way security thresholds, which are proven to be higher than the corresponding one-way counterparts in all cases. We perform the security analysis first reducing the general eavesdropping to a two-mode coherent Gaussian attack, and then showing that the superadditivity is achieved by exploiting the random on/off switching of the two-way quantum communication. This allows the parties to choose the appropriate communication instances to prepare the key, accordingly to the tomography of the quantum channel. The random opening and closing of the circuit represents, in fact, an additional degree of freedom allowing the parties to convert, a posteriori, the two-mode correlations of the eavesdropping into noise. The eavesdropper is assumed to have no access to the on/off switching and, indeed, cannot adapt her attack. We explicitly prove that this mechanism enhances the security performance, no matter if the eavesdropper performs collective or coherent attacks.

General immunity and superadditivity of two-way Gaussian quantum cryptography

PubMed Central

Ottaviani, Carlo; Pirandola, Stefano

2016-01-01

We consider two-way continuous-variable quantum key distribution, studying its security against general eavesdropping strategies. Assuming the asymptotic limit of many signals exchanged, we prove that two-way Gaussian protocols are immune to coherent attacks. More precisely we show the general superadditivity of the two-way security thresholds, which are proven to be higher than the corresponding one-way counterparts in all cases. We perform the security analysis first reducing the general eavesdropping to a two-mode coherent Gaussian attack, and then showing that the superadditivity is achieved by exploiting the random on/off switching of the two-way quantum communication. This allows the parties to choose the appropriate communication instances to prepare the key, accordingly to the tomography of the quantum channel. The random opening and closing of the circuit represents, in fact, an additional degree of freedom allowing the parties to convert, a posteriori, the two-mode correlations of the eavesdropping into noise. The eavesdropper is assumed to have no access to the on/off switching and, indeed, cannot adapt her attack. We explicitly prove that this mechanism enhances the security performance, no matter if the eavesdropper performs collective or coherent attacks. PMID:26928053

Operational support to collision avoidance activities by ESA's space debris office

NASA Astrophysics Data System (ADS)

Braun, V.; Flohrer, T.; Krag, H.; Merz, K.; Lemmens, S.; Bastida Virgili, B.; Funke, Q.

2016-09-01

The European Space Agency's (ESA) Space Debris Office provides a service to support operational collision avoidance activities. This support currently covers ESA's missions Cryosat-2, Sentinel-1A and -2A, the constellation of Swarm-A/B/C in low-Earth orbit (LEO), as well as missions of third-party customers. In this work, we describe the current collision avoidance process for ESA and third-party missions in LEO. We give an overview on the upgrades developed and implemented since the advent of conjunction summary messages (CSM)/conjunction data messages (CDM), addressing conjunction event detection, collision risk assessment, orbit determination, orbit and covariance propagation, process control, and data handling. We pay special attention to the effect of warning thresholds on the risk reduction and manoeuvre rates, as they are established through risk mitigation and analysis tools, such as ESA's Debris Risk Assessment and Mitigation Analysis (DRAMA) software suite. To handle the large number of CDMs and the associated risk analyses, a database-centric approach has been developed. All CDMs and risk analysis results are stored in a database. In this way, a temporary local "mini-catalogue" of objects close to our target spacecraft is obtained, which can be used, e.g., for manoeuvre screening and to update the risk analysis whenever a new ephemeris becomes available from the flight dynamics team. The database is also used as the backbone for a Web-based tool, which consists of the visualization component and a collaboration tool that facilitates the status monitoring and task allocation within the support team as well as communication with the control team. The visualization component further supports the information sharing by displaying target and chaser motion over time along with the involved uncertainties. The Web-based solution optimally meets the needs for a concise and easy-to-use way to obtain a situation picture in a very short time, and the support for

14 CFR 91.185 - IFR operations: Two-way radio communications failure.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false IFR operations: Two-way radio... RULES Flight Rules Instrument Flight Rules § 91.185 IFR operations: Two-way radio communications failure. (a) General. Unless otherwise authorized by ATC, each pilot who has two-way radio communications...

Lung Disease, Indigestion, and Two-Way Tables

ERIC Educational Resources Information Center

Watson, Jane; Callingham, Rosemary

2016-01-01

This paper considers the responses of 115 school students to two problems based on information provided in two-way tables. In each case the question asks if one of the variables involved depends on the other. Contextual knowledge might suggest a dependent relationship in both but in one problem the data show independence while in the other the…

A model of two-way selection system for human behavior.

PubMed

Zhou, Bin; Qin, Shujia; Han, Xiao-Pu; He, Zhe; Xie, Jia-Rong; Wang, Bing-Hong

2014-01-01

Two-way selection is a common phenomenon in nature and society. It appears in the processes like choosing a mate between men and women, making contracts between job hunters and recruiters, and trading between buyers and sellers. In this paper, we propose a model of two-way selection system, and present its analytical solution for the expectation of successful matching total and the regular pattern that the matching rate trends toward an inverse proportion to either the ratio between the two sides or the ratio of the state total to the smaller group's people number. The proposed model is verified by empirical data of the matchmaking fairs. Results indicate that the model well predicts this typical real-world two-way selection behavior to the bounded error extent, thus it is helpful for understanding the dynamics mechanism of the real-world two-way selection system.

Two-Way Gene Interaction From Microarray Data Based on Correlation Methods

PubMed Central

Alavi Majd, Hamid; Talebi, Atefeh; Gilany, Kambiz; Khayyer, Nasibeh

2016-01-01

Background Gene networks have generated a massive explosion in the development of high-throughput techniques for monitoring various aspects of gene activity. Networks offer a natural way to model interactions between genes, and extracting gene network information from high-throughput genomic data is an important and difficult task. Objectives The purpose of this study is to construct a two-way gene network based on parametric and nonparametric correlation coefficients. The first step in constructing a Gene Co-expression Network is to score all pairs of gene vectors. The second step is to select a score threshold and connect all gene pairs whose scores exceed this value. Materials and Methods In the foundation-application study, we constructed two-way gene networks using nonparametric methods, such as Spearman’s rank correlation coefficient and Blomqvist’s measure, and compared them with Pearson’s correlation coefficient. We surveyed six genes of venous thrombosis disease, made a matrix entry representing the score for the corresponding gene pair, and obtained two-way interactions using Pearson’s correlation, Spearman’s rank correlation, and Blomqvist’s coefficient. Finally, these methods were compared with Cytoscape, based on BIND, and Gene Ontology, based on molecular function visual methods; R software version 3.2 and Bioconductor were used to perform these methods. Results Based on the Pearson and Spearman correlations, the results were the same and were confirmed by Cytoscape and GO visual methods; however, Blomqvist’s coefficient was not confirmed by visual methods. Conclusions Some results of the correlation coefficients are not the same with visualization. The reason may be due to the small number of data. PMID:27621916

The Accuracy of Two-Way Satellite Time Transfer Calibrations

DTIC Science & Technology

2005-01-01

20392, USA Abstract Results from successive calibrations of Two-Way Satellite Time and Frequency Transfer ( TWSTFT ) operational equipment at...USNO and five remote stations using portable TWSTFT equipment are analyzed for internal and external errors, finding an average random error of ±0.35...most accurate means of operational long-distance time transfer are Two-Way Satellite Time and Frequency Transfer ( TWSTFT ) and carrier-phase GPS

Active Collision Avoidance for Planetary Landers

NASA Technical Reports Server (NTRS)

Rickman, Doug; Hannan, Mike; Srinivasan, Karthik

2015-01-01

The use of automotive radar systems are being evaluated for collision avoidance in planetary landers. Our focus is to develop a low-cost, light-weight collision avoidance system that overcomes the drawbacks identified with optical-based systems. We also seek to complement the Autonomous Landing and Hazard Avoidance Technology system by providing mission planners an alternative system that can be used on low-cost, small robotic missions and in close approach. Our approach takes advantage of how electromagnetic radiation interacts with solids. As the wavelength increases, the sensitivity of the radiation to isolated solids of a specific particle size decreases. Thus, rocket exhaust-blown dust particles, which have major significance in visible wavelengths, have much less significance at radar wavelengths.

Beneficial effect of commercial Rhodiola extract in rats with scopolamine-induced memory impairment on active avoidance.

PubMed

Vasileva, Liliya V; Getova, Damianka P; Doncheva, Nina D; Marchev, Andrey S; Georgiev, Milen I

2016-12-04

Rhodiola rosea L., family Crassulaceae also known as Golden Root or Arctic root is one of the most widely used medicinal plants with effect on cognitive dysfunction, psychological stress and depression. The aim of the study was to examine the effect of a standardized commercial Rhodiola extract on learning and memory processes in naive rats as well as its effects in rats with scopolamine-induced memory impairment. Sixty male Wistar rats were used in the study. The experiment was conducted in two series - on naive rats and on rats with scopolamine-induced model of impaired memory. The active avoidance test was performed in an automatic conventional shuttle box set-up. The criteria used were the number of conditional stimuli (avoidances), the number of unconditioned stimuli (escapes) as well as the number of intertrial crossings. The chemical fingerprinting of the standardized commercial Rhodiola extract was performed by means of nuclear magnetic resonance (NMR). Naive rats treated with standardized Rhodiola extract increased the number of avoidances during the learning session and memory retention test compared to the controls. Rats with scopolamine-induced memory impairment treated with Rhodiola extract showed an increase in the number of avoidances during the learning session and on the memory tests compared to the scopolamine group. The other two parameters were not changed in rats treated with the extract of Rhodiola in the two series. It was found that the studied Rhodiola extract exerts a beneficial effect on learning and memory processes in naive rats and rats with scopolamine-induced memory impairment. The observed effect is probably due to multiple underlying mechanisms including its modulating effect on acetylcholine levels in the brain and MAO-inhibitory activity leading to stimulation of the monoamines' neurotransmission. In addition the pronounced stress-protective properties of Rhodiola rosea L. could also play a role in the improvement of cognitive

10 Ways to Find More Time

ERIC Educational Resources Information Center

Hitch, Chris

2008-01-01

There are two ways to avoid time-crunch panic attacks: work smarter and delegate wisely. In this article, the author provides a list of some strategies and tactics he has used to help more than 500 school executives in North Carolina work smarter, delegate more effectively and become more effective instructional leaders. These strategies fall into…

Safety and economic impacts of converting two-way frontage roads to one-way : methodology and findings.

DOT National Transportation Integrated Search

2011-01-01

In the research documented here, researchers develop information to communicate the safety and : economic impacts of converting frontage roads from two-way to one-way. Researchers studied five : locations in Texas where frontage roads were converted ...

Time Out from Sex or Romance: Sexually Experienced Adolescents' Decisions to Purposefully Avoid Sexual Activity or Romantic Relationships.

PubMed

Byers, E Sandra; O'Sullivan, Lucia F; Brotto, Lori A

2016-05-01

Researchers have given significant attention to abstinence among adolescents, but far less is known about purposeful avoidance of sexual activity (and relationship involvement). Typically, it is assumed that, once adolescents have initiated sexual activity, they will thereafter engage in sexual activity if given the opportunity. However, it is unclear whether that is true as some research indicates that many adolescents engage in sexual activity intermittently. Sexually experienced adolescents may purposefully avoid engaging in sexual activity for a period of time and, if so, this has implications for understanding their sexual decision-making. We used a mixed methods approach to investigate sexually experienced adolescents' decisions to purposefully avoid further sexual activity and/or romantic relationships with a focus on how common these decisions are and factors influencing them. Participants were 411 (56 % female) adolescents (16-21 years old) who completed an on-line survey that assessed reasons for each type of avoidance, religiosity, sexual esteem, sexual distress, sexual coercion, and dysfunctional sexual beliefs. Overall, 27 % of participants had engaged in sexual avoidance and 47 % had engaged in romantic avoidance. Significantly more female than male adolescents reported sexual and romantic avoidance. Adolescents' reasons for sexual avoidance included: lack of sexual pleasure or enjoyment, relationship reasons, negative emotions, values, fear of negative outcomes, negative physical experience, and other priorities. Reasons for romantic avoidance included: effects of previous relationship, not interested in commitment, wrong time, other priorities, negative emotions, no one was good enough, and sexual concerns. Logistical regressions were used to assess associations between age, religiosity, sexual esteem, sexual distress, experience of sexual coercion, and dysfunctional sexual beliefs and having engaged in romantic and/or sexual avoidance. The

Numerical simulation of the optimal two-mode attacks for two-way continuous-variable quantum cryptography in reverse reconciliation

NASA Astrophysics Data System (ADS)

Zhang, Yichen; Li, Zhengyu; Zhao, Yijia; Yu, Song; Guo, Hong

2017-02-01

We analyze the security of the two-way continuous-variable quantum key distribution protocol in reverse reconciliation against general two-mode attacks, which represent all accessible attacks at fixed channel parameters. Rather than against one specific attack model, the expression of secret key rates of the two-way protocol are derived against all accessible attack models. It is found that there is an optimal two-mode attack to minimize the performance of the protocol in terms of both secret key rates and maximal transmission distances. We identify the optimal two-mode attack, give the specific attack model of the optimal two-mode attack and show the performance of the two-way protocol against the optimal two-mode attack. Even under the optimal two-mode attack, the performances of two-way protocol are still better than the corresponding one-way protocol, which shows the advantage of making double use of the quantum channel and the potential of long-distance secure communication using a two-way protocol.

Nitric oxide facilitates active avoidance learning via enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Wang, Shi; Pan, De-Xi; Wang, Dan; Wan, Peng; Qiu, De-Lai; Jin, Qing-Hua

2014-09-01

The hippocampus is a key structure for learning and memory in mammals, and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. Despite a number of studies indicating that nitric oxide (NO) is involved in the formation and maintenance of LTP as a retrograde messenger, few studies have used neurotransmitter release as a visual indicator in awake animals to explore the role of NO in learning-dependent long-term enhancement of synaptic efficiency. Therefore, in the present study, the effects of l-NMMA (a NO synthase inhibitor) and SNP (a NO donor) on extracellular glutamate (Glu) concentrations and amplitudes of field excitatory postsynaptic potential (fEPSP) were measured in the hippocampal dentate gyrus (DG) region during the acquisition and extinction of active-avoidance behavior in freely-moving conscious rats. In the control group, the extracellular concentration of Glu in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to baseline levels following extinction training. In the experimental group, the change in Glu concentration was significantly reduced by local microinjection of l-NMMA, as was the acquisition of the active-avoidance behavior. In contrast, the change in Glu concentration was significantly enhanced by SNP, and the acquisition of the active-avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in extracellular Glu were accompanied by corresponding changes in fEPSP amplitude and active-avoidance behavior. Our results suggest that NO in the hippocampal DG facilitates active avoidance learning via enhancements of glutamate levels and synaptic efficiency in rats. Copyright © 2014 Elsevier B.V. All rights reserved.

Avoidant Responses to Interpersonal Provocation Are Associated with Increased Amygdala and Decreased Mentalizing Network Activity

PubMed Central

Krämer, Ulrike M.

2017-01-01

When intentionally pushed or insulted, one can either flee from the provoker or retaliate. The implementation of such fight-or-flight decisions is a central aspect in the genesis and evolution of aggression episodes, yet it is usually investigated only indirectly or in nonsocial situations. In the present fMRI study, we aimed to distinguish brain regions associated with aggressive and avoidant responses to interpersonal provocation in humans. Participants (thirty-six healthy young women) could either avoid or face a highly (HP) and a lowly (LP) provoking opponent in a competitive reaction time task: the fight-or-escape (FOE) paradigm. Subjects avoided the HP more often, but retaliated when facing her. Moreover, they chose to fight the HP more quickly, and showed increased heart rate (HR) right before confronting her. Orbitofrontal cortex (OFC) and sensorimotor cortex were more active when participants decided to fight, whereas the mentalizing network was engaged when deciding to avoid. Importantly, avoiding the HP relative to the LP was associated with both higher activation in the right basolateral amygdala and lower relative activity in several mentalizing regions [e.g., medial and inferior frontal gyrus (IFG), temporal-parietal junction (TPJ)]. These results suggest that avoidant responses to provocation might result from heightened threat anticipation and are associated with reduced perspective taking. Furthermore, our study helps to reconcile conflicting findings on the role of the mentalizing network, the amygdala, and the OFC in aggression. PMID:28660251

Two-way against one-way nesting for climate downscaling in Europe and the Mediterranean region using LMDZ4

NASA Astrophysics Data System (ADS)

Li, Shan; Li, Laurent; Le Treut, Hervé

2016-04-01

In the 21st century, the estimated surface temperature warming projected by General Circulation Models (GCMs) is between 0.3 and 4.8 °C, depending on the scenario considered. GCMs exhibit a good representation of climate on a global scale, but they are not able to reproduce regional climate processes with the same level of accuracy. Society and policymakers need model projections to define climate change adaptation and mitigation policies on a global, regional and local scale. Climate downscaling is mostly conducted with a regional model nested into the outputs of a global model. This one-way nesting approach is generally used in the climate community without feedbacks from Regional Climate Models (RCMs) to GCMs. This lack of interaction between the two models may affect regional modes of variability, in particular those with a boundary conflict. The objective of this study is to evaluate a two-way nesting configuration that makes an interactive coupling between the RCM and the GCM, an approach against the traditional configuration of one-way nesting system. An additional aim of this work is to examine if the two-way nesting system can improve the RCM performance. The atmospheric component of the IPSL integrated climate model (LMDZ) is configured at both regional (LMDZ-regional) and global (LMDZ-global) scales. The two models have the same configuration for the dynamical framework and the physical forcings. The climatology values of sea surface temperature (SST) are prescribed for the two models. The stretched-grid of LMDZ-global is applied to a region defined by Europe, the Mediterranean, North Africa and Western North Atlantic. To ensure a good statistical significance of results, all simulations last at least 80 years. The nesting process of models is performed by a relaxation procedure of a time scale of 90 minutes. In the case of two-way nesting, the exchange between the two models is every two hours. The relaxation procedure induces a boundary conflict

Inflammasome and Autophagy Regulation: A Two-way Street

PubMed Central

Qian, Sun; Fan, Jie; Billiar, Timothy R; Scott, Melanie J

2017-01-01

Inflammation plays a significant role in protecting hosts against pathogens. Inflammation induced by noninfectious endogenous agents can be detrimental and, if excessive, can result in organ and tissue damage. The inflammasome is a major innate immune pathway that can be activated via both exogenous pathogen-associated molecular patterns (PAMPs) and endogenous damage-associated molecular patterns (DAMPs). Inflammasome activation involves formation and oligomerization of a protein complex including a nucleotide oligomerization domain (NOD)-like receptor (NLR), an adaptor protein and pro-caspase-1. This then allows cleavage and activation of caspase-1, followed by downstream cleavage and release of proinflammatory cytokines interleukin (IL)-1β and IL-18 from innate immune cells. Hyperinflammation caused by unrestrained inflammasome activation is linked with multiple inflammatory diseases, including inflammatory bowel disease, Alzheimer’s disease and multiple sclerosis. So there is an understandable rush to understand mechanisms that regulate such potent inflammatory pathways. Autophagy has now been identified as a main regulator of inflammasomes. Autophagy is a vital intracellular process involved in cellular homeostasis, recycling and removal of damaged organelles (eg, mitochondria) and intracellular pathogens. Autophagy is regulated by proteins that are important in endosomal/phagosomal pathways, as well as by specific autophagy proteins coded for by autophagy-related genes. Cytosolic components are surrounded and contained by a double-membraned vesicle, which then fuses with lysosomes to enable degradation of the contents. Autophagic removal of intracellular DAMPs, inflammasome components or cytokines can reduce inflammasome activation. Similarly, inflammasomes can regulate the autophagic process, allowing for a two-way mutual regulation of inflammation that may hold the key for treatment of multiple diseases. PMID:28741645

Predictors and outcome of pain-related avoidance of activities in persons with early symptomatic knee osteoarthritis: a five-year followup study.

PubMed

Holla, Jasmijn F M; van der Leeden, Marike; Knol, Dirk L; Roorda, Leo D; Hilberdink, Wim K H A; Lems, Willem F; Steultjens, Martijn P M; Dekker, Joost

2015-01-01

It has been hypothesized that pain and low vitality lead to an increase in avoidance of activities in persons with early symptomatic knee osteoarthritis (OA), and that avoidance of activities leads to an increase in activity limitations. The present study aimed to evaluate these hypotheses. Baseline, 2-year, and 5-year followup data of 828 participants from the Cohort Hip and Cohort Knee Study with early symptomatic knee OA were used. Autoregressive generalized estimating equations and linear regression models were used to analyze the longitudinal and cross-sectional associations between self-reported knee pain, vitality, pain-related avoidance of activities, and activity limitations. The models were adjusted for the covariates age, sex, education level, body mass index, comorbidity, radiographic severity, and hip pain. In longitudinal analyses, knee pain and vitality predicted a subsequent increase in avoidance of activities. Pain-related avoidance of activities predicted a subsequent increase in activity limitations; however, this relationship lost statistical significance (P = 0.089) after adjustment for covariates. Cross-sectional analyses showed strong relationships between knee pain, low vitality, pain-related avoidance of activities, and activity limitations at all time points. In persons with early symptomatic knee OA, knee pain and low vitality lead to a subsequent increase in avoidance of activities. Pain-related avoidance of activities is related to activity limitations at inception of symptoms, but also years later. Therefore, it can be recommended to monitor and target avoidance of activities at various stages of the disease. Copyright © 2015 by the American College of Rheumatology.

Two way time transfer results at NRL and USNO

NASA Technical Reports Server (NTRS)

Galysh, Ivan J.; Landis, G. Paul

1993-01-01

The Naval Research Laboratory (NRL) has developed a two way time transfer modem system for the United States Naval Observatory (USNO). Two modems in conjunction with a pair of Very Small Aperture Terminal (VSAT) and a communication satellite can achieve sub nanosecond time transfer. This performance is demonstrated by the results of testing at and between NRL and USNO. The modems use Code Division Multiple Access (CDMA) methods to separate their signals through a single path in the satellite. Each modem transmitted a different Pseudo Random Noise (PRN) code and received the others PRN code. High precision time transfer is possible with two way methods because of reciprocity of many of the terms of the path and hardware delay between the two modems. The hardware description was given in a previous paper.

Two-way and three-way approaches to ultra high performance liquid chromatography-photodiode array dataset for the quantitative resolution of a two-component mixture containing ciprofloxacin and ornidazole.

PubMed

Dinç, Erdal; Ertekin, Zehra Ceren; Büker, Eda

2016-09-01

Two-way and three-way calibration models were applied to ultra high performance liquid chromatography with photodiode array data with coeluted peaks in the same wavelength and time regions for the simultaneous quantitation of ciprofloxacin and ornidazole in tablets. The chromatographic data cube (tensor) was obtained by recording chromatographic spectra of the standard and sample solutions containing ciprofloxacin and ornidazole with sulfadiazine as an internal standard as a function of time and wavelength. Parallel factor analysis and trilinear partial least squares were used as three-way calibrations for the decomposition of the tensor, whereas three-way unfolded partial least squares was applied as a two-way calibration to the unfolded dataset obtained from the data array of ultra high performance liquid chromatography with photodiode array detection. The validity and ability of two-way and three-way analysis methods were tested by analyzing validation samples: synthetic mixture, interday and intraday samples, and standard addition samples. Results obtained from two-way and three-way calibrations were compared to those provided by traditional ultra high performance liquid chromatography. The proposed methods, parallel factor analysis, trilinear partial least squares, unfolded partial least squares, and traditional ultra high performance liquid chromatography were successfully applied to the quantitative estimation of the solid dosage form containing ciprofloxacin and ornidazole. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assessing factorial invariance of two-way rating designs using three-way methods

PubMed Central

Kroonenberg, Pieter M.

2015-01-01

Assessing the factorial invariance of two-way rating designs such as ratings of concepts on several scales by different groups can be carried out with three-way models such as the Parafac and Tucker models. By their definitions these models are double-metric factorially invariant. The differences between these models lie in their handling of the links between the concept and scale spaces. These links may consist of unrestricted linking (Tucker2 model), invariant component covariances but variable variances per group and per component (Parafac model), zero covariances and variances different per group but not per component (Replicated Tucker3 model) and strict invariance (Component analysis on the average matrix). This hierarchy of invariant models, and the procedures by which to evaluate the models against each other, is illustrated in some detail with an international data set from attachment theory. PMID:25620936

Functional Connectivity in Frequency-Tagged Cortical Networks During Active Harm Avoidance

PubMed Central

Miskovic, Vladimir; Príncipe, José C.; Keil, Andreas

2015-01-01

Abstract Many behavioral and cognitive processes are grounded in widespread and dynamic communication between brain regions. Thus, the quantification of functional connectivity with high temporal resolution is highly desirable for capturing in vivo brain function. However, many of the commonly used measures of functional connectivity capture only linear signal dependence and are based entirely on relatively simple quantitative measures such as mean and variance. In this study, the authors used a recently developed algorithm, the generalized measure of association (GMA), to quantify dynamic changes in cortical connectivity using steady-state visual evoked potentials (ssVEPs) measured in the context of a conditioned behavioral avoidance task. GMA uses a nonparametric estimator of statistical dependence based on ranks that are efficient and capable of providing temporal precision roughly corresponding to the timing of cognitive acts (∼100–200 msec). Participants viewed simple gratings predicting the presence/absence of an aversive loud noise, co-occurring with peripheral cues indicating whether the loud noise could be avoided by means of a key press (active) or not (passive). For active compared with passive trials, heightened connectivity between visual and central areas was observed in time segments preceding and surrounding the avoidance cue. Viewing of the threat stimuli also led to greater initial connectivity between occipital and central regions, followed by heightened local coupling among visual regions surrounding the motor response. Local neural coupling within extended visual regions was sustained throughout major parts of the viewing epoch. These findings are discussed in a framework of flexible synchronization between cortical networks as a function of experience and active sensorimotor coupling. PMID:25557925

One-way versus two-way text messaging on improving medication adherence: meta-analysis of randomized trials.

PubMed

Wald, David S; Butt, Shahena; Bestwick, Jonathan P

2015-10-01

Mobile telephone text messaging is a simple potential solution to the failure to take medications as directed. There is uncertainty over the effectiveness of 1-way text messaging (sending text message reminders only) compared with 2-way text messaging (sending reminders and receiving replies confirming whether medication has been taken) as a means of improving medication adherence. A meta-analysis of 8 randomized trials (1994 patients) that tested the effectiveness of text messaging on medication adherence was performed. The trials were divided into 2 groups: trials using 1-way text messaging versus no text messaging and trials using 2-way text messaging versus no text messaging. The summary estimates of the effect of the 2 methods of text messaging (1-way or 2-way) were compared. The summary relative risk estimate was 1.04 (95% confidence interval, 0.97-1.11) for 1-way text messaging and 1.23 (95% confidence interval, 1.13-1.35) for 2-way text messaging. The difference in effect between the 2 methods was statistically significant (P = .007). Two-way text messaging is associated with substantially improved medication adherence compared with 1-way text messaging. This has important implications in the provision of mobile-based messaging in the management of patients taking medication for the prevention of chronic disease. Copyright © 2015 Elsevier Inc. All rights reserved.

The dense core vesicle protein IA-2, but not IA-2β, is required for active avoidance learning.

PubMed

Carmona, G N; Nishimura, T; Schindler, C W; Panlilio, L V; Notkins, A L

2014-06-06

The islet-antigens IA-2 and IA-2β are major autoantigens in type-1 diabetes and transmembrane proteins in dense core vesicles (DCV). Recently we showed that deletion of both IA-2 and IA-2β alters the secretion of hormones and neurotransmitters and impairs behavior and learning. The present study was designed to evaluate the contribution to learning of each of these genes by using single knockout (SKO) and double knockout (DKO) mice in an active avoidance test. After 5 days of training, wild-type (WT) mice showed 60-70% active avoidance responses, whereas the DKO mice showed only 10-15% active avoidance responses. The degree of active avoidance responses in the IA-2 SKO mice was similar to that of the DKO mice, but in contrast, the IA-2β SKO mice behaved like WT mice showing 60-70% active avoidance responses. Molecular studies revealed a marked decrease in the phosphorylation of the cAMP response element-binding protein (CREB) and Ca(2+)/calmodulin-dependent protein kinase II (CAMKII) in the striatum and hippocampus of the IA-2 SKO and DKO mice, but not in the IA-2β SKO mice. To evaluate the role of CREB and CAMKII in the SKO and DKO mice, GBR-12909, which selectively blocks the dopamine uptake transporter and increases CREB and CAMKII phosphorylation, was administered. GBR-12909 restored the phosphorylation of CREB and CAMKII and increased active avoidance learning in the DKO and IA-2 SKO to near the normal levels found in the WT and IA-2β SKO mice. We conclude that in the absence of the DCV protein IA-2, active avoidance learning is impaired. Published by Elsevier Ltd.

Striatopallidal neurons control avoidance behavior in exploratory tasks.

PubMed

LeBlanc, Kimberly H; London, Tanisha D; Szczot, Ilona; Bocarsly, Miriam E; Friend, Danielle M; Nguyen, Katrina P; Mengesha, Marda M; Rubinstein, Marcelo; Alvarez, Veronica A; Kravitz, Alexxai V

2018-04-25

The dorsal striatum has been linked to decision-making under conflict, but the mechanism by which striatal neurons contribute to approach-avoidance conflicts remains unclear. We hypothesized that striatopallidal dopamine D2 receptor (D2R)-expressing neurons promote avoidance, and tested this hypothesis in two exploratory approach-avoidance conflict paradigms in mice: the elevated zero maze and open field. Genetic elimination of D2Rs on striatopallidal neurons (iMSNs), but not other neural populations, increased avoidance of the open areas in both tasks, in a manner that was dissociable from global changes in movement. Population calcium activity of dorsomedial iMSNs was disrupted in mice lacking D2Rs on iMSNs, suggesting that disrupted output of iMSNs contributes to heightened avoidance behavior. Consistently, artificial disruption of iMSN output with optogenetic stimulation heightened avoidance of open areas of these tasks, while inhibition of iMSN output reduced avoidance. We conclude that dorsomedial striatal iMSNs control approach-avoidance conflicts in exploratory tasks, and highlight this neural population as a potential target for reducing avoidance in anxiety disorders.

33 CFR 157.136 - Two-way voice communications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.136 Two-way voice communications. Each tank vessel having a COW system under § 157.10(e), § 157.10a(a...

Investigation of pedestrian crashes on two-way two-lane rural roads in Ethiopia.

PubMed

Tulu, Getu Segni; Washington, Simon; Haque, Md Mazharul; King, Mark J

2015-05-01

Understanding pedestrian crash causes and contributing factors in developing countries is critically important as they account for about 55% of all traffic crashes. Not surprisingly, considerable attention in the literature has been paid to road traffic crash prediction models and methodologies in developing countries of late. Despite this interest, there are significant challenges confronting safety managers in developing countries. For example, in spite of the prominence of pedestrian crashes occurring on two-way two-lane rural roads, it has proven difficult to develop pedestrian crash prediction models due to a lack of both traffic and pedestrian exposure data. This general lack of available data has further hampered identification of pedestrian crash causes and subsequent estimation of pedestrian safety performance functions. The challenges are similar across developing nations, where little is known about the relationship between pedestrian crashes, traffic flow, and road environment variables on rural two-way roads, and where unique predictor variables may be needed to capture the unique crash risk circumstances. This paper describes pedestrian crash safety performance functions for two-way two-lane rural roads in Ethiopia as a function of traffic flow, pedestrian flows, and road geometry characteristics. In particular, random parameter negative binomial model was used to investigate pedestrian crashes. The models and their interpretations make important contributions to road crash analysis and prevention in developing countries. They also assist in the identification of the contributing factors to pedestrian crashes, with the intent to identify potential design and operational improvements. Copyright © 2015. Published by Elsevier Ltd.

Life-threatening event reduces subjective well-being through activating avoidance motivation: a longitudinal study.

PubMed

Van Dijk, Dina; Seger-Guttmann, Tali; Heller, Daniel

2013-04-01

Drawing on the approach-avoidance theory, we have examined the role of avoidance motivation in explaining the negative effects of a life-threatening event on subjective well-being (SWB). Residents of the south of Israel were surveyed during heavy missile attacks in January 2009 (T1; n = 283), and again after 6 months (T2; n = 212) and 1 year (T3; n = 154). During the missile attacks, we also surveyed a group from the center of the country (T1; n = 102), not exposed to the attacks. The results indicate that avoidance motivation was activated by the life threat and further mediated its detrimental influence on SWB measures (positive/negative affects, anxiety, and subjective health). Moreover, within the southern sample, the drop in avoidance motivation over time mediated the parallel drop in SWB. In contrast to avoidance motivation, approach motivation remained stable over time and was related to positive emotions. The role of avoidance and approach motivations in life-threatening situations is further discussed. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Evaluation of coping resources and self-esteem as moderators of the relationship between threat appraisals and avoidance of activities after traumatic brain injury.

PubMed

Riley, Gerard A; Dennis, Rebecca K; Powell, Theresa

2010-12-01

It is not uncommon for people after a traumatic brain injury (TBI) to develop anxieties about possible negative outcomes (i.e., threat appraisals) in relation to participating in valued activities. Some respond to this anxiety by avoiding the activities, but others maintain their participation. The present study investigated two factors that may help explain this variation across individuals in their response to threat appraisals - self-esteem and the evaluation of coping resources. Forty-one individuals with a TBI completed the Avoidance and Threat Appraisals Questionnaire, the Rosenberg Self-Esteem Scale and the Coping Resources Questionnaire. The study's hypotheses were supported: Those low in self-esteem, and those with a negative evaluation of their ability to cope with the TBI, were significantly more likely to respond to threat appraisals with avoidance. Those whose injury was more recent and those whose injury was the result of an assault were also more likely to respond with avoidance. The theoretical and therapeutic implications of these results are discussed.

Repeating Patterns in Kindergarten: Findings from Children's Enactments of Two Activities

ERIC Educational Resources Information Center

Tsamir, Pessia; Tirosh, Dina; Levenson, Esther S.; Barkai, Ruthi; Tabach, Michal

2017-01-01

This paper describes kindergarten children's engagement with two patterning activities. The first activity includes two tasks in which children are asked to choose possible ways for extending two different repeating patterns and the second activity calls for comparing different pairs of repeating patterns. Children's recognition of the unit of…

Dispositional anger and the resolution of the approach-avoidance conflict.

PubMed

Robinson, Michael D; Boyd, Ryan L; Persich, Michelle R

2016-09-01

The approach-avoidance conflict is one in which approaching reward brings increased threat while avoiding threat means forgoing reward. This conflict can be uniquely informative because it will be resolved in different ways depending on whether approach (toward) or avoidance (away from) is the stronger motive. Two studies (total N = 191) created a computerized version of this conflict and used the test to examine questions of motivational direction in anger. In Study 1, noise blast provocations increased the frequency of approach behaviors at high levels of trait anger, but decreased their frequency at low levels. In Study 2, a simpler version of the conflict test was used to predict anger in daily life. As hypothesized, greater approach frequencies in the test predicted greater anger reactivity to daily provocations and frustrations. The discussion focuses on the utility of the approach-avoidance conflict test and on questions of motivational direction in anger. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

An Investigation of Two-Way Text Messaging Use with Deaf Students at the Secondary Level

ERIC Educational Resources Information Center

Akamatsu, C. Tane; Mayer, Connie; Farrelly, Shona

2006-01-01

Deaf and hard-of-hearing students are often delayed in developing their independent living skills because of parental restrictions on activities outside the home due to worries about their child's inability to communicate, their whereabouts, and their general safety. Recent accounts of the use of two-way text messagers suggests that, like…

Dealing with Activism in Canada: An Ideal Cultural Fit for the Two-Way Symmetrical Public Relations Model.

ERIC Educational Resources Information Center

Guiniven, John E.

2002-01-01

Notes that disputes are seen as much less confrontational, much less zero-sum games in Canada than in the United States. Interviews 15 communications and public relations practitioners and professors with experiences on both sides of the 49th parallel and reviews relevant literature. Concludes that the greater acceptance of two-way symmetrical…

Method of preparing a two-way shape memory alloy

DOEpatents

Johnson, Alfred D.

1984-01-01

A two-way shape memory alloy, a method of training a shape memory alloy, and a heat engine employing the two-way shape memory alloy to do external work during both heating and cooling phases. The alloy is heated under a first training stress to a temperature which is above the upper operating temperature of the alloy, then cooled to a cold temperature below the zero-force transition temperature of the alloy, then deformed while applying a second training stress which is greater in magnitude than the stress at which the alloy is to be operated, then heated back to the hot temperature, changing from the second training stress back to the first training stress.

Method of preparing a two-way shape memory alloy

DOEpatents

Johnson, A.D.

1984-03-06

A two-way shape memory alloy, a method of training a shape memory alloy, and a heat engine employing the two-way shape memory alloy to do external work during both heating and cooling phases are disclosed. The alloy is heated under a first training stress to a temperature which is above the upper operating temperature of the alloy, then cooled to a cold temperature below the zero-force transition temperature of the alloy, then deformed while applying a second training stress which is greater in magnitude than the stress at which the alloy is to be operated, then heated back to the hot temperature, changing from the second training stress back to the first training stress. 8 figs.

Two-way reflector based on two-dimensional sub-wavelength high-index contrast grating on SOI

NASA Astrophysics Data System (ADS)

Kaur, Harpinder; Kumar, Mukesh

2016-05-01

A two-dimensional (2D) high-index contrast grating (HCG) is proposed as a two-way reflector on Silicon-on-insulator (SOI). The proposed reflector provides high reflectivity over two (practically important) sets of angles of incidence- normal (θ = 0 °) and oblique/grazing (θ = 80 ° - 85 ° / 90 °). Analytical model of 2D HCG is presented using improved Fourier modal method. The vertical incidence is useful for application in VCSEL while oblique/grazing incidence can be utilized in high confinement (HCG mirrors based) hollow waveguides and Bragg reflectors. The proposed two-way reflector also exhibits a large reflection bandwidth (around telecom wavelength) which is an advantage for broadband photonic devices.

The biological basis of a universal constraint on color naming: cone contrasts and the two-way categorization of colors.

PubMed

Xiao, Youping; Kavanau, Christopher; Bertin, Lauren; Kaplan, Ehud

2011-01-01

Many studies have provided evidence for the existence of universal constraints on color categorization or naming in various languages, but the biological basis of these constraints is unknown. A recent study of the pattern of color categorization across numerous languages has suggested that these patterns tend to avoid straddling a region in color space at or near the border between the English composite categories of "warm" and "cool". This fault line in color space represents a fundamental constraint on color naming. Here we report that the two-way categorization along the fault line is correlated with the sign of the L- versus M-cone contrast of a stimulus color. Moreover, we found that the sign of the L-M cone contrast also accounted for the two-way clustering of the spatially distributed neural responses in small regions of the macaque primary visual cortex, visualized with optical imaging. These small regions correspond to the hue maps, where our previous study found a spatially organized representation of stimulus hue. Altogether, these results establish a direct link between a universal constraint on color naming and the cone-specific information that is represented in the primate early visual system.

The Multicultural Science Framework: Research on Innovative Two-Way Immersion Science Classrooms.

ERIC Educational Resources Information Center

Hadi-Tabassum, Samina

2000-01-01

Reviews the different approaches to multicultural science teaching that have emerged in the past decade, focusing on the Spanish-English two-way immersion classroom, which meets the needs of Spanish speakers learning English and introduces students to the idea of collaboration across languages and cultures. Two urban two-way immersion classrooms…

Are the carrot and the stick the two sides of same coin? A neural examination of approach/avoidance motivation during cognitive performance.

PubMed

Belayachi, Sanaâ; Majerus, Steve; Gendolla, Guido; Salmon, Eric; Peters, Frédéric; Van der Linden, Martial

2015-10-15

The present study examined neural circuit activity in a working memory (WM) task under conditions of approach and avoidance motivation. Eighteen participants were scanned with functional MRI while they performed a 3-back WM task under three conditions: in an avoidance condition incorrect responses were punished with monetary loss; in an approach condition correct responses were rewarded with monetary gain; in a neutral control condition there was no monetary incentive. Compared with the control condition, activation in fronto-parietal areas - which are associated with WM processing - was increased in both the approach and avoidance conditions. The results suggest that both approach and avoidance motivation increase task-related cognitive activation. Copyright © 2015 Elsevier B.V. All rights reserved.

Cbl-independent degradation of Met: ways to avoid agonism of bivalent Met-targeting antibody.

PubMed

Lee, J M; Kim, B; Lee, S B; Jeong, Y; Oh, Y M; Song, Y-J; Jung, S; Choi, J; Lee, S; Cheong, K H; Kim, D U; Park, H W; Han, Y K; Kim, G W; Choi, H; Song, P H; Kim, K A

2014-01-02

The Met receptor tyrosine kinase, found to be constitutively activated in many tumors, has become a leading target for cancer therapy. Disruptions in Met downregulation have been associated with aggressive tumor progression with several therapeutic strategies addressing this aspect of Met biology. Castias B-lineage lymphoma (Cbl) E3 ligase-mediated degradation, which attenuates Met signaling via ligand-dependent Met internalization, is a major negative regulator of Met expression. It is believed that one of the mechanisms by which the therapeutic anti-Met antibodies induce cancer cell death in Met overexpressing tumors is via internalization and subsequent degradation of Met from the cell surface. However, a previously reported Met-targeting antibody demonstrated intrinsic agonistic activity while being capable of inducing Cbl-mediated degradation of Met, suggesting that Cbl-mediated degradation requires receptor activation and impedes therapeutic application. We have developed a potent and selective bivalent Met-targeting antibody (SAIT301) that invokes Met degradation using an alternative regulator LRIG1. In this report, we demonstrate that LRIG1 mediates degradation of Met by SAIT301 and this degradation does not require Met activation. Furthermore, SAIT301 was able to downregulate Met and dramatically inhibit growth of tumors with low or no Cbl expression, as well as tumors with Met exon 14 deletion that prevents Met binding to Cbl. In summary, we demonstrate the enhanced therapeutic potential of a novel tumor-inhibiting anti-Met antibody, SAIT301, which utilizes a Cbl-independent, LRIG1-mediated Met degradation pathway and thereby avoids the agonism that limits the effectiveness of previously reported anti-Met antibodies.

Effect of a timebase mismatch in two-way optical frequency transfer

NASA Astrophysics Data System (ADS)

Tampellini, Anna; Clivati, Cecilia; Levi, Filippo; Mura, Alberto; Calonico, Davide

2017-12-01

Two-way frequency transfer on optical fibers is a powerful technique for the comparison of distant clocks over long and ultra-long hauls. In contrast to traditional Doppler noise cancellation, it is capable of sustaining higher link attenuation, mitigating the need of optical amplification and regeneration and thus reducing the setup complexity. We investigate the ultimate limitations of the two-way approach on a 300 km multiplexed fiber haul, considering fully independent setups and acquisition systems at the two link ends. We derive a theoretical model to predict the performance deterioration due to a bad synchronisation of the measurements, which is confirmed by experimental results. This study demonstrates that two-way optical frequency transfer is a reliable and performing technique, capable of sustaining remote clocks comparisons at the 10-19 resolution, and is relevant for the development of a fiber network of continental scale for frequency metrology in Europe.

New Trends in Two-Way Time and Frequency Transfer via Satellite

DTIC Science & Technology

1999-12-01

Recent developments performed with SATRE two-way time transfer ( TWSTFT ) modems resulted in significant performance upgrades and operational...improvements of the TWSTFT method These are aimed to reduce : manpower effort and to provide reliable, real-time data via a centralized monitoring and...collection have been used throughout the experiment INTRODUCTION Two-Way Time and Frequency Transfer via Satellite ( TWSTFT ) is a well established method to

Risk avoidance versus risk reduction: a framework and segmentation profile for understanding adolescent sexual activity.

PubMed

Hopkins, Christopher D; Tanner, John F; Raymond, Mary Anne

2004-01-01

The teen birthrate in the United States is twice that of other industrialized nations. Adolescents in the U.S. are among high-risk groups for HIV/AIDS and other sexually transmitted diseases. As a result, the Department of Health and Human Services changed its policy on the promotion of abstinence to teenagers from a focus on a risk reduction strategy to a focus on a risk avoidance strategy. In order to create more effective risk avoidance as well as risk reduction campaigns, this study proposes a framework to illustrate the distinction that teens make between spontaneous sexual activity and planned sexual activity, as well as those teens that make a commitment to abstinence versus abstinence by default. Furthermore, this study classifies teens into three behavior segments (abstemious, promiscuous and monogamous) and then assesses specific differences that exist within these groups relative to their attitudes and perceptions concerning abstinence, sexual activity, contraception, fear and norms. This change in focus from a risk reduction to a risk avoidance strategy has important implications for social marketing, public policy and marketing theory.

Automatic honesty forgoing reward acquisition and punishment avoidance: a functional MRI investigation

PubMed Central

Yoneda, Mei; Ueda, Ryuhei; Ashida, Hiroshi

2017-01-01

Recent neuroimaging investigations into human honesty suggest that honest moral decisions in individuals who consistently behave honestly occur automatically, without the need for active self-control. However, it remains unclear whether this observation can be applied to two different types of honesty: honesty forgoing dishonest reward acquisition and honesty forgoing dishonest punishment avoidance. To address this issue, a functional MRI study, using an incentivized prediction task in which participants were confronted with real and repeated opportunities for dishonest gain leading to reward acquisition and punishment avoidance, was conducted. Behavioral data revealed that the frequency of dishonesty was equivalent between the opportunities for dishonest reward acquisition and for punishment avoidance. Reaction time data demonstrated that two types of honest decisions in the opportunity for dishonest reward acquisition and punishment avoidance required no additional cognitive control. Neuroimaging data revealed that honest decisions in the opportunity for dishonest reward acquisition and those for punishment avoidance required no additional control-related activity compared with a control condition in which no opportunity for dishonest behavior was given. These results suggest that honesty flows automatically, irrespective of the concomitant motivation for dishonesty leading to reward acquisition and punishment avoidance. PMID:28746066

Automatic honesty forgoing reward acquisition and punishment avoidance: a functional MRI investigation.

PubMed

Yoneda, Mei; Ueda, Ryuhei; Ashida, Hiroshi; Abe, Nobuhito

2017-09-27

Recent neuroimaging investigations into human honesty suggest that honest moral decisions in individuals who consistently behave honestly occur automatically, without the need for active self-control. However, it remains unclear whether this observation can be applied to two different types of honesty: honesty forgoing dishonest reward acquisition and honesty forgoing dishonest punishment avoidance. To address this issue, a functional MRI study, using an incentivized prediction task in which participants were confronted with real and repeated opportunities for dishonest gain leading to reward acquisition and punishment avoidance, was conducted. Behavioral data revealed that the frequency of dishonesty was equivalent between the opportunities for dishonest reward acquisition and for punishment avoidance. Reaction time data demonstrated that two types of honest decisions in the opportunity for dishonest reward acquisition and punishment avoidance required no additional cognitive control. Neuroimaging data revealed that honest decisions in the opportunity for dishonest reward acquisition and those for punishment avoidance required no additional control-related activity compared with a control condition in which no opportunity for dishonest behavior was given. These results suggest that honesty flows automatically, irrespective of the concomitant motivation for dishonesty leading to reward acquisition and punishment avoidance.

Improvement of two-way continuous-variable quantum key distribution with virtual photon subtraction

NASA Astrophysics Data System (ADS)

Zhao, Yijia; Zhang, Yichen; Li, Zhengyu; Yu, Song; Guo, Hong

2017-08-01

We propose a method to improve the performance of two-way continuous-variable quantum key distribution protocol by virtual photon subtraction. The virtual photon subtraction implemented via non-Gaussian post-selection not only enhances the entanglement of two-mode squeezed vacuum state but also has advantages in simplifying physical operation and promoting efficiency. In two-way protocol, virtual photon subtraction could be applied on two sources independently. Numerical simulations show that the optimal performance of renovated two-way protocol is obtained with photon subtraction only used by Alice. The transmission distance and tolerable excess noise are improved by using the virtual photon subtraction with appropriate parameters. Moreover, the tolerable excess noise maintains a high value with the increase in distance so that the robustness of two-way continuous-variable quantum key distribution system is significantly improved, especially at long transmission distance.

Differences in Active Avoidance Conditioning in Male and Female Rats with Experimental Anxiety-Depressive Disorder.

PubMed

Khlebnikova, N N; Krupina, N A; Kushnareva, E Yu; Orlova, I N

2015-07-01

Using rat model of experimental anxiety-depressive disorder caused by postnatal administration of methionyl-2(S)-cyanopyrrolidine, an inhibitor of dipeptidyl peptidase IV, we compared conditioned active avoidance response and memory retention in males and females. In experimental males and females, conditioning was impaired in comparison with the control. In experimental groups, females were worse learners than males, while in control groups, females were better learners than males. Memory retention in experimental animals did not differ from that in controls 24 h after learning. Two months after learning, control females demonstrated better retention than control males.

[Effectively communicate active listening : Comparison of two concepts].

PubMed

Martin, O; Rockenbauch, K; Kleinert, E; Stöbel-Richter, Y

2017-09-01

Communication between physicians and patients has a great influence on patient adherence, patient satisfaction and the success of treatment. In this context, patient centered care and emotional support have a high positive impact; however, it is unclear how physicians can be motivated to communicate with patients in an appreciative and empathetic way. The implementation of such behavior requires a multitude of communicative skills. One of them is active listening, which is very important in two respects. On the one hand active listening provides the basis for several conversational contexts as a special communication technique and on the other hand active listening is presented in current textbooks in different ways: as an attitude or as a technique. In light of this, the question arises how active listening should be taught in order to be not only applicable in concrete conversations but also to lead to the highest possible level of patient satisfaction. The aim of this pilot study was to examine some variations in simulated doctor-patient conversations, which are the result of the different approaches to active listening. For this purpose three groups of first semester medical students were recruited, two of which were schooled in active listening in different ways (two groups of six students), i.e. attitude versus technique oriented. The third group (seven students) acted as the control group. In a pre-post design interviews with standardized simulation patients were conducted and subsequently evaluated. The analysis of these interviews was considered from the perspectives of participants and observers as well as the quantitative aspects. This study revealed some interesting tendencies despite its status as a pilot study: in general, the two interventional groups performed significantly better than the control group in which no relevant changes occurred. In a direct comparison, the group in which active listening was taught from an attitude approach achieved

PETOOL: MATLAB-based one-way and two-way split-step parabolic equation tool for radiowave propagation over variable terrain

NASA Astrophysics Data System (ADS)

Ozgun, Ozlem; Apaydin, Gökhan; Kuzuoglu, Mustafa; Sevgi, Levent

2011-12-01

A MATLAB-based one-way and two-way split-step parabolic equation software tool (PETOOL) has been developed with a user-friendly graphical user interface (GUI) for the analysis and visualization of radio-wave propagation over variable terrain and through homogeneous and inhomogeneous atmosphere. The tool has a unique feature over existing one-way parabolic equation (PE)-based codes, because it utilizes the two-way split-step parabolic equation (SSPE) approach with wide-angle propagator, which is a recursive forward-backward algorithm to incorporate both forward and backward waves into the solution in the presence of variable terrain. First, the formulation of the classical one-way SSPE and the relatively-novel two-way SSPE is presented, with particular emphasis on their capabilities and the limitations. Next, the structure and the GUI capabilities of the PETOOL software tool are discussed in detail. The calibration of PETOOL is performed and demonstrated via analytical comparisons and/or representative canonical tests performed against the Geometric Optic (GO) + Uniform Theory of Diffraction (UTD). The tool can be used for research and/or educational purposes to investigate the effects of a variety of user-defined terrain and range-dependent refractivity profiles in electromagnetic wave propagation. Program summaryProgram title: PETOOL (Parabolic Equation Toolbox) Catalogue identifier: AEJS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJS_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 143 349 No. of bytes in distributed program, including test data, etc.: 23 280 251 Distribution format: tar.gz Programming language: MATLAB (MathWorks Inc.) 2010a. Partial Differential Toolbox and Curve Fitting Toolbox required Computer: PC Operating system: Windows XP and

Behaviourally-inhibited temperament and female sex, two vulnerability factors for anxiety disorders, facilitate conditioned avoidance (also) in humans

PubMed Central

Sheynin, Jony; Beck, Kevin D.; Pang, Kevin C.H.; Servatius, Richard J.; Shikari, Saima; Ostovich, Jacqueline; Myers, Catherine E.

2014-01-01

Acquisition and maintenance of avoidance behaviour is a key feature of all human anxiety disorders. Animal models have been useful in understanding how anxiety vulnerability could translate into avoidance learning. For example, behaviourally-inhibited temperament and female sex, two vulnerability factors for clinical anxiety, are associated with faster acquisition of avoidance responses in rodents. However, to date, the translation of such empirical data to human populations has been limited since many features of animal avoidance paradigms are not typically captured in human research. Here, using a computer-based task that captures many features of rodent escape-avoidance learning paradigms, we investigated whether avoidance learning would be faster in humans with inhibited temperament and/or female sex and, if so, whether this facilitation would take the same form. Results showed that, as in rats, both vulnerability factors were associated with facilitated acquisition of avoidance behaviour in humans. Specifically, inhibited temperament was specifically associated with higher rate of avoidance responding, while female sex was associated with longer avoidance duration. These findings strengthen the direct link between animal avoidance work and human anxiety vulnerability, further motivating the study of animal models while also providing a simple testbed for a direct human testing. PMID:24412263

Violence Exposure and Psychopathology in Latino Youth: The Moderating Role of Active and Avoidant Coping.

PubMed

Gudiño, Omar G; Stiles, Allison A; Diaz, Kathleen I

2018-06-01

Despite high rates of exposure to community violence among Latino youth in urban communities, there is considerable variability in individual outcomes. This study examined (a) associations between coping and indices of Latino culture, (b) main effects of active/avoidant coping on psychopathology, and (c) whether coping moderates the impact of violence exposure on mental health in Latino youth. Participants included 168 Latino youth (56% female; ages 11-14) that took part in a short-term longitudinal study. Results indicate that youth acculturation was positively associated with active coping, but enculturation level and immigrant status were not associated with coping. Structural equation models suggested that active coping was negatively associated with internalizing problems (p = .046) while avoidant coping was positively associated with internalizing problems (p = .013) and posttraumatic stress symptoms (p = .024). Moderation analyses revealed that violence exposure was more strongly associated with internalizing problems as reliance on avoidance coping increased. However, at high levels of violence exposure, a greater reliance on active coping was related to increased posttraumatic stress problems. Findings suggest that consideration of the specific stressor, level of stress exposure, and mental health problem-type may be crucial in determining the effectiveness of a coping strategy. Implications for future research and intervention are discussed.

α1-Adrenoceptors in the hippocampal dentate gyrus involved in learning-dependent long-term potentiation during active-avoidance learning in rats.

PubMed

Lv, Jing; Zhan, Su-Yang; Li, Guang-Xie; Wang, Dan; Li, Ying-Shun; Jin, Qing-Hua

2016-11-09

The hippocampus is the key structure for learning and memory in mammals and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. The influences of norepinephrine (NE) on the modulation of learning and memory, as well as LTP, through β-adrenoceptors are well documented, whereas the role of α1-adrenoceptors in learning-dependent LTP is not yet clear. In the present study, we measured extracellular concentrations of NE in the hippocampal dentate gyrus (DG) region using an in-vivo brain microdialysis and high-performance liquid chromatography techniques during the acquisition and extinction of active-avoidance behavior in freely moving conscious rats. Next, the effects of prazosin (an antagonist of α1-adrenoceptor) and phenylephrine (an agonist of the α1-adrenoceptor) on amplitudes of field excitatory postsynaptic potential were measured in the DG region during the active-avoidance behavior. Our results showed that the extracellular concentration of NE in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to the baseline level following extinction training. A local microinjection of prazosin into the DG significantly accelerated the acquisition of the active-avoidance behavior, whereas a local microinjection of phenylephrine retarded the acquisition of the active-avoidance behavior. Furthermore, in all groups, the changes in field excitatory postsynaptic potential amplitude were accompanied by corresponding changes in active-avoidance behavior. Our results suggest that NE activation of α1-adrenoceptors in the hippocampal DG inhibits active-avoidance learning by modulation of synaptic efficiency in rats.

Avoidance of seismic survey activities by penguins.

PubMed

Pichegru, Lorien; Nyengera, Reason; McInnes, Alistair M; Pistorius, Pierre

2017-11-24

Seismic surveys in search for oil or gas under the seabed, produce the most intense man-made ocean noise with known impacts on invertebrates, fish and marine mammals. No evidence to date exists, however, about potential impacts on seabirds. Penguins may be expected to be particularly affected by loud underwater sounds, due to their largely aquatic existence. This study investigated the behavioural response of breeding endangered African Penguins Spheniscus demersus to seismic surveys within 100 km of their colony in South Africa, using a multi-year GPS tracking dataset. Penguins showed a strong avoidance of their preferred foraging areas during seismic activities, foraging significantly further from the survey vessel when in operation, while increasing their overall foraging effort. The birds reverted to normal behaviour when the operation ceased, although longer-term repercussions on hearing capacities cannot be precluded. The rapid industrialization of the oceans has increased levels of underwater anthropogenic noises globally, a growing concern for a wide range of taxa, now also including seabirds. African penguin numbers have decreased by 70% in the last 10 years, a strong motivation for precautionary management decisions, including the exclusion of seismic exploratory activities within at least 100 km of their breeding colonies.

Frequency transfer via a two-way optical phase comparison on a multiplexed fiber network.

PubMed

Calosso, C E; Bertacco, E; Calonico, D; Clivati, C; Costanzo, G A; Frittelli, M; Levi, F; Mura, A; Godone, A

2014-03-01

We performed a two-way remote optical phase comparison on optical fiber. Two optical frequency signals were launched in opposite directions in an optical fiber and their phases were simultaneously measured at the other end. In this technique, the fiber noise is passively canceled, and we compared two optical frequencies at the ultimate 10(-21) stability level. The experiment was performed on a 47 km fiber that is part of the metropolitan network for Internet traffic. The technique relies on the synchronous measurement of the optical phases at the two ends of the link, which is here performed by digital electronics. This scheme offers some advantages with respect to active noise cancellation schemes, as the light travels only once in the fiber.

Crash prediction modeling for curved segments of rural two-lane two-way highways in Utah.

DOT National Transportation Integrated Search

2015-10-01

This report contains the results of the development of crash prediction models for curved segments of rural : two-lane two-way highways in the state of Utah. The modeling effort included the calibration of the predictive : model found in the Highway ...

Mindfulness, Physical Activity and Avoidance of Secondhand Smoke: A Study of College Students in Shanghai.

PubMed

Gao, Yu; Shi, Lu

2015-08-21

To better understand the documented link between mindfulness and longevity, we examine the association between mindfulness and conscious avoidance of secondhand smoke (SHS), as well as the association between mindfulness and physical activity. In Shanghai University of Finance and Economics (SUFE) we surveyed a convenience sample of 1516 college freshmen. We measured mindfulness, weekly physical activity, and conscious avoidance of secondhand smoke, along with demographic and behavioral covariates. We used a multilevel logistic regression to test the association between mindfulness and conscious avoidance of secondhand smoke, and used a Tobit regression model to test the association between mindfulness and metabolic equivalent hours per week. In both models the home province of the student respondent was used as the cluster variable, and demographic and behavioral covariates, such as age, gender, smoking history, household registration status (urban vs. rural), the perceived smog frequency in their home towns, and the asthma diagnosis. The logistic regression of consciously avoiding SHS shows that a higher level of mindfulness was associated with an increase in the odds ratio of conscious SHS avoidance (logged odds: 0.22, standard error: 0.07, p < 0.01). The Tobit regression shows that a higher level of mindfulness was associated with more metabolic equivalent hours per week (Tobit coefficient: 4.09, standard error: 1.13, p < 0.001). This study is an innovative attempt to study the behavioral issue of secondhand smoke from the perspective of the potential victim, rather than the active smoker. The observed associational patterns here are consistent with previous findings that mindfulness is associated with healthier behaviors in obesity prevention and substance use. Research designs with interventions are needed to test the causal link between mindfulness and these healthy behaviors.

Mindfulness, Physical Activity and Avoidance of Secondhand Smoke: A Study of College Students in Shanghai

PubMed Central

Gao, Yu; Shi, Lu

2015-01-01

Introduction: To better understand the documented link between mindfulness and longevity, we examine the association between mindfulness and conscious avoidance of secondhand smoke (SHS), as well as the association between mindfulness and physical activity. Method: In Shanghai University of Finance and Economics (SUFE) we surveyed a convenience sample of 1516 college freshmen. We measured mindfulness, weekly physical activity, and conscious avoidance of secondhand smoke, along with demographic and behavioral covariates. We used a multilevel logistic regression to test the association between mindfulness and conscious avoidance of secondhand smoke, and used a Tobit regression model to test the association between mindfulness and metabolic equivalent hours per week. In both models the home province of the student respondent was used as the cluster variable, and demographic and behavioral covariates, such as age, gender, smoking history, household registration status (urban vs. rural), the perceived smog frequency in their home towns, and the asthma diagnosis. Results: The logistic regression of consciously avoiding SHS shows that a higher level of mindfulness was associated with an increase in the odds ratio of conscious SHS avoidance (logged odds: 0.22, standard error: 0.07, p < 0.01). The Tobit regression shows that a higher level of mindfulness was associated with more metabolic equivalent hours per week (Tobit coefficient: 4.09, standard error: 1.13, p < 0.001). Discussion: This study is an innovative attempt to study the behavioral issue of secondhand smoke from the perspective of the potential victim, rather than the active smoker. The observed associational patterns here are consistent with previous findings that mindfulness is associated with healthier behaviors in obesity prevention and substance use. Research designs with interventions are needed to test the causal link between mindfulness and these healthy behaviors. PMID:26308029

Learning processes underlying avoidance of negative outcomes.

PubMed

Andreatta, Marta; Michelmann, Sebastian; Pauli, Paul; Hewig, Johannes

2017-04-01

Successful avoidance of a threatening event may negatively reinforce the behavior due to activation of brain structures involved in reward processing. Here, we further investigated the learning-related properties of avoidance using feedback-related negativity (FRN). The FRN is modulated by violations of an intended outcome (prediction error, PE), that is, the bigger the difference between intended and actual outcome, the larger the FRN amplitude is. Twenty-eight participants underwent an operant conditioning paradigm, in which a behavior (button press) allowed them to avoid a painful electric shock. During two learning blocks, participants could avoid an electric shock in 80% of the trials by pressing one button (avoidance button), or by not pressing another button (punishment button). After learning, participants underwent two test blocks, which were identical to the learning ones except that no shocks were delivered. Participants pressed the avoidance button more often than the punishment button. Importantly, response frequency increased throughout the learning blocks but it did not decrease during the test blocks, indicating impaired extinction and/or habit formation. In line with a PE account, FRN amplitude to negative feedback after correct responses (i.e., unexpected punishment) was significantly larger than to positive feedback (i.e., expected omission of punishment), and it increased throughout the blocks. Highly anxious individuals showed equal FRN amplitudes to negative and positive feedback, suggesting impaired discrimination. These results confirm the role of negative reinforcement in motivating behavior and learning, and reveal important differences between high and low anxious individuals in the processing of prediction errors. © 2017 Society for Psychophysiological Research.

Two-Way Text Messaging: An Interactive Mobile Learning Environment in Higher Education

ERIC Educational Resources Information Center

Premadasa, H. K. Salinda; Meegama, R. G. N.

2016-01-01

Short messaging service (SMS) is perhaps the most popular mobile technology prevalent among students in higher education due to its ubiquitous nature and the capability of two-way communication. However, a major limitation in two-way text messaging is sending back a part of received data with the reply message. This limitation results in users of…

Selections from 2016: Hidden Galaxies Found Behind the Milky Way

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-01-01

Editors note:In these last two weeks of 2016, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume after the AAS winter meeting.The Parkes H I Zone of Avoidance SurveyPublished February2016Main takeaway:883 galaxies have been discoveredwithin a few hundredmillion light-years of us, hiding behind the Milky Way. The galaxies were found by a team led by Lister Staveley-Smith (International Center for Radio Astronomy Research, University of Western Australia) using the 64-m Parkes radio telescope in Australia.Distribution of the galaxies discovered in the Zone of Avoidance. Radial distance is measured by the recessional velocities of the galaxies. [Staveley-Smith et al. 2016]Why its interesting:These new galaxies were discovered in whats known as the Zone of Avoidance, a gap that extends roughly 5 above and 5 below the galactic plane. The Zone of Avoidance has been excluded from many past surveys because the stars and dust of the Milky Way prevent us from being able to identify background galaxies in this region. But the Parkes radio telescope equipped with an innovative new receiver was able to peer through the foreground of the Milky Way to detect the hidden galaxies behind it.What this could teach us:The discovery of hundreds of new galaxies may help explain the gravitational anomaly known as the Great Attractor region, a diffuse concentration of mass roughly 250 million light-years away that is pulling the Milky Way and hundreds of thousands of other galaxies toward it.CitationL. Staveley-Smith et al 2016 AJ 151 52. doi:10.3847/0004-6256/151/3/52

Two-Way Satellite Time Transfer Between USNO and PTB

DTIC Science & Technology

2005-08-01

Observatory 3450 Massachusetts Ave. NW Washington, DC 20392, USA Abstract—Two completely independent two-way time and frequency transfer ( TWSTFT ...for the realization of TAI. The X- band data are provided as a backup. To reach the full potential of TWSTFT , especially for time scale comparisons...ns for both links were achieved. A change of the TWSTFT transmission frequencies or satellite changes in general cause discontinuities in the series

Fear of movement and avoidance behaviour toward physical activity in chronic-fatigue syndrome and fibromyalgia: state of the art and implications for clinical practice.

PubMed

Nijs, Jo; Roussel, Nathalie; Van Oosterwijck, Jessica; De Kooning, Margot; Ickmans, Kelly; Struyf, Filip; Meeus, Mira; Lundberg, Mari

2013-08-01

Severe exacerbation of symptoms following physical activity is characteristic for chronic-fatigue syndrome (CFS) and fibromyalgia (FM). These exacerbations make it understandable for people with CFS and FM to develop fear of performing body movement or physical activity and consequently avoidance behaviour toward physical activity. The aims of this article were to review what measures are available for measuring fear of movement and avoidance behaviour, the prevalence fear of movement and avoidance behaviour toward physical activity and the therapeutic options with fear of movement and avoidance behaviour toward physical activity in patients with CFS and FM. The review revealed that fear of movement and avoidance behaviour toward physical activity is highly prevalent in both the CFS and FM population, and it is related to various clinical characteristics of CFS and FM, including symptom severity and self-reported quality of life and disability. It appears to be crucial for treatment (success) to identify CFS and FM patients displaying fear of movement and avoidance behaviour toward physical activity. Individually tailored cognitive behavioural therapy plus exercise training, depending on the patient's classification as avoiding or persisting, appears to be the most promising strategy for treating fear of movement and avoidance behaviour toward physical activity in patients with CFS and FM.

The influence of an atmospheric Two-Way coupled model system on the predictability of extratropical cyclones

NASA Astrophysics Data System (ADS)

Schuster, Mareike; Thürkow, Markus; Weiher, Stefan; Kirchner, Ingo; Ulbrich, Uwe; Will, Andreas

2016-04-01

A general bias of global atmosphere ocean models, and also of the MPI-ESM, is an under-representation of the high latitude cyclone activity and an overestimation of the mid latitude cyclone activity in the North Atlantic, thus representing the extra-tropical storm track too zonal. We will show, that this effect can be antagonized by applying an atmospheric Two-Way Coupling (TWC). In this study we present a newly developed Two-Way Coupled model system, which is based on the MPI-ESM, and show that it is able to capture the mean storm track location more accurate. It also influences the sub-decadal deterministic predictability of extra-tropical cyclones and shows significantly enhanced skill compared to the "uncoupled" MPI-ESM standalone system. This study evaluates a set of hindcast experiments performed with said Two-Way Coupled model system. The regional model COSMO CLM is Two-Way Coupled to the atmosphere of the global Max-Plack-Institute Earth System Model (MPI-ESM) and therefore integrates and exchanges the state of the atmosphere every 10 minutes (MPI-TWC-ESM). In the coupled source region (North Atlantic), mesoscale processes which are relevant for the formation and early-stage development of cyclones are expected to be better represented, and therefore influence the large scale dynamics of the target region (Europe). The database covers 102 "uncoupled" years and 102 Two-Way Coupled years of the recent climate (1960-2010). Results are validated against the ERA-Interim reanalysis. Besides the climatological point of view, the design of this single model ensemble allows for an analysis of the predictability of the first and second leadyears of the hindcasts. As a first step to understand the improved predictability of cyclones, we will show a detailed analysis of climatologies for specific cyclone categories, sorted by season and region. Especially for cyclones affecting Europe, the TWC is capable to counteract the AOGCM's biases in the North Atlantic. Also

The birth, death and resurrection of avoidance: a reconceptualization of a troubled paradigm.

PubMed

LeDoux, J E; Moscarello, J; Sears, R; Campese, V

2017-01-01

Research on avoidance conditioning began in the late 1930s as a way to use laboratory experiments to better understand uncontrollable fear and anxiety. Avoidance was initially conceived of as a two-factor learning process in which fear is first acquired through Pavlovian aversive conditioning (so-called fear conditioning), and then behaviors that reduce the fear aroused by the Pavlovian conditioned stimulus are reinforced through instrumental conditioning. Over the years, criticisms of both the avoidance paradigm and the two-factor fear theory arose. By the mid-1980s, avoidance had fallen out of favor as an experimental model relevant to fear and anxiety. However, recent progress in understanding the neural basis of Pavlovian conditioning has stimulated a new wave of research on avoidance. This new work has fostered new insights into contributions of not only Pavlovian and instrumental learning but also habit learning, to avoidance, and has suggested that the reinforcing event underlying the instrumental phase should be conceived in terms of cellular and molecular events in specific circuits rather than in terms of vague notions of fear reduction. In our approach, defensive reactions (freezing), actions (avoidance) and habits (habitual avoidance) are viewed as being controlled by unique circuits that operate nonconsciously in the control of behavior, and that are distinct from the circuits that give rise to conscious feelings of fear and anxiety. These refinements, we suggest, overcome older criticisms, justifying the value of the new wave of research on avoidance, and offering a fresh perspective on the clinical implications of this work.

The birth, death and resurrection of avoidance: a reconceptualization of a troubled paradigm

PubMed Central

LeDoux, J E; Moscarello, J; Sears, R; Campese, V

2017-01-01

Research on avoidance conditioning began in the late 1930s as a way to use laboratory experiments to better understand uncontrollable fear and anxiety. Avoidance was initially conceived of as a two-factor learning process in which fear is first acquired through Pavlovian aversive conditioning (so-called fear conditioning), and then behaviors that reduce the fear aroused by the Pavlovian conditioned stimulus are reinforced through instrumental conditioning. Over the years, criticisms of both the avoidance paradigm and the two-factor fear theory arose. By the mid-1980s, avoidance had fallen out of favor as an experimental model relevant to fear and anxiety. However, recent progress in understanding the neural basis of Pavlovian conditioning has stimulated a new wave of research on avoidance. This new work has fostered new insights into contributions of not only Pavlovian and instrumental learning but also habit learning, to avoidance, and has suggested that the reinforcing event underlying the instrumental phase should be conceived in terms of cellular and molecular events in specific circuits rather than in terms of vague notions of fear reduction. In our approach, defensive reactions (freezing), actions (avoidance) and habits (habitual avoidance) are viewed as being controlled by unique circuits that operate nonconsciously in the control of behavior, and that are distinct from the circuits that give rise to conscious feelings of fear and anxiety. These refinements, we suggest, overcome older criticisms, justifying the value of the new wave of research on avoidance, and offering a fresh perspective on the clinical implications of this work. PMID:27752080

49 CFR 232.405 - Design and performance standards for two-way end-of-train devices.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Design and performance standards for two-way end... Design and performance standards for two-way end-of-train devices. Two-way end-of-train devices shall be designed and perform with the features applicable to one-way end-of-train devices described in § 232.403...

49 CFR 232.405 - Design and performance standards for two-way end-of-train devices.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Design and performance standards for two-way end... Design and performance standards for two-way end-of-train devices. Two-way end-of-train devices shall be designed and perform with the features applicable to one-way end-of-train devices described in § 232.403...

49 CFR 232.405 - Design and performance standards for two-way end-of-train devices.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Design and performance standards for two-way end... Design and performance standards for two-way end-of-train devices. Two-way end-of-train devices shall be designed and perform with the features applicable to one-way end-of-train devices described in § 232.403...

49 CFR 232.405 - Design and performance standards for two-way end-of-train devices.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Design and performance standards for two-way end... Design and performance standards for two-way end-of-train devices. Two-way end-of-train devices shall be designed and perform with the features applicable to one-way end-of-train devices described in § 232.403...

It's Not the Way I Learned!

NASA Astrophysics Data System (ADS)

Mason, Diana S.

2003-11-01

Computer-enhanced learning as noted by Cole and Todd (5) is “somewhat less effective at the precollege level” (p 1339). Progress is slow due to a number of factors, including instructors who are resistant to change, the complexity of the subject, and the handling of chemistry laboratories. Many of our students politely go through the motions but are not actively engaged with the lesson. Simply listening to chemistry lectures may provide students with little in the way of substantial learning gains, because lectures do not necessarily actively involve students in the activity (9), yet with the incorporation of today’s technology into our curriculum and the flexible, asynchronous environment of online learning with the advantages immediate feedback provides (6) many students will expand their knowledge and skills. Careful monitoring by the instructor and setting of internal deadlines for students involved in online learning are known to encourage higher completion rates than are generally reported (10). We should take advantage of today’s advances, embrace them, and be the ones to change—set the pace and avoid the trap of “it’s not the way I learned to do it!”

A Preliminary Review of CATV as a Two-Way System. Working Paper V.

ERIC Educational Resources Information Center

Werntz, Ted

Equipment for two-way cable television (CATV) is becoming available and there are steps we can take to ensure that it is used efficiently. For example a possible obstacle to the orderly development of two-way CATV is competition between CATV and video cassettes. However the two could complement each other if videotape materials were prepared to be…

Neural substrates of approach-avoidance conflict decision-making.

PubMed

Aupperle, Robin L; Melrose, Andrew J; Francisco, Alex; Paulus, Martin P; Stein, Murray B

2015-02-01

Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to nonconflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the nonconflict trials elicited greater activation within bilateral anterior cingulate cortex, anterior insula, and caudate, as well as right dorsolateral prefrontal cortex (PFC). Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation related to individual differences in approach-avoidance decision-making. Therefore, the approach-avoidance conflict paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision

Avoidance of wind farms by harbour seals is limited to pile driving activities.

PubMed

Russell, Debbie J F; Hastie, Gordon D; Thompson, David; Janik, Vincent M; Hammond, Philip S; Scott-Hayward, Lindesay A S; Matthiopoulos, Jason; Jones, Esther L; McConnell, Bernie J

2016-12-01

As part of global efforts to reduce dependence on carbon-based energy sources there has been a rapid increase in the installation of renewable energy devices. The installation and operation of these devices can result in conflicts with wildlife. In the marine environment, mammals may avoid wind farms that are under construction or operating. Such avoidance may lead to more time spent travelling or displacement from key habitats. A paucity of data on at-sea movements of marine mammals around wind farms limits our understanding of the nature of their potential impacts.Here, we present the results of a telemetry study on harbour seals Phoca vitulina in The Wash, south-east England, an area where wind farms are being constructed using impact pile driving. We investigated whether seals avoid wind farms during operation, construction in its entirety, or during piling activity. The study was carried out using historical telemetry data collected prior to any wind farm development and telemetry data collected in 2012 during the construction of one wind farm and the operation of another.Within an operational wind farm, there was a close-to-significant increase in seal usage compared to prior to wind farm development. However, the wind farm was at the edge of a large area of increased usage, so the presence of the wind farm was unlikely to be the cause.There was no significant displacement during construction as a whole. However, during piling, seal usage (abundance) was significantly reduced up to 25 km from the piling activity; within 25 km of the centre of the wind farm, there was a 19 to 83% (95% confidence intervals) decrease in usage compared to during breaks in piling, equating to a mean estimated displacement of 440 individuals. This amounts to significant displacement starting from predicted received levels of between 166 and 178 dB re 1 μPa (p-p) . Displacement was limited to piling activity; within 2 h of cessation of pile driving, seals were distributed as

5 Ways to Be More Active in Your Everyday Life

Cancer.gov

In addition to meeting the physical activity recommendations, research suggests that getting more activity is better. Another way to increase your physical activity (and decrease the amount of time you spend sitting) is to get moving more in your everyday life.

Two-Way Radio in Schools (or, The Loneliness of the Long Distance Learner). An Evaluation of a High Frequency Short Wave, Two-Way Radio Trial.

ERIC Educational Resources Information Center

Conboy, Ian

The Country Education Project in Victoria, Australia, tested the use of two-way radios to bring educational resources to isolated children studying correspondence courses in small rural high schools and to increase interaction among rural schools. Eight rural Victoria schools and the Secondary Correspondence School in Melbourne used two-way…

A Two Way Approach to Understanding: Issues in Global Education. Second Edition.

ERIC Educational Resources Information Center

McDaniel, Rick, Comp.; Petrie, Jim, Comp.

By focusing on issues, global education provides students with a better understanding of the country and the world in which they live. The issues approach stresses that global education is a two-way approach to understanding: it is both a way of teaching and a way of learning. This book provides resources for the teacher who has decided to teach…

Meaning Making and Translanguaging in a Two-Way Dual-Language Program on the U.S.-Mexico Border

ERIC Educational Resources Information Center

Esquinca, Alberto; Araujo, Blanca; de la Piedra, María Teresa

2014-01-01

The article analyzes meaning-making practices in a two-way dual-language (TWDL) program on the U.S.-Mexico border among "transfronterizo" and Mexican-origin youth. In the article, we show that emergent bilingual learners and their teacher participate in activities that mediate understanding of science content knowledge. We show how the…

Two Formal Gas Models For Multi-Agent Sweeping and Obstacle Avoidance

NASA Technical Reports Server (NTRS)

Kerr, Wesley; Spears, Diana; Spears, William; Thayer, David

2004-01-01

The task addressed here is a dynamic search through a bounded region, while avoiding multiple large obstacles, such as buildings. In the case of limited sensors and communication, maintaining spatial coverage - especially after passing the obstacles - is a challenging problem. Here, we investigate two physics-based approaches to solving this task with multiple simulated mobile robots, one based on artificial forces and the other based on the kinetic theory of gases. The desired behavior is achieved with both methods, and a comparison is made between them. Because both approaches are physics-based, formal assurances about the multi-robot behavior are straightforward, and are included in the paper.

Exploring Student Integration Patterns in Two-Way Immersion Schools

ERIC Educational Resources Information Center

Martinez, Martha I.

2011-01-01

Two-way immersion (TWI) programs teach English Learners (ELs) and native English speakers in the same classroom using both languages in an immersion approach. Studies suggest that TWI programs result in greater student integration, thus providing a promising alternative for Spanish speaking ELs, who are frequently concentrated in high poverty,…

Neural substrates of approach-avoidance conflict decision-making

PubMed Central

Aupperle, Robin L.; Melrose, Andrew J.; Francisco, Alex; Paulus, Martin P.; Stein, Murray B.

2014-01-01

Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to non-conflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the non-conflict trials elicited greater activation within bilateral anterior cingulate cortex (ACC), anterior insula, and caudate, as well as right dorsolateral prefrontal cortex. Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation is related to individual differences in approach-avoidance decision-making. Therefore, the AAC paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision-making. PMID:25224633

Two Simple Activities to Bring Rainbows into the Classroom

ERIC Educational Resources Information Center

Isik, Hakan; Yurumezoglu, Kemal

2012-01-01

A rainbow reveals the colors of sunlight in a breathtaking way, but the formation of this natural event cannot be controlled by human beings. Transforming this out-of-class experience into a teaching activity is a challenge for science educators. This paper outlines two activities for rainbow formation in the science classroom in cases of good…

The Rapid Distortion of Two-Way Coupled Particle-Laden Turbulence

NASA Astrophysics Data System (ADS)

Kasbaoui, Mohamed; Koch, Donald; Desjardins, Olivier

2017-11-01

The modulation of sheared turbulence by dispersed particles is addressed in the two-way coupling regime. The preferential sampling of the straining regions of the flow by inertial particles in turbulence leads to the formation of clusters. These fast sedimenting particle structures cause the anisotropic alteration of turbulence at small scales in the direction of gravity. These effects are investigated in a revisited Rapid Distortion Theory (RDT), extended for two-way coupled particle-laden flows. To make the analysis tractable, we assume that particles have small but non-zero inertia. In the classical results for single-phase flows, the RDT assumption of fast shearing compared to the turbulence time scales leads to the distortion of ``frozen'' turbulence. In particle-laden turbulence, the coupling between the two phases remains strong even under fast shearing and leads to a dynamic modulation of the turbulence spectrum. Turbulence statistics obtained from RDT are compared with Euler-Lagrange simulations of homogeneously sheared particle-laden turbulence.

Two alternative ways for solving the coordination problem in multilevel optimization

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, Jaroslaw

1991-01-01

Two techniques for formulating the coupling between levels in multilevel optimization by linear decomposition, proposed as improvements over the original formulation, now several years old, that relied on explicit equality constraints which were shown by application experience as occasionally causing numerical difficulties. The two new techniques represent the coupling without using explicit equality constraints, thus avoiding the above diffuculties and also reducing computational cost of the procedure. The old and new formulations are presented in detail and illustrated by an example of a structural optimization. A generic version of the improved algorithm is also developed for applications to multidisciplinary systems not limited to structures.

Avoidance in hypochondriasis.

PubMed

Doherty-Torstrick, Emily R; Walton, Kate E; Barsky, Arthur J; Fallon, Brian A

2016-10-01

The DSM-5 diagnosis of illness anxiety disorder adds avoidance as a component of a behavioral response to illness fears - one that was not present in prior DSM criteria of hypochondriasis. However, maladaptive avoidance as a necessary or useful criterion has yet to be empirically supported. 195 individuals meeting DSM-IV criteria for hypochondriasis based on structured interview completed a variety of self-report and clinician-administered assessments. Data on maladaptive avoidance were obtained using the six-item subscale of the clinician-administered Hypochondriasis - Yale Brown Obsessive Compulsive Scale - Modified. To determine if avoidance emerged as a useful indicator in hypochondriasis, we compared the relative fit of continuous latent trait, categorical latent class, and hybrid factor mixture models. A two-class factor mixture model fit the data best, with Class 1 (n=147) exhibiting a greater level of severity of avoidance than Class 2 (n=48). The more severely avoidant group was found to have higher levels of hypochondriacal symptom severity, functional impairment, and anxiety, as well as lower quality of life. These results suggest that avoidance may be a valid behavioral construct and a useful component of the new diagnostic criteria of illness anxiety in the DSM-5, with implications for somatic symptom disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

For Which Side the Bell Tolls: The Laterality of Approach-Avoidance Associative Networks.

PubMed

Fetterman, Adam K; Ode, Scott; Robinson, Michael D

2013-03-01

The two hemispheres of the brain appear to play different roles in emotion and/or motivation. A great deal of previous research has examined the valence hypothesis (left hemisphere = positive; right = negative), but an increasing body of work has supported the motivational hypothesis (left hemisphere = approach; right = avoidance) as an alternative. The present investigation ( N = 117) sought to provide novel support for the latter perspective. Left versus right hemispheres were briefly activated by neutral lateralized auditory primes. Subsequently, participants categorized approach versus avoidance words as quickly and accurately as possible. Performance in the task revealed that approach-related thoughts were more accessible following left-hemispheric activation, whereas avoidance-related thoughts were more accessible following right-hemispheric activation. The present results are the first to examine such lateralized differences in accessible motivational thoughts, which may underlie more "downstream" manifestations of approach and avoidance motivation such as judgments, decision making, and behavior.

Avoidance-related EEG asymmetry predicts circulating interleukin-6.

PubMed

Shields, Grant S; Moons, Wesley G

2016-03-01

Recent research has linked avoidance-oriented motivational states to elevated pro-inflammatory cytokine levels. According to one of many theories regarding the association between avoidance and cytokine levels, because the evolutionarily basic avoidance system may be activated when an organism is threatened or overwhelmed, an associated inflammatory response may be adaptive for dealing with potential injury in such threatening situations. To examine this hypothesis, we tested whether the neural correlate of avoidance motivation associates with baseline levels of the circulating pro-inflammatory cytokine interleukin-6 (IL-6). Controlling for covariates, greater resting neural activity in the right frontal cortex relative to the left frontal cortex-the neural correlate of avoidance motivation-was associated with baseline IL-6. These results thus support the hypothesis that the avoidance motivational system may be closely linked to systemic inflammatory activity. (c) 2016 APA, all rights reserved).

Differential effects of 5-HT2C receptor activation by WAY 161503 on nicotine-induced place conditioning and locomotor activity in rats.

PubMed

Hayes, Dave J; Mosher, Tera M; Greenshaw, Andrew J

2009-02-11

Numerous studies indicate a role for both the serotonin 2C receptor (5-HT(2C)) and the nicotinic acetylcholine receptor in locomotion, reinforcement and motivated behaviours. Nicotine, a potent nicotinic acetylcholine receptor agonist, interacts with the dopaminergic and serotonergic systems and is known to positively affect reward-related behaviours. The current study examined the effects of 5-HT(2C) receptor activation on nicotine-induced (0.6 mg/kg) place conditioning and spontaneous locomotion. Using Sprague-Dawley rats, the effects of the selective 5-HT(2C) receptor agonist WAY 161503 (0-1.0 mg/kg) and the selective 5-HT(2C) receptor antagonist SB 242084 (1.0 mg/kg) alone, in combination, and on nicotine-induced (0.6 mg/kg) spontaneous locomotor activity were assessed. The effects of WAY 161503 (1.0, 3.0 mg/kg) were also investigated in nicotine-induced place conditioning using a two-compartment biased design; amphetamine (1.0 mg/kg) served as a positive control. As differential effects were observed between place conditioning and locomotor activity, the subjects used in the place conditioning experiments were also tested for effects on locomotor activity. WAY 161503 decreased baseline and nicotine-induced locomotor activity at the highest dose tested (1.0mg/kg) and these effects were attenuated by SB 242084. Amphetamine and nicotine both induced robust place preferences and WAY 161503 did not have any effects in the context of place conditioning. In contrast, WAY 161503 (1.0 mg/kg) blocked nicotine-induced locomotor activity. These results suggest that 5-HT(2C) receptors may play an inhibitory role in nicotine-induced locomotor activity, but do not appear to influence place conditioning under the current conditions.

Demonstration of Multisetting One-Way Einstein-Podolsky-Rosen Steering in Two-Qubit Systems

NASA Astrophysics Data System (ADS)

Xiao, Ya; Ye, Xiang-Jun; Sun, Kai; Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can

2017-04-01

Einstein-Podolsky-Rosen (EPR) steering describes the ability of one party to remotely affect another's state through local measurements. One of the most distinguishable properties of EPR steering is its asymmetric aspect. Steering can work in one direction but fail in the opposite direction. This type of one-way steering, which is different from the symmetry concepts of entanglement and Bell nonlocality, has garnered much interest. However, an experimental demonstration of genuine one-way EPR steering in the simplest scenario, i.e., one that employs two-qubit systems, is still lacking. In this Letter, we experimentally demonstrate one-way EPR steering with multimeasurement settings for a class of two-qubit states, which are still one-way steerable even with infinite settings. The steerability is quantified by the steering radius, which represents a necessary and sufficient steering criterion. The demonstrated one-way steering in the simplest bipartite quantum system is of fundamental interest and may provide potential applications in one-way quantum information tasks.

Virtual Classrooms: Educational Opportunity through Two-Way Interactive Television.

ERIC Educational Resources Information Center

Hobbs, Vicki M.; Christianson, J. Scott

This book describes in non-technical language how a small school can greatly expand its course offerings by forming a two-way interactive television (I-TV) network with surrounding school districts. I-TV is the linkage of 3 to 10 school districts over fiber optic, coaxial cable, or dedicated copper telephone lines which enables participating…

Can sequential parallel comparison design and two-way enriched design be useful in medical device clinical trials?

PubMed

Ivanova, Anastasia; Zhang, Zhiwei; Thompson, Laura; Yang, Ying; Kotz, Richard M; Fang, Xin

2016-01-01

Sequential parallel comparison design (SPCD) was proposed for trials with high placebo response. In the first stage of SPCD subjects are randomized between placebo and active treatment. In the second stage placebo nonresponders are re-randomized between placebo and active treatment. Data from the population of "all comers" and the subpopulations of placebo nonresponders then combined to yield a single p-value for treatment comparison. Two-way enriched design (TED) is an extension of SPCD where active treatment responders are also re-randomized between placebo and active treatment in Stage 2. This article investigates the potential uses of SPCD and TED in medical device trials.

Disgust as a disease-avoidance mechanism.

PubMed

Oaten, Megan; Stevenson, Richard J; Case, Trevor I

2009-03-01

Many researchers have claimed that the emotion of disgust functions to protect us from disease. Although there have been several discussions of this hypothesis, none have yet reviewed the evidence in its entirety. The authors derive 14 hypotheses from a disease-avoidance account and evaluate the evidence for each, drawing upon research on pathogen avoidance in animals and empirical research on disgust. In all but 1 case, the evidence favors a disease-avoidance account. It is suggested that disgust is evoked by objects/people that possess particular types of prepared features that connote disease. Such simple disgust are directly disease related, are acquired during childhood, and are able to contaminate other objects/people. The complex disgust, which emerge later in development, may be mediated by several emotions. In these cases, violations of societal norms that may subserve a disease-avoidance function, notably relating to food and sex, act as reminders of simple disgust elicitors and thus generate disgust and motivate compliance. The authors find strong support for a disease-avoidance account and suggest that it offers a way to bridge the divide between concrete and ideational accounts of disgust. (c) 2009 APA, all rights reserved.

Achieving Superior Two-Way Actuation by the Stress-Coupling of Nanoribbons and Nanocrystalline Shape Memory Alloy

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

Hao, Shijie; Liu, Yinong; Ren, Yang

2016-06-08

Inspired by the driving principle of traditional bias-type two-way actuators, we developed a novel two-way actuation nanocomposite wire in which a massive number of Nb nanoribbons with ultra-large elastic strains are loaded inside a shape memory alloy (SMA) matrix to form a continuous array of nano bias actuation pairs for two-way actuation. The composite exhibits a two-way actuation strain of 3.2% during a thermal cycle and an actuation stress of 934 MPa upon heating, which is about twice higher than that (~500 MPa) found in reported two-way SMAs. Upon cooling, the composite shows an actuation stress of 134 MPa andmore » a mechanical work output of 1.08*106 J/ m3, which are about three and five times higher than that of reported two-way SMAs, respectively. It is revealed that the massive number of Nb nanoribbons in compressive state provides the high actuation stress and high work output upon cooling and the SMA matrix with high yield strength offers the high actuation stress upon heating. Compared to traditional bias-type two-way actuators, the two-way actuation composite with small volume and simple construct is in favour of the miniaturization and simplification of actuators.« less

Two-way coupled SPH and particle level set fluid simulation.

PubMed

Losasso, Frank; Talton, Jerry; Kwatra, Nipun; Fedkiw, Ronald

2008-01-01

Grid-based methods have difficulty resolving features on or below the scale of the underlying grid. Although adaptive methods (e.g. RLE, octrees) can alleviate this to some degree, separate techniques are still required for simulating small-scale phenomena such as spray and foam, especially since these more diffuse materials typically behave quite differently than their denser counterparts. In this paper, we propose a two-way coupled simulation framework that uses the particle level set method to efficiently model dense liquid volumes and a smoothed particle hydrodynamics (SPH) method to simulate diffuse regions such as sprays. Our novel SPH method allows us to simulate both dense and diffuse water volumes, fully incorporates the particles that are automatically generated by the particle level set method in under-resolved regions, and allows for two way mixing between dense SPH volumes and grid-based liquid representations.

Feedback-induced phase transitions in active heterogeneous conductors.

PubMed

Ocko, Samuel A; Mahadevan, L

2015-04-03

An active conducting medium is one where the resistance (conductance) of the medium is modified by the current (flow) and in turn modifies the flow, so that the classical linear laws relating current and resistance, e.g., Ohm's law or Darcy's law, are modified over time as the system itself evolves. We consider a minimal model for this feedback coupling in terms of two parameters that characterize the way in which addition or removal of matter follows a simple local (or nonlocal) feedback rule corresponding to either flow-seeking or flow-avoiding behavior. Using numerical simulations and a continuum mean field theory, we show that flow-avoiding feedback causes an initially uniform system to become strongly heterogeneous via a tunneling (channel-building) phase separation; flow-seeking feedback leads to an immuring (wall-building) phase separation. Our results provide a qualitative explanation for the patterning of active conducting media in natural systems, while suggesting ways to realize complex architectures using simple rules in engineered systems.

Variability in emotional responsiveness and coping style during active avoidance as a window onto psychological vulnerability to stress.

PubMed

Gorka, Adam X; LaBar, Kevin S; Hariri, Ahmad R

2016-05-01

Individual differences in coping styles are associated with psychological vulnerability to stress. Recent animal research suggests that coping styles reflect trade-offs between proactive and reactive threat responses during active avoidance paradigms, with proactive responses associated with better stress tolerance. Based on these preclinical findings, we developed a novel instructed active avoidance paradigm to characterize patterns of proactive and reactive responses using behavioral, motoric, and autonomic measures in humans. Analyses revealed significant inter-individual variability not only in the magnitude of general emotional responsiveness but also the likelihood to specifically express proactive or reactive responses. In men but not women, individual differences in general emotional responsiveness were linked to increased trait anxiety while proactive coping style was linked to increased trait aggression. These patterns are consistent with preclinical findings and suggest that instructed active avoidance paradigms may be useful in assessing psychological vulnerability to stress using objective behavioral measures. Copyright © 2016. Published by Elsevier Inc.

For Which Side the Bell Tolls: The Laterality of Approach-Avoidance Associative Networks

PubMed Central

Fetterman, Adam K.; Ode, Scott; Robinson, Michael D.

2012-01-01

The two hemispheres of the brain appear to play different roles in emotion and/or motivation. A great deal of previous research has examined the valence hypothesis (left hemisphere = positive; right = negative), but an increasing body of work has supported the motivational hypothesis (left hemisphere = approach; right = avoidance) as an alternative. The present investigation (N = 117) sought to provide novel support for the latter perspective. Left versus right hemispheres were briefly activated by neutral lateralized auditory primes. Subsequently, participants categorized approach versus avoidance words as quickly and accurately as possible. Performance in the task revealed that approach-related thoughts were more accessible following left-hemispheric activation, whereas avoidance-related thoughts were more accessible following right-hemispheric activation. The present results are the first to examine such lateralized differences in accessible motivational thoughts, which may underlie more “downstream” manifestations of approach and avoidance motivation such as judgments, decision making, and behavior. PMID:23869114

Pyrazine Analogues Are Active Components of Wolf Urine That Induce Avoidance and Freezing Behaviours in Mice

PubMed Central

Osada, Kazumi; Kurihara, Kenzo; Izumi, Hiroshi; Kashiwayanagi, Makoto

2013-01-01

Background The common grey wolf (Canis lupus) is found throughout the entire Northern hemisphere and preys on many kinds of mammals. The urine of the wolf contains a number of volatile constituents that can potentially be used for predator–prey chemosignalling. Although wolf urine is put to practical use to keep rabbits, rodents, deer and so on at bay, we are unaware of any prior behavioural studies or chemical analyses regarding the fear-inducing impact of wolf urine on laboratory mice. Methodology/Principal Findings Three wolf urine samples harvested at different times were used in this study. All of them induced stereotypical fear-associated behaviors (i.e., avoidance and freezing) in female mice. The levels of certain urinary volatiles varied widely among the samples. To identify the volatiles that provoked avoidance and freezing, behavioural, chemical, and immunohistochemical analyses were performed. One of the urine samples (sample C) had higher levels of 2,6-dimethylpyrazine (DMP), trimethylpyrazine (TMP), and 3-ethyl-2,5-dimethyl pyrazine (EDMP) compared with the other two urine samples (samples A and B). In addition, sample C induced avoidance and freezing behaviours more effectively than samples A and B. Moreover, only sample C led to pronounced expression of Fos-immunoreactive cells in the accessory olfactory bulb (AOB) of female mice. Freezing behaviour and Fos immunoreactivity were markedly enhanced when the mice were confronted with a mixture of purified DMP, TMP, and EDMP vs. any one pyrazine alone. Conclusions/Significance The current results suggest that wolf urinary volatiles can engender aversive and fear-related responses in mice. Pyrazine analogues were identified as the predominant active components among these volatiles to induce avoidance and freezing behaviours via stimulation of the murine AOB. PMID:23637901

Avoiding Cancer Risk Information

PubMed Central

Emanuel, Amber S.; Kiviniemi, Marc T.; Howell, Jennifer L.; Hay, Jennifer L.; Waters, Erika A.; Orom, Heather; Shepperd, James A.

2015-01-01

RATIONALE Perceived risk for health problems such as cancer is a central construct in many models of health decision making and a target for behavior change interventions. However, some portion of the population actively avoids cancer risk information. The prevalence of, explanations for, and consequences of such avoidance are not well understood. OBJECTIVE We examined the prevalence and demographic and psychosocial correlates of cancer risk information avoidance preference in a nationally representative sample. We also examined whether avoidance of cancer risk information corresponds with avoidance of cancer screening. RESULTS Based on our representative sample, 39% of the population indicated that they agreed or strongly agreed that they would “rather not know [their] chance of getting cancer.” This preference was stronger among older participants, female participants, and participants with lower levels of education. Preferring to avoid cancer risk information was stronger among participants who agreed with the beliefs that everything causes cancer, that there’s not much one can do to prevent cancer, and that there are too many recommendations to follow. Finally, the preference to avoid cancer risk information was associated with lower levels of screening for colon cancer. CONCLUSION These findings suggest that cancer risk information avoidance is a multi-determined phenomenon that is associated with demographic characteristics and psychosocial individual differences and also relates to engagement in cancer screening. PMID:26560410

Sources of Instabilities in Two-Way Satellite Time Transfer

DTIC Science & Technology

2005-08-01

Frequency Division 325 Broadway Boulder, CO USA Abstract -- Two-Way Satellite Time and Frequency Transfer ( TWSTFT ) has become an important...stability of TWSTFT a more complete understanding of the sources of instabilities is required. This paper analyzes several sources of instabilities...Frequency Transfer ( TWSTFT ) regularly delivers subnanosecond time transfer stability at 1 day as measured by the time deviation (TDEV) statistic

Daytime avoidance of chemosensory alarm cues by adult sea lamprey (Petromyzon marinus)

USGS Publications Warehouse

Di Rocco, Richard; Belanger, Cowan; Imre, István; Brown, Grant; Johnson, Nicholas S.

2014-01-01

Sea lamprey (Petromyzon marinus) avoid damage-released and predator chemosensory cues at night, but their response to these cues during the day is unknown. Here, we explored (i) whether sea lamprey avoid these cues during the day and (ii) the effect of water temperature on the avoidance of chemosensory alarm cues in two diurnal laboratory experiments. We hypothesized that daytime activity would be temperature-dependent and that only sea lamprey vulnerable to predation (i.e., not hiding) would behaviourally respond to chemosensory alarm cues. Ten groups of ten sea lamprey were exposed to one of a variety of potential chemosensory cues. The experiments were conducted over a range of temperatures to quantify the effect of temperature on avoidance behaviour. Consistent with our hypothesis, a higher proportion of animals were active during daytime as water temperature increased. Moving sea lamprey showed an avoidance response to 2-phenylethylamine (a compound found in mammalian urine) and human saliva once water temperatures had risen to mean (±SD) = 13.7 (±1.4) °C. Resting and hiding sea lamprey did not show an avoidance response to any of the experimental stimuli.

Two-Way Satellite Time and Frequency Transfer (TWSTFT) Calibration Constancy From Closure Sums

DTIC Science & Technology

2008-12-01

40th Annual Precise Time and Time Interval (PTTI) Meeting 587 TWO-WAY SATELLITE TIME AND FREQUENCY TRANSFER ( TWSTFT ) CALIBRATION...Paris, France Abstract Two-way Satellite Time and Frequency Transfer ( TWSTFT ) is considered to be the most accurate means of long-distance...explanations for small, but non-zero, biases observed in the closure sums of uncalibrated data are presented. I. INTRODUCTION TWSTFT [1] has

Individual Differences in Approach and Avoidance Inclinations Moderate the Effect of Self-Control Depletion on Ad-Lib Drinking

PubMed Central

Schlauch, Robert C.; Christensen, Rita L.; Derrick, Jaye L.; Crane, Cory A.; Collins, R. Lorraine

2015-01-01

Background The current study sought to examine how exerting self-control to inhibit stereotype use affects alcohol consumption. In addition, we sought to expand previous findings via examination of how individual differences in motivations to approach or avoid alcohol consumption interact with self-control depletion to determine the regulation of ad-lib drinking behavior. Methods Sixty-one social drinkers (31 female) were recruited to participate in a socially relevant self-control depletion task in which they were randomly assigned to one of two creative writing conditions: 1) the self-control depletion condition with explicit instructions to refrain from using stereotypes, or 2) the non-depletion condition in which no instructions were given regarding the use of stereotypes. Participants then completed an ad-lib drinking task and self-report questionnaires pertaining to their motivation to consume alcohol. Results As predicted, results indicated a significant three-way interaction between depletion condition, approach inclinations, and avoidance inclinations. Specifically, self-control depletion predicted greater drinking disinhibition (i.e., mean sip size, total alcohol consumption) only among participants high in both approach and avoidance. Conclusions Taken together, results from the current study highlight the importance of both approach and avoidance inclinations in the failure to regulate alcohol consumption following a routine, socially relevant form of self-control depletion. Our results also suggest that the high approach / high avoidance motivational profile may predict the greatest risk among those actively trying to regulate their drinking. PMID:26756800

Language use and stereotyping: the role of approach and avoidance motivation goals.

PubMed

Gil de Montes, Lorena; Ortiz, Garbiñe; Valencia, José F; Larrañaga, Maider; Agirrezabal, Arrate

2012-11-01

The use of more abstract language to describe expected behaviors as opposed to unexpected behaviors has traditionally been considered a way of stereotype maintenance. This tendency is known as linguistic expectancy bias. Two experiments examined the influence of approach and avoidance motivational orientations on the production of this linguistic expectancy bias. It was predicted that approach strategic orientation is likely to describe expectancy consistent behaviors at a higher level of linguistic abstraction than expectancy inconsistent behaviors. In contrast, avoidance strategic orientation is likely to describe both expectancy consistent behaviors and expectancy inconsistent behaviors at a lower level of linguistic abstraction, thus facilitating the disappearance of linguistic expectancy bias. Two experiments confirmed these expectations, using strategic orientation manipulations based either on communication goals or on motor action, and measuring linguistic abstraction either on forced-choice answer format or on free descriptions. Implications for the generalisation of linguistic expectancy bias are discussed.

Real-time, two-way interaction during ST-segment elevation myocardial infarction management improves door-to-balloon times.

PubMed

Sardi, Gabriel L; Loh, Joshua P; Torguson, Rebecca; Satler, Lowell F; Waksman, Ron

2014-01-01

The study aimed to determine if utilization of the CodeHeart application (CHap) reduces door-to-balloon (DTB) times of ST-segment elevation myocardial infarction (STEMI) patients. A pre-hospital electrocardiogram improves the management of patients with STEMI. Current telecommunication systems do not permit real-time interaction with the initial care providers. Our institution developed a novel telecommunications system based on a software application that permits real-time, two-way video and voice interaction over a secured network. All STEMI system activations after implementation of the CHap were prospectively entered into a database. Consecutive CHap activations were compared to routine activations as controls, during the same time period. A total of 470 STEMI system activations occurred; CHap was used in 83 cases (17.7%). DTB time was reduced by the use of CHap when compared to controls (CHap 103 minutes, 95% CI [87.0-118.3] vs. standard 149 minutes, 95% CI [134.0-164.8], p<0.0001), as was first call-to-balloon time (CHap 70 minutes, 95% CI [60.8-79.5] vs. standard 92 minutes, 95% CI [85.8-98.9], p=0.0002). The percentage of 'true positive' catheterization laboratory activations was nominally higher with the use of CHap, although this did not reach statistical significance [CHap 47/83 (56.6%) vs. routine 178/387 (45.9%), p=0.103]. The implementation of a two-way telecommunications system allowing real-time interactions between interventional cardiologists and referring practitioners improves overall DTB time. In addition, it has the potential to decrease the frequency of false activations, thereby improving the cost efficiency of a network's STEMI system. Copyright © 2014. Published by Elsevier Inc.

Fall-related activity avoidance in relation to a history of falls or near falls, fear of falling and disease severity in people with Parkinson's disease.

PubMed

Kader, Manzur; Iwarsson, Susanne; Odin, Per; Nilsson, Maria H

2016-06-02

There is limited knowledge concerning fall-related activity avoidance in people with Parkinson's disease (PD); such knowledge would be of importance for the development of more efficient PD-care and rehabilitation. This study aimed to examine how fall-related activity avoidance relates to a history of self-reported falls/near falls and fear of falling (FOF) as well as to disease severity in people with PD. Data were collected from 251 (61 % men) participants with PD; their median (min-max) age and PD duration were 70 (45-93) and 8 (1-43) years, respectively. A self-administered postal survey preceded a home visit which included observations, clinical tests and interview-administered questionnaires. Fall-related activity avoidance was assessed using the modified Survey of Activities and Fear of Falling in the Elderly (mSAFFE) as well as by using a dichotomous (Yes/No) question. Further dichotomous questions concerned: the presence of FOF and the history (past 6 months) of falls or near falls, followed by stating the number of incidents. Disease severity was assessed according to the Hoehn and Yahr (HY) stages. In the total sample (n = 251), 41 % of the participants reported fall-related activity avoidance; the median mSAFFE score was 22. In relation to a history of fall, the proportions of participants (p < 0.001) that reported fall-related activity avoidance were: non-fallers (30 %), single fallers (50 %) and recurrent fallers, i.e. ≥ 2 falls (57 %). Among those that reported near falls (but no falls), 51 % (26 out of 51) reported fall-related activity avoidance. Of those that reported FOF, 70 % reported fall-related activity avoidance. Fall-related activity avoidance ranged from 24 % in the early PD-stage (HY I) to 74 % in the most severe stages (HY IV-V). Results indicate that fall-related activity avoidance may be related to a history of self-reported falls/near falls, FOF and disease severity in people with PD. Importantly, fall

Spatial avoidance to experimental increase of intermittent and continuous sound in two captive harbour porpoises.

PubMed

Kok, Annebelle C M; Engelberts, J Pamela; Kastelein, Ronald A; Helder-Hoek, Lean; Van de Voorde, Shirley; Visser, Fleur; Slabbekoorn, Hans

2018-02-01

The continuing rise in underwater sound levels in the oceans leads to disturbance of marine life. It is thought that one of the main impacts of sound exposure is the alteration of foraging behaviour of marine species, for example by deterring animals from a prey location, or by distracting them while they are trying to catch prey. So far, only limited knowledge is available on both mechanisms in the same species. The harbour porpoise (Phocoena phocoena) is a relatively small marine mammal that could quickly suffer fitness consequences from a reduction of foraging success. To investigate effects of anthropogenic sound on their foraging efficiency, we tested whether experimentally elevated sound levels would deter two captive harbour porpoises from a noisy pool into a quiet pool (Experiment 1) and reduce their prey-search performance, measured as prey-search time in the noisy pool (Experiment 2). Furthermore, we tested the influence of the temporal structure and amplitude of the sound on the avoidance response of both animals. Both individuals avoided the pool with elevated sound levels, but they did not show a change in search time for prey when trying to find a fish hidden in one of three cages. The combination of temporal structure and SPL caused variable patterns. When the sound was intermittent, increased SPL caused increased avoidance times. When the sound was continuous, avoidance was equal for all SPLs above a threshold of 100 dB re 1 μPa. Hence, we found no evidence for an effect of sound exposure on search efficiency, but sounds of different temporal patterns did cause spatial avoidance with distinct dose-response patterns. Copyright © 2017 Elsevier Ltd. All rights reserved.

Active avoidance: escape and dodging behaviors for reactive control

NASA Astrophysics Data System (ADS)

Arkin, Ronald C.; Carter, William M.

1992-03-01

New methods for producing avoidance behavior among moving obstacles within the context of reactive robotic control are described. These specifically include escape and dodging behaviors. Dodging is concerned with the avoidance of a ballistic projectile while escape is more useful within the context of chase. The motivation and formulation of these new reactive behaviors are presented. Simulation results of a robot in a cluttered and moving world are also provided.

An Administrative Perspective of a Two-Way Bilingual Immersion Program.

ERIC Educational Resources Information Center

Armendariz, Abe Lujan; Armendariz, Emma J.

2002-01-01

In this interview, a female Hispanic principal discusses the challenges, resources, and support involved in implementing a two-way bilingual immersion model in a Hispanic community in Albuquerque (New Mexico). Program success resulted primarily from supportive parents, faculty, and superintendent and the principal's leadership style, which is…

33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

Code of Federal Regulations, 2011 CFR

2011-07-01

... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas Atlantic East Coast § 167.173 Off Delaware Bay: Two-Way Traffic...

33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

Code of Federal Regulations, 2012 CFR

2012-07-01

... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas Atlantic East Coast § 167.173 Off Delaware Bay: Two-Way Traffic...

33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas Atlantic East Coast § 167.173 Off Delaware Bay: Two-Way Traffic...

33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

Code of Federal Regulations, 2013 CFR

2013-07-01

... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas Atlantic East Coast § 167.173 Off Delaware Bay: Two-Way Traffic...

33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

Code of Federal Regulations, 2014 CFR

2014-07-01

... SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES Description of Traffic Separation Schemes and Precautionary Areas Atlantic East Coast § 167.173 Off Delaware Bay: Two-Way Traffic...

Post-traumatic stress avoidance is attenuated by corticosterone and associated with brain levels of steroid receptor co-activator-1 in rats.

PubMed

Whitaker, Annie M; Farooq, Muhammad A; Edwards, Scott; Gilpin, Nicholas W

2016-01-01

Individuals with post-traumatic stress disorder (PTSD) avoid trauma-related stimuli and exhibit blunted hypothalamic-pituitary-adrenal (HPA) axis activation at the time of stress. Our rodent model of stress mimics the avoidance symptom cluster of PTSD. Rats are classified as "Avoiders" or "Non-Avoiders" post-stress based on the avoidance of a predator-odor paired context. Previously, we found Avoiders exhibit an attenuated HPA stress response to predator odor. We hypothesized that corticosterone administration before stress would reduce the magnitude and incidence of stress-paired context avoidance. Furthermore, we also predicted that Avoiders would exhibit altered expression of glucocorticoid receptor (GR) signaling machinery elements, including steroid receptor co-activator (SRC)-1. Male Wistar rats (n = 16) were pretreated with corticosterone (25 mg/kg) or saline and exposed to predator-odor stress paired with a context and tested for avoidance 24 h later. A second group of corticosterone-naïve rats (n = 24) were stressed (or not), indexed for avoidance 24 h later, and killed 48 h post-odor exposure to measure phosphorylated GR, FKBP51 and SRC-1 levels in the paraventricular nucleus (PVN), central amygdala (CeA) and ventral hippocampus (VH), all brain sites that highly express GRs and regulate HPA function. Corticosterone pretreatment reduced the magnitude and incidence of avoidance. In Avoiders, predator-odor exposure led to lower SRC-1 expression in the PVN and CeA, and higher SRC-1 expression in the VH. SRC-1 expression in PVN, CeA and VH was predicted by prior avoidance behavior. Hence, a blunted HPA stress response may contribute to stress-induced neuroadaptations in central SRC-1 levels and behavioral dysfunction in Avoider rats.

Automatic Collision Avoidance Technology (ACAT)

NASA Technical Reports Server (NTRS)

Swihart, Donald E.; Skoog, Mark A.

2007-01-01

This document represents two views of the Automatic Collision Avoidance Technology (ACAT). One viewgraph presentation reviews the development and system design of Automatic Collision Avoidance Technology (ACAT). Two types of ACAT exist: Automatic Ground Collision Avoidance (AGCAS) and Automatic Air Collision Avoidance (AACAS). The AGCAS Uses Digital Terrain Elevation Data (DTED) for mapping functions, and uses Navigation data to place aircraft on map. It then scans DTED in front of and around aircraft and uses future aircraft trajectory (5g) to provide automatic flyup maneuver when required. The AACAS uses data link to determine position and closing rate. It contains several canned maneuvers to avoid collision. Automatic maneuvers can occur at last instant and both aircraft maneuver when using data link. The system can use sensor in place of data link. The second viewgraph presentation reviews the development of a flight test and an evaluation of the test. A review of the operation and comparison of the AGCAS and a pilot's performance are given. The same review is given for the AACAS is given.

Approach/avoidance in dreams.

PubMed

Malcolm-Smith, Susan; Koopowitz, Sheri; Pantelis, Eleni; Solms, Mark

2012-03-01

The influential threat simulation theory (TST) asserts that dreaming yields adaptive advantage by providing a virtual environment in which threat-avoidance may be safely rehearsed. We have previously found the incidence of biologically threatening dreams to be around 20%, with successful threat avoidance occurring in approximately one-fifth of such dreams. TST asserts that threat avoidance is over-represented relative to other possible dream contents. To begin assessing this issue, we contrasted the incidence of 'avoidance' dreams with that of their opposite: 'approach' dreams. Because TST states that the threat-avoidance function is only fully activated in ecologically valid (biologically threatening) contexts, we also performed this contrast for populations living in both high- and low-threat environments. We find that 'approach' dreams are significantly more prevalent across both contexts. We suggest these results are more consistent with the view that dreaming is generated by reward-seeking systems than by fear-conditioning systems, although reward-seeking is clearly not the only factor determining the content of dreams. Copyright © 2011 Elsevier Inc. All rights reserved.

Serotonin Activates Overall Feeding by Activating Two Separate Neural Pathways in Caenorhabditis elegans

PubMed Central

Song, Bo-mi; Avery, Leon

2012-01-01

Food intake in the nematode Caenorhabditis elegans requires two distinct feeding motions, pharyngeal pumping and isthmus peristalsis. Bacteria, the natural food of C. elegans, activate both feeding motions (Croll, 1978; Horvitz et al., 1982; Chiang et al., 2006). The mechanisms by which bacteria activate the feeding motions are largely unknown. To understand the process, we studied how serotonin, an endogenous pharyngeal pumping activator whose action is triggered by bacteria, activates feeding motions. Here, we show that serotonin, like bacteria, activates overall feeding by activating isthmus peristalsis as well as pharyngeal pumping. During active feeding, the frequencies and the timing of onset of the two motions were distinct, but each isthmus peristalsis was coupled to the preceding pump. We found that serotonin activates the two feeding motions mainly by activating two separate neural pathways in response to bacteria. For activating pumping, the SER-7 serotonin receptor in the MC motor neurons in the feeding organ activated cholinergic transmission from MC to the pharyngeal muscles by activating the Gsα signaling pathway. For activating isthmus peristalsis, SER-7 in the M4 (and possibly M2) motor neuron in the feeding organ activated the G12α signaling pathway in a cell-autonomous manner, which presumably activates neurotransmission from M4 to the pharyngeal muscles. Based on our results and previous calcium imaging of pharyngeal muscles (Shimozono et al., 2004), we propose a model that explains how the two feeding motions are separately regulated yet coupled. The feeding organ may have evolved this way to support efficient feeding. PMID:22323705

Inhibition of memory consolidation after active avoidance conditioning by antisense intervention with ependymin gene expression.

PubMed

Schmidt, R; Brysch, W; Rother, S; Schlingensiepen, K H

1995-10-01

A rapid increase in ependymin mRNA expression demonstrated by semiquantitative in situ hybridization after avoidance conditioning on goldfish suggested a molecular demand for newly synthesized ependymin translation product. To inhibit de novo synthesis of ependymin molecules without interference with preexisting ones, 18 mer anti-ependymin mRNA-phosphorothioate oligodeoxynucleotides (S-ODNs) were injected into the perimeningeal brain fluid before active avoidance training. S-ODN-injected animals learned the avoidance response; however, they were amnesic in the test. When injected into overtrained animals, S-ODNs did not interfere with retrieval or performance of the avoidance response. Fish treated with randomized S-ODN sequences served as further controls. Incorporation of S-ODNs was analyzed by injection of fluorescein isothiocyanate (FITC)-conjugated oligodeoxynucleotide probes. Microscopic observation revealed strong FITC-S-ODN fluorescence in reticular-shaped fibroblasts, the only known site of ependymin synthesis. Results demonstrate that selective inhibition of ependymin gene expression in vivo can specifically prevent memory formation. We conclude that in particular the newly synthesized ependymin molecules are involved in memory consolidation, possibly because they have not yet undergone irreversible molecular changes, which have been reported of this glycoprotein in a low-calcium microenvironment.

Trade-offs between predator avoidance and electric shock avoidance in hermit crabs demonstrate a non-reflexive response to noxious stimuli consistent with prediction of pain.

PubMed

Magee, Barry; Elwood, Robert W

2016-09-01

Arthropods have long been thought to respond to noxious stimuli by reflex reaction. One way of testing if this is true is to provide the animal with a way to avoid the stimulus but to vary the potential cost of avoidance. If avoidance varies with potential cost then a decision making process is evident and the behaviour is not a mere reflex. Here we examine the responses of hermit crabs to electric shock within their shell when also exposed to predator or non-predator odours or to no odour. The electric shocks start with low voltage but increase in voltage with each repetition to determine how odour affects the voltage at which the shell is abandoned. There was no treatment effect on the voltage at which hermit crabs left their shells, however, those exposed to predator odours were less likely to evacuate their shells compared with no odour or low concentrations of non-predator odour. However, highly concentrated non-predator also inhibited evacuation. The data show that these crabs trade-off avoidance of electric shock with predator avoidance. They are thus not responding purely by reflex and the data are thus consistent with predictions of pain but do not prove pain. Copyright © 2016 Elsevier B.V. All rights reserved.

Thermomechanical behavior of a two-way shape memory composite actuator

NASA Astrophysics Data System (ADS)

Ge, Qi; Westbrook, Kristofer K.; Mather, Patrick T.; Dunn, Martin L.; Qi, H. Jerry

2013-05-01

Shape memory polymers (SMPs) are a class of smart materials that can fix a temporary shape and recover to their permanent (original) shape in response to an environmental stimulus such as heat, electricity, or irradiation, among others. Most SMPs developed in the past can only demonstrate the so-called one-way shape memory effect; i.e., one programming step can only yield one shape memory cycle. Recently, one of the authors (Mather) developed a SMP that exhibits both one-way shape memory (1W-SM) and two-way shape memory (2W-SM) effects (with the assistance of an external load). This SMP was further used to develop a free-standing composite actuator with a nonlinear reversible actuation under thermal cycling. In this paper, a theoretical model for the PCO SMP based composite actuator was developed to investigate its thermomechanical behavior and the mechanisms for the observed phenomena during the actuation cycles, and to provide insight into how to improve the design.

The Promise and Potential of Two-Way Immersion in Catholic Schools

ERIC Educational Resources Information Center

Fraga, Luis R.

2016-01-01

Two-Way Immersion (TWI) is a method of instruction designed to facilitate the learning of a second language by non-native speakers. Unlike traditional methods of teaching a second language, TWI is grounded in the equal presence, respect, and value of the two languages and their related cultures. Moreover, the goal of TWI is the building of…

Assessing Fan Flutter Stability in Presence of Inlet Distortion Using One-Way and Two-Way Coupled Methods

NASA Technical Reports Server (NTRS)

Herrick, Gregory P.

2014-01-01

Concerns regarding noise, propulsive efficiency, and fuel burn are inspiring aircraft designs wherein the propulsive turbomachines are partially (or fully) embedded within the airframe; such designs present serious concerns with regard to aerodynamic and aeromechanic performance of the compression system in response to inlet distortion. Previously, a preliminary design of a forward-swept high-speed fan exhibited flutter concerns in clean-inlet flows, and the present author then studied this fan further in the presence of off-design distorted in-flows. Continuing this research, a three-dimensional, unsteady, Navier-Stokes computational fluid dynamics code is again applied to analyze and corroborate fan performance with clean inlet flow and now with a simplified, sinusoidal distortion of total pressure at the aerodynamic interface plane. This code, already validated in its application to assess aerodynamic damping of vibrating blades at various flow conditions using a one-way coupled energy-exchange approach, is modified to include a two-way coupled timemarching aeroelastic simulation capability. The two coupling methods are compared in their evaluation of flutter stability in the presence of distorted in-flows.

Post-Traumatic Stress Avoidance is Attenuated by Corticosterone and Associated with Brain Levels of Steroid Receptor Co-Activator-1 in Rats

PubMed Central

Whitaker, Annie M.; Farooq, Muhammad A.; Edwards, Scott; Gilpin, Nicholas W.

2016-01-01

Individuals with post-traumatic stress disorder (PTSD) avoid trauma-related stimuli and exhibit blunted hypothalamic-pituitary-adrenal (HPA) axis activation at the time of stress. Our laboratory has established a rodent model of stress that mimics the avoidance symptom cluster of PTSD. Rats are classified as ‘Avoiders’ or ‘Non-Avoiders’ post-stress based on avoidance of a predator-odor paired context. Previously, we demonstrated that Avoiders exhibit an attenuated HPA stress response to predator odor. We hypothesized that corticosterone administration prior to stress would reduce magnitude and incidence of avoidance of a stress-paired context. Furthermore, we predicted that Avoiders would exhibit altered expression of GR signaling machinery elements, such as steroid receptor co-activator (SRC)-1. Male Wistar rats (n = 16) were pre-treated with corticosterone (25 mg/kg) or saline and exposed to predator odor stress paired with a context, and tested for avoidance 24 h later, A second group of corticosterone-naïve rats (n = 24) were stressed (or not stressed), indexed for avoidance 24 h later, and killed 48 h post-odor exposure for analysis of phosphorylated GR, FKBP51, and SRC-1 levels in the paraventricular nucleus (PVN), central amygdala (CeA) and ventral hippocampus (VH), all brain sites that express high quantities of GRs and regulate HPA function. Rats pre-treated with corticosterone exhibited lower magnitude and incidence of avoidance. Predator odor exposure also reduced SRC-1 expression in the PVN and CeA of Avoiders, and increased SRC-1 expression in the VH of Avoiders. SRC-1 expression in PVN, CeA, and VH was predicted by prior avoidance behavior. These results suggest that blunted HPA stress response may contribute to stress-induced neuroadaptations in central SRC-1 levels and behavioral dysfunction in Avoider rats. PMID:26482332

Approach/Avoidance Orientations Affect Self-Construal and Identification with In-group

PubMed Central

Nussinson, Ravit; Häfner, Michael; Seibt, Beate; Strack, Fritz; Trope, Yaacov

2011-01-01

Approach and avoidance are two basic motivational orientations. Their activation influences cognitive and perceptive processes: Previous work suggests that an approach orientation instigates a focus on larger units as compared to avoidance. Study 1 confirms this assumption using a paradigm that more directly taps a person’s tendency to represent objects as belonging to small or large units than prior studies. It was further predicted that the self should also be represented as belonging to larger units, and hence be more interdependent under approach than under avoidance. Study 2 supports this prediction. As a consequence of this focus on belonging to larger units, it was finally predicted that approach results in a stronger identification with one’s in-group than avoidance. Studies 3 and 4 support that prediction. PMID:22844229

Spectral analysis of one-way and two-way downscaling applications for a tidally driven coastal ocean forecasting system

NASA Astrophysics Data System (ADS)

Solano, Miguel; Gonzalez, Juan; Canals, Miguel; Capella, Jorge; Morell, Julio; Leonardi, Stefano

2017-04-01

A prevailing problem for a tidally driven coastal ocean has been the adequate imposition of open boundary conditions. This study aims at assessing the role of open boundary conditions and tidal forcing for one and two way downscaling applications at high resolution. The operational system is based on the Caribbean Coastal Ocean Forecasting System (COFS) that uses the Regional Ocean Modeling System (ROMS), a split-explicit ocean model in which the barotropic (2D) and baroclinic (3D) modes advance separately. This COFS uses a uniform horizontal grid with 1km resolution, but a grid sensitivity analysis is performed for both one and two way downscaling methodologies with horizontal resolutions up to 700m. Initial and lateral boundary conditions are derived from the U.S Naval Oceanographic Office (NAVOCEANO) operational AmSeas model forecast, a 3-km resolution of the regional Navy Coastal Ocean Model (NCOM) that encompasses the Gulf of Mexico and Caribbean Sea. Meteorological conditions are interpolated from the Navy's COAMPS model with the exception of surface stresses, which are computed from a 2-km application of the WRF model used by NCEP's National Digital Forecast Database. Tidal forcing is performed in two different ways: 1) tidal and sub-tidal variability is imposed to the barotropic and baroclinic modes by downscaling from the AmSeas NCOM regional model and 2) tidal variability is imposed using ROMS harmonic tidal forcing from OTPS and sub-tidal conditions are imposed by filtering high frequencies out the NCOM regional solution. Special focus is given to the latter approach, where the nudging time scales and the boundary update frequency play an important role in the evolution of the ocean state for short 3-day forecasts. A spectral analysis of the sea surface height and barotropic velocity is performed via Fourier's transform, continuous 1-D wavelet transforms, and classic harmonic analysis. Tide signals are then reconstructed and removed from the OBC's in 3

Stimulus conflict triggers behavioral avoidance.

PubMed

Dignath, David; Eder, Andreas B

2015-12-01

According to a recent extension of the conflict-monitoring theory, conflict between two competing response tendencies is registered as an aversive event and triggers a motivation to avoid the source of conflict. In the present study, we tested this assumption. Over five experiments, we examined whether conflict is associated with an avoidance motivation and whether stimulus conflict or response conflict triggers an avoidance tendency. Participants first performed a color Stroop task. In a subsequent motivation test, participants responded to Stroop stimuli with approach- and avoidance-related lever movements. These results showed that Stroop-conflict stimuli increased the frequency of avoidance responses in a free-choice motivation test, and also increased the speed of avoidance relative to approach responses in a forced-choice test. High and low proportions of response conflict in the Stroop task had no effect on avoidance in the motivation test. Avoidance of conflict was, however, obtained even with new conflict stimuli that had not been presented before in a Stroop task, and when the Stroop task was replaced with an unrelated filler task. Taken together, these results suggest that stimulus conflict is sufficient to trigger avoidance.

Establishing and Assessing Two-Way Communication Between Parents and School.

ERIC Educational Resources Information Center

Lordeman, Ann; And Others

The purpose of this study was to determine whether or not a written, two-way home-school feedback program could be established on a regular basis. The study assessed the effectiveness of three feedback procedures for improvement of communication between parents of 600 middle school students involved in a Preparation through Responsive Educational…

Enhancing hazard avoidance in teen-novice riders.

PubMed

Vidotto, Giulio; Bastianelli, Alessia; Spoto, Andrea; Sergeys, Filip

2011-01-01

Research suggests that novice drivers' safety performance is inferior to that of experienced drivers in different ways. One of the most critical skills related to accident avoidance by a novice driver is the detection, recognition and reaction to traffic hazards; it is called hazard perception and is defined as the ability to identify potentially dangerous traffic situations. The focus of this research is to assess how far a motorcycle simulator could improve hazard avoidance skills in teenagers. Four hundred and ten participants (207 in the experimental group and 203 in the control group) took part in this research. Results demonstrated that the mean proportion of avoided hazards increases as a function of the number of tracks performed in the virtual training. Participants of the experimental group after the training had a better proportion of avoided hazards than participants of the control group with a passive training based on a road safety lesson. Results provide good evidence that training with the simulator increases the number of avoided accidents in the virtual environment. It would be reasonable to explain this improvement by a higher level of hazard perception skills. Copyright © 2010 Elsevier Ltd. All rights reserved.

Tropospheric ozone simulated by a global-multi-regional two-way coupling model system

NASA Astrophysics Data System (ADS)

Yan, Y.; Lin, J.; Chen, J.; Hu, L.

2015-12-01

Current global chemical transport models are limited by horizontal resolutions (100-500 km), and they cannot capture small-scale processes affecting tropospheric ozone (O3). Here we use a recently built two-way coupling system of GEOS-Chem to simulate the global tropospheric O3 in 2009. The system couples the global model (~ 200 km) and its three nested models (~ 50 km) covering Asia, North America and Europe, respectively. Benefiting from the high resolution, the nested models better capture small-scale processes than the global model alone. In the coupling system, the nested models provide results to modify the global model simulation within respective nested domains while taking the lateral boundary conditions from the global model. Due to the "coupling" effects, the two-way system significantly improves the tropospheric O3 simulation upon the global model alone, as found by comparisons with a suite of ground (1420 sites from WDCGG, GMD, EMEP, and AQS), aircraft (HIPPO and MOZAIC), and satellite measurements (two OMI products). Compared to the global model alone, the two-way coupled simulation enhances the correlation in day-to-day variation of afternoon mean O3 with the ground measurements from 0.53 to 0.68 and reduces the mean model bias from 10.8 to 6.7 ppb. Regionally, the coupled model reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America, and 3.1 ppb over other regions. The two-way coupling brings O3 vertical profiles much closer to the HIPPO and MOZAIC data, reducing the tropospheric (0-9 km) mean bias by 3-10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO profiles. The two-way coupled simulation also reduces the global tropospheric column ozone by 3.0 DU (9.5%), bringing them closer to the OMI data in all seasons. Simulation improvements are more significant in the northern hemisphere, and are primarily a result of improved representation of the nonlinear ozone chemistry, including but not limited to urban-rural contrast. The two-way

Damage Assessment of Two-Way Bending RC Slabs Subjected to Blast Loadings

PubMed Central

Jia, Haokai; Wu, Guiying

2014-01-01

Terrorist attacks on vulnerable structures and their individual structural members may cause considerable damage and loss of life. However, the research work on response and damage analysis of single structural components, for example, a slab to blast loadings, is limited in the literature and this is necessary for assessing its vulnerability. This study investigates the blast response and damage assessment of a two-way bending reinforced concrete (RC) slab subjected to blast loadings. Numerical modeling and analysis are carried out using the commercial finite element code LS-DYNA 971. A damage assessment criterion for the two-way bending RC slab is defined based on the original and residual uniformly distributed load-carrying capacity. Parametric studies are carried out to investigate the effects of explosive weight and explosive position on the damage mode of the two-way RC slab. Some design parameters, such as the boundary conditions and the negative reinforcement steel bar length, are also discussed. The illustrated results show that the proposed criterion can apply to all failure modes. The damage assessment results are more accurate than the ones due to the conventional deformation criterion. PMID:25121134

Optical calibration of a new two-way optical component network analyzer

NASA Astrophysics Data System (ADS)

Tsao, Shyh-Lin; Ko, Chih-Han; Liou, Tai-Chi

2003-12-01

High-speed fiber communications show promising results recently [1,2]. Using of lightwave technology for measuring S parameters with optical component becoming important. For this purpose to develop a two-way network analyzer has been reported [3]. In this paper, we report the calibration method of a new two-way lightwave component analyze for applying in fiber optical signal processing elements. The background error and circulator wavelength response are all calibrated. We have designed a new probe for two-way optical component network analyzer. The probe is composed of frequency division multiplexer(FDM), electrical circulator, optical transmitter, optical receiver, and an optical circulator. We design 2-D grating structures as frequency division. The PCB we adopted is Kinstan GD1530 160 whose relative dielectric constantɛ= 4.3, length= 120 mm, and height= 1.8 mm. Two dimensional non-metal covered array square pads are designed on FR4 Glass-Epoxy board for FDM. The FDM can be achieved by the two dimensional non-metalized covered array square pads. Finally we use a single fiber ring resonator filter as our test samples. Comparing the numerical and experimental results, test the device we made. References [1] D. D. Curtis and E. E. Ames,"Optical Test Set for Microwave Fiber-Optic Network Analysis," IEEE Transactions on Microwave Theory and Techniques. , vol. 38, NO.5, pp. 552-559, 1990. [2] J. A. C. Bingham,"Multicarrier modulation for data transmission: an idea whose time has come," IEEE Commun. Magazine., pp. 5 -14, 1990. [3] M. Nakazawa, K. Suzuki, and Y. Kimura, " 3.2-5 Gbps 100km error-free soliton transmission with erbium amplifiers and repenters," IEEE Photonics Tech Lett.,vol.2,pp.216-219,1990.

Two-way sequential time synchronization: Preliminary results from the SIRIO-1 experiment

NASA Technical Reports Server (NTRS)

Detoma, E.; Leschiutta, S.

1981-01-01

A two-way time synchronization experiment performed in the spring of 1979 and 1980 via the Italian SIRIO-1 experimental telecommunications satellite is described. The experiment was designed and implemented to precisely monitor the satellite motion and to evaluate the possibility of performing a high precision, two-way time synchronization using a single communication channel, time-shared between the participating sites. Results show that the precision of the time synchronization is between 1 and 5 ns, while the evaluation and correction of the satellite motion effect was performed with an accuracy of a few nanoseconds or better over a time interval from 1 up to 20 seconds.

Fear-avoidance beliefs and parental responses to pain in adolescents with chronic pain.

PubMed

Wilson, Anna C; Lewandowski, Amy S; Palermo, Tonya M

2011-01-01

The fear-avoidance model of chronic pain posits that fear of pain is associated with fear and avoidance of activity, which can lead to deconditioning and persistence of pain and disability. Despite being well supported in adults, little is known about the role of fear-avoidance beliefs regarding physical activity in children. Research has shown that parental protectiveness contributes to activity limitations in children; however, no studies have examined relationships between protectiveness, and fear and avoidance. To conduct a cross-sectional study to provide additional information regarding the reliability and validity of the Fear-Avoidance Beliefs Questionnaire physical activity subscale among adolescents with chronic pain; examine fear-avoidance beliefs and depressive symptoms as concurrent predictors of physical activity limitations; and test competing models using fear-avoidance beliefs as mediators and moderators of the association between parental protectiveness and activity limitations. Adolescents (n=42) 11 to 17 years of age with chronic pain completed questionnaires assessing pain intensity, fear-avoidance beliefs, depressive symptoms and physical activity limitations. Their parents completed questionnaires regarding protectiveness and adolescent activity limitations. The Fear-Avoidance Beliefs Questionnaire physical activity subscale was useful for assessing fear-avoidance beliefs in the present population. In support of hypotheses, greater fear-avoidance beliefs were associated with greater activity limitations, above pain intensity and depressive symptoms. Support was found for fear-avoidance beliefs as mediators of the association between parental protectiveness and activity limitations. Tests of moderation were not significant. Fear-avoidance beliefs may be an important target for interventions focused on decreasing activity limitations in youth with chronic pain. Future research should investigate these associations longitudinally.

Remote Maneuver of Space Debris Using Photon Pressure for Active Collision Avoidance

NASA Astrophysics Data System (ADS)

Smith, C.

2014-09-01

The Space Environment Research Corporation (SERC) is a consortium of companies and research institutions that have joined together to pursue research and development of technologies and capabilities that will help to preserve the orbital space environment. The consortium includes, Electro Optics Systems (Australia), Lockheed Martin Australia, Optus Satellite Systems (Australia), The Australian national University, RMIT University, National Institute of Information and Communications Technology (NICT, Japan) as well as affiliates from NASA Ames and ESA. SERC is also the recipient of and Australian Government Cooperative Research Centre grant. SERC will pursue a wide ranging research program including technologies to improve tracking capability and capacity, orbit determination and propagation algorithms, conjunction analysis and collision avoidance. All of these technologies will contribute to the flagship program to demonstrate active collision avoidance using photon pressure to provide remote maneuver of space debris. This project joins of the proposed NASA Lightforce concept with infrastructure and capabilities provided by SERC. This paper will describe the proposed research and development program to provide an on-orbit demonstration within the next five years for remote maneuver of space debris.

Two Hop Adaptive Vector Based Quality Forwarding for Void Hole Avoidance in Underwater WSNs

PubMed Central

Javaid, Nadeem; Ahmed, Farwa; Wadud, Zahid; Alrajeh, Nabil; Alabed, Mohamad Souheil; Ilahi, Manzoor

2017-01-01

Underwater wireless sensor networks (UWSNs) facilitate a wide range of aquatic applications in various domains. However, the harsh underwater environment poses challenges like low bandwidth, long propagation delay, high bit error rate, high deployment cost, irregular topological structure, etc. Node mobility and the uneven distribution of sensor nodes create void holes in UWSNs. Void hole creation has become a critical issue in UWSNs, as it severely affects the network performance. Avoiding void hole creation benefits better coverage over an area, less energy consumption in the network and high throughput. For this purpose, minimization of void hole probability particularly in local sparse regions is focused on in this paper. The two-hop adaptive hop by hop vector-based forwarding (2hop-AHH-VBF) protocol aims to avoid the void hole with the help of two-hop neighbor node information. The other protocol, quality forwarding adaptive hop by hop vector-based forwarding (QF-AHH-VBF), selects an optimal forwarder based on the composite priority function. QF-AHH-VBF improves network good-put because of optimal forwarder selection. QF-AHH-VBF aims to reduce void hole probability by optimally selecting next hop forwarders. To attain better network performance, mathematical problem formulation based on linear programming is performed. Simulation results show that by opting these mechanisms, significant reduction in end-to-end delay and better throughput are achieved in the network. PMID:28763014

Two Hop Adaptive Vector Based Quality Forwarding for Void Hole Avoidance in Underwater WSNs.

PubMed

Javaid, Nadeem; Ahmed, Farwa; Wadud, Zahid; Alrajeh, Nabil; Alabed, Mohamad Souheil; Ilahi, Manzoor

2017-08-01

Underwater wireless sensor networks (UWSNs) facilitate a wide range of aquatic applications in various domains. However, the harsh underwater environment poses challenges like low bandwidth, long propagation delay, high bit error rate, high deployment cost, irregular topological structure, etc. Node mobility and the uneven distribution of sensor nodes create void holes in UWSNs. Void hole creation has become a critical issue in UWSNs, as it severely affects the network performance. Avoiding void hole creation benefits better coverage over an area, less energy consumption in the network and high throughput. For this purpose, minimization of void hole probability particularly in local sparse regions is focused on in this paper. The two-hop adaptive hop by hop vector-based forwarding (2hop-AHH-VBF) protocol aims to avoid the void hole with the help of two-hop neighbor node information. The other protocol, quality forwarding adaptive hop by hop vector-based forwarding (QF-AHH-VBF), selects an optimal forwarder based on the composite priority function. QF-AHH-VBF improves network good-put because of optimal forwarder selection. QF-AHH-VBF aims to reduce void hole probability by optimally selecting next hop forwarders. To attain better network performance, mathematical problem formulation based on linear programming is performed. Simulation results show that by opting these mechanisms, significant reduction in end-to-end delay and better throughput are achieved in the network.

Inhibition of long-term memory formation by anti-ependymin antisera after active shock-avoidance learning in goldfish.

PubMed

Piront, M L; Schmidt, R

1988-02-23

Ependymins are acidic glycoprotein constituents of goldfish brain cytoplasm and extracellular fluid which are known to participate in biochemical reactions of long-term memory formation. In earlier experiments, anti-ependymin antisera were found to cause amnesia when injected into goldfish brain ventricles after the acquisition of a vestibulomotoric training task. To investigate whether they also inhibit memory consolidation after other learning events the anti-ependymin antisera were injected after an active shock-avoidance learning paradigm, as follows: goldfish were trained in a shuttle-box to cross a barrier in order to avoid electric shocks (unconditioned stimulus) applied shortly after a light signal (conditioned stimulus). Anti-ependymin antisera blocked retention of the learned avoidance when injected 0.5, 4.5 or 24 h after acquisition of the new behavior. They had no effect, however, when injected 72 h after learning. Apparently, long-term memory was already consolidated at this point. Antisera injected 0.5 or 72 h prior to training, also did not influence learning or memory. Thirteen percent of the goldfish fled the light stimulus spontaneously. These fish therefore did not experience the unconditioned stimulus and thus were unable to learn the task. When they were treated with the anti-ependymin antisera and tested 3 days later, the spontaneous escape reaction was not affected (active control group). The ability of anti-ependymin antisera to inhibit memory consolidation and their efficacy after administration at specific time intervals are very similar for the active shock-avoidance learning and for the vestibulomotoric training. We conclude that ependymins are not task-specific, but serve a general function in biochemical reactions essential for long-term memory formation.

Incest avoidance: oedipal and preoedipal, natural and cultural.

PubMed

Paul, Robert A

2010-12-01

Why do most people experience a subjective aversion to the idea of incestuous sexual relations? To help answer this question, recent strands of thinking in both cultural and evolutionary anthropology are considered together with psychoanalytic theories regarding incest avoidance. Coevolutionary theories that propose ways to think about genetic and cultural inheritance as partially independent of each other, evolutionary arguments about the reproductive advantages of incest avoidance, structuralist theory arguing for a kind of incest aversion unrelated to any possible Darwinian selective advantage, and other trends in biosocial research into the origins of the incest avoidance are considered. Finally, a synthesis is proposed that seeks to expand our understanding of the oedipal and preoedipal dynamics of the aversion as these are conceptualized in psychoanalytic theory.

Interference and partial which-way information: A quantitative test of duality in two-atom resonance

NASA Astrophysics Data System (ADS)

Abranyos, Y.; Jakob, M.; Bergou, J.

2000-01-01

We propose for the experimental verification of an inequality concerning wave-particle duality by Englert [Phys. Rev. Lett. 77, 2154 (1996)] relating (or setting) an upper limit on distinguishability and visibility in a two-way interferometer. The inequality, quantifies the concept of wave-particle duality. The considered two-way interferometer is a Young's double-slit experiment involving two four-level atoms and is a slightly modified version of that of the recent experiment by Eichmann et al. [Phys. Rev. Lett. 70, 2359 (1993)]. The fringe visibility depends on the detected polarization direction of the scattered light and a read out of the internal state of one of the two atoms provides a partial which-way information.

Quantum one-way permutation over the finite field of two elements

NASA Astrophysics Data System (ADS)

de Castro, Alexandre

2017-06-01

In quantum cryptography, a one-way permutation is a bounded unitary operator U:{H} → {H} on a Hilbert space {H} that is easy to compute on every input, but hard to invert given the image of a random input. Levin (Probl Inf Transm 39(1):92-103, 2003) has conjectured that the unitary transformation g(a,x)=(a,f(x)+ax), where f is any length-preserving function and a,x \\in {GF}_{{2}^{\\Vert x\\Vert }}, is an information-theoretically secure operator within a polynomial factor. Here, we show that Levin's one-way permutation is provably secure because its output values are four maximally entangled two-qubit states, and whose probability of factoring them approaches zero faster than the multiplicative inverse of any positive polynomial poly( x) over the Boolean ring of all subsets of x. Our results demonstrate through well-known theorems that existence of classical one-way functions implies existence of a universal quantum one-way permutation that cannot be inverted in subexponential time in the worst case.

Data Quality Assessment of In Situ and Altimeter Observations Through Two-Way Intercomparison Methods

NASA Astrophysics Data System (ADS)

Guinehut, Stephanie; Valladeau, Guillaume; Legeais, Jean-Francois; Rio, Marie-Helene; Ablain, Michael; Larnicol, Gilles

2013-09-01

This proceeding presents an overview of the two-way inter-comparison activities performed at CLS for both space and in situ observation agencies and why this activity is a required step to obtain accurate and homogenous data sets that can then be used together for climate studies or in assimilation/validation tools. We first describe the work performed in the frame of the SALP program to assess the stability of altimeter missions through SSH comparisons with tide gauges (GLOSS/CLIVAR network). Then, we show how the SSH comparison between the Argo array and altimeter time series allows the detection of drifts or jumps in altimeter (SALP program) but also for some Argo floats (Ifremer/Coriolis center). Lastly, we describe how the combine use of altimeter and wind observations helps the detection of drogue loss of surface drifting buoys (GDP network) and allow the computation of a correction term for wind slippage.

How You Can Help Your Child Avoid & Address Bullying

MedlinePlus

... How You Can Help Your Child Avoid & Address Bullying Page Content Article Body Whether on the school ... other ways. Getting that response usually makes the bullying behavior continue. Your child should try to keep ...

Airborne Collision Detection and Avoidance for Small UAS Sense and Avoid Systems

NASA Astrophysics Data System (ADS)

Sahawneh, Laith Rasmi

The increasing demand to integrate unmanned aircraft systems (UAS) into the national airspace is motivated by the rapid growth of the UAS industry, especially small UAS weighing less than 55 pounds. Their use however has been limited by the Federal Aviation Administration regulations due to collision risk they pose, safety and regulatory concerns. Therefore, before civil aviation authorities can approve routine UAS flight operations, UAS must be equipped with sense-and-avoid technology comparable to the see-and-avoid requirements for manned aircraft. The sense-and-avoid problem includes several important aspects including regulatory and system-level requirements, design specifications and performance standards, intruder detecting and tracking, collision risk assessment, and finally path planning and collision avoidance. In this dissertation, our primary focus is on developing an collision detection, risk assessment and avoidance framework that is computationally affordable and suitable to run on-board small UAS. To begin with, we address the minimum sensing range for the sense-and-avoid (SAA) system. We present an approximate close form analytical solution to compute the minimum sensing range to safely avoid an imminent collision. The approach is then demonstrated using a radar sensor prototype that achieves the required minimum sensing range. In the area of collision risk assessment and collision prediction, we present two approaches to estimate the collision risk of an encounter scenario. The first is a deterministic approach similar to those been developed for Traffic Alert and Collision Avoidance (TCAS) in manned aviation. We extend the approach to account for uncertainties of state estimates by deriving an analytic expression to propagate the error variance using Taylor series approximation. To address unanticipated intruders maneuvers, we propose an innovative probabilistic approach to quantify likely intruder trajectories and estimate the probability of

The olfactory neuron AWC promotes avoidance of normally palatable food following chronic dietary restriction

PubMed Central

Olofsson, Birgitta

2014-01-01

Changes in metabolic state alter foraging behavior and food preference in animals. Here, I show that normally attractive food becomes repulsive to Caenorhabditis elegans if animals are chronically undernourished as a result of alimentary tract defects. This behavioral plasticity is achieved in two ways: increased food leaving and induction of aversive behavior towards food. A particularly strong food avoider is defective in the chitin synthase that makes the pharyngeal lining. Food avoidance induced by underfeeding is mediated by cGMP signaling in the olfactory neurons AWC and AWB, and the gustatory neurons ASJ and ASK. Food avoidance is enhanced by increased population density and is reduced if the animals are unable to correctly interpret their nutritional state as a result of defects in the AMP kinase or TOR/S6kinase pathways. The TGF-β/DBL-1 pathway suppresses food avoidance and the cellular basis for this is distinct from its role in aversive olfactory learning of harmful food. This study suggests that nutritional state feedback via nutrient sensors, population size and olfactory neurons guides food preference in C. elegans. PMID:24577446

Petrographic evidence shows that pottery exchange between the Olmec and their neighbors was two-way

PubMed Central

Stoltman, James B.; Marcus, Joyce; Flannery, Kent V.; Burton, James H.; Moyle, Robert G.

2005-01-01

Petrographic thin sections of pottery from five Formative Mexican archaeological sites show that exchanges of vessels between highland and lowland chiefly centers were reciprocal, or two-way. These analyses contradict recent claims that the Gulf Coast was the sole source of pottery carved with iconographic motifs. Those claims were based on neutron activation, which, by relying on chemical elements rather than actual minerals, has important limitations in its ability to identify nonlocal pottery from within large data sets. Petrography shows that the ceramics in question (and hence their carved motifs) have multiple origins and were widely traded. PMID:16061796

Avoiding horror autotoxicus: The importance of dendritic cells in peripheral T cell tolerance

PubMed Central

Steinman, Ralph Marvin; Nussenzweig, Michel C.

2002-01-01

The immune system generally avoids horror autotoxicus or autoimmunity, an attack against the body's own constituents. This avoidance requires that self-reactive T cells be actively silenced or tolerized. We propose that dendritic cells (DCs) play a critical role in establishing tolerance, especially in the periphery, after functioning T cells have been produced in the thymus. In the steady state, meaning in the absence of acute infection and inflammation, DCs are in an immature state and not fully differentiated to carry out their known roles as inducers of immunity. Nevertheless, immature DCs continuously circulate through tissues and into lymphoid organs, capturing self antigens as well as innocuous environmental proteins. Recent experiments have provided direct evidence that antigen-loaded immature DCs silence T cells either by deleting them or by expanding regulatory T cells. This capacity of DCs to induce peripheral tolerance can work in two opposing ways in the context of infection. In acute infection, a beneficial effect should occur. The immune system would overcome the risk of developing autoimmunity and chronic inflammation if, before infection, tolerance were induced to innocuous environmental proteins as well as self antigens captured from dying infected cells. For chronic or persistent pathogens, a second but dire potential could take place. Continuous presentation of a pathogen by immature DCs, HIV-1 for example, may lead to tolerance and active evasion of protective immunity. The function of DCs in defining immunologic self provides a new focus for the study of autoimmunity and chronic immune-based diseases. PMID:11773639

Assessing Fan Flutter Stability in the Presence of Inlet Distortion Using One-way and Two-way Coupled Methods

NASA Technical Reports Server (NTRS)

Herrick, Gregory P.

2014-01-01

Concerns regarding noise, propulsive efficiency, and fuel burn are inspiring aircraft designs wherein the propulsive turbomachines are partially (or fully) embedded within the airframe; such designs present serious concerns with regard to aerodynamic and aeromechanic performance of the compression system in response to inlet distortion. Previously, a preliminary design of a forward-swept high-speed fan exhibited flutter concerns in cleaninlet flows, and the present author then studied this fan further in the presence of off-design distorted in-flows. Continuing this research, a three-dimensional, unsteady, Navier-Stokes computational fluid dynamics code is again applied to analyze and corroborate fan performance with clean inlet flow and now with a simplified, sinusoidal distortion of total pressure at the aerodynamic interface plane. This code, already validated in its application to assess aerodynamic damping of vibrating blades at various flow conditions using a one-way coupled energy-exchange approach, is modified to include a two-way coupled time-marching aeroelastic simulation capability. The two coupling methods are compared in their evaluation of flutter stability in the presence of distorted in-flows.

Two Way Coupling RAM-SCB to the Space Weather Modeling Framework

NASA Astrophysics Data System (ADS)

Welling, D. T.; Jordanova, V. K.; Zaharia, S. G.; Toth, G.

2010-12-01

The Ring current Atmosphere interaction Model with Self-Consistently calculated 3D Magnetic field (RAM-SCB) has been used to successfully study inner magnetosphere dynamics during different solar wind and magnetosphere conditions. Recently, one way coupling of RAM-SCB with the Space Weather Modeling Framework (SWMF) has been achieved to replace all data or empirical inputs with those obtained through first-principles-based codes: magnetic field and plasma flux outer boundary conditions are provided by the Block Adaptive Tree Solar wind Roe-type Upwind Scheme (BATS-R-US) MHD code, convection electric field is provided by the Ridley Ionosphere Model (RIM), and ion composition is provided by the Polar Wind Outflow Model (PWOM) combined with a multi-species MHD approach. These advances, though creating a powerful inner magnetosphere virtual laboratory, neglect the important mechanisms through which the ring current feeds back into the whole system, primarily the stretching of the magnetic field lines and shielding of the convection electric field through strong region two Field Aligned Currents (FACs). In turn, changing the magnetosphere in this way changes the evolution of the ring current. To address this shortcoming, the coupling has been expanded to include feedback from RAM-SCB to the other coupled codes: region two FACs are returned to the RIM while total plasma pressure is used to nudge the MHD solution towards the RAM-SCB values. The impacts of the two way coupling are evaluated on three levels: the global magnetospheric level, focusing on the impact on the ionosphere and the shape of the magnetosphere, the regional level, examining the impact on the development of the ring current in terms of energy density, anisotropy, and plasma distribution, and the local level to compare the new results to in-situ measurements of magnetic and electric field and plasma. The results will also be compared to past simulations using the one way coupling and no coupling

Avoiding sports-related sudden cardiac death in children with congenital channelopathy : Recommendations for sports activities.

PubMed

Lang, C N; Steinfurt, J; Odening, K E

2017-04-01

For the past few years, children affected by an inherited channelopathy have been counseled to avoid (recreational) sports activities and all competitive sports so as to prevent exercise-induced arrhythmia and sudden cardiac death. An increased understanding of the pathophysiological mechanisms, better anti-arrhythmic strategies, and, in particular, more epidemiological data on exercise-induced arrhythmia in active athletes with channelopathies have changed the universal recommendation of "no sports," leading to revised, less strict, and more differentiated guidelines (published by the American Heart Association/American College of Cardiology in 2015). In this review, we outline the disease- and genotype-specific mechanisms of exercise-induced arrhythmia; give an overview of trigger-, symptom-, and genotype-dependent guidance in sports activities for children with long QT syndrome (LQTS), Brugada syndrome (BrS), catecholaminergic polymorphic ventricular tachycardia (CPVT), or short QT syndrome (SQTS); and highlight the novelties in the current guidelines compared with previous versions. While it is still recommended for patients with LQT1 and CPVT (even when asymptomatic) and all symptomatic LQTS patients (independent of genotype) to avoid any competitive and high-intensity sports, other LQTS patients successfully treated with anti-arrhythmic therapies and phenotype-negative genotype-positive patients may be allowed to perform sports at different activity levels - provided they undergo regular, sophisticated evaluations to detect any changes in arrhythmogenic risk.

The Impact of Two-Way Dual-Immersion Programs on Initially English-Dominant Latino Students' Attitudes

ERIC Educational Resources Information Center

Block, Nicholas

2011-01-01

Forty initially English-dominant Latino students in four 90:10 Spanish two-way dual-immersion programs and 62 of their peers in mainstream English programs were studied to find out if their attitudes toward Spanish and Spanish-dominant individuals differ. Significant differences were found on many variables, with two-way dual-immersion students…

Ways of coping of Chinese caregivers for family members with schizophrenia in two metropolitan cities: Guangzhou and Hong Kong, China.

PubMed

Lam, Paul Cw; Ng, Petrus; Pan, Jiayan; Young, Daniel Kw

2015-09-01

In Chinese societies, family caregivers play an important role in the recovery of persons with serious mental illness, such as schizophrenia. While family caregivers are often invaluable sources of caregiving in the community, a majority of them lack adequate knowledge and support skills to cope with the tasks involved. This study compares the coping strategies and psychological health of caregivers for family members with schizophrenia in two Chinese cities, Hong Kong and Guangzhou. A total of 109 caregivers, including 39 from Hong Kong and 70 from Guangzhou, were recruited from non-governmental mental health organizations in the two cities. They were assessed by the Chinese version of the Ways of Coping Questionnaire and the General Health Questionnaire. While there was no significant difference in the psychological distress of the family caregivers in the two locations, the Guangzhou caregivers adopt significantly more of the eight coping strategies, namely, confronting coping, distancing, self-control, seeking social support, accepting responsibility, escape-avoidance, planful problem solving and positive reappraisal, than their counterparts in Hong Kong. Significant correlations were also found between psychological distress and coping strategies of caregivers in the two cities. There were significant differences in the coping strategies of family caregivers for people with schizophrenia in the two Chinese cities. Further studies are warranted to investigate factors affecting their coping strategies and their effects on psychological health. © The Author(s) 2015.

Towards Efficient Wireless Body Area Network Using Two-Way Relay Cooperation.

PubMed

Waheed, Maham; Ahmad, Rizwan; Ahmed, Waqas; Drieberg, Micheal; Alam, Muhammad Mahtab

2018-02-13

The fabrication of lightweight, ultra-thin, low power and intelligent body-borne sensors leads to novel advances in wireless body area networks (WBANs). Depending on the placement of the nodes, it is characterized as in/on body WBAN; thus, the channel is largely affected by body posture, clothing, muscle movement, body temperature and climatic conditions. The energy resources are limited and it is not feasible to replace the sensor's battery frequently. In order to keep the sensor in working condition, the channel resources should be reserved. The lifetime of the sensor is very crucial and it highly depends on transmission among sensor nodes and energy consumption. The reliability and energy efficiency in WBAN applications play a vital role. In this paper, the analytical expressions for energy efficiency (EE) and packet error rate (PER) are formulated for two-way relay cooperative communication. The results depict better reliability and efficiency compared to direct and one-way relay communication. The effective performance range of direct vs. cooperative communication is separated by a threshold distance. Based on EE calculations, an optimal packet size is observed that provides maximum efficiency over a certain link length. A smart and energy efficient system is articulated that utilizes all three communication modes, namely direct, one-way relay and two-way relay, as the direct link performs better for a certain range, but the cooperative communication gives better results for increased distance in terms of EE. The efficacy of the proposed hybrid scheme is also demonstrated over a practical quasi-static channel. Furthermore, link length extension and diversity is achieved by joint network-channel (JNC) coding the cooperative link.

Towards Efficient Wireless Body Area Network Using Two-Way Relay Cooperation

PubMed Central

Waheed, Maham; Ahmad, Rizwan; Ahmed, Waqas

2018-01-01

The fabrication of lightweight, ultra-thin, low power and intelligent body-borne sensors leads to novel advances in wireless body area networks (WBANs). Depending on the placement of the nodes, it is characterized as in/on body WBAN; thus, the channel is largely affected by body posture, clothing, muscle movement, body temperature and climatic conditions. The energy resources are limited and it is not feasible to replace the sensor’s battery frequently. In order to keep the sensor in working condition, the channel resources should be reserved. The lifetime of the sensor is very crucial and it highly depends on transmission among sensor nodes and energy consumption. The reliability and energy efficiency in WBAN applications play a vital role. In this paper, the analytical expressions for energy efficiency (EE) and packet error rate (PER) are formulated for two-way relay cooperative communication. The results depict better reliability and efficiency compared to direct and one-way relay communication. The effective performance range of direct vs. cooperative communication is separated by a threshold distance. Based on EE calculations, an optimal packet size is observed that provides maximum efficiency over a certain link length. A smart and energy efficient system is articulated that utilizes all three communication modes, namely direct, one-way relay and two-way relay, as the direct link performs better for a certain range, but the cooperative communication gives better results for increased distance in terms of EE. The efficacy of the proposed hybrid scheme is also demonstrated over a practical quasi-static channel. Furthermore, link length extension and diversity is achieved by joint network-channel (JNC) coding the cooperative link. PMID:29438278

Escape from harm: linking affective vision and motor responses during active avoidance

PubMed Central

Keil, Andreas

2014-01-01

When organisms confront unpleasant objects in their natural environments, they engage in behaviors that allow them to avoid aversive outcomes. Here, we linked visual processing of threat to its behavioral consequences by including a motor response that terminated exposure to an aversive event. Dense-array steady-state visual evoked potentials were recorded in response to conditioned threat and safety signals viewed in active or passive behavioral contexts. The amplitude of neuronal responses in visual cortex increased additively, as a function of emotional value and action relevance. The gain in local cortical population activity for threat relative to safety cues persisted when aversive reinforcement was behaviorally terminated, suggesting a lingering emotionally based response amplification within the visual system. Distinct patterns of long-range neural synchrony emerged between the visual cortex and extravisual regions. Increased coupling between visual and higher-order structures was observed specifically during active perception of threat, consistent with a reorganization of neuronal populations involved in linking sensory processing to action preparation. PMID:24493849

A Review of Findings from Two-Way Bilingual Education Evaluation Reports.

ERIC Educational Resources Information Center

Mahrer, Cindy; Christian, Donna

A review of 35 reports evaluating 27 two-way bilingual education programs is reported. All programs represented meet basic criteria for language of instruction, student characteristics, and emphasis on developing bilingualism. The review examined program characteristics and student outcomes, when available. Results are summarized in the following…

Neural Mechanisms for Adaptive Learned Avoidance of Mental Effort.

PubMed

Mitsuto Nagase, Asako; Onoda, Keiichi; Clifford Foo, Jerome; Haji, Tomoki; Akaishi, Rei; Yamaguchi, Shuhei; Sakai, Katsuyuki; Morita, Kenji

2018-02-05

Humans tend to avoid mental effort. Previous studies have demonstrated this tendency using various demand-selection tasks; participants generally avoid options associated with higher cognitive demand. However, it remains unclear whether humans avoid mental effort adaptively in uncertain and non-stationary environments, and if so, what neural mechanisms underlie this learned avoidance and whether they remain the same irrespective of cognitive-demand types. We addressed these issues by developing novel demand-selection tasks where associations between choice options and cognitive-demand levels change over time, with two variations using mental arithmetic and spatial reasoning problems (29:4 and 18:2 males:females). Most participants showed avoidance, and their choices depended on the demand experienced on multiple preceding trials. We assumed that participants updated the expected cost of mental effort through experience, and fitted their choices by reinforcement learning models, comparing several possibilities. Model-based fMRI analyses revealed that activity in the dorsomedial and lateral frontal cortices was positively correlated with the trial-by-trial expected cost for the chosen option commonly across the different types of cognitive demand, and also revealed a trend of negative correlation in the ventromedial prefrontal cortex. We further identified correlates of cost-prediction-error at time of problem-presentation or answering the problem, the latter of which partially overlapped with or were proximal to the correlates of expected cost at time of choice-cue in the dorsomedial frontal cortex. These results suggest that humans adaptively learn to avoid mental effort, having neural mechanisms to represent expected cost and cost-prediction-error, and the same mechanisms operate for various types of cognitive demand. SIGNIFICANCE STATEMENT In daily life, humans encounter various cognitive demands, and tend to avoid high-demand options. However, it remains unclear

78 FR 31576 - Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-24

...-Way Global Satellite Communication Devices, System and Components Thereof; Notice of Institution of...-confidential documents filed in connection with this investigation are or will be available for inspection... importation of certain two-way global satellite communication devices, system and components thereof by reason...

Towards an explanation of age-related difficulties in crossing a two-way street.

PubMed

Dommes, Aurélie; Lay, Tristan Le; Vienne, Fabrice; Dang, Nguyen-Thong; Beaudoin, Alexandra Perrot; Do, Manh Cuong

2015-12-01

Crossing a two-way street is a complex task that involves visual, cognitive and motor abilities, all of which are known to decline with ageing. In particular, older pedestrians may experience difficulties when crossing two-way streets because of incorrect gap acceptance choices and impossible or unperceived evasive actions. To understand the overrepresentation of older pedestrians in crash statistics, several experimental studies have sought to identify traffic-related factors as well as those related to the abilities of the individuals themselves. However, none of these studies has required participants to actually walk across an experimental two-way street with curbs, which is a particularly challenging situation for older pedestrians. To fill this research gap, a quasi-experiment was conducted in a simulator including a total of 58 healthy aged participants (25 younger-old [age 60-72] and 33 older-old [age 72-92]) and 25 young adults (aged 18-25 years). Participants carried out a street-crossing task in a simulated two-way traffic environment; curbs were present on both sides of the experimental street. Participants also undertook a battery of tests to assess their visual and cognitive abilities. In addition, during the experiment, the participants' gait parameters were recorded. In line with earlier findings, the older-old group of participants made a higher number of decisions that led to collisions with approaching cars compared with the other groups. The two groups of older participants experienced specific difficulties when vehicles were in the far lane or when they approached rapidly. A regression analysis identified visual acuity, speed of processing (assessed using the UFOV(®) test), and step length as significant predictors of collisions. Our results have implications for understanding the difficulties experienced by older pedestrians and allow to draw up several recommendations for improving their safety. Copyright © 2015 Elsevier Ltd. All rights

One-Way Multishape-Memory Effect and Tunable Two-Way Shape Memory Effect of Ionomer Poly(ethylene-co-methacrylic acid).

PubMed

Lu, Lu; Li, Guoqiang

2016-06-15

Reversible elongation by cooling and contraction by heating, without the need for repeated programming, is well-known as the two-way shape-memory effect (2W-SME). This behavior is contrary to the common physics-contraction when cooling and expansion when heating. Materials with such behavior may find many applications in real life, such as self-sufficient grippers, fastening devices, optical gratings, soft actuators, and sealant. Here, it is shown that ionomer Surlyn 8940, a 50-year old polymer, exhibits both one-way multishape-memory effects and tunable two-way reversible actuation. The required external tensile stress to trigger the tunable 2W-SME is very low when randomly jumping the temperatures within the melting transition window. With a proper one-time programming, "true" 2W-SME (i.e., 2W-SME without the need for an external tensile load) is also achieved. A long training process is not needed to trigger the tunable 2W-SME. Instead, a proper one-time tensile programming is sufficient to trigger repeated and tunable 2W-SME. Because the 2W-SME of the ionomer Surlyn is driven by the thermally reversible network, here crystallization and melting transitions of the semicrystalline poly(ethylene-co-methacrylic acid), it is believed that a class of thermally reversible polymers should also exhibit tunable 2W-SMEs.

Plasma Sheet Injections into the Inner Magnetosphere: Two-way Coupled OpenGGCM-RCM model results

NASA Astrophysics Data System (ADS)

Raeder, J.; Cramer, W. D.; Toffoletto, F.; Gilson, M. L.; Hu, B.

2017-12-01

Plasma sheet injections associated with low flux tube entropy bubbles have been found to be the primary means of mass transport from the plasma sheet to the inner magnetosphere. A two-way coupled global magnetosphere-ring current model, where the magnetosphere is modeled by the OpenGGCM MHD model and the ring current is modeled by the Rice Convection Model (RCM), is used to determine the frequency of association of bubbles with injections and inward plasma transport, as well as typical injection characteristics. Multiple geomagnetic storms and quiet periods are simulated to track and characterize inward flow behavior. Dependence on geomagnetic activity levels or drivers is also examined.

Carrier-phase-based two-way satellite time and frequency transfer.

PubMed

Fujieda, Miho; Gotoh, Tadahiro; Nakagawa, Fumimaru; Tabuchi, Ryo; Aida, Masanori; Amagai, Jun

2012-12-01

We performed measurements of carrier-phase-based two-way satellite time and frequency transfer (TWST-FT) with an A/D sampler and conventional TWSTFT system. We found that an instability resulting from a local signal at the satellite transponder was negligible. The short-term stability of 4 × 10(-13) at 1 s was achieved in a short-baseline measurement. The results showed good agreement with the GPS carrier phase.

Proposed modification to avoidance test with Eisenia fetida to assess metal toxicity in agricultural soils affected by mining activities.

PubMed

Delgadillo, Víctor; Verdejo, José; Mondaca, Pedro; Verdugo, Gabriela; Gaete, Hernán; Hodson, Mark E; Neaman, Alexander

2017-06-01

Use of avoidance tests is a quick and cost-effective method of assessing contaminants in soils. One option for assessing earthworm avoidance behavior is a two-section test, which consists of earthworms being given the choice to move between a test soil and a control substrate. For ecological relevance, tested soils should be field-contaminated soils. For practical reasons, artificial soils are commonly used as the control substrate. Interpretation of the test results compromised when the test soil and the artificial substrate differ in their physico-chemical properties other than just contaminants. In this study we identified the physico-chemical properties that influence avoidance response and evaluated the usefulness of adjusting these in the control substrate in order to isolate metal-driven avoidance of field soils by earthworms. A standardized two-section avoidance test with Eisenia fetida was performed on 52 uncontaminated and contaminated (Cu >155mgkg -1 , As >19mgkg -1 ) agricultural soils from the Aconcagua River basin and the Puchuncaví Valley in Chile. Regression analysis indicated that the avoidance response was determined by soil organic matter (OM), electrical conductivity (EC) and total soil Cu. Organic matter content of the artificial substrate was altered by peat additions and EC by NaCl so that these properties matched those of the field soils. The resultant EC 80 for avoidance (indicative of soils of "limited habitat") was 433mg Cu kg -1 (339 - 528mgkg -1 95% confidence intervals). The earthworm avoidance test can be used to assess metal toxicity in field-contaminated soils by adjusting physico-chemical properties (OM and EC) of the artificial control substrate in order to mimic those of the field-collected soil. Copyright © 2017 Elsevier Inc. All rights reserved.

Ka-Band Waveguide Two-Way Hybrid Combiner for MMIC Amplifiers

NASA Technical Reports Server (NTRS)

Simons, Rainee N.; Chevalier, Christine T.; Wintucky, Edwin G.; Freeman, Jon C.

2010-01-01

The design, simulation, and characterization of a novel Ka-band (32.05 0.25 GHz) rectangular waveguide two-way branch-line hybrid unequal power combiner (with port impedances matched to that of a standard WR-28 waveguide) has been created to combine input signals, which are in phase and with an amplitude ratio of two. The measured return loss and isolation of the branch-line hybrid are better than 22 and 27 dB, respectively. The measured combining efficiency is 92.9 percent at the center frequency of 32.05 GHz. This circuit is efficacious in combining the unequal output power from two Ka-band GaAs pseudomorphic high electron mobility transistor (pHEMT) monolithic microwave integrated circuit (MMIC) power amplifiers (PAs) with high efficiency. The component parts include the branch-line hybrid-based power combiner and the MMIC-based PAs. A two-way branch-line hybrid is a four-port device with all ports matched; power entering port 1 is divided in phase, and into the ratio 2:1 between ports 3 and 4. No power is coupled to port 2. MMICs are a type of integrated circuit fabricated on GaAs that operates at microwave frequencies, and performs the function of signal amplification. The power combiner is designed to operate over the frequency band of 31.8 to 32.3 GHz, which is NASA's deep space frequency band. The power combiner would have an output return loss better than 20 dB. Isolation between the output port and the isolated port is greater than 25 dB. Isolation between the two input ports is greater than 25 dB. The combining efficiency would be greater than 90 percent when the ratio of the two input power levels is two. The power combiner is machined from aluminum with E-plane split-block arrangement, and has excellent reliability. The flexibility of this design allows the combiner to be customized for combining the power from MMIC PAs with an arbitrary power output ratio. In addition, it allows combining a low-power GaAs MMIC with a high-power GaN MMIC. The arbitrary

Lightweight Privacy-Preserving Authentication Protocols Secure against Active Attack in an Asymmetric Way

NASA Astrophysics Data System (ADS)

Cui, Yank; Kobara, Kazukuni; Matsuura, Kanta; Imai, Hideki

As pervasive computing technologies develop fast, the privacy protection becomes a crucial issue and needs to be coped with very carefully. Typically, it is difficult to efficiently identify and manage plenty of the low-cost pervasive devices like Radio Frequency Identification Devices (RFID), without leaking any privacy information. In particular, the attacker may not only eavesdrop the communication in a passive way, but also mount an active attack to ask queries adaptively, which is obviously more dangerous. Towards settling this problem, in this paper, we propose two lightweight authentication protocols which are privacy-preserving against active attack, in an asymmetric way. That asymmetric style with privacy-oriented simplification succeeds to reduce the load of low-cost devices and drastically decrease the computation cost for the management of server. This is because that, unlike the usual management of the identities, our approach does not require any synchronization nor exhaustive search in the database, which enjoys great convenience in case of a large-scale system. The protocols are based on a fast asymmetric encryption with specialized simplification and only one cryptographic hash function, which consequently assigns an easy work to pervasive devices. Besides, our results do not require the strong assumption of the random oracle.

Physical Activity among African American Women: Change and Ways of Knowing

ERIC Educational Resources Information Center

Henderson, Karla A.

2011-01-01

Research has grown in the 21st century regarding the physical activity patterns of racial and ethnic minorities. Although more is now known about some groups, disparities in health have not diminished. The purpose of this paper is to further explore the research about physical activity for African American women and suggest ways that future…

Rapid jamming avoidance in biosonar.

PubMed

Gillam, Erin H; Ulanovsky, Nachum; McCracken, Gary F

2007-03-07

The sonar systems of bats and dolphins are in many ways superior to man-made sonar and radar systems, and considerable effort has been devoted to understanding the signal-processing strategies underlying these capabilities. A major feature determining the efficiency of sonar systems is the sensitivity to noise and jamming signals. Previous studies indicated that echolocating bats may adjust their signal structure to avoid jamming ('jamming avoidance response'; JAR). However, these studies relied on behavioural correlations and not controlled experiments. Here, we provide the first experimental evidence for JAR in bats. We presented bats (Tadarida brasiliensis) with 'playback stimuli' consisting of recorded echolocation calls at one of six frequencies. The bats exhibited a JAR by shifting their call frequency away from the presented playback frequency. When the approaching bats were challenged by an abrupt change in the playback stimulus, they responded by shifting their call frequencies upwards, away from the playback. Interestingly, even bats initially calling below the playback's frequency shifted their frequencies upwards, 'jumping' over the playback frequency. These spectral shifts in the bats' calls occurred often within less than 200 ms, in the first echolocation call emitted after the stimulus switch-suggesting that rapid jamming avoidance is important for the bat.

Physiological and neural correlates of worry and rumination: Support for the contrast avoidance model of worry.

PubMed

Steinfurth, Elisa C K; Alius, Manuela G; Wendt, Julia; Hamm, Alfons O

2017-02-01

The current experiments tested neural and physiological correlates of worry and rumination in comparison to thinking about neutral events. According to the avoidance model-stating that worry is a strategy to reduce intense emotions-physiological and neurobiological activity during worried thinking should not differ from activation during neutral thinking. According to the contrast avoidance model-stating that worry is a strategy to reduce abrupt shifts of emotions-activity should be increased. To test these competing models, we induced worry and neutral thinking in healthy participants using personal topics. A rumination condition was added to investigate the specificity of changes induced by the mental process. Two experiments were conducted assessing the effects on different response levels: (1) neural activation using fMRI, and (2) physiological response mobilization using startle and autonomic measures. During worry, participants showed a potentiated startle response and BOLD activity indicative of emotional network activation. These data partly support the contrast avoidance model of worry. Both mental processes showed elevated activity in a common network referred to as default network indicating self-referential activity. © 2016 Society for Psychophysiological Research.

Two way coupling RAM-SCB to the space weather modeling framework

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

Welling, Daniel T; Jordanova, Vania K; Zaharia, Sorin G

The Ring current Atmosphere interaction Model with Self-Consistently calculated 3D Magnetic field (RAM-SCB) has been used to successfully study inner magnetosphere dynamics during different solar wind and magnetosphere conditions. Recently, one way coupling of RAM-SCB with the Space Weather Modeling Framework (SWMF) has been achieved to replace all data or empirical inputs with those obtained through first-principles-based codes: magnetic field and plasma flux outer boundary conditions are provided by the Block Adaptive Tree Solar wind Roe-type Upwind Scheme (BATS-R-US) MHO code, convection electric field is provided by the Ridley Ionosphere Model (RIM), and ion composition is provided by the Polarmore » Wind Outflow Model (PWOM) combined with a multi-species MHO approach. These advances, though creating a powerful inner magnetosphere virtual laboratory, neglect the important mechanisms through which the ring current feeds back into the whole system, primarily the stretching of the magnetic field lines and shielding of the convection electric field through strong region two Field Aligned Currents (FACs). In turn, changing the magnetosphere in this way changes the evolution of the ring current. To address this shortcoming, the coupling has been expanded to include feedback from RAM-SCB to the other coupled codes: region two FACs are returned to the RIM while total plasma pressure is used to nudge the MHO solution towards the RAMSCB values. The impacts of the two way coupling are evaluated on three levels: the global magnetospheric level, focusing on the impact on the ionosphere and the shape of the magnetosphere, the regional level, examining the impact on the development of the ring current in terms of energy density, anisotropy, and plasma distribution, and the local level to compare the new results to in-situ measurements of magnetic and electric field and plasma. The results will also be compared to past simulations using the one way coupling and no coupling

Hierarchical Brain Networks Active in Approach and Avoidance Goal Pursuit

PubMed Central

Spielberg, Jeffrey M.; Heller, Wendy; Miller, Gregory A.

2013-01-01

Effective approach/avoidance goal pursuit is critical for attaining long-term health and well-being. Research on the neural correlates of key goal-pursuit processes (e.g., motivation) has long been of interest, with lateralization in prefrontal cortex being a particularly fruitful target of investigation. However, this literature has often been limited by a lack of spatial specificity and has not delineated the precise aspects of approach/avoidance motivation involved. Additionally, the relationships among brain regions (i.e., network connectivity) vital to goal-pursuit remain largely unexplored. Specificity in location, process, and network relationship is vital for moving beyond gross characterizations of function and identifying the precise cortical mechanisms involved in motivation. The present paper integrates research using more spatially specific methodologies (e.g., functional magnetic resonance imaging) with the rich psychological literature on approach/avoidance to propose an integrative network model that takes advantage of the strengths of each of these literatures. PMID:23785328

Hierarchical brain networks active in approach and avoidance goal pursuit.

PubMed

Spielberg, Jeffrey M; Heller, Wendy; Miller, Gregory A

2013-01-01

Effective approach/avoidance goal pursuit is critical for attaining long-term health and well-being. Research on the neural correlates of key goal-pursuit processes (e.g., motivation) has long been of interest, with lateralization in prefrontal cortex being a particularly fruitful target of investigation. However, this literature has often been limited by a lack of spatial specificity and has not delineated the precise aspects of approach/avoidance motivation involved. Additionally, the relationships among brain regions (i.e., network connectivity) vital to goal-pursuit remain largely unexplored. Specificity in location, process, and network relationship is vital for moving beyond gross characterizations of function and identifying the precise cortical mechanisms involved in motivation. The present paper integrates research using more spatially specific methodologies (e.g., functional magnetic resonance imaging) with the rich psychological literature on approach/avoidance to propose an integrative network model that takes advantage of the strengths of each of these literatures.

[Receptor elements for biosensors in two ways of methylotrophic yeast immobilization].

PubMed

Zaĭtsev, M G; Arliapov, V A; Alferov, V A; Reshetilov, A N

2012-01-01

Receptor elements for biosensors based on Hansenula polymorpha NCYC 495 In yeast cells for ethanol assay were developed using two ways of cell immobilization, i.e., physical adsorption on a glass fiber membrane and covalent binding on a modified nitrocellulose membrane. The linear diapason of ethanol assays for a biosensor based on yeast cells adsorbed on glass fiber was 0.05-1.18; for a biosensor based on yeasts immobilized on a nitrocellulose membrane, 0.2-1.53 mM. Receptor elements based on sorbed cells possessed 2.5 times higher long-term stability. The time response was 1.5 times less for cells immobilized using DEAE-dextran and benzochinone. The results of ethyl alcohol assays using biosensors based on cells immobilized via adsorption and covalent binding, as well as using the standard areometric method, had high correlation coefficients (0.998 and 0.997, respectively, for the two ways of immobilization). The results indicate the possibility to consider the described models of receptor elements for biosensors as prototypes for experimental samples for practical use.

Disease avoidance as a functional basis for stigmatization

PubMed Central

Oaten, Megan; Stevenson, Richard J.; Case, Trevor I.

2011-01-01

Stigmatization is characterized by chronic social and physical avoidance of a person(s) by other people. Infectious disease may produce an apparently similar form of isolation—disease avoidance—but on symptom remission this often abates. We propose that many forms of stigmatization reflect the activation of this disease-avoidance system, which is prone to respond to visible signs and labels that connote disease, irrespective of their accuracy. A model of this system is presented, which includes an emotional component, whereby visible disease cues directly activate disgust and contamination, motivating avoidance, and a cognitive component, whereby disease labels bring to mind disease cues, indirectly activating disgust and contamination. The unique predictions of this model are then examined, notably that people who are stigmatized evoke disgust and are contaminating. That animals too show avoidance of diseased conspecifics, and that disease-related stigma targets are avoided in most cultures, also supports this evolutionary account. The more general implications of this approach are then examined, notably how it can be used to good (e.g. improving hygiene) or bad (e.g. racial vilification) ends, by yoking particular labels with cues that connote disease and disgust. This broadening of the model allows for stigmatization of groups with little apparent connection to disease. PMID:22042920

Portable Wireless LAN Device and Two-way Radio Threat Assessment for Aircraft Navigation Radios

NASA Technical Reports Server (NTRS)

Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Williams, Reuben A.; Smith, Laura J.; Salud, Maria Theresa P.

2003-01-01

Measurement processes, data and analysis are provided to address the concern for Wireless Local Area Network devices and two-way radios to cause electromagnetic interference to aircraft navigation radio systems. A radiated emission measurement process is developed and spurious radiated emissions from various devices are characterized using reverberation chambers. Spurious radiated emissions in aircraft radio frequency bands from several wireless network devices are compared with baseline emissions from standard computer laptops and personal digital assistants. In addition, spurious radiated emission data in aircraft radio frequency bands from seven pairs of two-way radios are provided, A description of the measurement process, device modes of operation and the measurement results are reported. Aircraft interference path loss measurements were conducted on four Boeing 747 and Boeing 737 aircraft for several aircraft radio systems. The measurement approach is described and the path loss results are compared with existing data from reference documents, standards, and NASA partnerships. In-band on-channel interference thresholds are compiled from an existing reference document. Using these data, a risk assessment is provided for interference from wireless network devices and two-way radios to aircraft systems, including Localizer, Glideslope, Very High Frequency Omnidirectional Range, Microwave Landing System and Global Positioning System. The report compares the interference risks associated with emissions from wireless network devices and two-way radios against standard laptops and personal digital assistants. Existing receiver interference threshold references are identified as to require more data for better interference risk assessments.

High-order Two-way Artificial Boundary Conditions for Nonlinear Wave Propagation with Backscattering

NASA Technical Reports Server (NTRS)

Fibich, Gadi; Tsynkov, Semyon

2000-01-01

When solving linear scattering problems, one typically first solves for the impinging wave in the absence of obstacles. Then, by linear superposition, the original problem is reduced to one that involves only the scattered waves driven by the values of the impinging field at the surface of the obstacles. In addition, when the original domain is unbounded, special artificial boundary conditions (ABCs) that would guarantee the reflectionless propagation of waves have to be set at the outer boundary of the finite computational domain. The situation becomes conceptually different when the propagation equation is nonlinear. In this case the impinging and scattered waves can no longer be separated, and the problem has to be solved in its entirety. In particular, the boundary on which the incoming field values are prescribed, should transmit the given incoming waves in one direction and simultaneously be transparent to all the outgoing waves that travel in the opposite direction. We call this type of boundary conditions two-way ABCs. In the paper, we construct the two-way ABCs for the nonlinear Helmholtz equation that models the laser beam propagation in a medium with nonlinear index of refraction. In this case, the forward propagation is accompanied by backscattering, i.e., generation of waves in the direction opposite to that of the incoming signal. Our two-way ABCs generate no reflection of the backscattered waves and at the same time impose the correct values of the incoming wave. The ABCs are obtained for a fourth-order accurate discretization to the Helmholtz operator; the fourth-order grid convergence is corroborated experimentally by solving linear model problems. We also present solutions in the nonlinear case using the two-way ABC which, unlike the traditional Dirichlet boundary condition, allows for direct calculation of the magnitude of backscattering.

Two-Way Communication Using RFID Equipment and Techniques

NASA Technical Reports Server (NTRS)

Jedry, Thomas; Archer, Eric

2007-01-01

Equipment and techniques used in radio-frequency identification (RFID) would be extended, according to a proposal, to enable short-range, two-way communication between electronic products and host computers. In one example of a typical contemplated application, the purpose of the short-range radio communication would be to transfer image data from a user s digital still or video camera to the user s computer for recording and/or processing. The concept is also applicable to consumer electronic products other than digital cameras (for example, cellular telephones, portable computers, or motion sensors in alarm systems), and to a variety of industrial and scientific sensors and other devices that generate data. Until now, RFID has been used to exchange small amounts of mostly static information for identifying and tracking assets. Information pertaining to an asset (typically, an object in inventory to be tracked) is contained in miniature electronic circuitry in an RFID tag attached to the object. Conventional RFID equipment and techniques enable a host computer to read data from and, in some cases, to write data to, RFID tags, but they do not enable such additional functions as sending commands to, or retrieving possibly large quantities of dynamic data from, RFID-tagged devices. The proposal would enable such additional functions. The figure schematically depicts an implementation of the proposal for a sensory device (e.g., a digital camera) that includes circuitry that converts sensory information to digital data. In addition to the basic sensory device, there would be a controller and a memory that would store the sensor data and/or data from the controller. The device would also be equipped with a conventional RFID chipset and antenna, which would communicate with a host computer via an RFID reader. The controller would function partly as a communication interface, implementing two-way communication protocols at all levels (including RFID if needed) between the

Discussing Difference: Color-Blind Collectivism and Dynamic Dissonance in Two-Way Immersion Contexts

ERIC Educational Resources Information Center

Stolte, Laurel

2017-01-01

This comparative case study (based on observational, interview, and picture-sort data) examines how teachers and students talk about cultural, linguistic, racial, and socioeconomic difference in two elementary Spanish-English two-way immersion programs. In addition, I analyze how those discourses are associated with both contextual conditions and…

“Assessment of the two-way Coupled WRF-CMAQ Model with ...

EPA Pesticide Factsheets

The main goal of this assessment is to evaluate the improved aerosol component of two-way coupled WRF-CMAQ model particularly in representing aerosol physical and optical properties by utilizing observations from the Carbonaceous Aerosol and Radiative Effects Study (CARES) in May 2010 which was held in central California. The objective of the CARES was to investigate the evolution of carbonaceous aerosols of different types and their optical and hygroscopic properties. Since various instruments (e.g. AMS, PSAP and FIMS) were deployed aboard two aircrafts (DOE G-1 and NASA B-200) during the field campaign, the available in situ measurements provide an opportunity to explore the aerosol radiative effects in a detailed manner. For example, measurements of particulate matter size, species and optical properties are made not only at the surface but also in the vertical - these can be utilized to assess the simulation output with a single column model. In addition, satellite data (e.g. SeaWiFS) will be used for regional assessment. The new two-way coupled model has been updated with several modifications such as densities and refractive indices for different particulate matter species based on OPAC dataset and Mie and Core-Shell scattering approaches. Two months (May and June 2010) simulations (feedback and no feedback) at 4-km horizontal resolution are conducted. Detailed comparisons of various meteorological (e.g., PBL heights, radiation fields), chemical (PM compos

Signal Delay-Stability of a Ku-Band Two-Way Satellite Time Transfer Terminal

DTIC Science & Technology

1995-12-01

Robnik Space Research Institute, Graz, Austria Abstract A filly automated huo-way time and frequency transfer ( TWSTFT ) system including a sateme...station. Such a system has been operated for longer than a year together with the two-way satellite time and frequency transfer ( TWSTFT ) station of...accuracy. MEASUREMENT SETUP A detailed description of the TWSTFT system used at TUG is given in [I]. The SATSIM used is of the de Jong type13,41 - this

Two-Way Communication with a Single Quantum Particle.

PubMed

Del Santo, Flavio; Dakić, Borivoje

2018-02-09

In this Letter we show that communication when restricted to a single information carrier (i.e., single particle) and finite speed of propagation is fundamentally limited for classical systems. On the other hand, quantum systems can surpass this limitation. We show that communication bounded to the exchange of a single quantum particle (in superposition of different spatial locations) can result in "two-way signaling," which is impossible in classical physics. We quantify the discrepancy between classical and quantum scenarios by the probability of winning a game played by distant players. We generalize our result to an arbitrary number of parties and we show that the probability of success is asymptotically decreasing to zero as the number of parties grows, for all classical strategies. In contrast, quantum strategy allows players to win the game with certainty.

Two-Way Communication with a Single Quantum Particle

NASA Astrophysics Data System (ADS)

Del Santo, Flavio; Dakić, Borivoje

2018-02-01

In this Letter we show that communication when restricted to a single information carrier (i.e., single particle) and finite speed of propagation is fundamentally limited for classical systems. On the other hand, quantum systems can surpass this limitation. We show that communication bounded to the exchange of a single quantum particle (in superposition of different spatial locations) can result in "two-way signaling," which is impossible in classical physics. We quantify the discrepancy between classical and quantum scenarios by the probability of winning a game played by distant players. We generalize our result to an arbitrary number of parties and we show that the probability of success is asymptotically decreasing to zero as the number of parties grows, for all classical strategies. In contrast, quantum strategy allows players to win the game with certainty.

Functional neuroimaging of avoidance habits in OCD

PubMed Central

Gillan, Claire M; Apergis-Schoute, Annemieke M; Morein-Zamir, Sharon; Urcelay, Gonzalo P; Sule, Akeem; Fineberg, Naomi A; Sahakian, Barbara J; Robbins, Trevor W

2016-01-01

Objective The goal of this study was to determine the neural correlates of excessive habit formation in obsessive-compulsive disorder (OCD). We aimed to (i) test for neurobiological convergence with the known pathophysiology of OCD and (ii) infer, based on abnormalities in brain activation, whether these habits arise from dysfunction in the goal-directed or habit system. Method Thirty-seven OCD patients and 33 controls learned to avoid shocks while undergoing a functional Magnetic Resonance Imaging (fMRI) scan. Following 4 blocks of training, we tested if the avoidance response had become a habit by removing the threat of shock and measuring continued avoidance. We tested for task-related differences in brain activity in 3 ROIs, the caudate, putamen and medial orbitofrontal cortex at a statistical threshold of p<.05, family-wise error (FWE) corrected. Results We observed excessive habit formation in OCD patients, which was associated with hyper-activation in the caudate. Activation in this region was also associated with subjective ratings of increased urge to perform habits. The OCD group, as a whole, showed hyper-activation in the medial orbitofrontal cortex (mOFC) during the acquisition of avoidance, however this did not relate directly to habit formation. Conclusions OCD patients exhibited excessive habits that were associated with hyper-activation in a key region implicated in the pathophysiology of OCD, the caudate nucleus. Prior studies suggest that this region is important for goal-directed behavior, suggesting that habit-forming biases in OCD may be a result of impairments in this system, rather than differences in the build up of stimulus-response habits themselves. PMID:25526600

Avoided crossings: A study of the nonadiabatic transition probabilities

NASA Astrophysics Data System (ADS)

Desouter-Lecomte, M.; Leyh-Nihant, B.; Praet, M. T.; Lorquet, J. C.

1987-06-01

An approximate solution to the problem of constructing a pair of diabatic states exists only if certain requirements are fulfilled, for example, when the nonadiabatic coupling results from an interaction between two electronic configurations which are doubly excited with respect to one another. It is then possible to build up a model in which the series expansion of the elements of the Hamiltonian matrix is truncated after the first nonzero term. This leads to several conclusions concerning the nonadiabatic transition probability which differentiate conical intersections from avoided crossings. For the latter, the nonadiabatic coupling matrix elements (which are Lorentzians with an area equal to π/2) reach their maximum at the nuclear geometry for which ΔE (the energy gap between adiabatic surfaces) is a minimum. The loci along which the angle θ of the orthogonal transformation which relates adiabatic and diabatic wave functions keeps a constant value are a set of parallel straight lines which coincides with the loci along which ΔE remains constant. This reference direction in the configuration space corresponds to nuclear trajectories which are unable to bring about a nonadiabatic transition. In the case of avoided crossings, there exists only one nuclear degree of freedom which gives rise to surface hopping. Conical intersections, on the other hand, have two such active degrees of freedom. This creates a qualitative difference between the two cases which makes conical intersections more efficient as funnels than avoided crossings. A two-dimensional extension of the Landau-Zener formula is derived for avoided crossings. It contains a factor of anisotropy. It is possible, at least in favorable cases, to extract approximate diabatic quantities from ab initio calculations and to compare them with the predictions of these models. This has been done for two 2A1 electronic states of the CH+2 ion. The results are found to agree with the predictions of the model, at

Multilevel regression analyses to investigate the relationship between two variables over time: examining the longitudinal association between intrusion and avoidance.

PubMed

Suvak, Michael K; Walling, Sherry M; Iverson, Katherine M; Taft, Casey T; Resick, Patricia A

2009-12-01

Multilevel modeling is a powerful and flexible framework for analyzing nested data structures (e.g., repeated measures or longitudinal designs). The authors illustrate a series of multilevel regression procedures that can be used to elucidate the nature of the relationship between two variables across time. The goal is to help trauma researchers become more aware of the utility of multilevel modeling as a tool for increasing the field's understanding of posttraumatic adaptation. These procedures are demonstrated by examining the relationship between two posttraumatic symptoms, intrusion and avoidance, across five assessment points in a sample of rape and robbery survivors (n = 286). Results revealed that changes in intrusion were highly correlated with changes in avoidance over the 18-month posttrauma period.

The inhibitory avoidance discrimination task to investigate accuracy of memory.

PubMed

Atucha, Erika; Roozendaal, Benno

2015-01-01

The present study was aimed at developing a new inhibitory avoidance task, based on training and/or testing rats in multiple contexts, to investigate accuracy of memory. In the first experiment, male Sprague-Dawley rats were given footshock in an inhibitory avoidance apparatus and, 48 h later, retention latencies of each rat were assessed in the training apparatus (Shock box) as well as in a novel, contextually modified, apparatus. Retention latencies in the Shock box were significantly longer than those in the Novel box, indicating accurate memory of the training context. When the noradrenergic stimulant yohimbine (0.3 mg/kg, sc) was administered after the training, 48-h retention latencies in the Shock box, but not Novel box, were increased, indicating that the noradrenergic activation enhanced memory of the training experience without reducing memory accuracy. In the second experiment, rats were trained on an inhibitory avoidance discrimination task: They were first trained in an inhibitory avoidance apparatus without footshock (Non-Shock box), followed 1 min later by footshock training in a contextually modified apparatus (Shock box). Forty-eight-hour retention latencies in the Shock and Non-Shock boxes did not differ from each other but were both significantly longer than those in a Novel box, indicating that rats remembered the two training contexts but did not have episodic-like memory of the association of footshock with the correct training context. When the interval between the two training episodes was increased to 2 min, rats showed accurate memory of the association of footshock with the training context. Yohimbine administered after the training also enhanced rats' ability to remember in which training context they had received actual footshock. These findings indicate that the inhibitory avoidance discrimination task is a novel variant of the well-established inhibitory avoidance task suitable to investigate accuracy of memory.

Genetic variation in MAOA modulates prefrontal cortical regulation of approach-avoidance reactions.

PubMed

Ernst, Lena H; Lutz, Elisabeth; Ehlis, Ann-Christine; Fallgatter, Andreas J; Reif, Andreas; Plichta, Michael M

2013-01-01

Regulation of automatic approach and avoidance behavior requires affective and cognitive control, which are both influenced by a genetic variation in the gene encoding Monoamine Oxidase A (termed MAOA-uVNTR). The current study investigated MAOA genotype as a moderator of prefrontal cortical activation measured with functional near-infrared spectroscopy (fNIRS) in 37 healthy young adults during performance of the approach-avoidance task with positive and negative pictures. Carriers of the low- compared to the high-expressing genetic variant (MAOA-L vs. MAOA-H) showed increasing regulatory activity in the right dorsolateral prefrontal cortex (DLPFC) during incompatible conditions (approach negative, avoid positive). This might have been a compensatory mechanism for stronger emotional reactions as shown in previous studies and might have prevented any influence of incompatibility on behavior. In contrast, fewer errors but also lower activity in the right DLPFC during processing of negative compared to positive stimuli indicated MAOA-H carriers to have used other regulatory areas. This resulted in slower reaction times in incompatible conditions, but--in line with the known better cognitive regulation efficiency--allowed them to perform incompatible reactions without activating the DLPFC as the highest control instance. Carriers of one low- and one high-expressing allele lay as an intermediate group between the reactions of the low- and high-expressing groups. The relatively small sample size and restriction to fNIRS for assessment of cortical activity limit our findings. Nevertheless, these first results suggest monoam-inergic mechanisms to contribute to interindividual differences in the two basic behavioral principles of approach and avoidance and their neuronal correlates. Copyright © 2013 S. Karger AG, Basel.

Imipramine attenuates neuroinflammatory signaling and reverses stress-induced social avoidance.

PubMed

Ramirez, Karol; Shea, Daniel T; McKim, Daniel B; Reader, Brenda F; Sheridan, John F

2015-05-01

Psychosocial stress is associated with altered immunity, anxiety and depression. Previously we showed that repeated social defeat (RSD) promoted microglia activation and social avoidance behavior that persisted for 24days after cessation of RSD. The aim of the present study was to determine if imipramine (a tricyclic antidepressant) would reverse RSD-inducedsocial avoidance and ameliorate neuroinflammatory responses. To test this, C57BL/6 mice were divided into treatment groups. One group from RSD and controls received daily injections of imipramine for 24days, following 6 cycles of RSD. Two other groups were treated with saline. RSD mice spent significantly less time in the interaction zone when an aggressor was present in the cage. Administration of imipramine reversed social avoidance behavior, significantly increasing the interaction time, so that it was similar to that of control mice. Moreover, 24days of imipramine treatment in RSD mice significantly decreased stress-induced mRNA levels for IL-6 in brain microglia. Following ex vivo LPS stimulation, microglia from mice exposed to RSD, had higher mRNA expression of IL-6, TNF-α, and IL-1β, and this was reversed by imipramine treatment. In a second experiment, imipramine was added to drinking water confirming the reversal of social avoidant behavior and decrease in mRNA expression of IL-6 in microglia. These data suggest that the antidepressant imipramine may exert its effect, in part, by down-regulating microglial activation. Copyright © 2015 Elsevier Inc. All rights reserved.

Imipramine attenuates neuroinflammatory signaling and reverses stress-induced social avoidance

PubMed Central

Ramirez, Karol; Shea, Daniel T.; McKim, Daniel B.; B.F., Reader; Sheridan, John F.

2015-01-01

Psychosocial stress is associated with altered immunity, anxiety and depression. Previously we showed that repeated social defeat (RSD) promoted microglia activation and social avoidance behavior that persisted for 24 days after cessation of RSD. The aim of the present study was to determine if imipramine (a tricyclic antidepressant) would reverse RSD-induced social avoidance and ameliorate neuroinflammatory responses. To test this, C57BL/6 mice were divided into treatment groups. One group from RSD and controls received daily injections of imipramine for 24 days, following 6 cycles of RSD. Two other groups were treated with saline. RSD mice spent significantly less time in the interaction zone when an aggressor was present in the cage. Administration of imipramine reversed social avoidance behavior, significantly increasing the interaction time, so that it was similar to that of control mice. Moreover, 24 days of imipramine treatment in RSD mice significantly decreased stress-induced mRNA levels for IL-6 in brain microglia. Following ex vivo LPS stimulation, microglia from mice exposed to RSD, had higher mRNA expression of IL-6, TNF-α, and IL-1β, and this was reversed by imipramine treatment. In a second experiment, imipramine was added to drinking water confirming the reversal of social avoidant behavior and decrease in mRNA expression of IL-6 in microglia. These data suggest that the antidepressant imipramine may exert its effect, in part, by down-regulating microglial activation. PMID:25701613

Impact of two-way ocean atmosphere coupling on precipitation forecast for the coastal Adriatic region

NASA Astrophysics Data System (ADS)

Smerkol, Peter; Cedilnik, Jure; Fettich, Anja; Licer, Matjaz; Strajnar, Benedikt; Jerman, Jure

2017-04-01

A two-way coupled ocean and atmosphere modeling system has been developed at Slovenian Environment Agency and the National Institute of Biology (Ličer at al., 2016). The system comprises 4.4 km ALADIN/ALARO limited-area numerical weather prediction model and Princeton Ocean Model (POM) for Adriatic sea and uses Mediterranean Forecasting System (MFS) as ocean component outside the POM model domain. The heat and momentum fluxes between sea surface and atmosphere as estimated by ALADIN model are transferred into POM every model time stamp, and sea surface temperature (SST) is returned from POM to ALADIN. A positive impact of such a coupling system with respect to one-way coupling was demonstrated mainly for sea surface variables. In this contribution we study the impact on atmospheric variables, mainly precipitation. Unlike in the previous work where the atmospheric part of the system was reinitialized every day from external (non-coupled) data assimilation cycle, we implement the two-way coupling in the data assimilation cycle for ALADIN. Rather than running long-term simulations which would presumably lack observational information given no data assimilation for the ocean component, we focus on several precipitation events and assess performance of the atmospheric model by running the coupled system for a short warm-up periods beforehand the events. We evaluate several approaches to applying the one- or two-way coupling (in the warm-up period, during the main forecast, or both) and several approaches to using SST information in ALADIN in the one-way coupled mode (POM, MFS, global atmospheric model). Preliminary results suggest that it is important that two-way coupling is applied not only during the long term (e.g. 72 h) forecast but also already in the data assimilation cycle prior to event.

Mate choice promotes inbreeding avoidance in the two-spotted spider mite.

PubMed

Tien, N S H; Massourakis, G; Sabelis, M W; Egas, M

2011-06-01

Since inbreeding in Tetranychus urticae can reduce offspring fitness, sexual selection may favour disassortative mate choice with respect to relatedness of the mating partners. We tested whether T. urticae shows this preference for mating with unrelated partners. We chose an experimental set-up with high potential for female choosiness, since females only mate once and are therefore expected to be the choosier gender. An adult virgin female was placed together with two adult males from the same population. One male was unrelated and the other male was related-a brother with whom she had grown up. Significantly more copulations (64%) took place with the unrelated male. Time to mating did not depend on the female-to-male relatedness. The remaining (non-copulating) male tried to interfere with the ongoing mating in the majority of cases, but this interference did not depend on the female-to-male relatedness. These results imply that T. urticae (a) can recognize kin (via genetic and/or environmental similarity) and (b) has the potential to avoid inbreeding through mate choice.

Two nursing mothers treated with zonisamide: Should breast-feeding be avoided?

PubMed

Ando, Hitoshi; Matsubara, Shigeki; Oi, Asako; Usui, Rie; Suzuki, Mitsuaki; Fujimura, Akio

2014-01-01

Zonisamide, an antiepileptic drug, is excreted into breast milk, but information regarding the safety of breast-feeding while using this drug is limited. We present the cases of two nursing mothers, taking 300 and 100 mg/day zonisamide. At 5 days after delivery, the milk concentrations and relative infant doses of the drug were 18.0 and 5.1 μg/mL, and 44 and 36%, respectively. In the first case, the mother fed colostrum and continued partial breast-feeding thus reducing the relative infant dose to 8%. The neonatal serum concentration of zonisamide declined to below the limit of detection at day 34 after birth. In the second case, the mother breast-fed partially until 2 weeks postpartum. No adverse effect was observed in the infants. These findings suggest that mothers taking zonisamide should not breast-feed exclusively, but may not have to avoid partial breast-feeding, with significant caution regarding adverse effects in infants. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

Inter-hospital communications and transport: turning one-way funnels into two-way networks.

PubMed

Rokos, Ivan C; Sanddal, Nels D; Pancioli, Arthur M; Wolff, Catherine; Gaieski, David F

2010-12-01

The Inter-hospital Communications and Transport workgroup was charged with exploring the current status, barriers, and data necessary to optimize the initial destination and subsequent transfer of patients between and among acute care settings. The subtitle, "Turning Funnels Into Two-way Networks," is descriptive of the approach that the workgroup took by exploring how and when smaller facilities in suburban, rural, and frontier areas can contribute to the daily business of caring for emergency patients across the lower-acuity spectrum-in some instances with consultant support from academic medical centers. It also focused on the need to identify high-acuity patients and expedite triage and transfer of those patients to facilities with specialty resources. Draft research recommendations were developed through an iterative writing process and presented to a breakout session of Academic Emergency Medicine's 2010 consensus conference, "Beyond Regionalization: Integrated Networks of Emergency Care." Priority research areas were determined by informal consensus of the breakout group. A subsequent iterative writing process was undertaken to complete this article. A number of broad research questions are presented. 2010 by the Society for Academic Emergency Medicine.

Dynamics of two interacting active Janus particles.

PubMed

Bayati, Parvin; Najafi, Ali

2016-04-07

Starting from a microscopic model for a spherically symmetric active Janus particle, we study the interactions between two such active motors. The ambient fluid mediates a long range hydrodynamic interaction between two motors. This interaction has both direct and indirect hydrodynamic contributions. The direct contribution is due to the propagation of fluid flow that originated from a moving motor and affects the motion of the other motor. The indirect contribution emerges from the re-distribution of the ionic concentrations in the presence of both motors. Electric force exerted on the fluid from this ionic solution enhances the flow pattern and subsequently changes the motion of both motors. By formulating a perturbation method for very far separated motors, we derive analytic results for the translation and rotational dynamics of the motors. We show that the overall interaction at the leading order modifies the translational and rotational speeds of motors which scale as O[1/D](3) and O[1/D](4) with their separation, respectively. Our findings open up the way for studying the collective dynamics of synthetic micro-motors.

Multi-actuators vehicle collision avoidance system - Experimental validation

NASA Astrophysics Data System (ADS)

Hamid, Umar Zakir Abdul; Zakuan, Fakhrul Razi Ahmad; Akmal Zulkepli, Khairul; Zulfaqar Azmi, Muhammad; Zamzuri, Hairi; Rahman, Mohd Azizi Abdul; Aizzat Zakaria, Muhammad

2018-04-01

The Insurance Institute for Highway Safety (IIHS) of the United States of America in their reports has mentioned that a significant amount of the road mishaps would be preventable if more automated active safety applications are adopted into the vehicle. This includes the incorporation of collision avoidance system. The autonomous intervention by the active steering and braking systems in the hazardous scenario can aid the driver in mitigating the collisions. In this work, a real-time platform of a multi-actuators vehicle collision avoidance system is developed. It is a continuous research scheme to develop a fully autonomous vehicle in Malaysia. The vehicle is a modular platform which can be utilized for different research purposes and is denominated as Intelligent Drive Project (iDrive). The vehicle collision avoidance proposed design is validated in a controlled environment, where the coupled longitudinal and lateral motion control system is expected to provide desired braking and steering actuation in the occurrence of a frontal static obstacle. Results indicate the ability of the platform to yield multi-actuators collision avoidance navigation in the hazardous scenario, thus avoiding the obstacle. The findings of this work are beneficial for the development of a more complex and nonlinear real-time collision avoidance work in the future.

Facing Off with Unfair Others: Introducing Proxemic Imaging as an Implicit Measure of Approach and Avoidance during Social Interaction

PubMed Central

McCall, Cade; Singer, Tania

2015-01-01

Nonverbal behavior expresses many of the dynamics underlying face-to-face social interactions, implicitly revealing one’s attitudes, emotions, and social motives. Although research has often described nonverbal behavior as approach versus avoidant (i.e., through the study of proxemics), psychological responses to many social contexts are a mix of these two. Fairness violations are an ideal example, eliciting strong avoidance-related responses such as negative attitudes, as well as strong approach-related responses such as anger and retaliation. As such, nonverbal behavior toward unfair others is difficult to predict in discrete approach versus avoidance terms. Here we address this problem using proxemic imaging, a new method which creates frequency images of dyadic space by combining motion capture data of interpersonal distance and gaze to provide an objective but nuanced analysis of social interactions. Participants first played an economic game with fair and unfair players and then encountered them in an unrelated task in a virtual environment. Afterwards, they could monetarily punish the other players. Proxemic images of the interactions demonstrate that, overall, participants kept the fair player closer. However, participants who actively punished the unfair players were more likely to stand directly in front of those players and even to turn their backs on them. Together these patterns illustrate that fairness violations influence nonverbal behavior in ways that further predict differences in more overt behavior (i.e., financial punishment). Moreover, they demonstrate that proxemic imaging can detect subtle combinations of approach and avoidance behavior during face-to-face social interactions. PMID:25675444

Strategies for obstacle avoidance during walking in the cat.

PubMed

Chu, Kevin M I; Seto, Sandy H; Beloozerova, Irina N; Marlinski, Vladimir

2017-08-01

Avoiding obstacles is essential for successful navigation through complex environments. This study aimed to clarify what strategies are used by a typical quadruped, the cat, to avoid obstacles during walking. Four cats walked along a corridor 2.5 m long and 25 or 15 cm wide. Obstacles, small round objects 2.5 cm in diameter and 1 cm in height, were placed on the floor in various locations. Movements of the paw were recorded with a motion capture and analysis system (Visualeyez, PTI). During walking in the wide corridor, cats' preferred strategy for avoiding a single obstacle was circumvention, during which the stride direction changed while stride duration and swing-to-stride duration ratio were preserved. Another strategy, stepping over the obstacle, was used during walking in the narrow corridor, when lateral deviations of walking trajectory were restricted. Stepping over the obstacle involved changes in two consecutive strides. The stride preceding the obstacle was shortened, and swing-to-stride ratio was reduced. The obstacle was negotiated in the next stride of increased height and normal duration and swing-to-stride ratio. During walking on a surface with multiple obstacles, both strategies were used. To avoid contact with the obstacle, cats placed the paw away from the object at a distance roughly equal to the diameter of the paw. During obstacle avoidance cats prefer to alter muscle activities without altering the locomotor rhythm. We hypothesize that a choice of the strategy for obstacle avoidance is determined by minimizing the complexity of neuro-motor processes required to achieve the behavioral goal. NEW & NOTEWORTHY In a study of feline locomotor behavior we found that the preferred strategy to avoid a small obstacle is circumvention. During circumvention, stride direction changes but length and temporal structure are preserved. Another strategy, stepping over the obstacle, is used in narrow walkways. During overstepping, two strides adjust. A stride

Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system

NASA Astrophysics Data System (ADS)

Yan, Y.; Lin, J.; Hu, L.; Chen, J.

2016-12-01

Small-scale nonlinear chemical and physical processes over pollution source regions affect the tropospheric ozone, but these processes are not captured by current global chemical transport models and chemistry-climate models that are limited by coarse horizontal resolutions. These models tend to contain large (and mostly positive) tropospheric O3 biases in the Northern Hemisphere. Here we use a recently built two-way coupling system of the GEOS-Chem CTM to simulate the regional and global tropospheric O3in 2009. The system couples the global model (at 2.5º long. x 2º lat.) and its three nested models (at 0.667º long. x 0.5º lat.) covering Asia, North America and Europe, respectively. Specifically, the nested models take lateral boundary conditions from the global model, better capture small-scale processes, and feed back to modify the global model simulation within the nested domains, with a subsequent effect on their LBCs. Compared to the global model alone, the two-way coupled system better simulates the tropospheric O3 both within and outside the nested domains, as found by evaluation against a suite of ground (1420 sites from WDCGG, GMD, EMEP, and AQS), aircraft (HIPPO and MOZAIC), and satellite measurements (two OMI products). The two-way coupled simulation enhances the correlation in day-to-day variation of afternoon mean surface O3 with the ground measurements from 0.53 to 0.68, and it reduces the mean model bias from 10.8 to 6.7 ppb. Regionally, the coupled system reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America, and 3.1 ppb over other regions. The two-way coupling brings O3vertical profiles much closer to the HIPPO (for remote areas) and MOZAIC (for polluted regions) data, reducing the tropospheric mean bias by 3-10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO profiles. The two-way coupled simulation also reduces the global tropospheric column ozone by 3.0 DU (9.5%, annual mean), bringing them closer to the OMI data in all

Drug–drug conditioning between citalopram and haloperidol or olanzapine in a conditioned avoidance response model: implications for polypharmacy in schizophrenia

PubMed Central

Sparkman, Nathan L.; Li, Ming

2016-01-01

Patients with schizophrenia often have anxiety and depression, and thus are treated with multiple psychotherapeutic medications. This practice of polypharmacy increases the possibility for drug–drug interactions. However, the pharmacological and behavioral mechanisms underlying drug–drug interactions in schizophrenia remain poorly understood. In the present study, we adopted a preclinical approach and examined a less known behavioral mechanism, drug–drug conditioning (DDC) between haloperidol (a typical antipsychotic) or olanzapine (atypical antipsychotic) and citalopram (a selective serotonin reuptake inhibitor). A rat two-way conditioned avoidance response paradigm was used to measure antipsychotic activity and determine how DDC may alter the antipsychotic efficacy in this model. Following acquisition of the avoidance response, rats were then randomly assigned to receive vehicle, citalopram (10.0 mg/kg, intraperitoneally), haloperidol (0.05 mg/kg, subcutaneously), olanzapine (1.0 mg/kg, subcutaneously), combined haloperidol with citalopram, or combined olanzapine with citalopram treatment for seven avoidance test sessions. In comparison with antipsychotic treatment alone, combined treatment with citalopram potentiated the antiavoidance effect of olanzapine or haloperidol (to a lesser extent) during the seven drug-test sessions. In addition, repeated pairing of citalopram with haloperidol or olanzapine caused citalopram to show a newly acquired avoidance-disruptive effect. This effect was context specific because citalopram paired with haloperidol or olanzapine outside the avoidance testing context (i.e. home cages) did not show such an effect. These findings indicate that concurrent antidepressant and antipsychotic treatments may engender a DDC process that follows the general Pavlovian associative conditioning principles. They also indicate that adjunctive citalopram treatment may enhance the antipsychotic efficacy of haloperidol and olanzapine in the

Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system

NASA Astrophysics Data System (ADS)

Yan, Yingying; Lin, Jintai; Chen, Jinxuan; Hu, Lu

2016-02-01

Small-scale nonlinear chemical and physical processes over pollution source regions affect the tropospheric ozone (O3), but these processes are not captured by current global chemical transport models (CTMs) and chemistry-climate models that are limited by coarse horizontal resolutions (100-500 km, typically 200 km). These models tend to contain large (and mostly positive) tropospheric O3 biases in the Northern Hemisphere. Here we use the recently built two-way coupling system of the GEOS-Chem CTM to simulate the regional and global tropospheric O3 in 2009. The system couples the global model (at 2.5° long. × 2° lat.) and its three nested models (at 0.667° long. × 0.5° lat.) covering Asia, North America and Europe, respectively. Specifically, the nested models take lateral boundary conditions (LBCs) from the global model, better capture small-scale processes and feed back to modify the global model simulation within the nested domains, with a subsequent effect on their LBCs. Compared to the global model alone, the two-way coupled system better simulates the tropospheric O3 both within and outside the nested domains, as found by evaluation against a suite of ground (1420 sites from the World Data Centre for Greenhouse Gases (WDCGG), the United States National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory Global Monitoring Division (GMD), the Chemical Coordination Centre of European Monitoring and Evaluation Programme (EMEP), and the United States Environmental Protection Agency Air Quality System (AQS)), aircraft (the High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observations (HIPPO) and Measurement of Ozone and Water Vapor by Airbus In- Service Aircraft (MOZAIC)) and satellite measurements (two Ozone Monitoring Instrument (OMI) products). The two-way coupled simulation enhances the correlation in day-to-day variation of afternoon mean surface O3 with the ground measurements

Haemodynamics of giant cerebral aneurysm: A comparison between the rigid-wall, one-way and two-way FSI models

NASA Astrophysics Data System (ADS)

Khe, A. K.; Cherevko, A. A.; Chupakhin, A. P.; Bobkova, M. S.; Krivoshapkin, A. L.; Orlov, K. Yu

2016-06-01

In this paper a computer simulation of a blood flow in cerebral vessels with a giant saccular aneurysm at the bifurcation of the basilar artery is performed. The modelling is based on patient-specific clinical data (both flow domain geometry and boundary conditions for the inlets and outlets). The hydrodynamic and mechanical parameters are calculated in the frameworks of three models: rigid-wall assumption, one-way FSI approach, and full (two-way) hydroelastic model. A comparison of the numerical solutions shows that mutual fluid- solid interaction can result in qualitative changes in the structure of the fluid flow. Other characteristics of the flow (pressure, stress, strain and displacement) qualitatively agree with each other in different approaches. However, the quantitative comparison shows that accounting for the flow-vessel interaction, in general, decreases the absolute values of these parameters. Solving of the hydroelasticity problem gives a more detailed solution at a cost of highly increased computational time.

Sociolinguistic Variation and Acquisition in Two-Way Language Immersion: Negotiating the Standard

ERIC Educational Resources Information Center

Starr, Rebecca Lurie

2016-01-01

This book investigates the acquisition of sociolinguistic knowledge in the early elementary school years of a Mandarin-English two-way immersion program in the United States. Using ethnographic observation and quantitative analysis of data, the author explores how input from teachers and classmates shapes students' language acquisition. The book…

Noise-induced hearing loss induces loudness intolerance in a rat Active Sound Avoidance Paradigm (ASAP).

PubMed

Manohar, Senthilvelan; Spoth, Jaclyn; Radziwon, Kelly; Auerbach, Benjamin D; Salvi, Richard

2017-09-01

Hyperacusis is a loudness hypersensitivity disorder in which moderate-intensity sounds are perceived as extremely loud, aversive and/or painful. To assess the aversive nature of sounds, we developed an Active Sound Avoidance Paradigm (ASAP) in which rats altered their place preference in a Light/Dark shuttle box in response to sound. When no sound (NS) was present, rats spent more than 95% of the time in the Dark Box versus the transparent Light Box. However, when a 60 or 90 dB SPL noise (2-20 kHz, 2-8 kHz, or 16-20 kHz bandwidth) was presented in the Dark Box, the rats'' preference for the Dark Box significantly decreased. Percent time in the dark decreased as sound intensity in the Dark Box increased from 60 dB to 90 dB SPL. Interestingly, the magnitude of the decrease was not a monotonic function of intensity for the 16-20 kHz noise and not related to the bandwidth of the 2-20 kHz and 2-8 kHz noise bands, suggesting that sound avoidance is not solely dependent on loudness but the aversive quality of the noise as well. Afterwards, we exposed the rats for 28 days to a 16-20 kHz noise at 102 dB SPL; this exposure produced a 30-40 dB permanent threshold shift at 16 and 32 kHz. Following the noise exposure, the rats were then retested on the ASAP paradigm. High-frequency hearing loss did not alter Dark Box preference in the no-sound condition. However, when the 2-20 kHz or 2-8 kHz noise was presented at 60 or 90 dB SPL, the rats avoided the Dark Box significantly more than they did before the exposure, indicating these two noise bands with energy below the region of hearing loss were perceived as more aversive. In contrast, when the 16-20 kHz noise was presented at 60 or 90 dB SPL, the rats remained in the Dark Box presumably because the high-frequency hearing loss made 16-20 kHz noise less audible and less aversive. These results indicate that when rats develop a high-frequency hearing loss, they become less tolerant of low frequency noise, i

Neuronal and non-neuronal signals regulate Caernorhabditis elegans avoidance of contaminated food.

PubMed

Anderson, Alexandra; McMullan, Rachel

2018-07-19

One way in which animals minimize the risk of infection is to reduce their contact with contaminated food. Here, we establish a model of pathogen-contaminated food avoidance using the nematode worm Caernorhabditis elegans We find that avoidance of pathogen-contaminated food protects C. elegans from the deleterious effects of infection and, using genetic approaches, demonstrate that multiple sensory neurons are required for this avoidance behaviour. In addition, our results reveal that the avoidance of contaminated food requires bacterial adherence to non-neuronal cells in the tail of C. elegans that are also required for the cellular immune response. Previous studies in C. elegans have contributed significantly to our understanding of molecular and cellular basis of host-pathogen interactions and our model provides a unique opportunity to gain basic insights into how animals avoid contaminated food.This article is part of the Theo Murphy meeting issue 'Evolution of pathogen and parasite avoidance behaviours'. © 2018 The Authors.

Learning To Value English: Cultural Capital in a Two-Way Bilingual Program.

ERIC Educational Resources Information Center

McCollum, Pam

1999-01-01

A 3-year ethnographic study of middle-school students in a two-way bilingual program found that Mexican-background students learned to value English over Spanish at school. The hidden curriculum, instructional practices, and assessment policy devalued the students' native linguistic cultural capital compelling them to use English in the classroom…

A Mandarin/English Two-Way Immersion Program: Language Proficiency and Academic Achievement

ERIC Educational Resources Information Center

Padilla, Amado M.; Fan, Lorraine; Xu, Xiaoqiu; Silva, Duarte

2013-01-01

A Mandarin/English two-way immersion elementary program is described from its inception and implementation through the fifth grade, the culminating year of the program. All students in all grades were assessed on their oral/listening, reading, and writing performance in Mandarin using program-created assessment measures. Fifth-grade students also…

Two-Way and Monolingual English Immersion in Preschool Education: An Experimental Comparison

ERIC Educational Resources Information Center

Barnett, W. Steven; Yarosz, Donald J.; Thomas, Jessica; Jung, Kwanghee; Blanco, Dulce

2007-01-01

An experimental study was conducted comparing the effects of dual language, or two-way immersion (TWI) and monolingual English immersion (EI) preschool education programs on children's learning. Three-and four-year old children were randomly assigned by lottery to either a newly established TWI Spanish/English program or a monolingual English…

Active avoidance from a crude oil soluble fraction by an Andean paramo copepod.

PubMed

Araújo, Cristiano V M; Moreira-Santos, Matilde; Sousa, José P; Ochoa-Herrera, Valeria; Encalada, Andrea C; Ribeiro, Rui

2014-09-01

Several oil spills due to ruptures in the pipeline oil systems have occurred at the Andean paramo. A sample of this crude oil was mixed with water from a nearby Andean lagoon and the toxicity of the soluble fraction was assessed through lethal and avoidance assays with a locally occurring copepod (Boeckella occidentalis intermedia). The integration of mortality and avoidance aimed at predicting the immediate decline of copepod populations facing an oil leakage. The 24-h median lethal PAH concentration was 42.7 (26.4-91.6) µg L(-1). In the 12-h avoidance assay, 30% avoidance was recorded at the highest PAH concentration (19.4 µg L(-1)). The mortality at this PAH concentration would be of 25% and, thus, the population immediate decline would be of 55%. The inclusion of non-forced exposure testing with the quantification of the avoidance response in environmental risk assessments is, therefore, supported due to underestimation of the lethal assays.

Value generalization in human avoidance learning

PubMed Central

Robbins, Trevor W; Seymour, Ben

2018-01-01

Generalization during aversive decision-making allows us to avoid a broad range of potential threats following experience with a limited set of exemplars. However, over-generalization, resulting in excessive and inappropriate avoidance, has been implicated in a variety of psychological disorders. Here, we use reinforcement learning modelling to dissect out different contributions to the generalization of instrumental avoidance in two groups of human volunteers (N = 26, N = 482). We found that generalization of avoidance could be parsed into perceptual and value-based processes, and further, that value-based generalization could be subdivided into that relating to aversive and neutral feedback − with corresponding circuits including primary sensory cortex, anterior insula, amygdala and ventromedial prefrontal cortex. Further, generalization from aversive, but not neutral, feedback was associated with self-reported anxiety and intrusive thoughts. These results reveal a set of distinct mechanisms that mediate generalization in avoidance learning, and show how specific individual differences within them can yield anxiety. PMID:29735014

Value generalization in human avoidance learning.

PubMed

Norbury, Agnes; Robbins, Trevor W; Seymour, Ben

2018-05-08

Generalization during aversive decision-making allows us to avoid a broad range of potential threats following experience with a limited set of exemplars. However, over-generalization, resulting in excessive and inappropriate avoidance, has been implicated in a variety of psychological disorders. Here, we use reinforcement learning modelling to dissect out different contributions to the generalization of instrumental avoidance in two groups of human volunteers ( N = 26, N = 482). We found that generalization of avoidance could be parsed into perceptual and value-based processes, and further, that value-based generalization could be subdivided into that relating to aversive and neutral feedback - with corresponding circuits including primary sensory cortex, anterior insula, amygdala and ventromedial prefrontal cortex. Further, generalization from aversive, but not neutral, feedback was associated with self-reported anxiety and intrusive thoughts. These results reveal a set of distinct mechanisms that mediate generalization in avoidance learning, and show how specific individual differences within them can yield anxiety. © 2018, Norbury et al.

Pathology crossword competition: an active and easy way of learning pathology in undergraduate medical education.

PubMed

Htwe, T T; Sabaridah, I; Rajyaguru, K M; Mazidah, A M

2012-02-01

In line with the trend to engage students in active learning, it is imperative to introduce new strategies that make learning more interesting, especially in undergraduate curricula. This study aimed to determine students' performance and perception in pathology crosswords as an active way of learning and to assess their ability to memorise difficult terms in pathology. A crossword competition in pathology was conducted for two batches (year 2009 and 2010) of Phase 2 medical students in Malaysia. Crossword puzzles were prepared using an online application. Two sets of puzzles were prepared, with 20 questions for the assessment of general pathology and 20 for systemic pathology. The purpose was to compare the students' recent and remote memorising abilities, as general pathology was taught a year before proceeding to systemic pathology teaching. There were 12 groups per batch, with 8-10 students in a group. Survey questionnaires were used to assess the students' perception of the competition. Descriptive analysis was performed for comparison of performance. The mean score of correctly answered questions in general pathology was 12.75 and 11.50 in batch 2009 and 2010, respectively. The mean score for systemic pathology was 14.50 in 2009 and 13.83 in 2010. Students in the 2009 batch performed better, but this was not statistically significant (p-value > 0.05). A positive response was observed from the questionnaires. Applying crossword puzzles as a new strategy is a useful and easy way for undergraduate medical students to learn pathology.

Parents as Learners and Teachers of Mathematics: Toward a Two-Way Dialogue.

ERIC Educational Resources Information Center

Civil, Marta

Three Spanish-speaking mothers of middle-school children, a relative of one of the mothers, a school librarian, and the researcher met regularly to establish a collaborative, two-way dialogue which would encourage social and educational equality and that would take contributions into consideration according to the validity of reasoning rather than…

Becoming Bilingual in the Amigos Two-Way Immersion Program. Research Report 3.

ERIC Educational Resources Information Center

Cazabon, Mary T.; Nicoladis, Elena; Lambert, Wallace E.

The design and effectiveness of the Amigos program, a two-way Spanish-English bilingual immersion program in Cambridge (Massachusetts) are described. In the program, half the instruction is in English, half in Spanish from kindergarten through eighth grade. Half the students are native Spanish-speakers and half are native English-speakers. The…

Assessing Instructional Strategies and Resulting Student Attitudes Regarding Two-Way Television Instruction.

ERIC Educational Resources Information Center

Denton, Jon J.; And Others

Designed to compare instructional strategies and effectiveness of medical school faculty using both in-person and two-way television delivery systems, this paper presents classroom observation data obtained from presentations by seven faculty members of the College of Medicine at Texas A&M University over a 9-month period. It includes a…

Two-Way Communication between Scientists and the Public: A View from Science Communication Trainers in North America

ERIC Educational Resources Information Center

Yuan, Shupei; Oshita, Tsuyoshi; AbiGhannam, Niveen; Dudo, Anthony; Besley, John C.; Koh, Hyeseung E.

2017-01-01

The current study explores the degree to which two-way communication is applied in science communication contexts in North America, based on the experiences of science communication trainers. Interviews with 24 science communication trainers suggest that scientists rarely focus on applying two-way communication tactics, such as listening to their…

47 CFR 74.403 - Frequency selection to avoid interference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Frequency selection to avoid interference. 74... Pickup Broadcast Stations § 74.403 Frequency selection to avoid interference. (a) Where two or more... select frequencies or schedule operation in such manner as to avoid mutual interference. If mutual...

47 CFR 74.403 - Frequency selection to avoid interference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Frequency selection to avoid interference. 74... Pickup Broadcast Stations § 74.403 Frequency selection to avoid interference. (a) Where two or more... select frequencies or schedule operation in such manner as to avoid mutual interference. If mutual...

Requiring both avoidance and emotional numbing in DSM-V PTSD: will it help?

PubMed

Forbes, David; Fletcher, Susan; Lockwood, Emma; O'Donnell, Meaghan; Creamer, Mark; Bryant, Richard A; McFarlane, Alexander; Silove, Derrick

2011-05-01

The proposed DSM-V criteria for posttraumatic stress disorder (PTSD) specifically require both active avoidance and emotional numbing symptoms for a diagnosis. In DSM-IV, since both are included in the same cluster, active avoidance is not essential. Numbing symptoms overlap with depression, which may result in spurious comorbidity or overdiagnosis of PTSD. This paper investigated the impact of requiring both active avoidance and emotional numbing on the rates of PTSD diagnosis and comorbidity with depression. We investigated PTSD and depression in 835 traumatic injury survivors at 3 and 12 months post-injury. We used the DSM-IV criteria but explored the potential impact of DSM-IV and DSM-V approaches to avoidance and numbing using comparison of proportion analyses. The DSM-V requirement of both active avoidance and emotional numbing resulted in significant reductions in PTSD caseness compared with DSM-IV of 22% and 26% respectively at 3 and 12 months posttrauma. By 12 months, the rates of comorbid PTSD in those with depression were significantly lower (44% vs. 34%) using the new criteria, primarily due to the lack of avoidance symptoms. These preliminary data suggest that requiring both active avoidance and numbing as separate clusters offers a useful refinement of the PTSD diagnosis. Requiring active avoidance may help to define the unique aspects of PTSD and reduce spurious diagnoses of PTSD in those with depression. Copyright © 2010. Published by Elsevier B.V.

Testing conditions in shock-based contextual fear conditioning influence both the behavioral responses and the activation of circuits potentially involved in contextual avoidance.

PubMed

Viellard, Juliette; Baldo, Marcus Vinicius C; Canteras, Newton Sabino

2016-12-15

Previous studies from our group have shown that risk assessment behaviors are the primary contextual fear responses to predatory and social threats, whereas freezing is the main contextual fear response to physically harmful events. To test contextual fear responses to a predator or aggressive conspecific threat, we developed a model that involves placing the animal in an apparatus where it can avoid the threat-associated environment. Conversely, in studies that use shock-based fear conditioning, the animals are usually confined inside the conditioning chamber during the contextual fear test. In the present study, we tested shock-based contextual fear responses using two different behavioral testing conditions: confining the animal in the conditioning chamber or placing the animal in an apparatus with free access to the conditioning compartment. Our results showed that during the contextual fear test, the animals confined to the shock chamber exhibited significantly more freezing. In contrast, the animals that could avoid the conditioning compartment displayed almost no freezing and exhibited risk assessment responses (i.e., crouch-sniff and stretch postures) and burying behavior. In addition, the animals that were able to avoid the shock chamber had increased Fos expression in the juxtadorsomedial lateral hypothalamic area, the dorsomedial part of the dorsal premammillary nucleus and the lateral and dorsomedial parts of the periaqueductal gray, which are elements of a septo/hippocampal-hypothalamic-brainstem circuit that is putatively involved in mediating contextual avoidance. Overall, the present findings show that testing conditions significantly influence both behavioral responses and the activation of circuits involved in contextual avoidance. Copyright © 2016 Elsevier B.V. All rights reserved.

Coherent destruction of tunneling in two-level system driven across avoided crossing via photon statistics

PubMed Central

Miao, Qiang; Zheng, Yujun

2016-01-01

In this paper, the nature of the multi-order resonance and coherent destruction of tunneling (CDT) for two-level system driven cross avoided crossing is investigated by employing the emitted photons 〈N〉 and the Mandel’s Q parameter based on the photon counting statistics. An asymmetric feature of CDT is shown in the spectrum of Mandel’s Q parameter. Also, the CDT can be employed to suppress the spontaneous decay and prolong waiting time noticeably. The photon emission pattern is of monotonicity in strong relaxation, and homogeneity in pure dephasing regime, respectively. PMID:27353375

A novel theory of experiential avoidance in generalized anxiety disorder: A review and synthesis of research supporting a contrast avoidance model of worry☆,☆☆

PubMed Central

Newman, Michelle G.; Llera, Sandra J.

2011-01-01

An important emphasis of the literature on generalized anxiety disorder (GAD) has been to achieve a greater understanding of the function of emotion (e.g., avoidance, dysregulation) in the etiology and maintenance of this disorder. The purpose of the following paper is to propose a new way of conceptualizing emotional sequelae in GAD by detailing the Contrast Avoidance Model of Worry. In presenting this model, we review theory and data that led to our current position, which is that individuals with GAD are more sensitive to feeling emotionally vulnerable to unexpected negative events, and that worry (the key pathological feature of GAD) is employed to prolong and maintain a negative emotional state thereby avoiding an unexpected negative emotional shift, or contrast experience. We also discuss implications for treatment given the presence of a new target for emotional exposure techniques. Finally, we establish the Contrast Avoidance Model within the framework of extant theories and models of pathogenic processes of GAD. PMID:21334285

Team Teaching among Mixed Messages: Implementing Two-Way Dual Language Bilingual Education at Third Grade in Texas

ERIC Educational Resources Information Center

Palmer, Deborah; Henderson, Kathryn; Wall, Dorothy; Zúñiga, Christian E.; Berthelsen, Stefan

2016-01-01

This article documents and interrogates top-down district-wide implementation of a two-way dual language bilingual education (DLBE) program in a large urban district. We carried out a language policy ethnography to explore the way two schools' teams of third grade teachers worked together to negotiate the intersection of DLBE implementation and…

Stress-induced activation of decomposition of organic explosives: a simple way to understand.

PubMed

Zhang, Chaoyang

2013-01-01

We provide a very simply way to understand the stress-induced activation of decomposition of organic explosives by taking the simplest explosive molecule nitromethane (NM) as a prototype and constraining one or two NM molecules in a shell to represent the condensed phrase of NM against the stress caused by tension and compression, sliding and rotational shear, and imperfection. The results show that the stress loaded on NM molecule can always reduce the barriers of its decomposition. We think the origin of this stress-induced activation is due to the increased repulsive intra- and/or inter- molecular interaction potentials in explosives resulted from the stress, whose release is positive to accelerate the decomposition. Besides, by these models, we can understand that the explosives in gaseous state are easier to analyze than those in condensed state and the voids in condensed explosives make them more sensitive to external stimuli relative to the perfect crystals.

Two-way satellite time transfer: Overview and recent developments

NASA Technical Reports Server (NTRS)

Dejong, Gerrit

1994-01-01

The experiment using small earth stations for transatlantic two-way satellite time transfer between the USA and Germany has had its 10th anniversary this year. Pseudo-random noise coded time signals were phase modulated and demodulated at each station using a modem. Recently, during the last two weeks of Aug. 1993, six European time laboratories have used the INTELSAT 307E satellite for line-up tests and preliminary time transfer sessions using the same type of MITREX modem. The need for a uniform format for the exchange of data was felt heavily after these sessions. This problem was foreseen and addressed in international working parties. During Apr. 1993, in Task Group 7/2 of the ITU Radiocommunication Sector, a very intense discussion has taken place about what procedure should be recommended for TWSTFT and what items the header and data lines of the resulting data fields should contain. A difficulty is that two different methods of calibration of the earth station delays exist which result in different sets of delay data to be exchanged. Further study and discussions are necessary. Also, a meeting of the CCDS Working Group on TWSTFT addressed this in Oct. 1993. The outcome of the discussions and the prospect for future developments are presented.

Food Approach and Food Avoidance in Young Children: Relation with Reward Sensitivity and Punishment Sensitivity

PubMed Central

Vandeweghe, Laura; Vervoort, Leentje; Verbeken, Sandra; Moens, Ellen; Braet, Caroline

2016-01-01

It has recently been suggested that individual differences in Reward Sensitivity and Punishment Sensitivity may determine how children respond to food. These temperamental traits reflect activity in two basic brain systems that respond to rewarding and punishing stimuli, respectively, with approach and avoidance. Via parent-report questionnaires, we investigate the associations of the general motivational temperamental traits Reward Sensitivity and Punishment Sensitivity with Food Approach and Food Avoidance in 98 preschool children. Consistent with the conceptualization of Reward Sensitivity in terms of approach behavior and Punishment Sensitivity in terms of avoidance behavior, Reward Sensitivity was positively related to Food Approach, while Punishment Sensitivity was positively related to Food Avoidance. Future research should integrate these perspectives (i.e., general temperamental traits Reward Sensitivity and Punishment Sensitivity, and Food Approach and Avoidance) to get a better understanding of eating behavior and related body weight. PMID:27445898

Avoiding the use of a femoral bridging catheter using a two-stage Hemodialysis Reliable Outflow (HeRO) graft implantation technique.

PubMed

Yoon, William J; Lorelli, David R

2015-01-01

To evaluate a two-stage Hemodialysis Reliable Outflow (HeRO) implantation technique that avoids the use of a femoral bridging catheter versus the conventional one-stage technique requiring a bridging catheter in selected patients. A retrospective review was performed on 20 end-stage renal disease patients with an internal jugular vein (IJV) catheter selected for two-stage HeRO implantation at our institution between January 2010 and March 2013. The arterial graft component (AGC) was implanted without anastomosing it to the target artery (first stage). After AGC incorporation, the venous outflow component was inserted (second stage). The preexisting IJV catheter was maintained for hemodialysis access during the interstage period. Patient characteristics, patency using Kaplan-Meier method and infection rates were analyzed. A total of 17 patients with a mean age of 59 years (70.6% women) completed the two-stage procedure. During the interstage period (mean 12 weeks, range 4-22 weeks), no graft- or surgery-related infection occurred. The need of a femoral bridging catheter was avoided by utilizing the preexisting IJV dialysis catheter. The accumulated HeRO days were 3,916 days with a mean follow-up of 7.7 months (range 1-22.6 months). The HeRO-related infection rate was 0.3/1,000 days. The primary assisted and secondary patency rates at 6 months were 69% and 82%, respectively, which were similar to those of arteriovenous grafts. Staging conferred immediate vascular accessibility. Avoiding the use of a femoral bridging catheter using the two-stage technique may lower infection rate, with comparable primary assisted and secondary patency to arteriovenous grafts and added benefit of immediate cannulatability in this subset of patients.

Screening for elevated levels of fear-avoidance beliefs regarding work or physical activities in people receiving outpatient therapy.

PubMed

Hart, Dennis L; Werneke, Mark W; George, Steven Z; Matheson, James W; Wang, Ying-Chih; Cook, Karon F; Mioduski, Jerome E; Choi, Seung W

2009-08-01

Screening people for elevated levels of fear-avoidance beliefs is uncommon, but elevated levels of fear could worsen outcomes. Developing short screening tools might reduce the data collection burden and facilitate screening, which could prompt further testing or management strategy modifications to improve outcomes. The purpose of this study was to develop efficient yet accurate screening methods for identifying elevated levels of fear-avoidance beliefs regarding work or physical activities in people receiving outpatient rehabilitation. A secondary analysis of data collected prospectively from people with a variety of common neuromusculoskeletal diagnoses was conducted. Intake Fear-Avoidance Beliefs Questionnaire (FABQ) data were collected from 17,804 people who had common neuromusculoskeletal conditions and were receiving outpatient rehabilitation in 121 clinics in 26 states (in the United States). Item response theory (IRT) methods were used to analyze the FABQ data, with particular emphasis on differential item functioning among clinically logical groups of subjects, and to identify screening items. The accuracy of screening items for identifying subjects with elevated levels of fear was assessed with receiver operating characteristic analyses. Three items for fear of physical activities and 10 items for fear of work activities represented unidimensional scales with adequate IRT model fit. Differential item functioning was negligible for variables known to affect functional status outcomes: sex, age, symptom acuity, surgical history, pain intensity, condition severity, and impairment. Items that provided maximum information at the median for the FABQ scales were selected as screening items to dichotomize subjects by high versus low levels of fear. The accuracy of the screening items was supported for both scales. This study represents a retrospective analysis, which should be replicated using prospective designs. Future prospective studies should assess the

A Demonstration of Approach and Avoidance Conflicts

ERIC Educational Resources Information Center

Terry, W. Scott

2010-01-01

Choosing between 2 unpleasant alternatives (Would you rather be less intelligent or less attractive?) is more difficult than choosing between two desirable options (Would you rather be more intelligent or more attractive?). Here I describe a classroom demonstration of avoidance-avoidance conflicts. Students make a series of approach-approach and…

Analysis of Delay Fluctuations on Two-Way Time Transfer Earth Stations

DTIC Science & Technology

2007-11-01

Two Way Satellite Time and Frequency Transfer ( TWSTFT ) has become one of the major techniques to compare atomic time scales and primary clocks over...the result of TWSTFT . On the TL’s earth station, the most of the equipment is located outside, including the up- and down-converters, solid-state...light/shade, wind speed, humidity, and thermal circulation, may affect the TWSTFT earth station. These conditions may cause both the change of path

47 CFR 74.803 - Frequency selection to avoid interference.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Frequency selection to avoid interference. 74... Power Auxiliary Stations § 74.803 Frequency selection to avoid interference. (a) Where two or more low... frequencies or schedule operation in such manner as to avoid mutual interference. If a mutually satisfactory...

47 CFR 74.803 - Frequency selection to avoid interference.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Frequency selection to avoid interference. 74... Power Auxiliary Stations § 74.803 Frequency selection to avoid interference. (a) Where two or more low... frequencies or schedule operation in such manner as to avoid mutual interference. If a mutually satisfactory...

Mutual research capacity strengthening: a qualitative study of two-way partnerships in public health research

PubMed Central

2012-01-01

Introduction Capacity building has been employed in international health and development sectors to describe the process of ‘experts’ from more resourced countries training people in less resourced countries. Hence the concept has an implicit power imbalance based on ‘expert’ knowledge. In 2011, a health research strengthening workshop was undertaken at Atoifi Adventist Hospital, Solomon Islands to further strengthen research skills of the Hospital and College of Nursing staff and East Kwaio community leaders through partnering in practical research projects. The workshop was based on participatory research frameworks underpinned by decolonising methodologies, which sought to challenge historical power imbalances and inequities. Our research question was, “Is research capacity strengthening a two-way process?” Methods In this qualitative study, five Solomon Islanders and five Australians each responded to four open-ended questions about their experience of the research capacity strengthening workshop and activities: five chose face to face interview, five chose to provide written responses. Written responses and interview transcripts were inductively analysed in NVivo 9. Results Six major themes emerged. These were: Respectful relationships; Increased knowledge and experience with research process; Participation at all stages in the research process; Contribution to public health action; Support and sustain research opportunities; and Managing challenges of capacity strengthening. All researchers identified benefits for themselves, their institution and/or community, regardless of their role or country of origin, indicating that the capacity strengthening had been a two-way process. Conclusions The flexible and responsive process we used to strengthen research capacity was identified as mutually beneficial. Using community-based participatory frameworks underpinned by decolonising methodologies is assisting to redress historical power imbalances and

Mutual research capacity strengthening: a qualitative study of two-way partnerships in public health research.

PubMed

Redman-MacLaren, Michelle; MacLaren, David J; Harrington, Humpress; Asugeni, Rowena; Timothy-Harrington, Relmah; Kekeubata, Esau; Speare, Richard

2012-12-18

Capacity building has been employed in international health and development sectors to describe the process of 'experts' from more resourced countries training people in less resourced countries. Hence the concept has an implicit power imbalance based on 'expert' knowledge. In 2011, a health research strengthening workshop was undertaken at Atoifi Adventist Hospital, Solomon Islands to further strengthen research skills of the Hospital and College of Nursing staff and East Kwaio community leaders through partnering in practical research projects. The workshop was based on participatory research frameworks underpinned by decolonising methodologies, which sought to challenge historical power imbalances and inequities. Our research question was, "Is research capacity strengthening a two-way process?" In this qualitative study, five Solomon Islanders and five Australians each responded to four open-ended questions about their experience of the research capacity strengthening workshop and activities: five chose face to face interview, five chose to provide written responses. Written responses and interview transcripts were inductively analysed in NVivo 9. Six major themes emerged. These were: Respectful relationships; Increased knowledge and experience with research process; Participation at all stages in the research process; Contribution to public health action; Support and sustain research opportunities; and Managing challenges of capacity strengthening. All researchers identified benefits for themselves, their institution and/or community, regardless of their role or country of origin, indicating that the capacity strengthening had been a two-way process. The flexible and responsive process we used to strengthen research capacity was identified as mutually beneficial. Using community-based participatory frameworks underpinned by decolonising methodologies is assisting to redress historical power imbalances and inequities and is helping to sustain the initial steps

Design considerations for computationally constrained two-way real-time video communication

NASA Astrophysics Data System (ADS)

Bivolarski, Lazar M.; Saunders, Steven E.; Ralston, John D.

2009-08-01

Today's video codecs have evolved primarily to meet the requirements of the motion picture and broadcast industries, where high-complexity studio encoding can be utilized to create highly-compressed master copies that are then broadcast one-way for playback using less-expensive, lower-complexity consumer devices for decoding and playback. Related standards activities have largely ignored the computational complexity and bandwidth constraints of wireless or Internet based real-time video communications using devices such as cell phones or webcams. Telecommunications industry efforts to develop and standardize video codecs for applications such as video telephony and video conferencing have not yielded image size, quality, and frame-rate performance that match today's consumer expectations and market requirements for Internet and mobile video services. This paper reviews the constraints and the corresponding video codec requirements imposed by real-time, 2-way mobile video applications. Several promising elements of a new mobile video codec architecture are identified, and more comprehensive computational complexity metrics and video quality metrics are proposed in order to support the design, testing, and standardization of these new mobile video codecs.

Experimental characterization of collision avoidance in pedestrian dynamics

NASA Astrophysics Data System (ADS)

Parisi, Daniel R.; Negri, Pablo A.; Bruno, Luciana

2016-08-01

In the present paper, the avoidance behavior of pedestrians was characterized by controlled experiments. Several conflict situations were studied considering different flow rates and group sizes in crossing and head-on configurations. Pedestrians were recorded from above, and individual two-dimensional trajectories of their displacement were recovered after image processing. Lateral swaying amplitude and step lengths were measured for free pedestrians, obtaining similar values to the ones reported in the literature. Minimum avoidance distances were computed in two-pedestrian experiments. In the case of one pedestrian dodging an arrested one, the avoidance distance did not depend on the relative orientation of the still pedestrian with respect to the direction of motion of the first. When both pedestrians were moving, the avoidance distance in a perpendicular encounter was longer than the one obtained during a head-on approach. It was found that the mean curvature of the trajectories was linearly anticorrelated with the mean speed. Furthermore, two common avoidance maneuvers, stopping and steering, were defined from the analysis of the acceleration and curvature in single trajectories. Interestingly, it was more probable to observe steering events than stopping ones, also the probability of simultaneous steering and stopping occurrences was negligible. The results obtained in this paper can be used to validate and calibrate pedestrian dynamics models.

Range Sensor-Based Efficient Obstacle Avoidance through Selective Decision-Making.

PubMed

Shim, Youngbo; Kim, Gon-Woo

2018-03-29

In this paper, we address a collision avoidance method for mobile robots. Many conventional obstacle avoidance methods have been focused solely on avoiding obstacles. However, this can cause instability when passing through a narrow passage, and can also generate zig-zag motions. We define two strategies for obstacle avoidance, known as Entry mode and Bypass mode. Entry mode is a pattern for passing through the gap between obstacles, while Bypass mode is a pattern for making a detour around obstacles safely. With these two modes, we propose an efficient obstacle avoidance method based on the Expanded Guide Circle (EGC) method with selective decision-making. The simulation and experiment results show the validity of the proposed method.

Celestial-mechanical interpretation of the two-way radio measurements of radial velocity of spacecraft for scientific applications

NASA Astrophysics Data System (ADS)

Komovkin, S. V.; Lavrenov, S. M.; Tuchin, A. G.; Tuchin, D. A.; Yaroshevsky, V. S.

2016-12-01

The article describes a model of the two-way measurements of radial velocity based on the Doppler effect. The relations are presented for the instantaneous value of the increment range at the time of measurement and the radial velocity of the mid-dimensional interval. The compensation of methodological errors of interpretation of the two-way Doppler measurements is considered.

Behavioral and experiential avoidance in patients with hoarding disorder.

PubMed

Ayers, Catherine R; Castriotta, Natalie; Dozier, Mary E; Espejo, Emmanuel P; Porter, Ben

2014-09-01

This study examined the relationship between experiential and behavioral avoidance and hoarding symptom severity, controlling for anxiety and depression symptoms, in 66 adult individuals (M age = 61.41; SD = 9.03) with HD. Hierarchical regression was used to test the associations between hoarding severity, as defined by the Savings Inventory-Revised (SI-R) total and its three subscales, and avoidance, as defined by the Acceptance and Action Questionnaire II (AAQ-II) and two scales from the Brief COPE (Self-Distraction and Behavioral Disengagement) when controlling for anxiety and depression symptoms. Experiential avoidance (AAQ-II) and behavioral avoidance (Brief COPE subscales Self-Distraction and Behavioral Disengagement) uniquely accounted for aspects of hoarding severity (SI-R) in regression models. Behavioral avoidance contributed significant additional variance to the SI-R Clutter subscale, whereas experiential avoidance was uniquely predictive of additional variance in the SI-R Difficulty Discarding and the SI-R Acquisition subscales. Future research should examine the effect of experiential avoidance on hoarding behaviors experimentally. Given that the AAQ-II and Self-Distraction and Behavioral Disengagement subscales were not correlated, these findings suggest that experiential and behavioral avoidance are two distinct processes contributing to the severity of specific HD. Results support the utility of avoidance in the cognitive-behavioral model for HD. Copyright © 2014 Elsevier Ltd. All rights reserved.

Physicians' Religious Topic Avoidance during Clinical Interactions.

PubMed

Villagran, Melinda M; MacArthur, Brenda L; Lee, Lauren E; Ledford, Christy J W; Canzona, Mollie R

2017-05-08

Religious and spiritual (R/S) conversations at the end-of-life function to help patients and their families find comfort in difficult circumstances. Physicians who feel uncertain about how to discuss topics related to religious beliefs may seek to avoid R/S conversations with their patients. This study utilized a two-group objective structured clinical examination with a standardized patient to explore differences in physicians' use of R/S topic avoidance tactics during a clinical interaction. Results indicated that physicians used more topic avoidance tactics in response to patients' R/S inquiries than patients' R/S disclosures; however, the use of topic avoidance tactics did not eliminate the need to engage in patient-initiated R/S interactions.

Physicians’ Religious Topic Avoidance during Clinical Interactions

PubMed Central

Villagran, Melinda M.; MacArthur, Brenda L.; Lee, Lauren E.; Ledford, Christy J. W.; Canzona, Mollie R.

2017-01-01

Religious and spiritual (R/S) conversations at the end-of-life function to help patients and their families find comfort in difficult circumstances. Physicians who feel uncertain about how to discuss topics related to religious beliefs may seek to avoid R/S conversations with their patients. This study utilized a two-group objective structured clinical examination with a standardized patient to explore differences in physicians’ use of R/S topic avoidance tactics during a clinical interaction. Results indicated that physicians used more topic avoidance tactics in response to patients’ R/S inquiries than patients’ R/S disclosures; however, the use of topic avoidance tactics did not eliminate the need to engage in patient-initiated R/S interactions. PMID:28481290

Two-Way Social Media Messaging in Postoperative Cataract Surgical Patients: Prospective Interventional Study

PubMed Central

Sanguansak, Thuss; Morley, Michael G; Thinkhamrop, Kavin; Thuanman, Jaruwan; Agarwal, Isha

2017-01-01

Background Social media offers a new way to provide education, reminders, and support for patients with a variety of health conditions. Most of these interventions use one-way, provider-patient communication. Incorporating social media tools to improve postoperative (postop) education and follow-up care has only been used in limited situations. Objective The aim of this study was to determine the feasibility and efficacy of two-way social media messaging to deliver reminders and educational information about postop care to cataract patients. Methods A total of 98 patients undergoing their first eye cataract surgery were divided into two groups: a no message group receiving usual pre- and postop care and a message group receiving usual care plus messages in a mobile social media format with standardized content and timing. Each patient in the message group received nine messages about hand and face hygiene, medication and postop visit adherence, and links to patient education videos about postop care. Patients could respond to messages as desired. Main outcome measures included medication adherence, postop visit adherence, clinical outcomes, and patients’ subjective assessments of two-way messaging. The number, types, content, and timing of responses by patients to messages were recorded. Results Medication adherence was better in the message group at postop day 7, with high adherence in 47 patients (96%, 47/49) versus 36 patients (73%, 36/49) in the no message group (P=.004), but no statistically significant differences in medication adherence between the groups were noted at preop and postop day 30. Visit adherence was higher at postop day 30 in the message group (100%, 49/49) versus the no message group (88%, 43/49; P=.03) but was 100% (49/49) in both groups at postop day 1 and 7. Final visual outcomes were similar between groups. A total of 441 standardized messages were sent to the message group. Out of 270 responses generated, 188 (70%) were simple

Integration of Weather Avoidance and Traffic Separation

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Chamberlain, James P.; Wilson, Sara R.

2011-01-01

This paper describes a dynamic convective weather avoidance concept that compensates for weather motion uncertainties; the integration of this weather avoidance concept into a prototype 4-D trajectory-based Airborne Separation Assurance System (ASAS) application; and test results from a batch (non-piloted) simulation of the integrated application with high traffic densities and a dynamic convective weather model. The weather model can simulate a number of pseudo-random hazardous weather patterns, such as slow- or fast-moving cells and opening or closing weather gaps, and also allows for modeling of onboard weather radar limitations in range and azimuth. The weather avoidance concept employs nested "core" and "avoid" polygons around convective weather cells, and the simulations assess the effectiveness of various avoid polygon sizes in the presence of different weather patterns, using traffic scenarios representing approximately two times the current traffic density in en-route airspace. Results from the simulation experiment show that the weather avoidance concept is effective over a wide range of weather patterns and cell speeds. Avoid polygons that are only 2-3 miles larger than their core polygons are sufficient to account for weather uncertainties in almost all cases, and traffic separation performance does not appear to degrade with the addition of weather polygon avoidance. Additional "lessons learned" from the batch simulation study are discussed in the paper, along with insights for improving the weather avoidance concept. Introduction

Prior fear conditioning does not impede enhanced active avoidance in serotonin transporter knockout rats.

PubMed

Schipper, Pieter; Henckens, Marloes J A G; Borghans, Bart; Hiemstra, Marlies; Kozicz, Tamas; Homberg, Judith R

2017-05-30

Stressors can be actively or passively coped with, and adequate adaption of the coping response to environmental conditions can reduce their potential deleterious effects. One major factor influencing stress coping behaviour is serotonin transporter (5-HTT) availability. Abolishment of 5-HTT is known to impair fear extinction but facilitates acquisition of signalled active avoidance (AA), a behavioural task in which an animal learns to avoid an aversive stimulus that is predicted by a cue. Flexibility in adapting coping behaviour to the nature of the stressor shapes resilience to stress-related disorders. Therefore, we investigated the relation between 5-HTT expression and ability to adapt a learned coping response to changing environmental conditions. To this end, we first established and consolidated a cue-conditioned passive fear response in 5-HTT -/- and wildtype rats. Next, we used the conditioned stimulus (CS) to signal oncoming shocks during signalled AA training in 5-HTT -/- and wildtype rats to study their capability to acquire an active coping response to the CS following fear conditioning. Finally, we investigated the behavioural response to the CS in a novel environment and measured freezing, exploration and self-grooming, behaviours reflective of stress coping strategy. We found that fear conditioned and sham conditioned 5-HTT -/- animals acquired the signalled AA response faster than wildtypes, while prior conditioning briefly delayed AA learning similarly in both genotypes. Subsequent exposure to the CS in the novel context reduced freezing and increased locomotion in 5-HTT -/- compared to wildtype rats. This indicates that improved AA performance in 5-HTT -/- rats resulted in a weaker residual passive fear response to the CS in a novel context. Fear conditioning prior to AA training did not affect freezing upon re-encountering the CS, although it did reduce locomotion in 5-HTT -/- rats. We conclude that independent of 5-HTT signalling, prior fear

Avoidance behaviour response and esterase inhibition in the earthworm, Lumbricus terrestris, after exposure to chlorpyrifos.

PubMed

Martínez Morcillo, S; Yela, J L; Capowiez, Y; Mazzia, C; Rault, M; Sanchez-Hernandez, Juan C

2013-05-01

The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylcholinesterase (AChE) and carboxylesterase (CbE) activities was also determined as indirect measures of pesticide bioavailability. The effects of different chlorpyrifos concentrations were examined in a standardised test (two-chamber system) with 0.6, 3 and 15 mg/kg chlorpyrifos. A modification of the test involved a pre-exposure step (24, 48 or 72 h) in soils spiked with 15 mg/kg. In both protocols, earthworms were unable to avoid the contaminated soils. However, the esterase activities showed that all earthworms were exposed to chlorpyrifos. Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test (0.58 ± 0.20 U/mg protein, mean ± SD; n = 72), whereas the CbE activity was significantly inhibited (62-87 % inhibition) in earthworms exposed to 3 and 15 mg/kg. In the modified test, earthworms had greatly inhibited AChE activity (0.088 ± 0.034 U/mg protein, n = 72), which was supported by reactivation of the inhibited enzyme activity in the presence of pralidoxime (2-PAM). Similarly, the CbE activity was significantly inhibited in earthworms with all treatments. This study suggests that the avoidance behaviour test for organophosphorus-contaminated soils could be supported by specific biomarkers to facilitate a better understanding of pesticide exposure and toxicity during this test.

Social and monetary incentives counteract fear-driven avoidance: Evidence from approach-avoidance decisions.

PubMed

Pittig, Andre; Hengen, Kristina; Bublatzky, Florian; Alpers, Georg W

2018-04-22

The reduction of avoidance behavior is a central target in the treatment of anxiety disorders, but it has rarely been studied how approach of fear-relevant stimuli may be initiated. In two studies, the impact of hypothetical monetary and symbolic social incentives on approach-avoidance behavior was examined. In Study 1, individuals high or low on fear of spiders (N = 84) could choose to approach a fear-relevant versus a neutral stimulus, which were equally rewarded. In a subsequent micro-intervention, approaching the fear-relevant stimulus was differentially rewarded either by monetary or social incentives. In Study 2 (N = 76), initial incentives for approach were discontinued to investigate the stability of approach. Hypothetical monetary and symbolic social incentives reduced or eliminated initial avoidance, even in highly fearful individuals. Approach resulted in a decrease of self-reported aversiveness towards the fear-relevant stimulus. However, even after successful approach, fearful individuals showed significant avoidance behavior when incentives for approach were discontinued. Future research should investigate the long-term effects of prolonged approach incentives on multiple levels of fear (e.g., self-report, behavioral, physiological). It should also be tested if such an intervention actually improves compliance with exposure based interventions. The present findings highlight that incentives are useful to initiate initial approach towards a feared stimulus. Although incentive-based approach may neither fully eliminate avoidance nor negative feelings towards the feared stimulus, such operant interventions may set the stage for more extensive extinction training. Copyright © 2018 Elsevier Ltd. All rights reserved.

Improved simulation of tropospheric ozone by a global-multi-regional two-way coupling model system

NASA Astrophysics Data System (ADS)

Yan, Y.-Y.; Lin, J.-T.; Chen, J.; Hu, L.

2015-09-01

Small-scale nonlinear chemical and physical processes over pollution source regions affect the global ozone (O3) chemistry, but these processes are not captured by current global chemical transport models (CTMs) and chemistry-climate models that are limited by coarse horizontal resolutions (100-500 km, typically 200 km). These models tend to contain large (and mostly positive) tropospheric O3 biases in the Northern Hemisphere. Here we use a recently built two-way coupling system of the GEOS-Chem CTM to simulate the global tropospheric O3 in 2009. The system couples the global model (at 2.5° long. × 2° lat.) and its three nested models (at 0.667° long. × 0.5° lat.) covering Asia, North America and Europe, respectively. Benefiting from the high resolution, the nested models better capture small-scale processes than the global model alone. In the coupling system, the nested models provide results to modify the global model simulation within respective nested domains while taking the lateral boundary conditions from the global model. Due to the "coupling" effects, the two-way system significantly improves the tropospheric O3 simulation upon the global model alone, as found by comparisons with a suite of ground (1420 sites from WDCGG, GMD, EMEP, and AQS), aircraft (HIPPO and MOZAIC), and satellite measurements (two OMI products). Compared to the global model alone, the two-way coupled simulation enhances the correlation in day-to-day variation of afternoon mean O3 with the ground measurements from 0.53 to 0.68, and it reduces the mean model bias from 10.8 to 6.7 ppb in annual average afternoon O3. Regionally, the coupled model reduces the bias by 4.6 ppb over Europe, 3.9 ppb over North America, and 3.1 ppb over other regions. The two-way coupling brings O3 vertical profiles much closer to the HIPPO (for remote areas) and MOZAIC (for polluted regions) data, reducing the tropospheric (0-9 km) mean bias by 3-10 ppb at most MOZAIC sites and by 5.3 ppb for HIPPO

Quantum error correction assisted by two-way noisy communication

PubMed Central

Wang, Zhuo; Yu, Sixia; Fan, Heng; Oh, C. H.

2014-01-01

Pre-shared non-local entanglement dramatically simplifies and improves the performance of quantum error correction via entanglement-assisted quantum error-correcting codes (EAQECCs). However, even considering the noise in quantum communication only, the non-local sharing of a perfectly entangled pair is technically impossible unless additional resources are consumed, such as entanglement distillation, which actually compromises the efficiency of the codes. Here we propose an error-correcting protocol assisted by two-way noisy communication that is more easily realisable: all quantum communication is subjected to general noise and all entanglement is created locally without additional resources consumed. In our protocol the pre-shared noisy entangled pairs are purified simultaneously by the decoding process. For demonstration, we first present an easier implementation of the well-known EAQECC [[4, 1, 3; 1

Quantum error correction assisted by two-way noisy communication.

PubMed

Wang, Zhuo; Yu, Sixia; Fan, Heng; Oh, C H

2014-11-26

Pre-shared non-local entanglement dramatically simplifies and improves the performance of quantum error correction via entanglement-assisted quantum error-correcting codes (EAQECCs). However, even considering the noise in quantum communication only, the non-local sharing of a perfectly entangled pair is technically impossible unless additional resources are consumed, such as entanglement distillation, which actually compromises the efficiency of the codes. Here we propose an error-correcting protocol assisted by two-way noisy communication that is more easily realisable: all quantum communication is subjected to general noise and all entanglement is created locally without additional resources consumed. In our protocol the pre-shared noisy entangled pairs are purified simultaneously by the decoding process. For demonstration, we first present an easier implementation of the well-known EAQECC [[4, 1, 3; 1

A problem of collision avoidance

NASA Technical Reports Server (NTRS)

Vincent, T. L.; Cliff, E. M.; Grantham, W. J.; Peng, W. Y.

1972-01-01

Collision avoidance between two vehicles of constant speed with limited turning radii, moving in a horizontal plane is investigated. Collision avoidance is viewed as a game by assuming that the operator of one vehicle has perfect knowledge of the state of the other, whereas the operator of the second vehicle is unaware of any impending danger. The situation envisioned is that of an encounter between a commercial aircraft and a small light aircraft. This worse case situation is examined to determine the conditions under which the commercial aircraft should execute a collision avoidance maneuver. Three different zones of vulnerability are defined and the boundaries, or barriers, between these zones are determined for a typical aircraft encounter. A discussion of the methods used to obtain the results as well as some of the salient features associated with the resultant barriers is included.

Role of B19' martensite deformation in stabilizing two-way shape memory behavior in NiTi

DOE PAGES

Benafan, O.; Padula, S. A.; Noebe, R. D.; ...

2012-11-01

Deformation of a B19' martensitic, polycrystallineNi49.9Ti50.1 (at. %) shape memoryalloy and its influence on the magnitude and stability of the ensuing two-way shape memory effect (TWSME) was investigated by combined ex situ mechanical experimentation and in situneutron diffraction measurements at stress and temperature. The microstructural changes (texture, lattice strains, and phase fractions) during room-temperature deformation and subsequent thermal cycling were captured and compared to the bulk macroscopic response of the alloy. With increasing uniaxial strain, it was observed that B19' martensite deformed by reorientation and detwinning with preferred selection of the (1¯50) M and (010) M variants, (201¯) B19' deformationmore » twinning, and dislocation activity. These mechanisms were indicated by changes in bulk texture from the neutron diffraction measurements. Partial reversibility of the reoriented variants and deformation twins was also captured upon load removal and thermal cycling, which after isothermal deformation to strains between 6% and 22% resulted in a strong TWSME. Consequently, TWSME functional parameters including TWSME strain, strain reduction, and transformation temperatures were characterized and it was found that prior martensite deformation to 14% strain provided the optimum condition for the TWSME, resulting in a stable two-way shape memory strain of 2.2%. Thus, isothermal deformation of martensite was found to be a quick and efficient method for creating a strong and stable TWSME in Ni₄₉.₉Ti₅₀.₁.« less

Two-way learning with one-way supervision for gene expression data.

PubMed

Wong, Monica H T; Mutch, David M; McNicholas, Paul D

2017-03-04

A family of parsimonious Gaussian mixture models for the biclustering of gene expression data is introduced. Biclustering is accommodated by adopting a mixture of factor analyzers model with a binary, row-stochastic factor loadings matrix. This particular form of factor loadings matrix results in a block-diagonal covariance matrix, which is a useful property in gene expression analyses, specifically in biomarker discovery scenarios where blood can potentially act as a surrogate tissue for other less accessible tissues. Prior knowledge of the factor loadings matrix is useful in this application and is reflected in the one-way supervised nature of the algorithm. Additionally, the factor loadings matrix can be assumed to be constant across all components because of the relationship desired between the various types of tissue samples. Parameter estimates are obtained through a variant of the expectation-maximization algorithm and the best-fitting model is selected using the Bayesian information criterion. The family of models is demonstrated using simulated data and two real microarray data sets. The first real data set is from a rat study that investigated the influence of diabetes on gene expression in different tissues. The second real data set is from a human transcriptomics study that focused on blood and immune tissues. The microarray data sets illustrate the biclustering family's performance in biomarker discovery involving peripheral blood as surrogate biopsy material. The simulation studies indicate that the algorithm identifies the correct biclusters, most optimally when the number of observation clusters is known. Moreover, the biclustering algorithm identified biclusters comprised of biologically meaningful data related to insulin resistance and immune function in the rat and human real data sets, respectively. Initial results using real data show that this biclustering technique provides a novel approach for biomarker discovery by enabling blood to be used

Harm avoidance and disability in old age.

PubMed

Wilson, Robert S; Buchman, Aron S; Arnold, Steven E; Shah, Raj C; Tang, Yuxiao; Bennett, David A

2006-01-01

The relation of personality to disability in old age is not well understood. The authors examined the relation of harm avoidance, a trait indicating a tendency to worry, fear uncertainty, be shy, and tire easily, to disability in a group of 474 older persons without dementia. Participants completed the 35-item Harm Avoidance scale. Disability was assessed with the Rosow-Breslau scale, a self-report measure of physical mobility. Performance-based tests of lower limb functions were also administered from which composite measures of gait, balance, and strength were derived. In a logistic regression model controlled for age, sex, education, and lower limb function, persons with high levels of harm avoidance were nearly three times as likely to report mobility limitations as persons with low levels, and these effects largely reflected fatigability and fear of uncertainty. The association of harm avoidance with disability was not explained or modified by frailty, physical activity, depressive symptoms, neuroticism, extraversion, or cognition. The results suggest that harm avoidance is associated with disability in old age.

Considerations for the Optimal Design of a Two-Way Interactive Distance Education Classroom.

ERIC Educational Resources Information Center

Gregg, Joe; Persichitte, Kay

To make effective use of a two-way interactive distance education system, classroom design should be a primary consideration. A properly designed classroom will enhance content objectives and increase acceptance of this type of instructional delivery. This paper describes key considerations for optimal design. Construction considerations include…

Two-Way Interactive Television: An Emerging Technology for University Level Business School Instruction.

ERIC Educational Resources Information Center

Heiens, Richard A.; Hulse, Deborah B.

1996-01-01

An organizational behavior course was delivered via two-way interactive television to a campus site (71 students) and three remote locations (48 students). Remote students were slightly older and predominantly female. There were no significant differences in academic performance between on-campus and remote students. (SK)

Pre-Teenage Children's Strategies for Avoiding Situations in Which They Might Be Exposed to Drugs

ERIC Educational Resources Information Center

McIntosh, James; MacDonald, Fiona; McKeganey, Neil

2005-01-01

This paper explores the ways in which pre-teenage children try to avoid coming into contact with illegal drugs and then examines the factors and circumstances that facilitate or impede their efforts to achieve this. Their main strategy of avoiding certain groups or individuals was complicated by the fluid nature of young people's social groups and…

Linear analysis of active-medium two-beam accelerator

NASA Astrophysics Data System (ADS)

Voin, Miron; Schächter, Levi

2015-07-01

We present detailed development of the linear theory of wakefield amplification by active medium and its possible application to a two-beam accelerator (TBA) is discussed. A relativistic train of triggering microbunches traveling along a vacuum channel in an active medium confined by a cylindrical waveguide excites Cherenkov wake in the medium. The wake is a superposition of azimuthally symmetric transverse magnetic modes propagating along a confining waveguide, with a phase velocity equal to the velocity of the triggering bunches. The structure may be designed in such a way that the frequency of one of the modes is close to active-medium resonant frequency, resulting in amplification of the former and domination of a single mode far behind the trigger bunches. Another electron bunch placed in proper phase with the amplified wakefield may be accelerated by the latter. Importantly, the energy for acceleration is provided by the active medium and not the drive bunch as in a traditional TBA. Based on a simplified model, we analyze extensively the impact of various parameters on the wakefield amplification process.

Passive Faraday-mirror attack in a practical two-way quantum-key-distribution system

NASA Astrophysics Data System (ADS)

Sun, Shi-Hai; Jiang, Mu-Sheng; Liang, Lin-Mei

2011-06-01

The Faraday mirror (FM) plays a very important role in maintaining the stability of two-way plug-and-play quantum key distribution (QKD) systems. However, the practical FM is imperfect, which will not only introduce an additional quantum bit error rate (QBER) but also leave a loophole for Eve to spy the secret key. In this paper we propose a passive Faraday mirror attack in two-way QKD system based on the imperfection of FM. Our analysis shows that if the FM is imperfect, the dimension of Hilbert space spanned by the four states sent by Alice is three instead of two. Thus Eve can distinguish these states with a set of Positive Operator Valued Measure (POVM) operators belonging to three-dimension space, which will reduce the QBER induced by her attack. Furthermore, a relationship between the degree of the imperfection of FM and the transmittance of the practical QKD system is obtained. The results show that the probability that Eve loads her attack successfully depends on the degree of the imperfection of FM rapidly, but the QBER induced by Eve’s attack changes slightly with the degree of the FM imperfection.

[Evaluation of a two-dimensional scale for the assessment of fear avoidance beliefs in elderly chronic low back pain patients].

PubMed

Quint, S; Raich, M; Luckmann, J

2011-06-01

There is evidence on the importance of fear avoidance beliefs (FAB) as prognostic risk factors in elderly patients suffering from chronic low back pain (CLBP). However, so far there is no validated German instrument for measuring FAB in elderly CLBP patients. The aim of the study presented was to evaluate the psychometric properties of the Catastrophizing Avoidance Scale D-65+ (CAS-D-65+) within a population of elderly patients with CLBP. A cross-sectional study was conducted with measurement repeated after 4 weeks in 68 CLBP patients aged 64 years and older. The CAS-D-65+ was analyzed performing an item analysis and retest reliability. For validation standardized assessment methods (Tampa Scale of Kinesiophobia [TSK], Photography of Daily Activity - Short electronic Version [Phoda-SeV], 5-Item-FAB, pain, disability, well-being and strain) were used. Internal consistency (Cronbach's α) ranged from 0.87 to 0.92 for total scale and from 0.71 to 0.89 for the sub-scales "catastrophizing" and "avoidance", retest reliability (r(tt)) ranged from 0.67 for the sub-scale "catastrophizing" to 0.70 for total scale and sub-scale "avoidance". The CAS-D-65+ showed moderate and strong effect sizes (Cohen's d) with other related FAB scales and external criteria. As shown in this study the CAS-D-65+ is a reliable and a valid instrument for the assessment of FAB in older patients with CLBP.

Divergent stress responses and coping styles in psychogenetically selected Roman high-(RHA) and low-(RLA) avoidance rats: behavioural, neuroendocrine and developmental aspects.

PubMed

Steimer, Thierry; Driscoll, Peter

2003-06-01

The Swiss sublines of Roman high-(RHA/Verh) and low-(RLA/Verh) avoidance rats have been genetically selected for good vs. poor performance in two-way active avoidance since 1972. RLA/Verh rats show increased stress responses (e.g. freezing behaviour, ACTH, corticosterone and prolactin secretion) and adopt a more passive (or reactive) coping style when confronted with a novel environment. In the open field, elevated plus-maze, black/white box test, and in a new light/dark open field test, RLA/Verh rats appear to be more anxious than their RHA/Verh counterparts. Anxiety may result from their particular psychophysiological profile, i.e. increased emotionality combined with a passive coping style. In contrast, RHA/Verh rats are less responsive to stress, they show little anxiety in novel situations and tend to be impulsive and novelty (sensation) seekers. Some behavioural differences are already noticeable shortly after birth, but the full pattern appears to stabilize only after puberty. Gene-environment interactions are critical in establishing this pattern. The data reviewed indicate that the differences between RHA/Verh and RLA/Verh rats probably result from a complex interaction among divergent anxiety/emotionality characteristics, differences in locomotor activity and novelty/reward seeking, as well as active vs. passive coping styles. It is proposed further that these divergent personality types are to be found not only in other selective breeding programs but in the form of individual differences in most populations of rats used for this type of research.

Ways of problem solving as predictors of relapse in alcohol dependent male inpatients.

PubMed

Demirbas, Hatice; Ilhan, Inci Ozgur; Dogan, Yildirim Beyatli

2012-01-01

The purpose of this study was to identify how remitters and relapsers view their everyday problem solving strategies. A total of 128 male alcohol dependent male inpatients who were hospitalized at the Ankara University Psychiatry Clinic, Alcohol and Substance Abuse Treatment Unit were recruited for the study. Subjects demographic status and alcohol use histories were assessed by a self-report questionnaire. Also, patients were evaluated with The Coopersmith Self-esteem Inventory (CSI), The Spielberger State-Trait Anxiety Scale (STAI-I-II), and The Problem Solving Inventory (PSI). Patients were followed for six months with monthly intervals after hospital discharge. Drinking status was assessed in terms of abstinence and relapse. Data were assessed with Student t-test, and univariate and multivariate analyses. In the logistic regression analysis, age, marital status, employment status and PSI subscores were taken as the independent variables and drinking state at the end of six months as the dependent variable. There were significant differences in reflective and avoidant styles, and monitoring style of problem solving between abstainers and relapses. It was found that subjects who perceived their problem solving style as less avoidant and less reflective were at greater risk to relapse. The findings demonstrated that active engagement in problem solving like utilizing avoidant and reflective styles of problem solving enhances abstinence. In treatment, expanding the behavior repertoire and increasing the variety of ways of problem solving ways that can be utilized in daily life should be one of the major goals of the treatment program. Copyright © 2011 Elsevier Ltd. All rights reserved.

More Powerful Tests of Simple Interaction Contrasts in the Two-Way Factorial Design

ERIC Educational Resources Information Center

Hancock, Gregory R.; McNeish, Daniel M.

2017-01-01

For the two-way factorial design in analysis of variance, the current article explicates and compares three methods for controlling the Type I error rate for all possible simple interaction contrasts following a statistically significant interaction, including a proposed modification to the Bonferroni procedure that increases the power of…

Biointerfaces for Two-way Communication to Assess Hazards in the Aquatic Environment.

DTIC Science & Technology

1999-11-01

to provide timely information on contaminants in freshwater and marine environments. 14. SUBJECT TERMS 15. NUMBER OF PAGES Sentinel species, aquatic ...for using aquatic organisms to provide timely information on contaminants in freshwater and marine environments. Some of the research challenges that...Technical Report 0001 Biointerfaces for Two-way Communication to Assess Hazards in the Aquatic Environment U.S. Army Center for Environmental Health

Congruence between Spouses’ Perceptions and Observers’ Ratings of Responsiveness: The Role of Attachment Avoidance

PubMed Central

Beck, Lindsey A.; Pietromonaco, Paula R.; DeVito, Cassandra C.; Powers, Sally I.; Boyle, Alysia M.

2016-01-01

Although close relationships require partners to depend on one another for mutual responsiveness, avoidantly-attached individuals are especially averse to risking such dependency. The authors propose that both avoidant and non-avoidant individuals perceive signs of their own and their partners’ responsiveness in ways that reflect motivated perceptions of dependency. The present research examined how the interplay between spouses’ attachment avoidance and observed responsive behaviors during marital conflict shaped perceptions of their own and their partners’ responsiveness. Newlywed couples attempted to resolve a relationship conflict, then reported perceptions of their own and their partners’ responsiveness during the conflict. Observers also coded both partners’ responsive behaviors during the conflict. Avoidant husbands perceived themselves as less responsive than did observers; avoidant wives’ perceptions that their husbands were less responsive matched observers’ ratings. The discussion highlights the role of gender role norms in understanding links between attachment and responsiveness. PMID:24132245

Strategies for Pre-Emptive Mid-Air Collision Avoidance in Budgerigars

PubMed Central

Schiffner, Ingo; Srinivasan, Mandyam V.

2016-01-01

We have investigated how birds avoid mid-air collisions during head-on encounters. Trajectories of birds flying towards each other in a tunnel were recorded using high speed video cameras. Analysis and modelling of the data suggest two simple strategies for collision avoidance: (a) each bird veers to its right and (b) each bird changes its altitude relative to the other bird according to a preset preference. Both strategies suggest simple rules by which collisions can be avoided in head-on encounters by two agents, be they animals or machines. The findings are potentially applicable to the design of guidance algorithms for automated collision avoidance on aircraft. PMID:27680488

The relationship between breast cancer anxiety and mammography: experiential avoidance as a moderator.

PubMed

Miller, Sarah J; O'Hea, Erin L; Lerner, Jennifer Block; Moon, Simon; Foran-Tuller, Kelly A

2011-10-01

Although mammography can aid in the early detection and prevention of breast cancer, many women do not receive annual mammograms. It remains unclear whether anxiety about breast cancer inhibits or promotes mammography rates. The way in which women regulate their anxiety (ie, level of experiential avoidance) may play a role in predicting mammography adherence. A community sample of women (N = 84) completed a questionnaire which assessed mammography rates, experiential avoidance, and breast cancer anxiety. The results suggest that, while controlling for breast cancer anxiety, experiential avoidance (β = .31, p < .01) significantly predicted mammography rates. When examining experiential avoidance as a moderator, a multiple regression analysis approached significance (R2 Δ = .04, p = .07), suggesting that a woman's level of experiential avoidance influences the relationship between anxiety and mammography. These findings will help enable health care practitioners to better identify women at risk of non-adherence to mammography recommendations.

Two-Way Social Media Messaging in Postoperative Cataract Surgical Patients: Prospective Interventional Study.

PubMed

Sanguansak, Thuss; Morley, Katharine E; Morley, Michael G; Thinkhamrop, Kavin; Thuanman, Jaruwan; Agarwal, Isha

2017-12-19

Social media offers a new way to provide education, reminders, and support for patients with a variety of health conditions. Most of these interventions use one-way, provider-patient communication. Incorporating social media tools to improve postoperative (postop) education and follow-up care has only been used in limited situations. The aim of this study was to determine the feasibility and efficacy of two-way social media messaging to deliver reminders and educational information about postop care to cataract patients. A total of 98 patients undergoing their first eye cataract surgery were divided into two groups: a no message group receiving usual pre- and postop care and a message group receiving usual care plus messages in a mobile social media format with standardized content and timing. Each patient in the message group received nine messages about hand and face hygiene, medication and postop visit adherence, and links to patient education videos about postop care. Patients could respond to messages as desired. Main outcome measures included medication adherence, postop visit adherence, clinical outcomes, and patients' subjective assessments of two-way messaging. The number, types, content, and timing of responses by patients to messages were recorded. Medication adherence was better in the message group at postop day 7, with high adherence in 47 patients (96%, 47/49) versus 36 patients (73%, 36/49) in the no message group (P=.004), but no statistically significant differences in medication adherence between the groups were noted at preop and postop day 30. Visit adherence was higher at postop day 30 in the message group (100%, 49/49) versus the no message group (88%, 43/49; P=.03) but was 100% (49/49) in both groups at postop day 1 and 7. Final visual outcomes were similar between groups. A total of 441 standardized messages were sent to the message group. Out of 270 responses generated, 188 (70%) were simple acknowledgments or "thank you," and 82 (30

Predictors of avoiding medical care and reasons for avoidance behavior.

PubMed

Kannan, Viji Diane; Veazie, Peter J

2014-04-01

Delayed medical care has negative health and economic consequences; interventions have focused on appraising symptoms, with limited success in reducing delay. To identify predictors of care avoidance and reasons for avoiding care. Using the Health Information National Trends Survey (2007), we conducted logistic regressions to identify predictors of avoiding medical visits deemed necessary by the respondents; and, we then conducted similar analyses on reasons given for avoidance behavior. Independent variables included geographic, demographic, socioeconomic, personal health, health behavior, health care system, and cognitive characteristics. Approximately one third of adults avoided doctor visits they had deemed necessary. Although unadjusted associations existed, avoiding needed care was not independently associated with geographic, demographic, and socioeconomic characteristics. Avoidance behavior is characterized by low health self-efficacy, less experience with both quality care and getting help with uncertainty about health, having your feelings attended to by your provider, no usual source of care, negative affect, smoking daily, and fatalistic attitude toward cancer. Reasons elicited for avoidance include preference for self-care or alternative care, dislike or distrust of doctors, fear or dislike of medical treatments, time, and money; respondents also endorsed discomfort with body examinations, fear of having a serious illness, and thoughts of dying. Distinct predictors distinguish each of these reasons. Interventions to reduce patient delay could be improved by addressing the health-related behavioral, belief, experiential, and emotional traits associated with delay. Attention should also be directed toward the interpersonal communications between patients and providers.

Ethical Issues Relating to Teaching via an Interactive Two-Way Television System (ITV).

ERIC Educational Resources Information Center

Thoms, Karen Jarrett

The information age has introduced new methods of delivering educational materials to students. One method is two-way interactive television (ITV). As more schools utilize ITV, for distance education and other educational purposes, certain administrative, legal, and ethical issues need to be addressed. This paper focuses on human and ethical…

Chemometric analysis of soil pollution data using the Tucker N-way method.

PubMed

Stanimirova, I; Zehl, K; Massart, D L; Vander Heyden, Y; Einax, J W

2006-06-01

N-way methods, particularly the Tucker method, are often the methods of choice when analyzing data sets arranged in three- (or higher) way arrays, which is the case for most environmental data sets. In the future, applying N-way methods will become an increasingly popular way to uncover hidden information in complex data sets. The reason for this is that classical two-way approaches such as principal component analysis are not as good at revealing the complex relationships present in data sets. This study describes in detail the application of a chemometric N-way approach, namely the Tucker method, in order to evaluate the level of pollution in soil from a contaminated site. The analyzed soil data set was five-way in nature. The samples were collected at different depths (way 1) from two locations (way 2) and the levels of thirteen metals (way 3) were analyzed using a four-step-sequential extraction procedure (way 4), allowing detailed information to be obtained about the bioavailability and activity of the different binding forms of the metals. Furthermore, the measurements were performed under two conditions (way 5), inert and non-inert. The preferred Tucker model of definite complexity showed that there was no significant difference in measurements analyzed under inert or non-inert conditions. It also allowed two depth horizons, characterized by different accumulation pathways, to be distinguished, and it allowed the relationships between chemical elements and their biological activities and mobilities in the soil to be described in detail.

Emotional valence and contextual affordances flexibly shape approach-avoidance movements

PubMed Central

Saraiva, Ana Carolina; Schüür, Friederike; Bestmann, Sven

2013-01-01

Behavior is influenced by the emotional content—or valence—of stimuli in our environment. Positive stimuli facilitate approach, whereas negative stimuli facilitate defensive actions such as avoidance (flight) and attack (fight). Facilitation of approach or avoidance movements may also be influenced by whether it is the self that moves relative to a stimulus (self-reference) or the stimulus that moves relative to the self (object-reference), adding flexibility and context-dependence to behavior. Alternatively, facilitation of approach avoidance movements may happen in a pre-defined and muscle-specific way, whereby arm flexion is faster to approach positive (e.g., flexing the arm brings a stimulus closer) and arm extension faster to avoid negative stimuli (e.g., extending the arm moves the stimulus away). While this allows for relatively fast responses, it may compromise the flexibility offered by contextual influences. Here we asked under which conditions approach-avoidance actions are influenced by contextual factors (i.e., reference-frame). We manipulated the reference-frame in which actions occurred by asking participants to move a symbolic manikin (representing the self) toward or away from a positive or negative stimulus, and move a stimulus toward or away from the manikin. We also controlled for the type of movements used to approach or avoid in each reference. We show that the reference-frame influences approach-avoidance actions to emotional stimuli, but additionally we find muscle-specificity for negative stimuli in self-reference contexts. We speculate this muscle-specificity may be a fast and adaptive response to threatening stimuli. Our results confirm that approach-avoidance behavior is flexible and reference-frame dependent, but can be muscle-specific depending on the context and valence of the stimulus. Reference-frame and stimulus-evaluation are key factors in guiding approach-avoidance behavior toward emotional stimuli in our environment. PMID

Third Space Openings at a Two-Way Immersion Elementary School in North Carolina: Lessons from Parent Language Classes

ERIC Educational Resources Information Center

Turner, Alison M.

2016-01-01

Two-way immersion schools are growing in popularity throughout the United States. An emerging issue is to what extent these schools are able to connect with parents from multiple communities. This article describes an effort to connect parents with the school and one another through parent language classes at a Spanish/English two-way immersion…

Potential Market Demand for Two-Way Information Services to the Home, 1970-1990.

ERIC Educational Resources Information Center

Baran, Paul

Two-way information services to the home may become a $20 billion per year industry by the end of the next decade; this report presents some market forecasts for thirty such home information services. The thirty possible home information services are grouped into six major categories: education, business, general information access, shopping…

Translanguaging and Positioning in Two-Way Dual Language Classrooms: A Case for Criticality

ERIC Educational Resources Information Center

Hamman, Laura

2018-01-01

This article examines the role of translanguaging practices and pedagogies in two-way dual language classrooms. Much of the recent expansion of dual language programs across the US has occurred in mid-sized cities and rural communities where English monolingualism is the norm; however, the extant literature on flexible language practices in…

On the Control of Social Approach-Avoidance Behavior: Neural and Endocrine Mechanisms.

PubMed

Kaldewaij, Reinoud; Koch, Saskia B J; Volman, Inge; Toni, Ivan; Roelofs, Karin

The ability to control our automatic action tendencies is crucial for adequate social interactions. Emotional events trigger automatic approach and avoidance tendencies. Although these actions may be generally adaptive, the capacity to override these emotional reactions may be key to flexible behavior during social interaction. The present chapter provides a review of the neuroendocrine mechanisms underlying this ability and their relation to social psychopathologies. Aberrant social behavior, such as observed in social anxiety or psychopathy, is marked by abnormalities in approach-avoidance tendencies and the ability to control them. Key neural regions involved in the regulation of approach-avoidance behavior are the amygdala, widely implicated in automatic emotional processing, and the anterior prefrontal cortex, which exerts control over the amygdala. Hormones, especially testosterone and cortisol, have been shown to affect approach-avoidance behavior and the associated neural mechanisms. The present chapter also discusses ways to directly influence social approach and avoidance behavior and will end with a research agenda to further advance this important research field. Control over approach-avoidance tendencies may serve as an exemplar of emotional action regulation and might have a great value in understanding the underlying mechanisms of the development of affective disorders.

Quantum hacking of two-way continuous-variable quantum key distribution using Trojan-horse attack

NASA Astrophysics Data System (ADS)

Ma, Hong-Xin; Bao, Wan-Su; Li, Hong-Wei; Chou, Chun

2016-08-01

We present a Trojan-horse attack on the practical two-way continuous-variable quantum key distribution system. Our attack mainly focuses on the imperfection of the practical system that the modulator has a redundancy of modulation pulse-width, which leaves a loophole for the eavesdropper inserting a Trojan-horse pulse. Utilizing the unique characteristics of two-way continuous-variable quantum key distribution that Alice only takes modulation operation on the received mode without any measurement, this attack allows the eavesdropper to render all of the final keys shared between the legitimate parties insecure without being detected. After analyzing the feasibility of the attack, the corresponding countermeasures are put forward. Project supported by the National Basic Research Program of China (Grant No. 2013CB338002) and the National Natural Science Foundation of China (Grant Nos. 11304397 and 61505261).

Unconditional security proof of a deterministic quantum key distribution with a two-way quantum channel

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

Lu Hua; Department of Mathematics and Physics, Hubei University of Technology, Wuhan 430068; Fung, Chi-Hang Fred

2011-10-15

In a deterministic quantum key distribution (DQKD) protocol with a two-way quantum channel, Bob sends a qubit to Alice who then encodes a key bit onto the qubit and sends it back to Bob. After measuring the returned qubit, Bob can obtain Alice's key bit immediately, without basis reconciliation. Since an eavesdropper may attack the qubits traveling on either the Bob-Alice channel or the Alice-Bob channel, the security analysis of DQKD protocol with a two-way quantum channel is complicated and its unconditional security has been controversial. This paper presents a security proof of a single-photon four-state DQKD protocol against generalmore » attacks.« less

Autonomous collision avoidance system by combined control of steering and braking using geometrically optimised vehicular trajectory

NASA Astrophysics Data System (ADS)

Hayashi, Ryuzo; Isogai, Juzo; Raksincharoensak, Pongsathorn; Nagai, Masao

2012-01-01

This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.

Attention Bias of Avoidant Individuals to Attachment Emotion Pictures.

PubMed

Liu, Ying; Ding, Yi; Lu, Luluzi; Chen, Xu

2017-01-27

How attachment style affects emotion processing is tightly connected with individuals' attention bias. This experiment explored avoidant individuals' attentional engagement and attentional disengagement using a cue-target paradigm in fMRI. The experimental group consisted of 17 avoidant participants, while the control group consisted of 16 secure participants; these were identified by the Experiences in Close Relationships inventory and the Relationship Questionnaire. Each reacted to pictures of positive parent-child attachment, negative parent-child attachment, positive romantic attachment, negative romantic attachment, and neutral non-attachment. Behaviorally, avoidant individuals were slower than secure individuals in responding to emotions and their attentional disengagement effect for negative parent-child emotions was stronger than positive ones. fMRI results showed that avoidant compared to secure individuals activated more strongly in the right superior temporal gyrus, middle occipital gyrus, and the left medial frontal gyrus, middle occipital gyrus, supplementary motor area, and cingulate gyrus. They also showed stronger activation in disengaging from positive than negative emotions in the bilateral fusiform and middle occipital gyri. In conclusion, avoidant individuals could detect emotions as effective as secure individuals in attentioal engaging stages. They can disengage from positive emotions with effective cognitive resources and were harder to get rid of negative emotions with insufficient resource.

High-precision two-way optic-fiber time transfer using an improved time code.

PubMed

Wu, Guiling; Hu, Liang; Zhang, Hao; Chen, Jianping

2014-11-01

We present a novel high-precision two-way optic-fiber time transfer scheme. The Inter-Range Instrumentation Group (IRIG-B) time code is modified by increasing bit rate and defining new fields. The modified time code can be transmitted directly using commercial optical transceivers and is able to efficiently suppress the effect of the Rayleigh backscattering in the optical fiber. A dedicated codec (encoder and decoder) with low delay fluctuation is developed. The synchronization issue is addressed by adopting a mask technique and combinational logic circuit. Its delay fluctuation is less than 27 ps in terms of the standard deviation. The two-way optic-fiber time transfer using the improved codec scheme is verified experimentally over 2 m to100 km fiber links. The results show that the stability over 100 km fiber link is always less than 35 ps with the minimum value of about 2 ps at the averaging time around 1000 s. The uncertainty of time difference induced by the chromatic dispersion over 100 km is less than 22 ps.

Sounds Like Fun: Activities for Developing Phonological Awareness, Revised Edition

ERIC Educational Resources Information Center

Spector, Cecile Cyrul

2009-01-01

Kids love jokes--and teachers and SLPs love fast and easy ways to improve students' phonological awareness. That's why every elementary and middle-school SLP and educator needs this playful, effective activity book, packed with jokes and riddles that increase students' awareness of the phonemes that make up words. The perfect way to avoid "drill…

Assessing fear-avoidance beliefs in patients with cervical radiculopathy.

PubMed

Dedering, Asa; Börjesson, Tina

2013-12-01

The study sought to evaluate validity and reliability of the Fear Avoidance Beliefs Questionnaire and the Tampa Scale for Kinesiophobia in patients with cervical radiculopathy. A test-retest design was used to test stability over time in 46 patients with cervical radiculopathy. Differences between patients and healthy subjects were also evaluated comparing the patients with 41 physically active and healthy subjects. The patients answered the Fear Avoidance Beliefs Questionnaire and the Tampa Scale for Kinesiophobia twice. To test for differences between the patients and the healthy subjects, the latter answered the same questionnaires once. Questionnaires about activity, personal factors and health were also used. The test-retest reliability assessed with weighted kappa was 0.68 for the Fear Avoidance Beliefs Questionnaire and 0.45 for the Tampa Scale for Kinesiophobia. Only six of the 11 single items of the Fear Avoidance Beliefs Questionnaire and none of the single items of the Tampa Scale of Kinesiophobia showed kappa coefficients exceeding 0.60 (good reliability). Patients with cervical radiculopathy rated significantly worse on the Fear Avoidance Beliefs Questionnaire and the Tampa Scale for Kinesiophobia than the healthy subjects did. The Fear Avoidance Beliefs Questionnaire may be recommended for test-retest evaluations because 'good' reliability was found. The Tampa Scale for Kinesiophobia had only 'moderate' test-retest reliability, and this should be considered when using this scale in test-retest evaluations. Both questionnaires can discriminate between patients with cervical radiculopathy and healthy subjects. Copyright © 2012 John Wiley & Sons, Ltd.

Two-Way Satellite Time and Frequency Transfer Using 1 MChips/s Codes

DTIC Science & Technology

2009-11-01

Abstract The Ku-band transatlantic and Europe-to-Europe two-way satellite time and frequency transfer ( TWSTFT ) operations used 2.5 MChip/s...pseudo-random codes with 3.5 MHz bandwidth until the end of July 2009. The cost of TWSTFT operation is associated with the bandwidth used on a...geostationary satellite. The transatlantic and Europe-to-Europe TWSTFT operations faced a significant increase in cost for using 3.5 MHz bandwidth on a new

Dynamic Grouping of Hippocampal Neural Activity During Cognitive Control of Two Spatial Frames

PubMed Central

Kelemen, Eduard; Fenton, André A.

2010-01-01

Cognitive control is the ability to coordinate multiple streams of information to prevent confusion and select appropriate behavioral responses, especially when presented with competing alternatives. Despite its theoretical and clinical significance, the neural mechanisms of cognitive control are poorly understood. Using a two-frame place avoidance task and partial hippocampal inactivation, we confirmed that intact hippocampal function is necessary for coordinating two streams of spatial information. Rats were placed on a continuously rotating arena and trained to organize their behavior according to two concurrently relevant spatial frames: one stationary, the other rotating. We then studied how information about locations in these two spatial frames is organized in the action potential discharge of ensembles of hippocampal cells. Both streams of information were represented in neuronal discharge—place cell activity was organized according to both spatial frames, but almost all cells preferentially represented locations in one of the two spatial frames. At any given time, most coactive cells tended to represent locations in the same spatial frame, reducing the risk of interference between the two information streams. An ensemble's preference to represent locations in one or the other spatial frame alternated within a session, but at each moment, location in the more behaviorally relevant spatial frame was more likely to be represented. This discharge organized into transient groups of coactive neurons that fired together within 25 ms to represent locations in the same spatial frame. These findings show that dynamic grouping, the transient coactivation of neural subpopulations that represent the same stream of information, can coordinate representations of concurrent information streams and avoid confusion, demonstrating neural-ensemble correlates of cognitive control in hippocampus. PMID:20585373

Mechanisms of Oxidase and Superoxide Dismutation-like Activities of Gold, Silver, Platinum, and Palladium, and Their Alloys: A General Way to the Activation of Molecular Oxygen.

PubMed

Shen, Xiaomei; Liu, Wenqi; Gao, Xuejiao; Lu, Zhanghui; Wu, Xiaochun; Gao, Xingfa

2015-12-23

Metal and alloy nanomaterials have intriguing oxidase- and superoxide dismutation-like (SOD-like) activities. However, origins of these activities remain to be studied. Using density functional theory (DFT) calculations, we investigate mechanisms of oxidase- and SOD-like properties for metals Au, Ag, Pd and Pt and alloys Au4-xMx (x = 1, 2, 3; M = Ag, Pd, Pt). We find that the simple reaction-dissociation of O2-supported on metal surfaces can profoundly account for the oxidase-like activities of the metals. The activation (Eact) and reaction energies (Er) calculated by DFT can be used to effectively predict the activity. As verification, the calculated activity orders for series of metal and alloy nanomaterials are in excellent agreement with those obtained by experiments. Briefly, the activity is critically dependent on two factors, metal compositions and exposed facets. On the basis of these results, an energy-based model is proposed to account for the activation of molecular oxygen. As for SOD-like activities, the mechanisms mainly consist of protonation of O2(•-) and adsorption and rearrangement of HO2(•) on metal surfaces. Our results provide atomistic-level insights into the oxidase- and SOD-like activities of metals and pave a way to the rational design of mimetic enzymes based on metal nanomaterials. Especially, the O2 dissociative adsorption mechanism will serve as a general way to the activation of molecular oxygen by nanosurfaces and help understand the catalytic role of nanomaterials as pro-oxidants and antioxidants.

A two-way nesting procedure for the WAM model: Application to the Spanish coast

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

Lahoz, M.G.; Albiach, J.C.C.

1997-02-01

The performance of the standard one-way nesting procedure for a regional application of a third-generation wave model is investigated. It is found that this nesting procedure is not applicable when the resolution has to be enhanced drastically, unless intermediate grids are placed between the coarse and the fine grid areas. This solution, in turn, requires an excess of computing resources. A two-way nesting procedure is developed and implemented in the model. Advantages and disadvantages of both systems are discussed. The model output for a test case is compared with observed data and the results are discussed in the paper.

Students' Ways of Thinking about Two-Variable Functions and Rate of Change in Space

ERIC Educational Resources Information Center

Weber, Eric David

2012-01-01

This dissertation describes an investigation of four students' ways of thinking about functions of two variables and rate of change of those two-variable functions. Most secondary, introductory algebra, pre-calculus, and first and second semester calculus courses do not require students to think about functions of more than one variable. Yet…

[Effect of serotonin-modulated anticonsolidation protein on formation of long-term memory in carps Cyprinus carpio in the model of active avoidance learning].

PubMed

Garina, D V; Mekhtiev, A A

2014-01-01

Effect of serotonin-modulated anticonsolidation protein (SMAP) that has property of disturbing formation of memory trace in mammals and of learning and memory in teleost fish was studied in the model of active avoidance learning. The experiment was performed in three stages: (1) fry of carps Cyprinus carpio L. was injected intracerebrovenricularly with the SMAP protein at a dose of 0.3 μg/g; control individuals were administered with equal amount of the buffered saline for poikilothermic animals; (2) 24 h after the injection, fish were learnt during 8 sèances for 2 days the conditioned reflex of active avoidance; (3) 48 h after the learning the testing of the skill was performed. The administration of the protein was shown to lead to disturbance of reproduction of the skill in the fish: the latent time of the skill reproduction in experimental individuals exceeded that in control fish more than two times, while the number of individuals succeeding the task in the experimental group was non-significantly lower than in the control group. However, unlike mammals, injection of the SMAP protein in this model produced no effect on the process of learning in carps. Thus, there was first demonstrated the inhibiting effect of the SMAP protein whose concentration correlated positively with the content of the neurotransmitter serotonin in brain on consolidation of memory traces in teleost fish.

Inhibition of memory consolidation by antibodies against cell adhesion molecules after active avoidance conditioning in zebrafish.

PubMed

Pradel, G; Schachner, M; Schmidt, R

1999-05-01

Cell adhesion molecules are expected to play an important role in long-term storage of information in the central nervous system. Several of these glycoproteins, such as NCAM, L1, and the ependymins, express the HNK-1 carbohydrate structure, which is known to be involved in cell-cell and cell-matrix interactions. To investigate the contribution of the HNK-1 epitope and the secretory glycoproteins ependymins to memory formation in zebrafish (Brachydanio rerio), we developed an active avoidance conditioning paradigm. Zebrafish were trained in a shuttle-box to cross a hurdle, to avoid mild electric shocks following a conditioning light signal. One hour after acquisition of the task, zebrafish were injected intracerebroventricularly with monoclonal antibodies against the HNK-1 epitope or polyclonal antibodies against ependymins. Control fish received immunoglobulins G (IgGs) from nonimmune rat serum or the monoclonal antibody C183 against an unrelated cell-surface protein of the cyprinid brain. Two days later, injected zebrafish were tested for recall, and for quantitative evaluation a retention score (RS), ranging from 1.0 for immediate recall to 0.0, indicating no saving, was calculated. The average RS of anti-HNK-1-injected fish (RS = 0.30) and anti-ependymin-injected fish (0.24) were significantly different from the RS of uninjected fish (0.77), of controls injected with nonimmune serum IgGs (0.68), of C183-injected controls (0.78), and of overtrained fish injected with anti-HNK-1 antibodies (0.81). Anti-HNK-1 and anti-ependymin antibodies were characterized by Western blot analyses of subcellular brain fractions and immunohistochemical staining of the zebrafish optic tectum. Our data suggest that the antibodies influence cell recognition events at synaptic membranes and/or associated intracellular signaling cascades, and thereby block memory consolidation.

Avoiding Intellectual Stagnation: The Starship as an Expander of Minds

NASA Astrophysics Data System (ADS)

Crawford, Ian A.

2014-06-01

Interstellar exploration will advance human knowledge and culture in multiple ways. Scientifically, it will advance our understanding of the interstellar medium, stellar astrophysics, planetary science and astrobiology. In addition, significant societal and cultural benefits will result from a programme of interstellar exploration and colonisation. Most important will be the cultural stimuli resulting from expanding the horizons of human experience, and increased opportunities for the spread and diversification of life and culture through the Galaxy. Ultimately, a programme of interstellar exploration may be the only way for human (and post-human) societies to avoid the intellectual stagnation predicted for the `end of history'.

Measuring human betterment through avoidable mortality: a case for universal health care in the USA.

PubMed

Hisnanick, J J; Coddington, D A

1995-10-01

The USA system of health care has begun a monumental change that will affect everyone, irrespective of their socioeconomic status, professional status or pre-existing health insurance status. Whatever type of plan is finally implemented through the legislative process, there will need to be a way to evaluate its success (or failure). One way to evaluate the plan's effectiveness is through its impact on human betterment as viewed by a reduction in 'avoidable mortality' for those most in need of health care; the poor and uninsured. For one USA minority population, universal health care has improved human betterment by reducing avoidable mortality, even in the face of a severe burden of poverty.

Contamination avoidance devices for poppet type shutoff valves

NASA Technical Reports Server (NTRS)

Endicott, D. L.

1972-01-01

The technology required to provide acceptable contamination damage avoidance characteristics for poppet type shutoff valves is discussed. Evaluation of the contamination avoidance characteristics of the basic 1T32095 propellant shutoff valve, the cycle life performance of these valves in an uncontaminated environment, and the effectiveness of various auxiliary contamination avoidance devices when used in conjunction with these poppet type valves are included. In addition, a secondary objective is to evaluate two methods of monitoring the performance of the test valves during actual operations using acoustical monitoring instrumentation.

Low-loss reciprocal optical terminals for two-way time-frequency transfer.

PubMed

Swann, W C; Sinclair, L C; Khader, I; Bergeron, H; Deschênes, J-D; Newbury, N R

2017-12-01

We present the design and performance of a low-cost, reciprocal, compact free-space terminal employing tip/tilt pointing compensation that enables optical two-way time-frequency transfer over free-space links across the turbulent atmosphere. The insertion loss of the terminals is ∼1.5  dB with total link losses of 15 dB, 24 dB, and 50 dB across horizontal, turbulent 2-km, 4-km, and 12-km links, respectively. The effects of turbulence on pointing control and aperture size, and their influence on the terminal design, are discussed.

Assessing Mongolian gerbil emotional behavior: effects of two shock intensities and response-independent shocks during an extended inhibitory-avoidance task.

PubMed

Hurtado-Parrado, Camilo; González-León, Camilo; Arias-Higuera, Mónica A; Cardona, Angelo; Medina, Lucia G; García-Muñoz, Laura; Sánchez, Christian; Cifuentes, Julián; Forigua, Juan Carlos; Ortiz, Andrea; Acevedo-Triana, Cesar A; Rico, Javier L

2017-01-01

Despite step-down inhibitory avoidance procedures that have been widely implemented in rats and mice to study learning and emotion phenomena, performance of other species in these tasks has received less attention. The case of the Mongolian gerbil is of relevance considering the discrepancies in the parameters of the step-down protocols implemented, especially the wide range of foot-shock intensities (i.e., 0.4-4.0 mA), and the lack of information on long-term performance, extinction effects, and behavioral patterning during these tasks. Experiment 1 aimed to (a) characterize gerbils' acquisition, extinction, and steady-state performance during a multisession (i.e., extended) step-down protocol adapted for implementation in a commercially-available behavioral package (Video Fear Conditioning System-MED Associates Fairfax, VT, USA), and (b) compare gerbils' performance in this task with two shock intensities - 0.5 vs. 1.0 mA-considered in the low-to-mid range. Results indicated that the 1.0 mA protocol produced more reliable and clear evidence of avoidance learning, extinction, and reacquisition in terms of increments in freezing and on-platform time as well as suppression of platform descent. Experiment 2 aimed to (a) assess whether an alternate protocol consisting of a random delivery of foot shocks could replicate the effects of Experiment 1 and (b) characterize gerbils' exploratory behavior during the step-down task (jumping, digging, rearing, and probing). Random shocks did not reproduce the effects observed with the first protocol. The data also indicated that a change from random to response-dependent shocks affects (a) the length of each visit to the platform, but not the frequency of platform descends or freezing time, and (b) the patterns of exploratory behavior, namely, suppression of digging and rearing, as well as increments in probing and jumping. Overall, the study demonstrated the feasibility of the extended step-down protocol for studying steady

Assessing Mongolian gerbil emotional behavior: effects of two shock intensities and response-independent shocks during an extended inhibitory-avoidance task

PubMed Central

González-León, Camilo; Arias-Higuera, Mónica A.; Cardona, Angelo; Medina, Lucia G.; García-Muñoz, Laura; Sánchez, Christian; Cifuentes, Julián; Forigua, Juan Carlos; Ortiz, Andrea; Acevedo-Triana, Cesar A.; Rico, Javier L.

2017-01-01

Despite step-down inhibitory avoidance procedures that have been widely implemented in rats and mice to study learning and emotion phenomena, performance of other species in these tasks has received less attention. The case of the Mongolian gerbil is of relevance considering the discrepancies in the parameters of the step-down protocols implemented, especially the wide range of foot-shock intensities (i.e., 0.4–4.0 mA), and the lack of information on long-term performance, extinction effects, and behavioral patterning during these tasks. Experiment 1 aimed to (a) characterize gerbils’ acquisition, extinction, and steady-state performance during a multisession (i.e., extended) step-down protocol adapted for implementation in a commercially-available behavioral package (Video Fear Conditioning System—MED Associates Fairfax, VT, USA), and (b) compare gerbils’ performance in this task with two shock intensities – 0.5 vs. 1.0 mA—considered in the low-to-mid range. Results indicated that the 1.0 mA protocol produced more reliable and clear evidence of avoidance learning, extinction, and reacquisition in terms of increments in freezing and on-platform time as well as suppression of platform descent. Experiment 2 aimed to (a) assess whether an alternate protocol consisting of a random delivery of foot shocks could replicate the effects of Experiment 1 and (b) characterize gerbils’ exploratory behavior during the step-down task (jumping, digging, rearing, and probing). Random shocks did not reproduce the effects observed with the first protocol. The data also indicated that a change from random to response-dependent shocks affects (a) the length of each visit to the platform, but not the frequency of platform descends or freezing time, and (b) the patterns of exploratory behavior, namely, suppression of digging and rearing, as well as increments in probing and jumping. Overall, the study demonstrated the feasibility of the extended step-down protocol for

Attachment avoidance, but not anxiety, minimizes the joys of caregiving.

PubMed

Nelson-Coffey, S Katherine; Borelli, Jessica L; River, Laura M

2017-10-01

Perhaps unlike other social roles that people may hold, caring for children offers opportunities for both immense joy and incredible frustration. Yet what predicts how parents will feel during caregiving experiences? In the current study, we examined parents' (N = 152) positive emotion, negative emotion, and felt meaning during caregiving using the Day Reconstruction Method. In addition, we tested attachment anxiety and avoidance as predictors of parents' emotion during caregiving relative to their other daily experiences. We found that attachment avoidance was associated with elevated negative emotion and reduced positive emotion and meaning in life across the entire day, whereas attachment anxiety was associated with elevated negative emotion and marginally greater meaning in life, but not positive emotion, across the entire day. Furthermore, caregiving was associated with greater positive emotion and meaning, but not negative emotion, compared to parents' other daily activities. Finally, attachment avoidance, but not anxiety, was associated with lower levels of positive emotion, negative emotion, and felt meaning during caregiving compared to other daily activities. These findings are consistent with other evidence that attachment avoidance is associated with deactivation of emotion in close relationships and suggest that attachment avoidance minimizes the joys of parenting.

Identifying patient fear-avoidance beliefs by physical therapists managing patients with low back pain.

PubMed

Calley, Darren Q; Jackson, Steven; Collins, Heather; George, Steven Z

2010-12-01

Cross-sectional. To evaluate the accuracy with which physical therapists identify fear-avoidance beliefs in patients with low back pain by comparing therapist ratings of perceived patient fear-avoidance to the Fear-Avoidance Beliefs Questionnaire (FABQ), Tampa Scale of Kinesiophobia 11-item (TSK-11), and Pain Catastrophizing Scale (PCS). To compare the concurrent validity of therapist ratings of perceived patient fear-avoidance and a 2-item questionnaire on fear of physical activity and harm, with clinical measures of fear-avoidance (FABQ, TSK-11, PCS), pain intensity as assessed with a numeric pain rating scale (NPRS), and disability as assessed with the Oswestry Disability Questionnaire (ODQ). The need to consider psychosocial factors for identifying patients at risk for disability and chronic low back pain has been well documented. Yet the ability of physical therapists to identify fear-avoidance beliefs using direct observation has not been studied. Eight physical therapists and 80 patients with low back pain from 3 physical therapy clinics participated in the study. Patients completed the FABQ, TSK-11, PCS, ODQ, NPRS, and a dichotomous 2-item fear-avoidance screening questionnaire. Following the initial evaluation, physical therapists rated perceived patient fear-avoidance on a 0-to-10 scale and recorded 2 influences on their ratings. Spearman correlation and independent t tests determined the level of association of therapist 0-to-10 ratings and 2-item screening with fear-avoidance and clinical measures. Therapist ratings of perceived patient fear-avoidance had fair to moderate interrater reliability (ICC2,1 = 0.663). Therapist ratings did not strongly correlate with FABQ or TSK-11 scores. Instead, they unexpectedly had stronger associations with ODQ and PCS scores. Both 2-item screening questions were associated with FABQ-physical activity scores, while the fear of physical activity question was also associated with FABQ-work, TSK-11, PCS, and ODQ scores

Genotype-environment interaction in passive avoidance learning of the paradise fish (Macropodus opercularis).

PubMed

Csányi, V; Gervai, J

1985-01-01

Passive dark avoidance conditioning and effects of the presence and absence of a fish-like dummy on the training process were studied in four inbred strains of paradise fish. Strain differences were found in the shuttle activity during habituation trials, and in the sensitivity to the mild electric shock punishment. The presence or absence of the dummy in the punished dark side of the shuttle box had a genotype-dependent effect on the measures taken during the conditioning process. The statistical analysis of the learning curves revealed differences in the way the strains varied in the different environments, i.e. genotype--environment interaction components of variances were identified. The results are discussed in the light of previous investigations and their implication in further genetic analysis.

77 FR 58579 - Certain Two-Way Global Satellite Communication Devices, System and Components Thereof...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-21

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-854] Certain Two-Way Global Satellite... AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on August 17, 2012, under section 337 of...

A spatial paradigm, the allothetic place avoidance alternation task, for testing visuospatial working memory and skill learning in rats.

PubMed

Dockery, Colleen A; Wesierska, Malgorzata J

2010-08-30

We present a paradigm for assessing visuospatial working memory and skill learning in a rodent model, based on the place avoidance test. In our allothetic place avoidance alternation task (APAAT) the paradigm is comprised of minimal training sessions, tests various aspects of learning and memory and provides a rich set of parameters. A single working memory session consists of four conditions: habituation (no shock), two place avoidance training intervals (shock activated) and a retrieval test (shock inactivated). The location of the shock sector is alternated for each training day which initially requires extinction of previous representations and further working memory to achieve effective place avoidance across sessions. Visuospatial skill memory was evaluated by the shock/entrance ratio by tracking locomotor activity which is essential to execute a place avoidance strategy. For each day rats learned to avoid a new place with shock, as shown by a decreased number of entrances, and an increased time to the first entrance and maximum avoidance time. Skill learning improved according to the decreased number of shocks per entrance across conditions. These results indicate that complex cognitive functions are captured by this behavioral method. This APAAT paradigm expands and complements existing tools for studying hippocampal-prefrontal dependent functions to support development of treatment interventions. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Reducing shade avoidance responses in a cereal crop

PubMed Central

Wille, Wibke; Pipper, Christian B; Rosenqvist, Eva; Andersen, Sven B

2017-01-01

Abstract Several researchers have hypothesized that shade avoidance behaviour is favoured by natural selection because it increases the fitness of individuals. Shade avoidance can be disadvantageous for crops, however, because it reduces allocation of resources to reproductive yield, increases the risk of lodging and reduces weed suppression. One approach to develop varieties with reduced shade avoidance and enhanced agronomic performance is by inducing mutations followed by phenotypic screening. We treated spring wheat seeds with ethyl methanesulfonate and screened the seedlings repeatedly under green filters for plants showing reduced elongation of the first leaf sheath and second leaf lamina. The shade avoidance responses of five promising mutant lines were further compared to non-mutated plants in a climate chamber experiment with added far-red light. Two of the selected lines displayed significantly reduced elongation under all light treatments while two lines showed reduced elongation only in added far-red light. The most promising mutant line did not differ in height from the non-mutated cultivar in neutral light, but elongated 20.6% less in strong far-red light. This traditional forward approach of screening mutagenized spring wheat produced plants with reduced shade avoidance responses. These mutants may generate new molecular handles to modify the reaction of plants to changes in light spectral distribution in traditional and novel cultivation systems. PMID:29071064

Instructors' Experiences of Web Based Synchronous Communication using Two Way Audio and Direct Messaging

ERIC Educational Resources Information Center

Murphy, Elizabeth; Ciszewska-Carr, Justyna

2007-01-01

This paper reports on an exploratory case study designed to gain insight into instructors' experiences with web based synchronous communication using two way audio and direct messaging. We conducted semi-structured interviews with eight instructors who used "Elluminate Live" in their web based, asynchronous courses in Education, Nursing,…

Two-Way Bilingual Education: A Progress Report on the Amigos Program. Research Report: 7.

ERIC Educational Resources Information Center

Cazabon, Mary; And Others

The progress report on the Amigos two-way bilingual education program in the Cambridge (Massachusetts) public schools describes: research on the achievement in mathematics, Spanish, and English of Amigos students and students in control/comparison groups; data gathered on students' and parents' attitudes toward bilingualism and biculturalism;…

The association in a two-way contingency table through log odds ratio analysis: the case of Sarno river pollution.

PubMed

Camminatiello, Ida; D'Ambra, Antonello; Sarnacchiaro, Pasquale

2014-01-01

In this paper we are proposing a general framework for the analysis of the complete set of log Odds Ratios (ORs) generated by a two-way contingency table. Starting from the RC (M) association model and hypothesizing a Poisson distribution for the counts of the two-way contingency table we are obtaining the weighted Log Ratio Analysis that we are extending to the study of log ORs. Particularly we are obtaining an indirect representation of the log ORs and some synthesis measures. Then for studying the matrix of log ORs we are performing a generalized Singular Value Decomposition that allows us to obtain a direct representation of log ORs. We also expect to get summary measures of association too. We have considered the matrix of complete set of ORs, because, it is linked to the two-way contingency table in terms of variance and it allows us to represent all the ORs on a factorial plan. Finally, a two-way contingency table, which crosses pollution of the Sarno river and sampling points, is to be analyzed to illustrate the proposed framework.

Detection and avoidance of a carnivore odor by prey

PubMed Central

Ferrero, David M.; Lemon, Jamie K.; Fluegge, Daniela; Pashkovski, Stan L.; Korzan, Wayne J.; Datta, Sandeep Robert; Spehr, Marc; Fendt, Markus; Liberles, Stephen D.

2011-01-01

Predator–prey relationships provide a classic paradigm for the study of innate animal behavior. Odors from carnivores elicit stereotyped fear and avoidance responses in rodents, although sensory mechanisms involved are largely unknown. Here, we identified a chemical produced by predators that activates a mouse olfactory receptor and produces an innate behavioral response. We purified this predator cue from bobcat urine and identified it to be a biogenic amine, 2-phenylethylamine. Quantitative HPLC analysis across 38 mammalian species indicates enriched 2-phenylethylamine production by numerous carnivores, with some producing >3,000-fold more than herbivores examined. Calcium imaging of neuronal responses in mouse olfactory tissue slices identified dispersed carnivore odor-selective sensory neurons that also responded to 2-phenylethylamine. Two prey species, rat and mouse, avoid a 2-phenylethylamine odor source, and loss-of-function studies involving enzymatic depletion of 2-phenylethylamine from a carnivore odor indicate it to be required for full avoidance behavior. Thus, rodent olfactory sensory neurons and chemosensory receptors have the capacity for recognizing interspecies odors. One such cue, carnivore-derived 2-phenylethylamine, is a key component of a predator odor blend that triggers hard-wired aversion circuits in the rodent brain. These data show how a single, volatile chemical detected in the environment can drive an elaborate danger-associated behavioral response in mammals. PMID:21690383

Filter methods to preserve local contrast and to avoid artifacts in gamut mapping

NASA Astrophysics Data System (ADS)

Meili, Marcel; Küpper, Dennis; Barańczuk, Zofia; Caluori, Ursina; Simon, Klaus

2010-01-01

Contrary to high dynamic range imaging, the preservation of details and the avoidance of artifacts is not explicitly considered in popular color management systems. An effective way to overcome these difficulties is image filtering. In this paper we investigate several image filter concepts for detail preservation as part of a practical gamut mapping strategy. In particular we define four concepts including various image filters and check their performance with a psycho-visual test. Additionally, we compare our performance evaluation to two image quality measures with emphasis on local contrast. Surprisingly, the most simple filter concept performs highly efficient and achieves an image quality which is comparable to the more established but slower methods.

Avoiding shame: young LGBT people, homophobia and self-destructive behaviours.

PubMed

McDermott, Elizabeth; Roen, Katrina; Scourfield, Jonathan

2008-11-01

This paper reports on findings from qualitative research conducted in the UK that sought to explore the connections between sexual identities and self-destructive behaviours in young people. International evidence demonstrates that there are elevated rates of suicide and alcohol abuse amongst lesbian, gay, bisexual and transgender (LGBT) youth. Rarely included in this body of research are investigations into young LGBT people's views and experiences of self-destructive behaviours. Data from interviews and focus groups with young LGBT participants suggest a strong link between homophobia and self-destructive behaviours. Utilising a discourse analytic approach, we argue that homophobia works to punish at a deep individual level and requires young LGBT people to manage being positioned, because of their sexual desire or gendered ways of being, as abnormal, dirty and disgusting. At the centre of the complex and multiple ways in which young LGBT people negotiate homophobia are 'modalities of shame-avoidance' such as: the routinization and minimizing of homophobia; maintaining individual 'adult' responsibility; and constructing 'proud' identities. The paper argues that these strategies of shame-avoidance suggest young LGBT people manage homophobia individually, without expectation of support and, as such, may make them vulnerable to self-destructive behaviours.

Sense-and-Avoid Equivalent Level of Safety Definition for Unmanned Aircraft Systems. Revision 9

NASA Technical Reports Server (NTRS)

2005-01-01

Since unmanned aircraft do not have a pilot on-board the aircraft, they cannot literally comply with the "see and avoid" requirement beyond a short distance from the location of the unmanned pilot. No performance standards are presently defined for unmanned Sense and Avoid systems, and the FAA has no published approval criteria for a collision avoidance system. Before the FAA can develop the necessary guidance (rules / regulations / policy) regarding the see-and-avoid requirements for Unmanned Aircraft Systems (UAS), a concise understanding of the term "equivalent level of safety" must be attained. Since this term is open to interpretation, the UAS industry and FAA need to come to an agreement on how this term can be defined and applied for a safe and acceptable collision avoidance capability for unmanned aircraft. Defining an equivalent level of safety (ELOS) for sense and avoid is one of the first steps in understanding the requirement and developing a collision avoidance capability. This document provides a functional level definition of see-and-avoid as it applies to unmanned aircraft. The sense and avoid ELOS definition is intended as a bridge between the see and avoid requirement and the system level requirements for unmanned aircraft sense and avoid systems. Sense and avoid ELOS is defined in a rather abstract way, meaning that it is not technology or system specific, and the definition provides key parameters (and a context for those parameters) to focus the development of cooperative and non-cooperative sense and avoid system requirements.

Signal Delay Stability of a Ku-Band Two-Way Satellite Time Transfer Terminal

NASA Technical Reports Server (NTRS)

Kirchner, Dieter; Robnik, R.

1996-01-01

A fully automated two-way time and frequency transfer (TWSTFT) system including a satellite simulator, which allows the user to carry out signal delay measurements in conjunction with each time transfer measurement, is operated at the Technical University of Graz (TUG). After a brief description of the system, results obtained during fifteen months of operation are presented and discussed. Finally, envisaged experiments are mentioned.

Automotive collision avoidance system field operational test

DOT National Transportation Integrated Search

2005-03-01

The Automotive Collision Avoidance System field operational test (or ACAS FOT) program was led by General Motors (GM) under a cooperative agreement with the U.S. Department of Transportation. This report summarizes the activities of the entire progra...

Innovative hazard detection and avoidance strategy for autonomous safe planetary landing

NASA Astrophysics Data System (ADS)

Jiang, Xiuqiang; Li, Shuang; Tao, Ting

2016-09-01

Autonomous hazard detection and avoidance (AHDA) is one of the key technologies for future safe planetary landing missions. In this paper, we address the latest progress on planetary autonomous hazard detection and avoidance technologies. First, the innovative autonomous relay hazard detection and avoidance strategy adopted in Chang'e-3 lunar soft landing mission and its flight results are reported in detail. Second, two new conceptual candidate schemes of hazard detection and avoidance are presented based on the Chang'e-3 AHDA system and the latest developing technologies for the future planetary missions, and some preliminary testing results are also given. Finally, the related supporting technologies for the two candidate schemes above are analyzed.

One-way membrane trafficking of SOS in receptor-triggered Ras activation.

PubMed

Christensen, Sune M; Tu, Hsiung-Lin; Jun, Jesse E; Alvarez, Steven; Triplet, Meredith G; Iwig, Jeffrey S; Yadav, Kamlesh K; Bar-Sagi, Dafna; Roose, Jeroen P; Groves, Jay T

2016-09-01

SOS is a key activator of the small GTPase Ras. In cells, SOS-Ras signaling is thought to be initiated predominantly by membrane recruitment of SOS via the adaptor Grb2 and balanced by rapidly reversible Grb2-SOS binding kinetics. However, SOS has multiple protein and lipid interactions that provide linkage to the membrane. In reconstituted-membrane experiments, these Grb2-independent interactions were sufficient to retain human SOS on the membrane for many minutes, during which a single SOS molecule could processively activate thousands of Ras molecules. These observations raised questions concerning how receptors maintain control of SOS in cells and how membrane-recruited SOS is ultimately released. We addressed these questions in quantitative assays of reconstituted SOS-deficient chicken B-cell signaling systems combined with single-molecule measurements in supported membranes. These studies revealed an essentially one-way trafficking process in which membrane-recruited SOS remains trapped on the membrane and continuously activates Ras until being actively removed via endocytosis.

One-way membrane trafficking of SOS in receptor-triggered Ras activation

PubMed Central

Christensen, Sune M.; Tu, Hsiung-Lin; Jun, Jesse E.; Alvarez, Steven; Triplet, Meredith G.; Iwig, Jeffrey S.; Yadav, Kamlesh K.; Bar-Sagi, Dafna; Roose, Jeroen P.; Groves, Jay T.

2016-01-01

SOS is a key activator of the small GTPase Ras. In cells, SOS-Ras signaling is thought to be initiated predominantly by membrane-recruitment of SOS via the adaptor Grb2 and balanced by rapidly reversible Grb2:SOS binding kinetics. However, SOS has multiple protein and lipid interactions that provide linkage to the membrane. In reconstituted membrane experiments, these Grb2-independent interactions are sufficient to retain SOS on the membrane for many minutes, during which a single SOS molecule can processively activate thousands of Ras molecules. These observations raise questions concerning how receptors maintain control of SOS in cells and how membrane-recruited SOS is ultimately released. We addressed these questions in quantitative reconstituted SOS-deficient chicken B cell signaling systems combined with single molecule measurements in supported membranes. These studies reveal an essentially one-way trafficking process in which membrane-recruited SOS remains trapped on the membrane and continuously activates Ras until it is actively removed via endocytosis. PMID:27501536

Drosophila TRPA1 channel is required to avoid the naturally occurring insect repellent citronellal.

PubMed

Kwon, Young; Kim, Sang Hoon; Ronderos, David S; Lee, Youngseok; Akitake, Bradley; Woodward, Owen M; Guggino, William B; Smith, Dean P; Montell, Craig

2010-09-28

Plants produce insect repellents, such as citronellal, which is the main component of citronellal oil. However, the molecular pathways through which insects sense botanical repellents are unknown. Here, we show that Drosophila use two pathways for direct avoidance of citronellal. The olfactory coreceptor OR83b contributes to citronellal repulsion and is essential for citronellal-evoked action potentials. Mutations affecting the Ca(2+)-permeable cation channel TRPA1 result in a comparable defect in avoiding citronellal vapor. The TRPA1-dependent aversion to citronellal relies on a G protein (Gq)/phospholipase C (PLC) signaling cascade rather than direct detection of citronellal by TRPA1. Loss of TRPA1, Gq, or PLC causes an increase in the frequency of citronellal-evoked action potentials in olfactory receptor neurons. Absence of the Ca(2+)-activated K(+) channel (BK channel) Slowpoke results in a similar impairment in citronellal avoidance and an increase in the frequency of action potentials. These results suggest that TRPA1 is required for activation of a BK channel to modulate citronellal-evoked action potentials and for aversion to citronellal. In contrast to Drosophila TRPA1, Anopheles gambiae TRPA1 is directly and potently activated by citronellal, thereby raising the possibility that mosquito TRPA1 may be a target for developing improved repellents to reduce insect-borne diseases such as malaria. Copyright © 2010 Elsevier Ltd. All rights reserved.

Avoidance behaviour of Eisenia fetida to carbofuran, chlorpyrifos, mancozeb and metamidophos in natural soils from the highlands of Colombia.

PubMed

García-Santos, Glenda; Keller-Forrer, Karin

2011-07-01

Earthworm avoidance behaviour test is an important screening tool in soil eco-toxicology. This test has been developed and validated under North American and European conditions. However, little research has been performed on the avoidance test in the tropics. This work demonstrates the potential suitability of the avoidance behaviour test as screening method in the highlands of Colombia using Eisenia fetida as the bio-indicator species on contaminated soils with carbofuran and chlorpyrifos. Though for the two active ingredients 100% avoidance was not reached, a curve with six meaningful concentrations is provided. No significant avoidance behaviour trend was found for mancozeb and methamidophos. Tests were conducted in the field yielded similar results to the tests carried out in the laboratory for chlorpyrifos and mancozeb. However, for the case of carbofuran and methamidophos, differences of more than double in avoidance were obtained. Divergence might be explained by soil and temperature conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Optimal consensus algorithm integrated with obstacle avoidance

NASA Astrophysics Data System (ADS)

Wang, Jianan; Xin, Ming

2013-01-01

This article proposes a new consensus algorithm for the networked single-integrator systems in an obstacle-laden environment. A novel optimal control approach is utilised to achieve not only multi-agent consensus but also obstacle avoidance capability with minimised control efforts. Three cost functional components are defined to fulfil the respective tasks. In particular, an innovative nonquadratic obstacle avoidance cost function is constructed from an inverse optimal control perspective. The other two components are designed to ensure consensus and constrain the control effort. The asymptotic stability and optimality are proven. In addition, the distributed and analytical optimal control law only requires local information based on the communication topology to guarantee the proposed behaviours, rather than all agents' information. The consensus and obstacle avoidance are validated through simulations.

Our Milky Way Gets a Makeover

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Click on image for Fully Annotated Version Click on image for Poster Version

Like early explorers mapping the continents of our globe, astronomers are busy charting the spiral structure of our galaxy, the Milky Way. Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms.

This artist's concept illustrates the new view of the Milky Way, along with other findings presented at the 212th American Astronomical Society meeting in St. Louis, Mo. The galaxy's two major arms (Scutum-Centaurus and Perseus) can be seen attached to the ends of a thick central bar, while the two now-demoted minor arms (Norma and Sagittarius) are less distinct and located between the major arms. The major arms consist of the highest densities of both young and old stars; the minor arms are primarily filled with gas and pockets of star-forming activity.

The artist's concept also includes a new spiral arm, called the 'Far-3 kiloparsec arm,' discovered via a radio-telescope survey of gas in the Milky Way. This arm is shorter than the two major arms and lies along the bar of the galaxy.

Our sun lies near a small, partial arm called the Orion Arm, or Orion Spur, located between the Sagittarius and Perseus arms.

Common Mistakes in Teaching Elementary Math--And How to Avoid Them

ERIC Educational Resources Information Center

Liu, Fuchang

2017-01-01

Learn the most effective ways to teach elementary math, no matter how much experience you have with the subject. In this book, Fuchang Liu takes you through many common mistakes in math instruction and explains the misunderstandings behind them. He points out practices that should be avoided, helping you to adjust your lessons so that all students…

Summary of avoidable cancers in the Nordic countries.

PubMed

Olsen, J H; Andersen, A; Dreyer, L; Pukkala, E; Tryggvadottir, L; Gerhardsson de Verdier, M; Winther, J F

1997-01-01

An overview is given of the most important known causes of cancer in the five Nordic countries and the resulting number of cancers that are potentially avoidable. The main causes include active and passive smoking, alcohol consumption, exposure to asbestos and other occupational carcinogens, solar and ionizing radiation, obesity, human papillomavirus infection in the female genital tract and infection with Helicobacter pylori. The organs most commonly affected are those of the respiratory system, the upper digestive tract and stomach, skin, the lower urinary tract and the uterine cervix. Annually, more than 18,000 cancers in men and 11,000 in women in the Nordic populations could be avoided by eliminating exposure to known carcinogens which is equivalent to 33% and 20% of all cancers arising in men and women, respectively, around the year 2000. Smoking habits account for a little more than half of these avoidable cases. Estimates of avoidable cancers are given for each Nordic country, separately.

Ensuring Interoperability between UAS Detect-and-Avoid and Manned Aircraft Collision Avoidance

NASA Technical Reports Server (NTRS)

Thipphavong, David; Cone, Andrew; Lee, Seung Man; Santiago, Confesor

2017-01-01

The UAS community in the United States has identified the need for a collision avoidance region in which UAS Detect-and-Avoid (DAA) vertical guidance is restricted to preclude interoperability issues with manned aircraft collision avoidance system vertical resolution advisories (RAs). This paper documents the process by which the collision avoidance region was defined. Three candidate definitions were evaluated on 1.3 million simulated pairwise encounters between UAS and manned aircraft covering a wide range of horizontal and vertical closure rates, angles, and miss distances. They were evaluated with regard to UAS DAA interoperability with manned aircraft collision avoidance systems in terms of: 1) the primary objective of restricting DAA vertical guidance before RAs when the aircraft are close, and 2) the secondary objective of avoiding unnecessary restrictions of DAA vertical guidance at a DAA alert when the aircraft are further apart. The collision avoidance region definition that fully achieves the primary objective and best achieves the secondary objective was recommended to and accepted by the UAS community in the United States. By this definition, UAS and manned aircraft are in the collision avoidance region--during which DAA vertical guidance is restricted--when the time to closest point of approach is less than 50 seconds and either the time to co-altitude is less than 50 seconds or the current vertical separation is less than 800 feet.

Two-way wireless-over-fibre and FSO-over-fibre communication systems with an optical carrier transmission

NASA Astrophysics Data System (ADS)

Huang, Xu-Hong; Lu, Hai-Han; Donati, Silvano; Li, Chung-Yi; Wang, Yun-Chieh; Jheng, Yu-Bo; Chang, Jen-Chieh

2018-07-01

Two-way wireless-over-fiber and free-space optical (FSO)-over-fiber communication systems, with an optical carrier transmission for a hybrid 10 Gbps baseband data stream, are proposed and practically demonstrated. 10 Gbps/50 GHz and 10 Gbps/100 GHz millimeter-wave data signal transmissions are also proposed and practically demonstrated. An optical carrier with a 10 Gbps baseband data stream is delivered via a 50 km single-mode fiber transportation to effectively lower dispersion-induced limitation due to fiber links and distortion produced by beating among multiple optical sidebands. To our understanding, this experiment is foremost in employing an optical carrier transmission approach to a two-way wireless-over-fiber and FSO-over-fiber communication system to suppress fiber dispersion and distortion effectively. Bit error rate performs well for downlink and uplink deliveries via a 50 km single-mode fiber transportation with a 100 m FSO link/5 m RF wireless delivery. The offered two-way wireless-over-fiber and FSO-over-fiber communication system with an optical carrier transmission is a promising option. It should be interesting for signifying the progress in the integration of long-haul fiber-based trunks and short-range RF/optical wireless link-based branches.

Development of a Portable Two-Way Communication and Information Device for Deafblind People.

PubMed

Ozioko, Oliver; Hersh, Marion

2015-01-01

This paper presents research on the development of a wearable two-way communication and information device for deafblind people who use tactile communications methods, namely the British deafblind manual alphabet and/or Braille. The device has two components: a glove worn by the deafblind person and a handheld display with keypad to be used by their hearing and sighted communication partner. Users can send messages using pressure sensors embedded in the glove and receive them by means of vibration on the palm. The two components are linked by Bluetooth and the use of Bluetooth to communicate with computers, mobile phones and other Bluetooth enabled devices is being investigated. The design was informed by feedback obtained from a survey of deafblind people and interviews with staff in two organisations for deafblind people. Research and development of the device is still ongoing.

Configurational Molecular Glue: One Optically Active Polymer Attracts Two Oppositely Configured Optically Active Polymers.

PubMed

Tsuji, Hideto; Noda, Soma; Kimura, Takayuki; Sobue, Tadashi; Arakawa, Yuki

2017-03-24

D-configured poly(D-lactic acid) (D-PLA) and poly(D-2-hydroxy-3-methylbutanoic acid) (D-P2H3MB) crystallized separately into their homo-crystallites when crystallized by precipitation or solvent evaporation, whereas incorporation of L-configured poly(L-2-hydroxybutanoic acid) (L-P2HB) in D-configured D-PLA and D-P2H3MB induced co-crystallization or ternary stereocomplex formation between D-configured D-PLA and D-P2H3MB and L-configured L-P2HB. However, incorporation of D-configured poly(D-2-hydroxybutanoic acid) (D-P2HB) in D-configured D-PLA and D-P2H3MB did not cause co-crystallization between D-configured D-PLA and D-P2H3MB and D-configured D-P2HB but separate crystallization of each polymer occurred. These findings strongly suggest that an optically active polymer (L-configured or D-configured polymer) like unsubstituted or substituted optically active poly(lactic acid)s can act as "a configurational or helical molecular glue" for two oppositely configured optically active polymers (two D-configured polymers or two L-configured polymers) to allow their co-crystallization. The increased degree of freedom in polymer combination is expected to assist to pave the way for designing polymeric composites having a wide variety of physical properties, biodegradation rate and behavior in the case of biodegradable polymers.

Configurational Molecular Glue: One Optically Active Polymer Attracts Two Oppositely Configured Optically Active Polymers

NASA Astrophysics Data System (ADS)

Tsuji, Hideto; Noda, Soma; Kimura, Takayuki; Sobue, Tadashi; Arakawa, Yuki

2017-03-01

D-configured poly(D-lactic acid) (D-PLA) and poly(D-2-hydroxy-3-methylbutanoic acid) (D-P2H3MB) crystallized separately into their homo-crystallites when crystallized by precipitation or solvent evaporation, whereas incorporation of L-configured poly(L-2-hydroxybutanoic acid) (L-P2HB) in D-configured D-PLA and D-P2H3MB induced co-crystallization or ternary stereocomplex formation between D-configured D-PLA and D-P2H3MB and L-configured L-P2HB. However, incorporation of D-configured poly(D-2-hydroxybutanoic acid) (D-P2HB) in D-configured D-PLA and D-P2H3MB did not cause co-crystallization between D-configured D-PLA and D-P2H3MB and D-configured D-P2HB but separate crystallization of each polymer occurred. These findings strongly suggest that an optically active polymer (L-configured or D-configured polymer) like unsubstituted or substituted optically active poly(lactic acid)s can act as “a configurational or helical molecular glue” for two oppositely configured optically active polymers (two D-configured polymers or two L-configured polymers) to allow their co-crystallization. The increased degree of freedom in polymer combination is expected to assist to pave the way for designing polymeric composites having a wide variety of physical properties, biodegradation rate and behavior in the case of biodegradable polymers.

Benefits of positive relationship experiences for avoidantly attached individuals.

PubMed

Stanton, Sarah C E; Campbell, Lorne; Pink, Jennifer C

2017-10-01

Attachment avoidance is characterized by discomfort with closeness and a reluctance to develop intimacy with romantic partners, which contribute to heightened general negativity and lower satisfaction and self-disclosure in and out of their relationships. Recent research, however, has begun to uncover circumstances in which romantic partners and positive relationships buffer more avoidantly attached individuals against deleterious individual and relationship outcomes. Across 3 studies, using a multimethod approach encompassing both experimental and dyadic longitudinal diary methods, we investigated the effects of positive, intimacy-related relationship experiences on more avoidant persons' positive and negative affect, relationship quality, self-disclosure, and attachment security immediately and over time. Results revealed that more avoidant individuals exhibit a reduction of general negative affect in particular (Studies 1-2) and report greater relationship quality (Studies 2-3) in response to positive relationship experiences, and, following intimacy-promoting activities with their partner, engage in greater self-disclosure over time and demonstrate decreased attachment avoidance 1 month later (Study 3). These findings identify novel circumstances in which more avoidant persons' negative expectations of relationships may be countered, and suggest that relatively simple techniques can have potentially important short- and long-term implications for more avoidant individuals and their relationships. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Future singularity avoidance in phantom dark energy models

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

Haro, Jaume de, E-mail: jaime.haro@upc.edu

2012-07-01

Different approaches to quantum cosmology are studied in order to deal with the future singularity avoidance problem. Our results show that these future singularities will persist but could take different forms. As an example we have studied the big rip which appear when one considers the state equation P = ωρ with ω < −1, showing that it does not disappear in modified gravity. On the other hand, it is well-known that quantum geometric effects (holonomy corrections) in loop quantum cosmology introduce a quadratic modification, namely proportional to ρ{sup 2}, in Friedmann's equation that replace the big rip by amore » non-singular bounce. However this modified Friedmann equation could have been obtained in an inconsistent way, what means that the obtained results from this equation, in particular singularity avoidance, would be incorrect. In fact, we will show that instead of a non-singular bounce, the big rip singularity would be replaced, in loop quantum cosmology, by other kind of singularity.« less

Improving Barotropic Tides by Two-way Nesting High and Low Resolution Domains

NASA Astrophysics Data System (ADS)

Jeon, C. H.; Buijsman, M. C.; Wallcraft, A. J.; Shriver, J. F.; Hogan, P. J.; Arbic, B. K.; Richman, J. G.

2017-12-01

In a realistically forced global ocean model, relatively large sea-surface-height root-mean-square (RMS) errors are observed in the North Atlantic near the Hudson Strait. These may be associated with large tidal resonances interacting with coastal bathymetry that are not correctly represented with a low resolution grid. This issue can be overcome by using high resolution grids, but at a high computational cost. In this paper we apply two-way nesting as an alternative solution. This approach applies high resolution to the area with large RMS errors and a lower resolution to the rest. It is expected to improve the tidal solution as well as reduce the computational cost. To minimize modification of the original source codes of the ocean circulation model (HYCOM), we apply the coupler OASIS3-MCT. This coupler is used to exchange barotropic pressures and velocity fields through its APIs (Application Programming Interface) between the parent and the child components. The developed two-way nesting framework has been validated with an idealized test case where the parent and the child domains have identical grid resolutions. The result of the idealized case shows very small RMS errors between the child and parent solutions. We plan to show results for a case with realistic tidal forcing in which the resolution of the child grid is three times that of the parent grid. The numerical results of this realistic case are compared to TPXO data.

Two-way QKD with single-photon-added coherent states

NASA Astrophysics Data System (ADS)

Miranda, Mario; Mundarain, Douglas

2017-12-01

In this work we present a two-way quantum key distribution (QKD) scheme that uses single-photon-added coherent states and displacement operations. The first party randomly sends coherent states (CS) or single-photon-added coherent states (SPACS) to the second party. The latter sends back the same state it received. Both parties decide which kind of states they are receiving by detecting or not a photon on the received signal after displacement operations. The first party must determine whether its sent and received states are equal; otherwise, the case must be discarded. We are going to show that an eavesdropper provided with a beam splitter gets the same information in any of the non-discarded cases. The key can be obtained by assigning 0 to CS and 1 to SPACS in the non-discarded cases. This protocol guarantees keys' security in the presence of a beam splitter attack even for states with a high number of photons in the sent signal. It also works in a lossy quantum channel, becoming a good bet for improving long-distance QKD.

Experimental Evidence of Threat-Sensitive Collective Avoidance Responses in a Large Wild-Caught Herring School

PubMed Central

Rieucau, Guillaume; Boswell, Kevin M.; De Robertis, Alex; Macaulay, Gavin J.; Handegard, Nils Olav

2014-01-01

Aggregation is commonly thought to improve animals' security. Within aquatic ecosystems, group-living prey can learn about immediate threats using cues perceived directly from predators, or from collective behaviours, for example, by reacting to the escape behaviours of companions. Combining cues from different modalities may improve the accuracy of prey antipredatory decisions. In this study, we explored the sensory modalities that mediate collective antipredatory responses of herring (Clupea harengus) when in a large school (approximately 60 000 individuals). By conducting a simulated predator encounter experiment in a semi-controlled environment (a sea cage), we tested the hypothesis that the collective responses of herring are threat-sensitive. We investigated whether cues from potential threats obtained visually or from the perception of water displacement, used independently or in an additive way, affected the strength of the collective avoidance reactions. We modified the sensory nature of the simulated threat by exposing the herring to 4 predator models differing in shape and transparency. The collective vertical avoidance response was observed and quantified using active acoustics. The combination of sensory cues elicited the strongest avoidance reactions, suggesting that collective antipredator responses in herring are mediated by the sensory modalities involved during threat detection in an additive fashion. Thus, this study provides evidence for magnitude-graded threat responses in a large school of wild-caught herring which is consistent with the “threat-sensitive hypothesis”. PMID:24489778

Tax Compliance Inventory: TAX-I Voluntary tax compliance, enforced tax compliance, tax avoidance, and tax evasion

PubMed Central

Kirchler, Erich; Wahl, Ingrid

2010-01-01

Surveys on tax compliance and non-compliance often rely on ad hoc formulated items which lack standardization and empirical validation. We present an inventory to assess tax compliance and distinguish between different forms of compliance and non-compliance: voluntary versus enforced compliance, tax avoidance, and tax evasion. First, items to measure voluntary and enforced compliance, avoidance, and evasion were drawn up (collected from past research and newly developed), and tested empirically with the aim of producing four validated scales with a clear factorial structure. Second, findings from the first analyses were replicated and extended to validation on the basis of motivational postures. A standardized inventory is provided which can be used in surveys in order to collect data which are comparable across research focusing on self-reports. The inventory can be used in either of two ways: either in its entirety, or by applying the single scales independently, allowing an economical and fast assessment of different facets of tax compliance. PMID:20502612

Tax Compliance Inventory: TAX-I Voluntary tax compliance, enforced tax compliance, tax avoidance, and tax evasion.

PubMed

Kirchler, Erich; Wahl, Ingrid

2010-06-01

Surveys on tax compliance and non-compliance often rely on ad hoc formulated items which lack standardization and empirical validation. We present an inventory to assess tax compliance and distinguish between different forms of compliance and non-compliance: voluntary versus enforced compliance, tax avoidance, and tax evasion. First, items to measure voluntary and enforced compliance, avoidance, and evasion were drawn up (collected from past research and newly developed), and tested empirically with the aim of producing four validated scales with a clear factorial structure. Second, findings from the first analyses were replicated and extended to validation on the basis of motivational postures. A standardized inventory is provided which can be used in surveys in order to collect data which are comparable across research focusing on self-reports. The inventory can be used in either of two ways: either in its entirety, or by applying the single scales independently, allowing an economical and fast assessment of different facets of tax compliance.

Exploring the association between body weight, stigma of obesity, and health care avoidance.

PubMed

Drury, Christine Aramburu Alegria; Louis, Margaret

2002-12-01

To explore the stigma of obesity and its effect on health care utilization, associations between self-esteem, attribution for weight, body mass index (BMI), satisfaction with medical care and the behavior of delaying/avoiding health care were examined. A convenience sample of 216 women recruited from church sites in Las Vegas completed self-administered questionnaires. The findings show an increase in BMI is associated with an increase in the delay/avoidance of health care. Weight-related reasons for delaying/avoiding health care included having "gained weight since last health care visit," not wanting to "get weighted on the provider's scale," and knowing they would be told to "lose weight." The obese are a stigmatized and vulnerable population. Nurse practitioners are challenged to be aware of attitudes towards obesity and to identify ways to promote continuity of care and regular health maintenance. The goals of Healthy People 2010 to reduce obesity-related morbidity cannot be met if health care is delayed/avoided.

Not so bad: avoidance and aversive discounting modulate threat appraisal in anterior cingulate and medial prefrontal cortex

PubMed Central

Schlund, Michael W.; Brewer, Adam T.; Richman, David M.; Magee, Sandy K.; Dymond, Simon

2015-01-01

The dorsal anterior cingulate (adACC) and dorsal medial prefrontal cortex (dmPFC) play a central role in the discrimination and appraisal of threatening stimuli. Yet, little is known about what specific features of threatening situations recruit these regions and how avoidance may modulate appraisal and activation through prevention of aversive events. In this investigation, 30 healthy adults underwent functional neuroimaging while completing an avoidance task in which responses to an Avoidable CS+ threat prevented delivery of an aversive stimulus, but not to an Unavoidable CS+ threat. Extinction testing was also completed where CSs were presented without aversive stimulus delivery and an opportunity to avoid. The Avoidable CS+ relative to the Unavoidable CS+ was associated with reductions in ratings of negative valence, fear, and US expectancy and activation. Greater regional activation was consistently observed to the Unavoidable CS+ during avoidance, which declined during extinction. Individuals exhibiting greater aversive discounting—that is, those more avoidant of immediate monetary loss compared to a larger delayed loss—also displayed greater activation to the Unavoidable CS+, highlighting aversive discounting as a significant individual difference variable. These are the first results linking adACC/dmPFC reactivity to avoidance-based reductions of aversive events and modulation of activation by individual differences in aversive discounting. PMID:26113813

Modeling and deadlock avoidance of automated manufacturing systems with multiple automated guided vehicles.

PubMed

Wu, Naiqi; Zhou, MengChu

2005-12-01

An automated manufacturing system (AMS) contains a number of versatile machines (or workstations), buffers, an automated material handling system (MHS), and is computer-controlled. An effective and flexible alternative for implementing MHS is to use automated guided vehicle (AGV) system. The deadlock issue in AMS is very important in its operation and has extensively been studied. The deadlock problems were separately treated for parts in production and transportation and many techniques were developed for each problem. However, such treatment does not take the advantage of the flexibility offered by multiple AGVs. In general, it is intractable to obtain maximally permissive control policy for either problem. Instead, this paper investigates these two problems in an integrated way. First we model an AGV system and part processing processes by resource-oriented Petri nets, respectively. Then the two models are integrated by using macro transitions. Based on the combined model, a novel control policy for deadlock avoidance is proposed. It is shown to be maximally permissive with computational complexity of O (n2) where n is the number of machines in AMS if the complexity for controlling the part transportation by AGVs is not considered. Thus, the complexity of deadlock avoidance for the whole system is bounded by the complexity in controlling the AGV system. An illustrative example shows its application and power.

Universal cements: dual activated and chemically activated

PubMed Central

de Lima, Eliane; Santos, Ricardo; Durão, Márcia; Nascimento, Armiliana; Braz, Rodivan

2016-01-01

Abstract Objective: The aim of the present study was to assess the bond strength of universal cements cured either dually or chemically only. Methods: Three cements were assessed using different types of application: dual activated (DA) or chemically activated (CA). In total 80 dentin blocks were used, obtained through the enamel wear of the lingual and buccal surfaces of bovine incisors. Standard cone-shaped cavity preparations were created using diamond burs. Subsequently, indirect restoration blocks were designed with Filtek Z350 (3M ESPE) composite resin. The teeth were divided into two groups (DA and CA) and then subdivided into four subgroups (n = 10) prior to cementation with the respective products: Duo-Link (Bisco); RelyX Ultimate (3M ESPE); Nexus 3 (Kerr) and conventional RelyX ARC (3M ESPE) as the control. The cementation in the PA group was applied following the manufacturer’s instructions. The CA group was cemented in a darkroom to avoid exposure to light. They were stored in distilled water at 37 °C for 24 h and submitted to the push-out test. Data were analyzed by two-way ANOVA and Tukey’s post-hoc test (p < .05). Results: The greatest bond strength results were obtained for photoactivated universal cements. Conclusion: Chemical activation is not sufficient to ensure acceptable bond strength. PMID:28642922

Achievable degrees of freedom of MIMO two-way relay interference channel with delayed CSIT

NASA Astrophysics Data System (ADS)

Li, Qingyun; Wu, Gang; Li, Shaoqian

2016-10-01

In this paper, assuming each node has delayed channel state information at the transmitter (CSIT), we investigate the achievable degrees of freedom (DOF) of MIMO two-way relay interference channel in frequency division duplex (FDD) systems, where there are K user pairs (i.e., 2K users) and each user in a user pair exchanges messages with the other user in the same user pair simultaneously via an intermediate relay. We propose a two-stage transmission scheme and derive the closed-form expressions for its achievable DOF.

Higher threat avoidance costs reduce avoidance behaviour which in turn promotes fear extinction in humans.

PubMed

Rattel, Julina A; Miedl, Stephan F; Blechert, Jens; Wilhelm, Frank H

2017-09-01

Theoretical models specifying the underlying mechanisms of the development and maintenance of anxiety and related disorders state that fear responses acquired through classical Pavlovian conditioning are maintained by repeated avoidance behaviour; thus, it is assumed that avoidance prevents fear extinction. The present study investigated behavioural avoidance decisions as a function of avoidance costs in a naturalistic fear conditioning paradigm. Ecologically valid avoidance costs - manipulated between participant groups - were represented via time-delays during a detour in a gamified computer task. After differential acquisitions of shock-expectancy to a predictive conditioned stimulus (CS+), participants underwent extinction where they could either take a risky shortcut, while anticipating shock signaled by the CS+, or choose a costly avoidance option (lengthy detour); thus, they were faced with an approach-avoidance conflict. Groups with higher avoidance costs (longer detours) showed lower proportions of avoiders. Avoiders gave heightened shock-expectancy ratings post-extinction, demonstrating 'protecting from extinction', i.e. failure to extinguish. Moreover, there was an indirect effect of avoidance costs on protection from extinction through avoidance behaviour. No moderating role of trait-anxiety was found. Theoretical implications of avoidance behaviour are discussed, considering the involvement of instrumental learning in the maintenance of fear responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Use of Two-Way Interactive Television in Education. Training and Development Research Center. Project Number Eighteen.

ERIC Educational Resources Information Center

McClelland, Jerry

Four case studies in varying stages of completion are currently being conducted in the Department of Vocational and Technical Education at the University of Minnesota using live, two-way television to link multiple sites for interactive television classes. Two of the four classes, which are offered via closed-circuit television, are a vocational…

Intra-Amygdala ZIP Injections Impair the Memory of Learned Active Avoidance Responses and Attenuate Conditioned Taste-Aversion Acquisition in Rats

ERIC Educational Resources Information Center

Gamiz, Fernando; Gallo, Milagros

2011-01-01

We have investigated the effect of protein kinase Mzeta (PKM[zeta]) inhibition in the basolateral amygdala (BLA) upon the retention of a nonspatial learned active avoidance response and conditioned taste-aversion (CTA) acquisition in rats. ZIP (10 nmol/[mu]L) injected into the BLA 24 h after training impaired retention of a learned…

Group vs. single mindfulness meditation: exploring avoidance, impulsivity, and weight management in two separate mindfulness meditation settings.

PubMed

Mantzios, Michail; Giannou, Kyriaki

2014-07-01

Recent research has identified that mindfulness meditation in group settings supports people who are trying to lose weight. The present research investigated mindfulness meditation in group and individual settings, and explored the potential impact on weight loss and other factors (i.e. mindfulness, impulsivity, and avoidance) that may assist or hinder weight loss. Specifically, the hypotheses tested were that the group setting assisted dieters more than the individual setting by reducing weight, cognitive-behavioral avoidance, and impulsivity and by increasing mindfulness. Participants (n = 170) who were trying to lose weight were randomly assigned to practice meditation for 6 weeks within a group or independently. Measurements in mindfulness, cognitive-behavioral avoidance, impulsivity, and weight occurred twice (pre- and post-intervention). Results indicated that participants in the group setting lost weight and lowered their levels of cognitive-behavioral avoidance, while impulsivity and mindfulness remained stable. On the other hand, participants in the individual condition lost less weight, while there was an increase in cognitive-behavioral avoidance and mindfulness scores, but a decrease in impulsivity. Seeing that benefits and limitations observed in group settings are not replicated when people meditate alone, this study concluded that mindfulness meditation in individual settings needs to be used with caution, although there are some potential benefits that could aid future weight loss research. © 2014 The International Association of Applied Psychology.

Active Ways to Teach Health Concepts in the Elementary Setting

ERIC Educational Resources Information Center

Gregory, Julie

2015-01-01

This article provides three movement-based activities for teaching health concepts to elementary school students. Two activities focus on nutrition concepts and the other focuses on teaching body systems. Diagrams are provided to show the setup of activities, as well as links for accessing materials to help implement the activities.

“Assessment of the two-way Coupled WRF-CMAQ Model with Observations from the CARES”

EPA Science Inventory

The main goal of this assessment is to evaluate the improved aerosol component of two-way coupled WRF-CMAQ model particularly in representing aerosol physical and optical properties by utilizing observations from the Carbonaceous Aerosol and Radiative Effects Study (CARES) in May...

A Transient Dopamine Signal Represents Avoidance Value and Causally Influences the Demand to Avoid

PubMed Central

Pultorak, Katherine J.; Schelp, Scott A.; Isaacs, Dominic P.; Krzystyniak, Gregory

2018-01-01

Abstract While an extensive literature supports the notion that mesocorticolimbic dopamine plays a role in negative reinforcement, recent evidence suggests that dopamine exclusively encodes the value of positive reinforcement. In the present study, we employed a behavioral economics approach to investigate whether dopamine plays a role in the valuation of negative reinforcement. Using rats as subjects, we first applied fast-scan cyclic voltammetry (FSCV) to determine that dopamine concentration decreases with the number of lever presses required to avoid electrical footshock (i.e., the economic price of avoidance). Analysis of the rate of decay of avoidance demand curves, which depict an inverse relationship between avoidance and increasing price, allows for inference of the worth an animal places on avoidance outcomes. Rapidly decaying demand curves indicate increased price sensitivity, or low worth placed on avoidance outcomes, while slow rates of decay indicate reduced price sensitivity, or greater worth placed on avoidance outcomes. We therefore used optogenetics to assess how inducing dopamine release causally modifies the demand to avoid electrical footshock in an economic setting. Increasing release at an avoidance predictive cue made animals more sensitive to price, consistent with a negative reward prediction error (i.e., the animal perceives they received a worse outcome than expected). Increasing release at avoidance made animals less sensitive to price, consistent with a positive reward prediction error (i.e., the animal perceives they received a better outcome than expected). These data demonstrate that transient dopamine release events represent the value of avoidance outcomes and can predictably modify the demand to avoid. PMID:29766047

Clozapine and Olanzapine Exhibit an Intrinsic Anxiolytic Property in Two Conditioned Fear Paradigms: Contrast with Haloperidol and Chlordiazepoxide

PubMed Central

Mead, Alexa; Li, Ming; Kapur, Shitij

2008-01-01

Psychotic fear and anxiety disturbances are seen at a relatively high frequency in patients with schizophrenia. Atypical antipsychotics are believed to show superior efficacy in reducing these symptoms. However, clinical and preclinical evidence regarding their anxiolytic efficacy has been mixed. In this study, we evaluated the possible anxiolytic property of two atypicals clozapine and olanzapine and compared them with typical haloperidol and chlordiazepoxide (a prototype of sedative-anxiolytic drug) in two preclinical models of fear. In Experiment 1, we used a fear-induced passive avoidance and conditioned place aversion paradigm and examined the effects of clozapine (20 mg/kg, sc), haloperidol (0.05 mg/kg, sc) and chlordiazepoxide (10 mg/kg, ip). In Experiments 2 and 3, we used a two-way active avoidance conditioning paradigm and further compared the effects of clozapine (20 mg/kg, sc), haloperidol (0.05 mg/kg, sc), chlordiazepoxide (10 mg/kg, ip) and three doses of olanzapine (0.5, 1.0, and 2.0 mg/kg, sc). Results show that clozapine and chlordiazepoxide, but not haloperidol, significantly attenuated the shock conditioning-induced place aversion, decreased the amount of defecations and the number of the 22 kHz vocalizations. Clozapine also reduced the shock conditioning-induced hyperthermia. Similar to clozapine, olanzapine also significantly decreased the amount of defecations and reduced the shock conditioning-induced hyperthermia, but it did not inhibit the 22 kHz vocalizations. This study demonstrates that clozapine and olanzapine possess an intrinsic anxiolytic property, which is not attributable to its superior anti-“psychotic” effect or its favorable effects on motor functions or learning and memory processes. These findings also suggest that the combined use of passive avoidance and active avoidance conditioning models can be useful in better differentiating typical and atypical antipsychotics as well as anxiolytics. PMID:18547622

Bimodal behavior of post-measured entropy and one-way quantum deficit for two-qubit X states

NASA Astrophysics Data System (ADS)

Yurischev, Mikhail A.

2018-01-01

A method for calculating the one-way quantum deficit is developed. It involves a careful study of post-measured entropy shapes. We discovered that in some regions of X-state space the post-measured entropy \\tilde{S} as a function of measurement angle θ \\in [0,π /2] exhibits a bimodal behavior inside the open interval (0,π /2), i.e., it has two interior extrema: one minimum and one maximum. Furthermore, cases are found when the interior minimum of such a bimodal function \\tilde{S}(θ ) is less than that one at the endpoint θ =0 or π /2. This leads to the formation of a boundary between the phases of one-way quantum deficit via finite jumps of optimal measured angle from the endpoint to the interior minimum. Phase diagram is built up for a two-parameter family of X states. The subregions with variable optimal measured angle are around 1% of the total region, with their relative linear sizes achieving 17.5%, and the fidelity between the states of those subregions can be reduced to F=0.968. In addition, a correction to the one-way deficit due to the interior minimum can achieve 2.3%. Such conditions are favorable to detect the subregions with variable optimal measured angle of one-way quantum deficit in an experiment.

Simultaneous Two-Way Clustering of Multiple Correspondence Analysis

ERIC Educational Resources Information Center

Hwang, Heungsun; Dillon, William R.

2010-01-01

A 2-way clustering approach to multiple correspondence analysis is proposed to account for cluster-level heterogeneity of both respondents and variable categories in multivariate categorical data. Specifically, in the proposed method, multiple correspondence analysis is combined with k-means in a unified framework in which "k"-means is…

The Feasibility of Avoiding Future Climate Impacts: Results from the AVOID Programmes

NASA Astrophysics Data System (ADS)

Lowe, J. A.; Warren, R.; Arnell, N.; Buckle, S.

2014-12-01

The AVOID programme and its successor, AVOID2, have focused on answering three core questions: how do we characterise potentially dangerous climate change and impacts, which emissions pathways can avoid at least some of these impacts, and how feasible are the future reductions needed to significantly deviate from a business-as-usual future emissions pathway. The first AVOID project succeeded in providing the UK Government with evidence to inform its position on climate change. A key part of the work involved developing a range of global emissions pathways and estimating and understanding the corresponding global impacts. This made use of a combination of complex general circulation models, simple climate models, pattern-scaling and state-of-the art impacts models. The results characterise the range of avoidable impacts across the globe in several key sectors including river and coastal flooding, cooling and heating energy demand, crop productivity and aspects of biodiversity. The avoided impacts between a scenario compatible with a 4ºC global warming and one with a 2ºC global warming were found to be highly sector dependent and avoided fractions typically ranged between 20% and 70%. A further key aspect was characterising the magnitude of the uncertainty involved, which is found to be very large in some impact sectors although the avoided fraction appears a more robust metric. The AVOID2 programme began in 2014 and will provide results in the run up to the Paris CoP in 2015. This includes new post-IPCC 5th assessment evidence to inform the long-term climate goal, a more comprehensive assessment of the uncertainty ranges of feasible emission pathways compatible with the long-term goal and enhanced estimates of global impacts using the latest generation of impact models and scenarios.

The two-way relationship between ionospheric outflow and the ring current

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

Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex

It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring current dynamics. However, because the ring current deposits energy into the ionosphere, the inverse may also be true: the ring current can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring current-driven region 2 field-aligned currents (FACs). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptivemore » Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring current model (ring current atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 FACs in BATS-R-US. It is found that the region 2 FACs increase heavy ion outflow by up to 6 times over the non-coupled results. The additional outflow further energizes the ring current, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring current system.« less

The two-way relationship between ionospheric outflow and the ring current

DOE PAGES

Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex; ...

2015-06-01

It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring current dynamics. However, because the ring current deposits energy into the ionosphere, the inverse may also be true: the ring current can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring current-driven region 2 field-aligned currents (FACs). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptivemore » Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring current model (ring current atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 FACs in BATS-R-US. It is found that the region 2 FACs increase heavy ion outflow by up to 6 times over the non-coupled results. The additional outflow further energizes the ring current, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring current system.« less

Interactive Two-Way mHealth Interventions for Improving Medication Adherence: An Evaluation Using The Behaviour Change Wheel Framework

PubMed Central

Amico, K Rivet; Atkins, Lou; Lester, Richard T

2018-01-01

potential mechanisms of action. Results Our evaluation of WelTel using the Behavior Change Wheel suggests that most of its impact is delivered primarily through its personalized communication component, in which 8 different behavior change techniques were identified and linked with 5 intervention functions (environmental restructuring, enablement, education, persuasion, and training). Its mechanisms of action in promoting antiretroviral therapy adherence may involve addressing all Capability Opportunity Motivation-Behavior influences on behavior (physical and psychological capability, physical and social opportunity, reflective and automatic motivation). Conclusions Systematically unpacking the potential active ingredients of effective interventions facilitates the creation and implementation of more parsimonious, tailored, and targeted approaches. Evaluating WelTel using the Behavior Change Wheel has provided valuable insights into how and why such interactive two-way mHealth interventions may produce greater impact than one-way in addressing both nonintentional and intentional forms of nonadherence. The application of the Behavior Change Wheel for evidence synthesis across mHealth interventions targeting various conditions would contribute to strengthening the knowledge base regarding how they may work to impact medication adherence behavior. PMID:29650504

Extinction maps toward the Milky Way bulge: Two-dimensional and three-dimensional tests with apogee

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

Schultheis, M.; Zasowski, G.; Allende Prieto, C.

Galactic interstellar extinction maps are powerful and necessary tools for Milky Way structure and stellar population analyses, particularly toward the heavily reddened bulge and in the midplane. However, due to the difficulty of obtaining reliable extinction measures and distances for a large number of stars that are independent of these maps, tests of their accuracy and systematics have been limited. Our goal is to assess a variety of photometric stellar extinction estimates, including both two-dimensional and three-dimensional extinction maps, using independent extinction measures based on a large spectroscopic sample of stars toward the Milky Way bulge. We employ stellar atmosphericmore » parameters derived from high-resolution H-band Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectra, combined with theoretical stellar isochrones, to calculate line-of-sight extinction and distances for a sample of more than 2400 giants toward the Milky Way bulge. We compare these extinction values to those predicted by individual near-IR and near+mid-IR stellar colors, two-dimensional bulge extinction maps, and three-dimensional extinction maps. The long baseline, near+mid-IR stellar colors are, on average, the most accurate predictors of the APOGEE extinction estimates, and the two-dimensional and three-dimensional extinction maps derived from different stellar populations along different sightlines show varying degrees of reliability. We present the results of all of the comparisons and discuss reasons for the observed discrepancies. We also demonstrate how the particular stellar atmospheric models adopted can have a strong impact on this type of analysis, and discuss related caveats.« less

Grouping facilitates avoidance of parasites by fish

PubMed Central

2013-01-01

Background Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Methods Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish could make a choice between areas with different risk of being infected. Intensity of infection was assessed and compared with the number of fish recorded in the compartment with parasites and level of fish motility. Results Both solitary fish and fish in groups avoided parasitized areas, but fish in groups avoided it more strongly and thus acquired significantly fewer parasites than solitary fish. Prevalence of infection among grouped and solitary fish was 66 and 92 %, respectively, with the mean abundance two times higher in the solitary fish. Between-individual variation in the number of parasites per fish was higher in the “groups” treatment (across all individuals) than in the “solitary” treatment. Avoidance behaviour was more efficient when fish were allowed to explore the experimental arena prior to parasite exposure. High motility of fish was shown to increase the acquisition of D. pseudospathaceum. Conclusion Fish in groups better avoided parasitized habitat, and acquired significantly fewer parasites than solitary fish. We suggest that fish in groups benefit from information about parasites gained from other members of a group. Grouping behaviour may be an efficient mechanism of parasite avoidance, together with individual behaviour and immune responses of fishes

Grouping facilitates avoidance of parasites by fish.

PubMed

Mikheev, Victor N; Pasternak, Anna F; Taskinen, Jouni; Valtonen, Tellervo E

2013-10-17

Parasite distribution is often highly heterogeneous, and intensity of infection depends, among other things, on how well hosts can avoid areas with a high concentration of parasites. We studied the role of fish behaviour in avoiding microhabitats with a high infection risk using Oncorhynchus mykiss and cercariae of Diplostomum pseudospathaceum as a model. Spatial distribution of parasites in experimental tanks was highly heterogeneous. We hypothesized that fish in groups are better at recognizing a parasitized area and avoiding it than solitary fish. Number of fish, either solitary or in groups of 5, was recorded in different compartments of a shuttle tank where fish could make a choice between areas with different risk of being infected. Intensity of infection was assessed and compared with the number of fish recorded in the compartment with parasites and level of fish motility. Both solitary fish and fish in groups avoided parasitized areas, but fish in groups avoided it more strongly and thus acquired significantly fewer parasites than solitary fish. Prevalence of infection among grouped and solitary fish was 66 and 92 %, respectively, with the mean abundance two times higher in the solitary fish. Between-individual variation in the number of parasites per fish was higher in the "groups" treatment (across all individuals) than in the "solitary" treatment. Avoidance behaviour was more efficient when fish were allowed to explore the experimental arena prior to parasite exposure. High motility of fish was shown to increase the acquisition of D. pseudospathaceum. Fish in groups better avoided parasitized habitat, and acquired significantly fewer parasites than solitary fish. We suggest that fish in groups benefit from information about parasites gained from other members of a group. Grouping behaviour may be an efficient mechanism of parasite avoidance, together with individual behaviour and immune responses of fishes. Avoidance of habitats with a high parasite risk

Examining the Role of the Human Hippocampus in Approach-Avoidance Decision Making Using a Novel Conflict Paradigm and Multivariate Functional Magnetic Resonance Imaging.

PubMed

O'Neil, Edward B; Newsome, Rachel N; Li, Iris H N; Thavabalasingam, Sathesan; Ito, Rutsuko; Lee, Andy C H

2015-11-11

Rodent models of anxiety have implicated the ventral hippocampus in approach-avoidance conflict processing. Few studies have, however, examined whether the human hippocampus plays a similar role. We developed a novel decision-making paradigm to examine neural activity when participants made approach/avoidance decisions under conditions of high or absent approach-avoidance conflict. Critically, our task required participants to learn the associated reward/punishment values of previously neutral stimuli and controlled for mnemonic and spatial processing demands, both important issues given approach-avoidance behavior in humans is less tied to predation and foraging compared to rodents. Participants played a points-based game where they first attempted to maximize their score by determining which of a series of previously neutral image pairs should be approached or avoided. During functional magnetic resonance imaging, participants were then presented with novel pairings of these images. These pairings consisted of images of congruent or opposing learned valences, the latter creating conditions of high approach-avoidance conflict. A data-driven partial least squares multivariate analysis revealed two reliable patterns of activity, each revealing differential activity in the anterior hippocampus, the homolog of the rodent ventral hippocampus. The first was associated with greater hippocampal involvement during trials with high as opposed to no approach-avoidance conflict, regardless of approach or avoidance behavior. The second pattern encompassed greater hippocampal activity in a more anterior aspect during approach compared to avoid responses, for conflict and no-conflict conditions. Multivoxel pattern classification analyses yielded converging findings, underlining a role of the anterior hippocampus in approach-avoidance conflict decision making. Approach-avoidance conflict has been linked to anxiety and occurs when a stimulus or situation is associated with reward

Head-on crashes on two-way interurban roads: a public health concern in road safety.

PubMed

Olabarria, Marta; Santamariña-Rubio, Elena; Marí-Dell'Olmo, Marc; Gotsens, Mercè; Novoa, Ana M; Borrell, Carme; Pérez, Katherine

2015-09-01

To describe the magnitude and characteristics of crashes and drivers involved in head-on crashes on two-way interurban roads in Spain between 2007 and 2012, and to identify the factors associated with the likelihood of head-on crashes on these roads compared with other types of crash. A cross-sectional study was conducted using the National Crash Register. The dependent variables were head-on crashes with injury (yes/no) and drivers involved in head-on crashes (yes/no). Factors associated with head-on crashes and with being a driver involved in a head-on crash versus other types of crash were studied using a multivariate robust Poisson regression model to estimate proportion ratios (PR) and confidence intervals (95% CI). There were 9,192 head-on crashes on two-way Spanish interurban roads. A total of 15,412 men and 3,862 women drivers were involved. Compared with other types of crash, head-on collisions were more likely on roads 7 m or more wide, on road sections with curves, narrowings or drop changes, on wet or snowy surfaces, and in twilight conditions. Transgressions committed by drivers involved in head-on crashes were driving in the opposite direction and incorrectly overtaking another vehicle. Factors associated with a lower probability of head-on crashes were the existence of medians (PR=0.57; 95%CI: 0.48-0.68) and a paved shoulder of less than 1.5 meters (PR=0.81; 95%CI: 0.77-0.86) or from 1.5 to 2.45 meters (PR=0.90; 95%CI: 0.84-0.96). This study allowed the characterization of crashes and drivers involved in head-on crashes on two-way interurban roads. The lower probability observed on roads with median strips point to these measures as an effective way to reduce these collisions. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Obstacle-avoiding navigation system

DOEpatents

Borenstein, Johann; Koren, Yoram; Levine, Simon P.

1991-01-01

A system for guiding an autonomous or semi-autonomous vehicle through a field of operation having obstacles thereon to be avoided employs a memory for containing data which defines an array of grid cells which correspond to respective subfields in the field of operation of the vehicle. Each grid cell in the memory contains a value which is indicative of the likelihood, or probability, that an obstacle is present in the respectively associated subfield. The values in the grid cells are incremented individually in response to each scan of the subfields, and precomputation and use of a look-up table avoids complex trigonometric functions. A further array of grid cells is fixed with respect to the vehicle form a conceptual active window which overlies the incremented grid cells. Thus, when the cells in the active window overly grid cell having values which are indicative of the presence of obstacles, the value therein is used as a multiplier of the precomputed vectorial values. The resulting plurality of vectorial values are summed vectorially in one embodiment of the invention to produce a virtual composite repulsive vector which is then summed vectorially with a target-directed vector for producing a resultant vector for guiding the vehicle. In an alternative embodiment, a plurality of vectors surrounding the vehicle are computed, each having a value corresponding to obstacle density. In such an embodiment, target location information is used to select between alternative directions of travel having low associated obstacle densities.

Functional neuroimaging of avoidance habits in obsessive-compulsive disorder.

PubMed

Gillan, Claire M; Apergis-Schoute, Annemieke M; Morein-Zamir, Sharon; Urcelay, Gonzalo P; Sule, Akeem; Fineberg, Naomi A; Sahakian, Barbara J; Robbins, Trevor W

2015-03-01

The purpose of this study was to determine the neural correlates of excessive habit formation in obsessive-compulsive disorder (OCD). The authors aimed to test for neurobiological convergence with the known pathophysiology of OCD and to infer, based on abnormalities in brain activation, whether these habits arise from dysfunction in the goal-directed or habit system. Thirty-seven OCD patients and 33 healthy comparison subjects learned to avoid shocks while undergoing a functional MRI scan. Following four blocks of training, the authors tested whether the avoidance response had become a habit by removing the threat of shock and measuring continued avoidance. Task-related differences in brain activity in three regions of interest (the caudate, the putamen, and the medial orbitofrontal cortex) were tested at a statistical threshold set at <0.05 (family-wise-error corrected). Excessive habit formation in OCD patients, which was associated with hyperactivation in the caudate, was observed. Activation in this region was also associated with subjective ratings of increased urge to perform habits. The OCD group, as a whole, showed hyperactivation in the medial orbitofrontal cortex during the acquisition of avoidance; however, this did not relate directly to habit formation. OCD patients exhibited excessive habits that were associated with hyperactivation in a key region implicated in the pathophysiology of OCD, the caudate nucleus. Previous studies indicate that this region is important for goal-directed behavior, suggesting that habit-forming biases in OCD may be a result of impairments in this system, rather than differences in the buildup of stimulus-response habits themselves.

"Watch out!": Effects of instructed threat and avoidance on human free-operant approach-avoidance behavior.

PubMed

Schlund, Michael W; Treacher, Kay; Preston, Oli; Magee, Sandy K; Richman, David M; Brewer, Adam T; Cameron, Gemma; Dymond, Simon

2017-01-01

Approach-avoidance paradigms create a competition between appetitive and aversive contingencies and are widely used in nonhuman research on anxiety. Here, we examined how instructions about threat and avoidance impact control by competing contingencies over human approach-avoidance behavior. Additionally, Experiment 1 examined the effects of threat magnitude (money loss amount) and avoidance cost (fixed ratio requirements), whereas Experiment 2 examined the effects of threat information (available, unavailable and inaccurate) on approach-avoidance. During the task, approach responding was modeled by reinforcing responding with money on a FR schedule. By performing an observing response, participants produced an escalating "threat meter". Instructions stated that the threat meter levels displayed the current probability of losing money, when in fact loss only occurred when the level reached the maximum. Instructions also stated pressing an avoidance button lowered the threat level. Overall, instructions produced cycles of approach and avoidance responding with transitions from approach to avoidance when threat was high and transitions back to approach after avoidance reduced threat. Experiment 1 revealed increasing avoidance cost, but not threat magnitude, shifted approach-avoidance transitions to higher threat levels and increased anxiety ratings, but did not influence the frequency of approach-avoidance cycles. Experiment 2 revealed when threat level information was available or absent earnings were high, but earnings decreased when inaccurate threat information was incompatible with contingencies. Our findings build on prior nonhuman and human approach-avoidance research by highlighting how instructed threat and avoidance can impact human AA behavior and self-reported anxiety. © 2017 Society for the Experimental Analysis of Behavior.

The time course of location-avoidance learning in fear of spiders.

PubMed

Rinck, Mike; Koene, Marieke; Telli, Sibel; Moerman-van den Brink, Wiltine; Verhoeven, Barbara; Becker, Eni S

2016-01-01

Two experiments were designed to study the time course of avoidance learning in spider fearfuls (SFs) under controlled experimental conditions. To achieve this, we employed an immersive virtual environment (IVE): While walking freely through a virtual art museum to search for specific paintings, the participants were exposed to virtual spiders. Unbeknown to the participants, only two of four museum rooms contained spiders, allowing for avoidance learning. Indeed, the more SF the participants were, the faster they learned to avoid the rooms that contained spiders (Experiment. 1), and within the first six trials, high fearfuls already developed a preference for starting their search task in rooms without spiders (Experiment 2). These results illustrate the time course of avoidance learning in SFs, and they speak to the usefulness of IVEs in fundamental anxiety research.

Cueing properties of the decrease of white noise intensity for avoidance conditioning in cats.

PubMed

Zieliński, K

1979-01-01

In the main experiment two groups of 6 cats each were trained in active bar-pressing avoidance to a CS consisting of either a 10 dB or 20 dB decrease of the background white noise of 70 dB intensity. The two groups did not differ in rapidity of learning, however cats trained to the greater change .in background noise performed avoidance responses with shorter latencies than did cats trained to smaller change. Within-groups comparisons of cumulative distributions of response latencies for consecutive Vincentized fifths of avoidance acquisition showed the greatest changes in the region of latencies longer than the median latency of instrumental responses. On the other hand, the effects of CS intensity found in between-groups comparisons were located in the region of latencies shorter than the median latency of either group. Comparisons with data obtained in a complementary experiment employing additional 17 cats showed that subjects trained to stimuli less intense than the background noise level were marked by an exceptionally low level of avoidance responding with latencies shorter than 1.1 s, which was lower than expected from the probability of intertrial responses for this period of time. Due to this property of stimuli less intense than the background, the distributions of response latencies were moved to the right, in effect, prefrontal lesions influenced a greater part of latency distributions than in cats trained to stimuli more intense than the background.

Eight Ways to Take More Effective Control of Your Life

ERIC Educational Resources Information Center

Parish, Thomas S.; Mahoney, Shay

2007-01-01

This paper, entitled, "Eight Ways to Take More Effective Control of Your Life," provides some sound ideas regarding how to become more effective and efficient in your actions and your attitudes, by developing certain "choice" behaviors that should help you to avoid much stress and achieve greater success.

Avoiding the Flu

MedlinePlus

... of this page please turn Javascript on. Feature: Flu Avoiding the Flu Past Issues / Fall 2009 Table of Contents Children ... help avoid getting and passing on the flu. Influenza (Seasonal) The flu is a contagious respiratory illness ...

Innovation for the Common Man: Avoiding the Pitfalls of Implementing New Technologies.

ERIC Educational Resources Information Center

Troxel, Steve

Citing the failure of film, radio, and television to revolutionize the American education system, this paper identifies reasons for those failures and suggests ways to avoid similar failure in the diffusion of computer use in education and the diffusion of "datafication" into the homes of rural America. Four steps are identified to facilitate the…

GLP-1 acts on habenular avoidance circuits to control nicotine intake.

PubMed

Tuesta, Luis M; Chen, Zuxin; Duncan, Alexander; Fowler, Christie D; Ishikawa, Masago; Lee, Brian R; Liu, Xin-An; Lu, Qun; Cameron, Michael; Hayes, Matthew R; Kamenecka, Theodore M; Pletcher, Matthew; Kenny, Paul J

2017-05-01

Tobacco smokers titrate their nicotine intake to avoid its noxious effects, sensitivity to which may influence vulnerability to tobacco dependence, yet mechanisms of nicotine avoidance are poorly understood. Here we show that nicotine activates glucagon-like peptide-1 (GLP-1) neurons in the nucleus tractus solitarius (NTS). The antidiabetic drugs sitagliptin and exenatide, which inhibit GLP-1 breakdown and stimulate GLP-1 receptors, respectively, decreased nicotine intake in mice. Chemogenetic activation of GLP-1 neurons in NTS similarly decreased nicotine intake. Conversely, Glp1r knockout mice consumed greater quantities of nicotine than wild-type mice. Using optogenetic stimulation, we show that GLP-1 excites medial habenular (MHb) projections to the interpeduncular nucleus (IPN). Activation of GLP-1 receptors in the MHb-IPN circuit abolished nicotine reward and decreased nicotine intake, whereas their knockdown or pharmacological blockade increased intake. GLP-1 neurons may therefore serve as 'satiety sensors' for nicotine that stimulate habenular systems to promote nicotine avoidance before its aversive effects are encountered.

Avoidance and depression vulnerability: An examination of avoidance in remitted and currently depressed individuals.

PubMed

Quigley, Leanne; Wen, Alainna; Dobson, Keith S

2017-10-01

Behavioral theories posit that depression is characterized by heightened levels of avoidance, and recent research has supported this notion. Whether avoidance persists after remission from depression is unknown, however. In this study, we investigated levels of cognitive and behavioral avoidance in remitted, currently, and never depressed individuals. We also examined relationships among avoidance and purported adaptive and maladaptive emotion regulation strategies. Remitted depressed individuals exhibited levels of cognitive and behavioral avoidance, in social and nonsocial domains, that were greater than nonclinical control individuals but lower than currently depressed individuals. Avoidance was significantly associated with use of maladaptive emotion regulation strategies, although the pattern of relationships differed across remitted and currently depressed individuals. In contrast, avoidance was largely unrelated to use of adaptive emotion regulation strategies, among remitted and currently depressed individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

CAHOST: An Excel Workbook for Facilitating the Johnson-Neyman Technique for Two-Way Interactions in Multiple Regression.

PubMed

Carden, Stephen W; Holtzman, Nicholas S; Strube, Michael J

2017-01-01

When using multiple regression, researchers frequently wish to explore how the relationship between two variables is moderated by another variable; this is termed an interaction. Historically, two approaches have been used to probe interactions: the pick-a-point approach and the Johnson-Neyman (JN) technique. The pick-a-point approach has limitations that can be avoided using the JN technique. Currently, the software available for implementing the JN technique and creating corresponding figures lacks several desirable features-most notably, ease of use and figure quality. To fill this gap in the literature, we offer a free Microsoft Excel 2013 workbook, CAHOST (a concatenation of the first two letters of the authors' last names), that allows the user to seamlessly create publication-ready figures of the results of the JN technique.

A Transformation Yielding an Additive Representation of Data in a Two-Way Array.

DTIC Science & Technology

1980-08-15

Psychological Association 1200 17th Street N.W. 1 Dr. Gary Marco Washington, DC 20036 Educational Testing Service Princeton, NJ 08450 Dr. Wilson A. Judd...ADA,11 b6b PORTLAND STATE UNIV OR DEPT OF PSYCHOLOGY F/G 12/1 A TRANSFORMATION YILLDING AN ADDITIVE REPRESENTATION OF DATA IN--ETC(U) AUG bO J A PAUL...DATA IN A TWO-WAY ARRAY James A. Paulson Psychology Department Portland State University Approved for public release; distribution unlimited

A neuro-collision avoidance strategy for robot manipulators

NASA Technical Reports Server (NTRS)

Onema, Joel P.; Maclaunchlan, Robert A.

1992-01-01

The area of collision avoidance and path planning in robotics has received much attention in the research community. Our study centers on a combination of an artificial neural network paradigm with a motion planning strategy that insures safe motion of the Articulated Two-Link Arm with Scissor Hand System relative to an object. Whenever an obstacle is encountered, the arm attempts to slide along the obstacle surface, thereby avoiding collision by means of the local tangent strategy and its artificial neural network implementation. This combination compensates the inverse kinematics of a robot manipulator. Simulation results indicate that a neuro-collision avoidance strategy can be achieved by means of a learning local tangent method.

A Case for Adult Two-Way Bilingual Immersion

ERIC Educational Resources Information Center

Van Booven, Christopher D.

2012-01-01

The present study investigates 2-way bilingual immersion (TWBI) as a potentially viable pedagogical model for adult language learners. A review of the literature on TWBI at the K-6 level is provided, followed by an examination of key issues in adult second and foreign language education. Implications for potential adult TWBI programs are discussed…

Practical way to avoid spurious geometrical contributions in Brillouin light scattering experiments at variable scattering angles.

PubMed

Battistoni, Andrea; Bencivenga, Filippo; Fioretto, Daniele; Masciovecchio, Claudio

2014-10-15

In this Letter, we present a simple method to avoid the well-known spurious contributions in the Brillouin light scattering (BLS) spectrum arising from the finite aperture of collection optics. The method relies on the use of special spatial filters able to select the scattered light with arbitrary precision around a given value of the momentum transfer (Q). We demonstrate the effectiveness of such filters by analyzing the BLS spectra of a reference sample as a function of scattering angle. This practical and inexpensive method could be an extremely useful tool to fully exploit the potentiality of Brillouin acoustic spectroscopy, as it will easily allow for effective Q-variable experiments with unparalleled luminosity and resolution.

[Comparison of physical activity and favourite ways of spending free time in preschool girls and boys from the Mazowsze region].

PubMed

Merkiel, Sylwia; Chalcarz, Wojciech; Deptuła, Monika

2011-01-01

The aim of this study was to compare physical activity of preschool girls and boys from the Mazowsze region and their favourite ways of spending free time. The studied population included 131 children aged 3 to 7 years. Parents filled in questionnaires about their children's physical activity and favourite ways of spending free time, as well as about general information on the children and their families. Gender had statistically significant influence on the children's birth weight, attending karate outside the preschool and on riding a bicycle, playing with a ball and playing with a dog as favourite ways of spending free time during sunny weather as well as playing on a computer and playing with dolls as favourite ways of spending free time during rainy weather. Gender had little influence on the studied preschoolers' physical activity. However favourite ways of spending free time turned out to be significantly different according to gender. Physical activity level in both girls and boys was low, similarly to their peers from the previous studies.

Intelligent power consumption with two-way shift able feature and its implementation

NASA Astrophysics Data System (ADS)

Xu, Jing; Liu, Youwei

2017-10-01

This paper proposes an intelligent power consumption system with two-way shift able feature and its implementation. Based on power consumption information of standby load and load in working state, a dispatching system decomposes load regulation demand top-down to smart appliances and makes them response orderly as required. It designs a code-based representation method for power consumption information and takes account of standby load, which lays the information foundation for load increment. It also presents a shift able index, which can be used to comprehensively reflect feature of electrical equipment and users and provides a basis for load priority.

Families Finding the Balance: A Parent Handbook. We Can! Ways to Enhance Children's Activity & Nutrition.

ERIC Educational Resources Information Center

US Department of Health and Human Services, 2005

2005-01-01

We Can! (Ways to Enhance Children's Activity & Nutrition) is a new public education outreach program designed to help children 8-13 years old stay at a healthy weight through improving food choices, increasing physical activity, and reducing screen time. The program is a collaboration of four Institutes of the National Institutes of Health (NIH):…

Avoidance behavior of ruffe exposed to selected formulations of piscicides

USGS Publications Warehouse

Dawson, Verdel K.; Bills, Terry D.; Boogaard, Michael A.

1998-01-01

Ruffe were introduced into Duluth Harbor, Minnesota in the early 1980s, probably by release of ballast water from sea-going freighters. Since then, it has become the most abundant species in the fish community. The sensitivity of ruffe to a number of piscicides has been demonstrated, however, the feasibility of using piscicides to control populations depends on whether ruffe cart detect piscicides and move to untreated water, We used a two-choice preference resting system to evaluate avoidance or attraction reactions of ruffe during exposures to the lampricides TFM and bayluscide and the general fish toxicants rotenone and antimycin. We used a second testing system to evaluate the potential for benthic ruffe to move vertically in the water column to avoid piscicides dissolving from experimental bottom-release formulations of bayluscide and antimycin. Near-lethal concentrations of TFM and rotenone tended to repel ruffe. Antimycin and bayluscide did not seem to repel ruffe in the avoidance chamber, but bottom-release formulations (antimycin granules-0.25% a.i. And bayluscide granules-3.2% a.i.) did cause increased swimming and surfacing activity among ruffe in column tests. We conclude that TFM and rotenone could be used to trent entire bodies of water, while bottom-release formulations of antimycin and bayluscide may have more application for treating localized concentrations of ruffe.

Rayleigh-Benard turbulence modified by two-way coupled particles

NASA Astrophysics Data System (ADS)

Park, Hyungwon; O'Keefe, Kevin; Richter, David

2017-11-01

Direct numerical simulation (DNS) with Lagrangian point particles is used to study Rayleigh-Bénard convection to understand modifications due to the interaction of inertial particle, gauged by the turbulent kinetic energy (TKE) and Nusselt number (Nu). The initially dispersed particles experience gravitational settling, and become introduced at the lower wall such that turbulence must overcome the settling velocity for the particles to vertically distribute throughout the domain. The particle properties of interest are inertia, as characterized by the Stokes number, and settling velocity. Furthermore, individual contributions by the momentum-coupling and thermal-coupling are studied to see which most significantly changes Nu and TKE. Our results show that particles with Stokes number of order unity maximize Nu, corresponding to a peak of clustering and attenuation of TKE. It is also shown that particles two-way coupled only through momentum attenuate Nu and weaken TKE, while thermal-only coupling also weakens TKE but enhances Nu. When both couplings are present, however, thermal coupling overwhelms the attenuation caused by momentum coupling and the net result is an enhancement of Nu. NSF - Grant No. AGS-1429921, ONR - Grant No. N00014-16-1-2472, and Notre Dame Center for Research Computing.

Food risk perceptions, gender, and individual differences in avoidance and approach motivation, intuitive and analytic thinking styles, and anxiety.

PubMed

Leikas, Sointu; Lindeman, Marjaana; Roininen, Katariina; Lähteenmäki, Liisa

2007-03-01

Risks appear to be perceived in two different ways, affectively and rationally. Finnish adult internet users were contacted via e-mail and asked to fill an internet questionnaire consisting of questions of food risks and measures of avoidance and approach motivation, analytic and intuitive information processing style, trait anxiety, and gender in order to find out (1) whether food risks are perceived two-dimensionally, (2) how individual differences in motivation, information processing, and anxiety are associated with the different dimensions of food risk perceptions, and (3) whether gender moderates these associations. The data were analyzed by factor, correlation and regression analyses. Three factors emerged: risk scariness, risk likelihood, and risks of cardiovascular disease. Personality and gender x personality interactions predicted food risk perceptions. Results showed that food risk perceptions generally form two dimensions; scariness and likelihood, but that this may depend on the nature of the risk. In addition, results imply that individuals with high avoidance motivation perceive food risks as scarier and more likely than others, and that individuals with an analytic information processing style perceive food risks as less likely than others. Trait anxiety seems to be associated with higher food risk perceptions only among men.

Two-Way Immersion Students' Home Languages, Proficiency Levels, and Responses to Form-Focused Instruction

ERIC Educational Resources Information Center

Tedick, Diane J.; Young, Amy I.

2018-01-01

Two-way immersion (TWI) programs in the U.S. integrate learners with different home languages and varied proficiencies in Spanish and English. Although both English home language (EHL) and Spanish home language (SHL) TWI students succeed academically in English, they often experience incomplete acquisition (Montrul 2011. "Morphological Errors…

Solar Avoided Cost Solution SunShot 6 Final Report

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

Tucker, John; Danziger, Eric

2014-01-29

The core objectives of this project were two separate but integrated products, collectively providing game-changing Avoided Cost capabilities. The first was a kit of avoided cost tools and data that any solar provider can use a-lacarte or as a whole. It’s open and easily accessible nature allows the rapid and accurate calculation of avoided cost in whatever context and software that make sense (“Typical and Avoided Cost Tools”). This kit includes a dataset of typical energy rates, costs and usage that can be used for solar prospecting, lead generation and any situation where data about an opportunity is missing ormore » imperfect. The second is a web application and related APIs specifically built for solar providers to radically streamline their lead-to-sale process (“Solar Provider Module”). The typical and Avoided Cost tools are built directly into this, and allow for solar providers to track their opportunities, collaborate with their installers and financiers, and close more sales faster.« less

Behavioral approach and avoidance in schizophrenia: an evaluation of motivational profiles.

PubMed

Felice Reddy, L; Green, Michael F; Rizzo, Shemra; Sugar, Catherine A; Blanchard, Jack J; Gur, Raquel E; Kring, Ann M; Horan, William P

2014-10-01

Schizophrenia is associated with motivational deficits that interfere with a wide range of goal directed activities. Despite their clinical importance, our current understanding of these motivational impairments is limited. Furthermore, different types of motivational problems are commonly seen among individuals within the broad diagnosis of schizophrenia. The goal of the current study was to examine whether clinically meaningful subgroups could be identified based on approach and avoidance motivational tendencies. We measured these tendencies in 151 individuals with schizophrenia. Although prior studies demonstrate elevated BIS sensitivity in schizophrenia at the overall group level, none have explored various combinations of BIS/BAS sensitivities within this disorder. Cluster analyses yielded five subgroups with different combinations of low, moderate, or high BIS and BAS. The subgroups had interpretable differences in clinically rated negative symptoms and self-reported anhedonia/socio-emotional attitudes, which were not detectable with the more commonly used linear BIS/BAS scores. Two of the subgroups had significantly elevated negative symptoms but different approach/avoidance profiles: one was characterized by markedly low BIS, low BAS and an overall lack of social approach motivation; the other had markedly high BIS but moderate BAS and elevated social avoidance motivation. The two subgroups with relatively good clinical functioning showed patterns of BAS greater than BIS. Our findings indicate that there are distinct motivational pathways that can lead to asociality in schizophrenia and highlight the value of considering profiles based on combined patterns of BIS and BAS in schizophrenia. Published by Elsevier B.V.

Navigational choice between reversal and curve during acidic pH avoidance behavior in Caenorhabditis elegans.

PubMed

Wakabayashi, Tokumitsu; Sakata, Kazumi; Togashi, Takuya; Itoi, Hiroaki; Shinohe, Sayaka; Watanabe, Miwa; Shingai, Ryuzo

2015-11-19

Under experimental conditions, virtually all behaviors of Caenorhabditis elegans are achieved by combinations of simple locomotion, including forward, reversal movement, turning by deep body bending, and gradual shallow turning. To study how worms regulate these locomotion in response to sensory information, acidic pH avoidance behavior was analyzed by using worm tracking system. In the acidic pH avoidance, we characterized two types of behavioral maneuvers that have similar behavioral sequences in chemotaxis and thermotaxis. A stereotypic reversal-turn-forward sequence of reversal avoidance caused an abrupt random reorientation, and a shallow gradual turn in curve avoidance caused non-random reorientation in a less acidic direction to avoid the acidic pH. Our results suggest that these two maneuvers were each triggered by a distinct threshold pH. A simulation study using the two-distinct-threshold model reproduced the avoidance behavior of the real worm, supporting the presence of the threshold. Threshold pH for both reversal and curve avoidance was altered in mutants with reduced or enhanced glutamatergic signaling from acid-sensing neurons. C. elegans employ two behavioral maneuvers, reversal (klinokinesis) and curve (klinotaxis) to avoid acidic pH. Unlike the chemotaxis in C. elegans, reversal and curve avoidances were triggered by absolute pH rather than temporal derivative of stimulus concentration in this behavior. The pH threshold is different between reversal and curve avoidance. Mutant studies suggested that the difference results from a differential amount of glutamate released from ASH and ASK chemosensory neurons.

Low back pain patients' responses to videos of avoided movements.

PubMed

Pincus, T; Henderson, J

2013-02-01

Fear avoidance (FA) has been identified as a risk factor for poor prognosis and a target for intervention in patients with low back pain (LBP), but the mechanisms involved need clarification. Experimental studies would benefit from the use of carefully developed and controlled stimuli representing avoided movements in back pain, and matched stimuli of movements to provide a credible control stimuli. Existing stimuli depicting avoided movements in LBP are static, do not include a set of control stimuli and do not control for possible systematic observer biases. Two studies were carried out aiming to develop and test LBP patients' responses to videos of models depicting commonly avoided movements associated with back pain, and those associated with a control condition, wrist pain. Two samples of LBP patients rated how much pain and harm each movement would cause them. They also reported how often they avoided the movement. The findings from the first study (n = 99) indicate that using videos of commonly avoided movements in low back pain is viable, and that movements associated with wrist pain provide an acceptable control stimuli. Participants in the second study (n = 85) consistently rated movements depicted by females as causing more harm, and more frequently avoided than the same movements depicted by males. The use of video stimuli could advance research into the processes associated with FA through experimental paradigms. However, although small, the model gender effects should be carefully considered. © 2012 European Federation of International Association for the Study of Pain Chapters.

Positive Ways To Avoid Instructor Burnout.

ERIC Educational Resources Information Center

Kaikai, Septimus M.; Kaikai, Regina E.

Multiple demands and pressures on teachers have increased instructor burnout, a state characterized by boredom, depression, envy, and physical and emotional fatigue. In response to the high incidence of burnout, teachers and professors may use a job diversification approach similar to one used in industry to combat boredom and monotony.…

Comparing digraph and Petri net approaches to deadlock avoidance in FMS.

PubMed

Fanti, M P; Maione, B; Turchiano, B

2000-01-01

Flexible manufacturing systems (FMSs) are modern production facilities with easy adaptability to variable production plans and goals. These systems may exhibit deadlock situations occurring when a circular wait arises because each piece in a set requires a resource currently held by another job in the same set. Several authors have proposed different policies to control resource allocation in order to avoid deadlock problems. These approaches are mainly based on some formal models of manufacturing systems, such as Petri nets (PNs), directed graphs, etc. Since they describe various peculiarities of the FMS operation in a modular and systematic way, PNs are the most extensively used tool to model such systems. On the other hand, digraphs are more synthetic than PNs because their vertices are just the system resources. So, digraphs describe the interactions between jobs and resources only, while neglecting other details on the system operation. The aim of this paper is to show the tight connections between the two approaches to the deadlock problem, by proposing a unitary framework that links graph-theoretic and PN models and results. In this context, we establish a direct correspondence between the structural elements of the PN (empty siphons) and those of the digraphs (maximal-weight zero-outdegree strong components) characterizing a deadlock occurrence. The paper also shows that the avoidance policies derived from digraphs can be implemented by controlled PNs.

Evaluating an in-home multicomponent cognitive behavioural programme to manage concerns about falls and associated activity avoidance in frail community-dwelling older people: Design of a randomised control trial [NCT01358032

PubMed Central

2011-01-01

Background Concerns about falls are frequently reported by older people. These concerns can have serious consequences such as an increased risk of falls and the subsequent avoidance of activities. Previous studies have shown the effectiveness of a multicomponent group programme to reduce concerns about falls. However, owing to health problems older people may not be able to attend a group programme. Therefore, we adapted the group approach to an individual in-home programme. Methods/Design A two-group randomised controlled trial has been developed to evaluate the in-home multicomponent cognitive behavioural programme to manage concerns about falls and associated activity avoidance in frail older people living in the community. Persons were eligible for study if they were 70 years of age or over, perceived their general health as fair or poor, had at least some concerns about falls and associated avoidance of activity. After screening for eligibility in a random sample of older people, eligible persons received a baseline assessment and were subsequently allocated to the intervention or control group. Persons assigned to the intervention group were invited to participate in the programme, while those assigned to the control group received care as usual. The programme consists of seven sessions, comprising three home visits and four telephone contacts. The sessions are aimed at instilling adaptive and realistic views about falls, as well as increasing activity and safe behaviour. An effect evaluation, a process evaluation and an economic evaluation are conducted. Follow-up measurements for the effect evaluation are carried out 5 and 12 months after the baseline measurement. The primary outcomes of the effect evaluation are concerns about falls and avoidance of activity as a result of these concerns. Other outcomes are disability and falls. The process evaluation measures: the population characteristics reached; protocol adherence by facilitators; protocol adherence