Science.gov

Sample records for two-way active avoidance

  1. Nucleus accumbens core lesions enhance two-way active avoidance.

    PubMed

    Lichtenberg, N T; Kashtelyan, V; Burton, A C; Bissonette, G B; Roesch, M R

    2014-01-31

    The majority of work examining the nucleus accumbens core (NAc) has focused on functions pertaining to behaviors guided by appetitive outcomes. These studies have pointed to the NAc as being critical for motivating behavior toward desirable outcomes. For example, we have recently shown that lesions of the NAc impaired performance on a reward-guided decision-making task that required rats to choose between differently valued rewards. Unfortunately, much less is known about the role that the NAc plays in motivating behavior when aversive outcomes are predicted. To address this issue we asked if NAc lesions impact performance on a two-way active avoidance task in which rats must learn to shuttle back and forth in a behavioral training box in order to avoid a footshock predicted by an auditory tone. Although bilateral NAc lesions initially impaired reward-guided decision-making, we found that the same lesions improved acquisition and retention of two-way active avoidance. PMID:24275320

  2. The Role of Amygdala Nuclei in the Expression of Auditory Signaled Two-Way Active Avoidance in Rats

    ERIC Educational Resources Information Center

    Choi, June-Seek; Cain, Christopher K.; LeDoux, Joseph E.

    2010-01-01

    Using a two-way signaled active avoidance (2-AA) learning procedure, where rats were trained in a shuttle box to avoid a footshock signaled by an auditory stimulus, we tested the contributions of the lateral (LA), basal (B), and central (CE) nuclei of the amygdala to the expression of instrumental active avoidance conditioned responses (CRs).…

  3. The role of amygdala nuclei in the expression of auditory signaled two-way active avoidance in rats

    PubMed Central

    Choi, June-Seek; Cain, Christopher K.; LeDoux, Joseph E.

    2010-01-01

    Using a two-way signaled active avoidance (2-AA) learning procedure, where rats were trained in a shuttle box to avoid a footshock signaled by an auditory stimulus, we tested the contributions of the lateral (LA), basal (B), and central (CE) nuclei of the amygdala to the expression of instrumental active avoidance conditioned responses (CRs). Discrete or combined lesions of the LA and B, performed after the rats had reached an asymptotic level of avoidance performance, produced deficits in the CR, whereas CE lesions had minimal effect. Fiber-sparing excitotoxic lesions of the LA/B produced by infusions of N-methyl-d-aspartate (NMDA) also impaired avoidance performance, confirming that neurons in the LA/B are involved in mediating avoidance CRs. In a final series of experiments, bilateral electrolytic lesions of the CE were performed on a subgroup of animals that failed to acquire the avoidance CR after 3 d of training. CE lesions led to an immediate rescue of avoidance learning, suggesting that activity in CE was inhibiting the instrumental CR. Taken together, these results indicate that the LA and B are essential for the performance of a 2-AA response. The CE is not required, and may in fact constrain the instrumental avoidance response by mediating the generation of competing Pavlovian responses, such as freezing. PMID:20189958

  4. Effects of nootropic agents on the performing of active two-way avoidance tasks in young and old rats.

    PubMed

    Petkov, V D; Belcheva, S; Stoyanova, V; Petkov, V V

    1990-01-01

    Experiments were made on 2- and 18-month-old male rats to test the effects on the acquisition and retention of piracetam, meclofenoxate and four newly-synthesized substances with assumed nootropic action: pyrrolidine derivatives with code names p-F, p-P and A-T, as well as the derivative of para-chlorophenoxypropionic acid, with code name 4-Cl-alpha PA. The method of two-way active avoidance was used, with punishment reinforcement during 5-day training and retention tests on the 14th day after the beginning of training. The agents studied were applied orally in doses of 30 and 150 mg/kg for 3 days (2 days before training and on the first day of training) and then again one hour before the retention testing. The older rats manifested a poorer learning capacity than the younger ones. Piracetam produced the best effect both on learning and on retention. Compounds with code names p-F, p-P and A-T induced an increase in the number of avoidances compared with the controls on isolated days only, according to the tests for acquisition. The favourable effects observed are not in close dependence either on the dose applied, or on the age of the experimental animal. No significant effects were observed under the effect of meclofenoxate and of its structural analogue 4-Cl-alpha PA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2101540

  5. Acquisition and Performance of Two-Way Shuttlebox Avoidance: Effects of Aversive Air Intensity

    ERIC Educational Resources Information Center

    Myers, T.M.; Cohn, S.I.; Clark, M.G.

    2005-01-01

    Thirty-two male C57BL/6J mice were trained on a signaled shuttlebox avoidance task using pressurized air as an aversive stimulus. Subjects were randomly assigned to one of four different air intensities (10, 20, 40, or 55psi) and exposed to 51 trials per session for 20 sessions. Area under the curve analyses and a two-parameter, nonlinear…

  6. Association between prepulse inhibition of the startle response and latent inhibition of two-way avoidance acquisition: A study with heterogeneous NIH-HS rats.

    PubMed

    Sánchez-González, Ana; Esnal, Aitor; Río-Álamos, Cristóbal; Oliveras, Ignasi; Cañete, Toni; Blázquez, Gloria; Tobeña, Adolf; Fernández-Teruel, Alberto

    2016-03-01

    This study presents the first evaluation of the associations between responses in two paradigms related to schizophrenia in the genetically heterogeneous NIH-HS rat stock. NIH-HS rats are a stock of genetically heterogeneous animals that have been derived from eight different inbred strains. A rotational breeding schedule has been followed for more than eighty generations, leading to a high level of genetic recombination that makes the NIH-HS rats a unique tool for studying the genetic basis of (biological, behavioral, disease-related) complex traits. Previous work has dealt with the characterization of coping styles, cognitive and anxiety/fear-related profiles of NIH-HS rats. In the present study we have completed their characterization in two behavioral models, prepulse inhibition (PPI) and latent inhibition (LI) of the two-way active avoidance response, that appear to be related to schizophrenia or to schizophrenia-relevant symptoms. We have found that these rats display PPI for each of the four prepulse intensities tested, allowing their stratification in high, medium and low PPI subgroups. When testing these three subgroups for LI of two-way active avoidance acquisition it has been observed that the LowPPI and MediumPPI subgroups present impaired LI, which, along with the fact that the HighPPI group presents significant LI, allows us to hypothesize that responses in these two paradigms are somehow related and that selection of NIH-HS rats for Low vs HighPPI could make a promising animal model for the study of clusters of schizophrenia-relevant symptoms and their underlying neurobiological mechanisms. PMID:26700617

  7. Neonatal handling decreases unconditioned anxiety, conditioned fear, and improves two-way avoidance acquisition: a study with the inbred Roman high (RHA-I)- and low-avoidance (RLA-I) rats of both sexes

    PubMed Central

    Río-Ȧlamos, Cristóbal; Oliveras, Ignasi; Cañete, Toni; Blázquez, Gloria; Martínez-Membrives, Esther; Tobeña, Adolf; Fernández-Teruel, Alberto

    2015-01-01

    The present study evaluated the long-lasting effects of neonatal handling (NH; administered during the first 21 days of life) on unlearned and learned anxiety-related responses in inbred Roman High- (RHA-I) and Low-avoidance (RLA-I) rats. To this aim, untreated and neonatally-handled RHA-I and RLA-I rats of both sexes were tested in the following tests/tasks: a novel object exploration (NOE) test, the elevated zero maze (ZM) test, a “baseline acoustic startle” (BAS) test, a “context-conditioned fear” (CCF) test and the acquisition of two-way active—shuttle box—avoidance (SHAV). RLA-I rats showed higher unconditioned (novel object exploration test -“NOE”-, elevated zero maze test -“ZM”-, BAS), and conditioned (CCF, SHAV) anxiety. NH increased exploration of the novel object in the NOE test as well as exploration of the open sections of the ZM test in both rat strains and sexes, although the effects were relatively more marked in the (high anxious) RLA-I strain and in females. NH did not affect BAS, but reduced CCF in both strains and sexes, and improved shuttle box avoidance acquisition especially in RLA-I (and particularly in females) and in female RHA-I rats. These are completely novel findings, which indicate that even some genetically-based anxiety/fear-related phenotypes can be significantly modulated by previous environmental experiences such as the NH manipulation. PMID:26217201

  8. 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…

  9. The acquisition of passive avoidance, active avoidance, and spatial navigation tasks by animals prenatally exposed to cocaine.

    PubMed

    Riley, E P; Foss, J A

    1991-01-01

    Pregnant Long-Evans rats were administered cocaine orally (60 mg/kg) on gestational days 14-21. One control group was administered the vehicle and another left untreated. Cocaine treatment produced some maternal lethality, and the weight gain of the surviving dams was reduced approximately 15%. Offspring of mothers treated with cocaine did not differ from those of untreated mothers in their numbers, birth weight, or growth. Weanling offspring were tested in a passive avoidance task, and adult offspring were tested for two-way active avoidance and in a spatial navigation task. Although a few animals in the cocaine group showed poor retention of passive avoidance, the group differences were not statistically significant. The adult animals showed normal performance in both the active avoidance and spatial navigation tasks. PMID:1758412

  10. Active Collision Avoidance for Planetary Landers

    NASA Technical Reports Server (NTRS)

    Rickman, Doug; Hannan, Mike; Srinivasan, Karthik

    2014-01-01

    Present day robotic missions to other planets require precise, a priori knowledge of the terrain to pre-determine a landing spot that is safe. Landing sites can be miles from the mission objective, or, mission objectives may be tailored to suit landing sites. Future robotic exploration missions should be capable of autonomously identifying a safe landing target within a specified target area selected by mission requirements. Such autonomous landing sites must (1) 'see' the surface, (2) identify a target, and (3) land the vehicle. Recent advances in radar technology have resulted in small, lightweight, low power radars that are used for collision avoidance and cruise control systems in automobiles. Such radar systems can be adapted for use as active hazard avoidance systems for planetary landers. The focus of this CIF proposal is to leverage earlier work on collision avoidance systems for MSFC's Mighty Eagle lander and evaluate the use of automotive radar systems for collision avoidance in planetary landers.

  11. The Two-Way Immersion Toolkit

    ERIC Educational Resources Information Center

    Howard, Elizabeth; Sugarman, Julie; Perdomo, Marleny; Adger, Carolyn Temple

    2005-01-01

    This Toolkit is meant to be a resource for teachers, parents, and administrators involved with two-way immersion (TWI) programs, particularly those at the elementary level. Two-way immersion is a form of dual language instruction that brings together students from two native language groups for language, literacy, and academic content instruction…

  12. Two-way coherent tracking systems.

    NASA Technical Reports Server (NTRS)

    Lindsey, W. C.; Yuen, J. H.

    1971-01-01

    Review of some results pertinent to the development of nonlinear theory on two-way coherent tracking systems. In particular, the model of cascaded systems is presented, and approximations to steady state probability density functions of the two-way system phase and Doppler error are developed. From these, certain numerical results required in the design and planning of these systems are derived.

  13. Two-Way Radio for Extension

    ERIC Educational Resources Information Center

    Swoboda, Donald W.

    1970-01-01

    Nebraska has been developing a two-way radio communication system for the Cooperative Extension Service, using the master microwave towers of the statewide emergency communication network. It has increased the efficiency of their limited human and economic resources. (NL)

  14. Differential effects of bupropion on acquisition and performance of an active avoidance task in male mice.

    PubMed

    Gómez, M C; Redolat, R; Carrasco, M C

    2016-03-01

    Bupropion is an antidepressant drug that is known to aid smoking cessation, although little experimental evidence exists about its actions on active avoidance learning tasks. Our aim was to evaluate the effects of this drug on two-way active avoidance conditioning. In this study, NMRI mice received bupropion (10, 20 and 40mg/kg) or saline before a daily training session (learning phase, days 1-4) in the active avoidance task. Performance was evaluated on the fifth day (retention phase): in each bupropion-treated group half of the mice continued with the same dose of bupropion, and the other half received saline. Among the vehicle-treated mice, different sub-groups were challenged with different doses of bupropion. Results indicated that mice treated with 10 and 20mg/kg bupropion exhibited more number of avoidances during acquisition. The response latency confirmed this learning improvement, since this parameter decreased after bupropion administration. No differences between groups were observed in the retention phase. In conclusion, our data show that bupropion influences the learning process during active avoidance conditioning, suggesting that this drug can improve the control of emotional responses. PMID:26688488

  15. Stationkeeping with two-way electromagnetic launchers

    NASA Astrophysics Data System (ADS)

    Nordley, Gerald David

    1994-11-01

    This study is motivated by previous proposals for electromagnetic launchers (EML) to launch payloads from the moon and space stations. With the advent of modern computer-controlled attitude and velocity control systems on the payload it is possible for EML to decelerate as well as launch payloads. In view of this, a two-way EML-equipped design to generate significant outward velocity without loss of reaction mass is realized. This model indicates that, in-addition to L1 stationkeeping, satellite could be pushed away from planets, or planets away from the sun, without loss of reaction mass.

  16. The role of nucleus accumbens and dorsolateral striatal D2 receptors in active avoidance conditioning.

    PubMed

    Boschen, Suelen Lucio; Wietzikoski, Evellyn Claudia; Winn, Philip; Da Cunha, Claudio

    2011-09-01

    The role of dopamine (DA) in rewarding motivated actions is well established but its role in learning how to avoid aversive events is still controversial. Here we tested the role of D2-like DA receptors in the nucleus accumbens (NAc) and the dorsolateral striatum (DLS) of rats in the learning and performance of conditioned avoidance responses (CAR). Adult male Wistar rats received systemic, intra-NAc or intra-DLS (pre- or post-training) administration of a D2-like receptor agonist (quinpirole) or antagonist ((-)sulpiride) and were given two sessions in the two-way active avoidance task. The main effects observed were: (i) sulpiride and lower (likely pre-synaptic) doses of quinpirole decreased the number of CARs and increased the number of escape failures; (ii) higher doses of quinpirole (likely post-synaptic) increased inter-trial crossings and failures; (iii) pre-training administration of sulpiride decreased the number of CARs in both training and test sessions when infused into the NAc, but this effect was observed only in the test session when it was infused into the DLS; (iv) post-training administration of sulpiride decreased CARs in the test session when infused into the NAc but not DLS. These findings suggest that activation of D2 receptors in the NAc is critical for fast adaptation to responding to unconditioned and conditioned aversive stimuli while activation of these receptors in the DLS is needed for a slower learning of how to respond to the same stimuli based on previous experiences. PMID:21619938

  17. Active core rewarming avoids bioelectrical impedance changes in postanesthetic patients

    PubMed Central

    2011-01-01

    Background Postoperative hypothermia is a common cause of complications in patients who underwent laparoscopic cholecystectomy. Hypothermia is known to elicit electrophysiological, biochemical, and cellular alterations thus leading to changes in the active and passive membrane properties. These changes might influence the bioelectrical impedance (BI). Our aim was to determine whether the BI depends on the core temperature. Methods We studied 60 patients (52 female and 8 male) age 40 to 80 years with an ASA I-II classification that had undergone laparoscopic cholecystectomy under balanced inhalation anesthesia. The experimental group (n = 30) received active core rewarming during the transanesthetic and postanesthesic periods. The control group (n = 30) received passive external rewarming. The BI was recorded by using a 4-contact electrode system to collect dual sets of measurements in the deltoid muscle. The body temperature, hemodynamic variables, respiratory rate, blood-gas levels, biochemical parameters, and shivering were also measured. The Mann-Whitney unpaired t-test was used to determine the differences in shivering between each group at each measurement period. Measurements of body temperature, hemodynamics variables, respiratory rate, and BI were analyzed using the two-way repeated-measures ANOVA. Results The gradual decrease in the body temperature was followed by the BI increase over time. The highest BI values (95 ± 11 Ω) appeared when the lowest values of the temperature (35.5 ± 0.5°C) were reached. The active core rewarming kept the body temperature within the physiological range (over 36.5°C). This effect was accompanied by low stable values (68 ± 3 Ω) of BI. A significant decrease over time in the hemodynamic values, respiratory rate, and shivering was seen in the active core-rewarming group when compared with the controls. The temporal course of shivering was different from those of body temperatue and BI. The control patients showed a

  18. 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…

  19. Persistent active avoidance correlates with activity in prelimbic cortex and ventral striatum.

    PubMed

    Bravo-Rivera, Christian; Roman-Ortiz, Ciorana; Montesinos-Cartagena, Marlian; Quirk, Gregory J

    2015-01-01

    Persistent avoidance is a prominent symptom of anxiety disorders and is often resistant to extinction-based therapies. Little is known about the circuitry mediating persistent avoidance. Using a recently described platform-mediated active avoidance task, we assessed activity in several structures with c-Fos immuno-labeling. In Task 1, rats were conditioned to avoid a tone-signaled shock by moving to a safe platform, and then were extinguished over two days. One day later, failure to retrieve extinction correlated with increased activity in the prelimbic prefrontal cortex (PL), ventral striatum (VS), and basal amygdala (BA), and decreased activity in infralimbic prefrontal cortex (IL), consistent with pharmacological inactivation studies. In Task 2, the platform was removed during extinction training and fear (suppression of bar pressing) was extinguished to criterion over 3-5 days. The platform was then returned in a post-extinction test. Under these conditions, avoidance levels were equivalent to Experiment 1 and correlated with increased activity in PL and VS, but there was no correlation with activity in IL or BA. Thus, persistent avoidance can occur independently of deficits in fear extinction and its associated structures. PMID:26236209

  20. Persistent active avoidance correlates with activity in prelimbic cortex and ventral striatum

    PubMed Central

    Bravo-Rivera, Christian; Roman-Ortiz, Ciorana; Montesinos-Cartagena, Marlian; Quirk, Gregory J.

    2015-01-01

    Persistent avoidance is a prominent symptom of anxiety disorders and is often resistant to extinction-based therapies. Little is known about the circuitry mediating persistent avoidance. Using a recently described platform-mediated active avoidance task, we assessed activity in several structures with c-Fos immuno-labeling. In Task 1, rats were conditioned to avoid a tone-signaled shock by moving to a safe platform, and then were extinguished over two days. One day later, failure to retrieve extinction correlated with increased activity in the prelimbic prefrontal cortex (PL), ventral striatum (VS), and basal amygdala (BA), and decreased activity in infralimbic prefrontal cortex (IL), consistent with pharmacological inactivation studies. In Task 2, the platform was removed during extinction training and fear (suppression of bar pressing) was extinguished to criterion over 3–5 days. The platform was then returned in a post-extinction test. Under these conditions, avoidance levels were equivalent to Experiment 1 and correlated with increased activity in PL and VS, but there was no correlation with activity in IL or BA. Thus, persistent avoidance can occur independently of deficits in fear extinction and its associated structures. PMID:26236209

  1. 33 CFR 157.136 - Two-way voice communications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Two-way voice communications. 157....136 Two-way voice communications. Each tank vessel having a COW system under § 157.10(e), § 157.10a(a)(2), or § 157.10c(b)(2) must have a means that enables two-way voice communications between the...

  2. Bilingual Two-Way Immersion Programs Benefit Academic Achievement

    PubMed Central

    Marian, Viorica; Shook, Anthony; Schroeder, Scott R.

    2013-01-01

    The effects of bilingual education on reading and math achievement were examined by comparing test scores across different elementary-school programs. Results revealed that bilingual Two-Way Immersion programs benefited both minority-language and majority-language students. Minority-language students in Two-Way Immersion outperformed their peers in Transitional Programs of Instruction, while majority-language students in Two-Way Immersion outperformed their peers in Mainstream monolingual classrooms. Bilingual Two-Way Immersion programs may enhance reading and math skills in both minority-language and majority-language elementary-school children. PMID:24277993

  3. 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…

  4. Two-way MANCOVA: An application to public health

    NASA Astrophysics Data System (ADS)

    Ramos, M. R.; Carolino, E.; Oliveira, T.; Bicho, M.

    2012-09-01

    The aim of this work is to use the MANCOVA model to study the influence of the phenotype of an enzyme - Acid phosphatase - and a genetic factor - Haptoglobin genotype - on two dependent variables - Activity of Acid Phosphatase (ACP1) and the Body Mass Index (BMI). Therefore it's used a general linear model, namely a multivariate analysis of covariance (Two-way MANCOVA). The covariate is the age of the subject. This covariate works as control variable for the independent factors, serving to reduce the error term in the model. The main results showed that only the ACP1 phenotype has a significant effect on the activity of ACP1 and the covariate has a significant effect in both dependent variables. The univariate analysis showed that ACP1 phenotype accounts for about 12.5% of the variability in the activity of ACP1. In respect to this covariate it can be seen that accounts for about 4.6% of the variability in the activity of ACP1 and 37.3% in the BMI.

  5. 33 CFR 157.136 - Two-way voice communications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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), §...

  6. 33 CFR 157.136 - Two-way voice communications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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), §...

  7. 33 CFR 157.136 - Two-way voice communications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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), §...

  8. 33 CFR 157.136 - Two-way voice communications.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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), §...

  9. 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

  10. 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.

  11. Follicular DEAs for two-way tactile communication

    NASA Astrophysics Data System (ADS)

    Knoop, Lars E.; Rossiter, Jonathan; Assaf, Tareq

    2015-04-01

    Follicular structures in skin combine sensing and actuation in a soft and compliant continuous surface. We have developed a tactile display device inspired by this structure, using a Dielectric Elastomer Actuator (DEA). DEAs allow for combined sensing and actuation, making possible two-way tactile communication between the user and the device. The device can obtain tactile information about the environment, or a user touching it, and it can also present tactile information to the user. We characterise the sensing properties of the tactile display device, and perform classification of tactile stimuli. We demonstrate two-way tactile interaction between a user and the device.

  12. Two-Way Bilingual Programs: Language-Learning-as-Resource.

    ERIC Educational Resources Information Center

    Baecher, Richard E.; Coletti, Charles D.

    A study assessed the performance of language-minority and language-majority children in a two-way Spanish-English bilingual education program in Port Chester, New York. The program treats language learning as a resource for all students, with each group of children teaching their native languages to the other. Second- and third-grade classes are…

  13. 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…

  14. Bayesian Full Rank Marginalization for Two-Way Contingency Tables.

    ERIC Educational Resources Information Center

    Leonard, Tom; Novick, Melvin R.

    A general approach is proposed for modeling the structure of a two-way contingency table, and for drawing inferences about the marginal and interaction effects, cell parameters, and conditional probabilities. The prior distribution expresses uncertainty in a simple reduced model, in particular the independence model. The posterior estimates of the…

  15. Bilingual Two-Way Immersion Programs Benefit Academic Achievement

    ERIC Educational Resources Information Center

    Marian, Viorica; Shook, Anthony; Schroeder, Scott R.

    2013-01-01

    The effects of bilingual education on reading and math achievement were examined by comparing test scores across different elementary school programs. Results revealed that bilingual Two-Way Immersion (TWI) programs benefited both minority-language and majority-language students. Minority-language students in TWI programs outperformed their peers…

  16. The Rich Promise of Two-Way Immersion

    ERIC Educational Resources Information Center

    Lindholm-Leary, Kathryn J.

    2005-01-01

    A key to closing the achievement gap between students who come to school speaking a language other than English and native English speakers is adoption of two-way bilingual immersion (TWBI) programs. The bilingual immersion approach fosters excellent academic achievement and positive school attitudes in students of any ethnicity who participate.…

  17. 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…

  18. Antecedents of Approach-Avoidance Achievement Goal Adoption: An Analysis of Two Physical Education Activities

    ERIC Educational Resources Information Center

    Warburton, Victoria; Spray, Christopher

    2013-01-01

    The purpose of this study was to determine the relationship between implicit theories of ability and competence perceptions to changes in approach-avoidance goal adoption in two specific activities in the curriculum. Four hundred and thirty pupils, aged 11-15 years, completed measures of approach-avoidance goals, perceived competence and implicit…

  19. Graduated Exposure and Positive Reinforcement to Overcome Setting and Activity Avoidance in an Adolescent with Autism

    ERIC Educational Resources Information Center

    Schmidt, Jonathan D.; Luiselli, James K.; Rue, Hanna; Whalley, Katherine

    2013-01-01

    Some students who have developmental disabilities avoid settings and activities that can improve their learning and quality of life. This two-phase study concerned an adolescent boy with autism who avoided the gross-motor exercise room, gymnasium, and music room at his school; he demonstrated distress, agitation, and problem behaviors when…

  20. 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.

  1. 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.

  2. 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.

  3. Transfer as a Two-Way Process: Testing a Model

    ERIC Educational Resources Information Center

    Vermeulen, Rita; Admiraal, Wilfried

    2009-01-01

    Purpose: The purpose of this exploratory research is to test the model of training transfer as a two-way process. Design/methodology/approach: Based on self-report data gathered from 58 to 44 respondents in a field experiment, it is argued that there is not just learning in the context of training and not just application in the context of work.…

  4. Teaching nursing research using two-way video technology.

    PubMed

    Parks, P L; O'Shea, K

    1995-06-01

    Schools of nursing are meeting the needs of students by instituting distance education courses that use two-way video technology. This article describes the structural features of the classroom that are changed and provides strategies that can be effective for teaching nursing research. These strategies are related to: teaching and demonstrating use of statistical formulas; selecting and teaching use of software for data analysis; teaching about research design, sampling, and data collection procedures; and critiquing empirical articles. PMID:7539973

  5. Graduated exposure and positive reinforcement to overcome setting and activity avoidance in an adolescent with autism.

    PubMed

    Schmidt, Jonathan D; Luiselli, James K; Rue, Hanna; Whalley, Katherine

    2013-01-01

    Some students who have developmental disabilities avoid settings and activities that can improve their learning and quality of life. This two-phase study concerned an adolescent boy with autism who avoided the gross-motor exercise room, gymnasium, and music room at his school; he demonstrated distress, agitation, and problem behaviors when prompted to enter these areas. Using graduated exposure combined with positive reinforcement, he learned to enter these settings without resisting and eventually to participate in activities within the settings. This article discusses this intervention approach for reducing and eliminating avoidant behavior. PMID:22987915

  6. Anxiety, not anger, induces inflammatory activity: An avoidance/approach model of immune system activation.

    PubMed

    Moons, Wesley G; Shields, Grant S

    2015-08-01

    Psychological stressors reliably trigger systemic inflammatory activity as indexed by levels of proinflammatory cytokines. This experiment demonstrates that one's specific emotional reaction to a stressor may be a significant determinant of whether an inflammatory reaction occurs in response to that stressor. Based on extant correlational evidence and theory, a causal approach was used to determine whether an avoidant emotion (anxiety) triggers more inflammatory activity than an approach emotion (anger). In an experimental design (N = 40), a 3-way Emotion Condition × Time × Analyte interaction revealed that a writing-based anxiety induction, but not a writing-based anger induction, increased mean levels of interferon-γ (IFN- γ) and interleukin-1β (IL-1β), but not interleukin-6 (IL-6) in oral mucous, F(2, 54) = 4.64, p = .01, ηp(²) = .15. Further, self-reported state anxiety predicted elevated levels of proinflammatory cytokines, all ΔR(²) >.06, ps <.04, but self-reported state anger did not. These results constitute the first evidence to our knowledge that specific negative emotions can differentially cause inflammatory activity and support a theoretical model explaining these effects based on the avoidance or approach motivations associated with emotions. PMID:26053247

  7. Two-way communication promote value-added services

    SciTech Connect

    1996-06-01

    This article reviews a number of developments in the efforts of electric utilities to establish two-way communications with their customers in order to develop products and services to fit each customer`s needs. In their efforts, utilities are facing an array of technology, including broadband, radio frequency, cellular, satellite, dial inbound, and power line carrier current. Individual efforts with each technology are noted. In many cases, the utilities are finding that existing cable and telephone companies are powerful allies in their efforts. Finding that their technology is marketable, the electric utilities are also diversifying horizontally and marketing their communications tools to other, both inside and outside of the utility industry.

  8. Two-way laser link over interplanetary distance.

    PubMed

    Smith, David E; Zuber, Maria T; Sun, Xiaoli; Neumann, Gregory A; Cavanaugh, John F; McGarry, Jan F; Zagwodzki, Thomas W

    2006-01-01

    Here we report timed observations with subnanosecond precision of short laser pulses at a distance of nearly 24 million kilometers between the Mercury Laser Altimeter (MLA) aboard the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) spacecraft and the NASA Goddard Geophysical and Astronomical Observatory (GGAO). Forty MLA downlink observations and 90 uplink observations were obtained during observing sessions on 27 and 31 May 2005. Precise standard ground timing allowed a solution for spacecraft range, range rate, and acceleration, as well as clock bias. This experiment established a new distance record for laser detection and accomplished a two-way laser link at an interplanetary distance. PMID:16400141

  9. 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…

  10. Altered activity of the medial prefrontal cortex and amygdala during acquisition and extinction of an active avoidance task

    PubMed Central

    Jiao, Xilu; Beck, Kevin D.; Myers, Catherine E.; Servatius, Richard J.; Pang, Kevin C. H.

    2015-01-01

    Altered medial prefrontal cortex (mPFC) and amygdala function is associated with anxiety-related disorders. While the mPFC-amygdala pathway has a clear role in fear conditioning, these structures are also involved in active avoidance. Given that avoidance perseveration represents a core symptom of anxiety disorders, the neural substrate of avoidance, especially its extinction, requires better understanding. The present study was designed to investigate the activity, particularly, inhibitory neuronal activity in mPFC and amygdala during acquisition and extinction of lever-press avoidance in rats. Neural activity was examined in the mPFC, intercalated cell clusters (ITCs) lateral (LA), basal (BA) and central (CeA) amygdala, at various time points during acquisition and extinction, using induction of the immediate early gene product, c-Fos. Neural activity was greater in the mPFC, LA, BA, and ITC during the extinction phase as compared to the acquisition phase. In contrast, the CeA was the only region that was more activated during acquisition than during extinction. Our results indicate inhibitory neurons are more activated during late phase of acquisition and extinction in the mPFC and LA, suggesting the dynamic involvement of inhibitory circuits in the development and extinction of avoidance response. Together, these data start to identify the key brain regions important in active avoidance behavior, areas that could be associated with avoidance perseveration in anxiety disorders. PMID:26441578

  11. 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. PMID:22142214

  12. 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

  13. 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

  14. Quantum error correction assisted by two-way noisy communication

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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

  15. Quantum error correction assisted by two-way noisy communication.

    PubMed

    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

  16. Dual valve plate two-way pressure relief valve

    NASA Astrophysics Data System (ADS)

    Angeli, Robert J.

    1994-02-01

    There is disclosed a two-way valve which includes dual valve plates to be positioned between first and second chambers having varying pressure therein, to relieve excess pressure in either chamber by permitting fluid flow from one chamber to the other. The valve includes a body portion having disposed therein dual valve plates. In the equilibrium state, the first valve plate is spring biased against the valve body in the direction of the first chamber to seal off any flow through the valve. The second valve plate is separately spring biased against the first valve plate in the direction of the second chamber, scaling off flow between the valve plates. When the pressure of the first chamber is greater than the pressure of the second chamber by a pre-determined amount, the first and second valve plates move away from the valve body permitting fluid flow from the first chamber to the second chamber.

  17. Active Avoidance Requires a Serial Basal Amygdala to Nucleus Accumbens Shell Circuit

    PubMed Central

    Ramirez, Franchesca; Moscarello, Justin M.; LeDoux, Joseph E.

    2015-01-01

    Freezing is a species-typical defensive reaction to conditioned threats. While the neural circuitry of aversive Pavlovian behavior has been extensively studied, less is known about the circuitry underlying more active responses to danger. Here we show that the flow of information between the basal amygdala (BA) and the nucleus accumbens (NAcc) is necessary for signaled active avoidance behavior. Rats trained to avoid shock by shuttling during an auditory conditioned stimulus showed increased expression of the activity-dependent protein c-Fos in the NAcc, specifically the shell subregion (NAccSh). Silencing neural activity in the NAccSh, but not in the adjacent NAcc core, disrupted avoidance behavior. Disconnection of the BA and the NAccSh was just as effective at disrupting avoidance behavior as bilateral NAccSh inactivations, suggesting learned avoidance behavior requires an intact BA-NAccSh circuit. Together, these data highlight an essential role for the amygdalar projection to the ventral striatum in aversively motivated actions. PMID:25716846

  18. 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

  19. Diabetes and Hepatitis C: A Two-Way Association

    PubMed Central

    Hammerstad, Sara Salehi; Grock, Shira Frankel; Lee, Hanna J.; Hasham, Alia; Sundaram, Nina; Tomer, Yaron

    2015-01-01

    Diabetes and hepatitis C infection are both prevalent diseases worldwide, and are associated with increased morbidity and mortality. Most studies, but not all, have shown that patients with chronic hepatitis C are more prone to develop type 2 diabetes (T2D) compared to healthy controls, as well as when compared to patients with other liver diseases, including hepatitis B. Furthermore, epidemiological studies have revealed that patients with T2D may also be at higher risk for worse outcomes of their hepatitis C infection, including reduced rate of sustained virological response, progression to fibrosis and cirrhosis, and higher risk for development of hepatocellular carcinoma. Moreover, hepatitis C infection and mainly its treatment, interferon α, can trigger the development of type 1 diabetes. In this review, we discuss the existing data on this two-way association between diabetes and hepatitis C infection with emphasis on possible mechanisms. It remains to be determined whether the new curative therapies for chronic hepatitis C will improve outcomes in diabetic hepatitis C patients, and conversely whether treatment with Metformin will reduce complications from hepatitis C virus infection. We propose an algorithm for diabetes screening and follow-up in hepatitis C patients. PMID:26441826

  20. 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.

  1. Diabetes and Hepatitis C: A Two-Way Association.

    PubMed

    Hammerstad, Sara Salehi; Grock, Shira Frankel; Lee, Hanna J; Hasham, Alia; Sundaram, Nina; Tomer, Yaron

    2015-01-01

    Diabetes and hepatitis C infection are both prevalent diseases worldwide, and are associated with increased morbidity and mortality. Most studies, but not all, have shown that patients with chronic hepatitis C are more prone to develop type 2 diabetes (T2D) compared to healthy controls, as well as when compared to patients with other liver diseases, including hepatitis B. Furthermore, epidemiological studies have revealed that patients with T2D may also be at higher risk for worse outcomes of their hepatitis C infection, including reduced rate of sustained virological response, progression to fibrosis and cirrhosis, and higher risk for development of hepatocellular carcinoma. Moreover, hepatitis C infection and mainly its treatment, interferon α, can trigger the development of type 1 diabetes. In this review, we discuss the existing data on this two-way association between diabetes and hepatitis C infection with emphasis on possible mechanisms. It remains to be determined whether the new curative therapies for chronic hepatitis C will improve outcomes in diabetic hepatitis C patients, and conversely whether treatment with Metformin will reduce complications from hepatitis C virus infection. We propose an algorithm for diabetes screening and follow-up in hepatitis C patients. PMID:26441826

  2. Dual valve plate two-way pressure relief valve

    NASA Astrophysics Data System (ADS)

    Angeli, Robert J.

    1993-02-01

    This patent application discloses a two-way valve which includes dual valve plates to be positioned between first and second chambers having varying pressure therein, to relieve excess pressure in either chamber by permitting fluid flow from one chamber to the other. The valve includes a body portion having disposed therein dual valve plates. In the equilibrium state, the first valve plate is spring biased against the valve body in the direction of the first chamber to seal off any flow through the valve. The second valve plate is separately spring biased against the first valve plate in the direction of the second chamber, sealing off flow between the valve plates. When the pressure of the first chamber is greater than the pressure of the second chamber by a predetermined amount, the first and second valve plates move away from the valve body permitting fluid flow from the first chamber to the second chamber. When the pressure of the second chamber exerted on the second valve plate through apertures in the first valve plate is greater than the pressure of the first chamber by a predetermined amount, the second valve plate moves away from the face of the first valve plate permitting fluid flow from the second chamber to the first chamber.

  3. Passive and active place avoidance as a tool of spatial memory research in rats.

    PubMed

    Cimadevilla, J M; Kaminsky, Y; Fenton, A; Bures, J

    2000-10-30

    A modified model of the arena described by Bures et al. (Bures J, Fenton AA, Kaminsky Y, Zinyuk L. Place cells and place navigation, Proc. Natl. Acad. Sci. USA. 1997a;94:343-350) was applied to the place learning of adult male rats in two different avoidance paradigms. In the passive avoidance task rats exploring a stationary circular arena had to avoid a 60 degrees sector entering of which was punished by mild footshocks. Intramaze as well as extramaze cues could be used for adequate solution of this task. In the active avoidance paradigm rats were trained to avoid a room frame defined sector (e.g. North-East) of a slowly rotating arena the movement of which forced the animals to rely on extramaze cues and to ignore intramaze information. Rats had to find an active solution of the task since otherwise they were passively transported into the room frame defined punished zone. The suitability of these tasks for testing spatial abilities of rats is discussed. PMID:11040412

  4. Two way push videoenteroscopy in investigation of small bowel disease

    PubMed Central

    Bouhnik, Y; Bitoun, A; Coffin, B; Moussaoui, R; Oudghiri, A; Rambaud, J

    1998-01-01

    Aims—To evaluate the diagnostic yield and safety of a new push type videoenteroscope (PVE) for diagnosis of small bowel disease. 
Methods—Three hundred and thirteen patients were referred for one or two way PVE from December 1993 to June 1996. Indications for PVE were: an unexplained iron deficiency anaemia with or without clinically evident gastrointestinal bleeding; or a complementary investigation for suspected small bowel disease, after a small bowel barium follow through (SBBFT) considered as normal or abnormal, but without a definite diagnosis. 
Results—A jejunoscopy and a retrograde ileoscopy were carried out in 306 and 234 patients, respectively. In patients with isolated anaemia (n=131) and those with clinically evident gastrointestinal bleeding associated anaemia (n=72), PVE provided a diagnosis in 26 (19.8%) and 22 (30.5%) cases, respectively. Lesions found were located in the jejunoileum in 30 (14.7%) patients and in the gastroduodenum or the colon in 18 (8.8%) patients—that is, within the reach of the conventional gastroscope/colonoscope. In patients with normal (n=54) or abnormal (n=56) SBBFT, PVE provided a diagnosis in 17(31%) and 27 (48%) cases, respectively. In 25% of cases, the abnormal appearance of SBBFT was not confirmed. The site of the radiological abnormality was not reached in 27% of cases. Lesions were located at the jejunum and the ileum in 59 (64%) and 33 (36%) cases, respectively. 
Conclusions—PVE is useful in around 30% of cases of unexplained anaemia or after an SBBFT which failed to provide an accurate aetiological diagnosis. Use of retrograde videoenteroscopy increases diagnostic yield by one third. 

 Keywords: enteroscopy; small intestine; gastrointestinal bleeding; anaemia; chronic diarrhoea; intestinal tumour PMID:10189858

  5. Visual avoidance in phobia: particularities in neural activity, autonomic responding, and cognitive risk evaluations

    PubMed Central

    Aue, Tatjana; Hoeppli, Marie-Eve; Piguet, Camille; Sterpenich, Virginie; Vuilleumier, Patrik

    2013-01-01

    We investigated the neural mechanisms and the autonomic and cognitive responses associated with visual avoidance behavior in spider phobia. Spider phobic and control participants imagined visiting different forest locations with the possibility of encountering spiders, snakes, or birds (neutral reference category). In each experimental trial, participants saw a picture of a forest location followed by a picture of a spider, snake, or bird, and then rated their personal risk of encountering these animals in this context, as well as their fear. The greater the visual avoidance of spiders that a phobic participant demonstrated (as measured by eye tracking), the higher were her autonomic arousal and neural activity in the amygdala, orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and precuneus at picture onset. Visual avoidance of spiders in phobics also went hand in hand with subsequently reduced cognitive risk of encounters. Control participants, in contrast, displayed a positive relationship between gaze duration toward spiders, on the one hand, and autonomic responding, as well as OFC, ACC, and precuneus activity, on the other hand. In addition, they showed reduced encounter risk estimates when they looked longer at the animal pictures. Our data are consistent with the idea that one reason for phobics to avoid phobic information may be grounded in heightened activity in the fear circuit, which signals potential threat. Because of the absence of alternative efficient regulation strategies, visual avoidance may then function to down-regulate cognitive risk evaluations for threatening information about the phobic stimuli. Control participants, in contrast, may be characterized by a different coping style, whereby paying visual attention to potentially threatening information may help them to actively down-regulate cognitive evaluations of risk. PMID:23754994

  6. 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

  7. 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. PMID:16237186

  8. 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. PMID:25779982

  9. Avoidance behavior and swimming activity of fish to detect pH changes

    SciTech Connect

    Nakamura, F.

    1986-12-01

    Usually, the initial response of an animal to an environmental perturbation is changing its behavior. With fish, this may hold an alteration in swimming activity or reactions like avoidance or attraction. The usefulness of fish behavior to detect the changes in chemical water quality was recognized more than 70 years ago. Since that time, many laboratory studies have been performed on the behavioral reactions of aquatic organisms to pollutants, including those resulting from pH changes. However, still there is no conclusive evidence that fish behavior offers an adequate tool to detect chemical pollution. In this study, the use of R-value for swimming activity and D/sup 2/-value for avoidance behavior of toxic warning methods to indicate the development of toxic condition is discussed based on experimental data on pH effects.

  10. Language Universals and Misidentification: A Two-Way Street

    ERIC Educational Resources Information Center

    Berent, Iris; Lennertz, Tracy; Balaban, Evan

    2012-01-01

    Certain ill-formed phonological structures are systematically under-represented across languages and misidentified by human listeners. It is currently unclear whether this results from grammatical phonological knowledge that actively recodes ill-formed structures, or from difficulty with their phonetic encoding. To examine this question, we gauge…

  11. Two ways fungal spores can affect cotton color

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For a long time, we have observed that cotton can undergo color change when moisture conditions of the cotton sample would not be expected to support bacterial activity which normally requires free water. Several fungi can grow under low moisture pressures. It has been speculated that the spores p...

  12. Hooked: The Two Way Seduction of Working with Gifted Children.

    ERIC Educational Resources Information Center

    Baker, Sally

    2001-01-01

    This article discusses strategies for differentiating the curriculum for gifted students by using a creative approach to language teaching. It provides suggestions for co-operative and creative classroom language activities, including making a syllable pie, starting a dictionary of sub-cult words, cryptic crosswords, poetry, and tracing language…

  13. Gustatory-mediated avoidance of bacterial lipopolysaccharides via TRPA1 activation in Drosophila

    PubMed Central

    Soldano, Alessia; Alpizar, Yeranddy A; Boonen, Brett; Franco, Luis; López-Requena, Alejandro; Liu, Guangda; Mora, Natalia; Yaksi, Emre; Voets, Thomas; Vennekens, Rudi; Hassan, Bassem A; Talavera, Karel

    2016-01-01

    Detecting pathogens and mounting immune responses upon infection is crucial for animal health. However, these responses come at a high metabolic price (McKean and Lazzaro, 2011, Kominsky et al., 2010), and avoiding pathogens before infection may be advantageous. The bacterial endotoxins lipopolysaccharides (LPS) are important immune system infection cues (Abbas et al., 2014), but it remains unknown whether animals possess sensory mechanisms to detect them prior to infection. Here we show that Drosophila melanogaster display strong aversive responses to LPS and that gustatory neurons expressing Gr66a bitter receptors mediate avoidance of LPS in feeding and egg laying assays. We found the expression of the chemosensory cation channel dTRPA1 in these cells to be necessary and sufficient for LPS avoidance. Furthermore, LPS stimulates Drosophila neurons in a TRPA1-dependent manner and activates exogenous dTRPA1 channels in human cells. Our findings demonstrate that flies detect bacterial endotoxins via a gustatory pathway through TRPA1 activation as conserved molecular mechanism. DOI: http://dx.doi.org/10.7554/eLife.13133.001 PMID:27296646

  14. Avoidant symptoms in PTSD predict fear circuit activation during multimodal fear extinction

    PubMed Central

    Sripada, Rebecca K.; Garfinkel, Sarah N.; Liberzon, Israel

    2013-01-01

    Convergent evidence suggests that individuals with posttraumatic stress disorder (PTSD) exhibit exaggerated avoidance behaviors as well as abnormalities in Pavlonian fear conditioning. However, the link between the two features of this disorder is not well understood. In order to probe the brain basis of aberrant extinction learning in PTSD, we administered a multimodal classical fear conditioning/extinction paradigm that incorporated affectively relevant information from two sensory channels (visual and tactile) while participants underwent fMRI scanning. The sample consisted of fifteen OEF/OIF veterans with PTSD. In response to conditioned cues and contextual information, greater avoidance symptomatology was associated with greater activation in amygdala, hippocampus, vmPFC, dmPFC, and insula, during both fear acquisition and fear extinction. Heightened responses to previously conditioned stimuli in individuals with more severe PTSD could indicate a deficiency in safety learning, consistent with PTSD symptomatology. The close link between avoidance symptoms and fear circuit activation suggests that this symptom cluster may be a key component of fear extinction deficits in PTSD and/or may be particularly amenable to change through extinction-based therapies. PMID:24146643

  15. Effects of memantine on latent inhibition of active avoidance in wistar rats.

    PubMed

    Loskutova, L V; Kostjunina, N V

    2009-06-01

    Latent inhibition of active avoidance reaction was acquired by mature Wistar rats. It manifested in marked delay of habit acquisition after preexposure to the conditional stimulus in the first experimental session. Single dose of NMDA-receptor antagonist memantine (10 and 14 mg/kg) was applied 60 min before training in the second session. Failure of latent inhibition formation was registered after administration of the higher memantine dose; it manifested in accelerated attaining of the criterion (7 successive conditioned avoidance reactions) compared to training results after administration of the lower dose or physiological saline. The effects of memantine on attention were found to depend on the presence of pathology. It was hypothesized that the preparation can produce a positive effect on memory in Alzheimer-type dementia due to primary recovery of the inhibitory aspect of attention. PMID:19902058

  16. 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. PMID:27498147

  17. Two-way communication and analysis program on LANDSAT

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Community workshops, field visits, telephone surveys, and other research reveals that professionals at the substate level are interested in and open to consideration of LANDSAT as a planning and resource management tool, but are at the same time skeptical about some of the inherent problems with LANDSAT such as cost, resolution, frequency of coverage, and data continuity. The principal requirements for increasing the utilization of LANDSAT by potential substate users were identified and documented. Without a committment from the Federal Government for increased substrate utilization and the availability of trained professionals to meet the needs of a largely new user community, substrate activity is likely to remain at a minimum. Well conceived and well executed demonstration projects could play a critical role is shaping the technology's ability to be more sensitive to substate user needs and interests as well as validating the effectiveness of this data to a skeptical audience.

  18. 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

  19. 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

  20. 30 CFR 57.20032 - Two-way communication equipment for underground operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Two-way communication equipment for underground... NONMETAL MINES Miscellaneous § 57.20032 Two-way communication equipment for underground operations. Telephones or other two-way communication equipment with instructions for their use shall be provided...

  1. 47 CFR 22.589 - One-way or two-way application requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false One-way or two-way application requirements. 22... SERVICES PUBLIC MOBILE SERVICES Paging and Radiotelephone Service One-Way Or Two-Way Mobile Operation § 22.589 One-way or two-way application requirements. In addition to information required by subparts B...

  2. 33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Off Delaware Bay: Two-Way Traffic... Separation Schemes and Precautionary Areas Atlantic East Coast § 167.173 Off Delaware Bay: Two-Way Traffic Route. The Two-Way Traffic Route is recommended for use predominantly by tug and tow traffic...

  3. 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...

  4. 47 CFR 22.561 - Channels for one-way or two-way mobile operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Channels for one-way or two-way mobile... CARRIER SERVICES PUBLIC MOBILE SERVICES Paging and Radiotelephone Service One-Way Or Two-Way Mobile Operation § 22.561 Channels for one-way or two-way mobile operation. The following channels are...

  5. Profiles in Two-Way Immersion Education. Language in Education: Theory and Practice 89.

    ERIC Educational Resources Information Center

    Christian, Donna; And Others

    This monograph discusses issues in the design and implementation of two-way immersion, or two-way bilingual education programs, and describes three exemplary programs. An introductory section examines briefly the rationale for two-way immersion and the extent of its use in the United States. Three school program profiles follow: (1) Francis Scott…

  6. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 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...

  7. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 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...

  8. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 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...

  9. 14 CFR 91.185 - IFR operations: Two-way radio communications failure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 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...

  10. 47 CFR 22.561 - Channels for one-way or two-way mobile operation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Channels for one-way or two-way mobile... CARRIER SERVICES PUBLIC MOBILE SERVICES Paging and Radiotelephone Service One-Way Or Two-Way Mobile Operation § 22.561 Channels for one-way or two-way mobile operation. The following channels are...

  11. Requirement of Dopamine Signaling in the Amygdala and Striatum for Learning and Maintenance of a Conditioned Avoidance Response

    ERIC Educational Resources Information Center

    Darvas, Martin; Fadok, Jonathan P.; Palmiter, Richard D.

    2011-01-01

    Two-way active avoidance (2WAA) involves learning Pavlovian (association of a sound cue with a foot shock) and instrumental (shock avoidance) contingencies. To identify regions where dopamine (DA) is involved in mediating 2WAA, we restored DA signaling in specific brain areas of dopamine-deficient (DD) mice by local reactivation of conditionally…

  12. 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

  13. 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

  14. 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.

  15. 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…

  16. Active faults crossing trunk pipeline routes: some important steps to avoid the disaster

    NASA Astrophysics Data System (ADS)

    Besstrashnov, Vladimir; Strom, Alexander

    2010-05-01

    Trunk pipelines that pass through tectonically active areas connecting oil and gas reservoirs with terminals and refineries cross active faults that can produce large earthquakes. Besides strong motion affecting vast areas, these earthquakes are often associated with surface faulting that provides additional hazard to pipelines. To avoid significant economic losses and environmental pollution, pipelines should be designed to sustain both effects (shaking and direct rupturing) without pipe damage and spill. Special studies aimed to provide necessary input data for the designers should be performed in the course of engineering survey. However, our experience on conducting and review of such studies for several oil and gas trunk pipelines in Russia show urgent need of more strict definition of basic conceptions and approaches used for identification and localization of these potentially hazardous tectonic features. Identification of active faults (fault zones) considered as causative faults - sources of strong motion caused by seismic waves that affect dozens kilometers of pipeline route can be done by use of both direct and indirect evidence of Late Pleistocene - Holocene activity of faults and fault zones. Since strong motion parameters can be considered as constant within the near-field zone, which width in case of large earthquake is up to dozens kilometers, accuracy of active fault location is not so critical and ±1-2 km precision provided by use of indirect evidence is acceptable. In contrast, if one have to identify and characterize zones of potential surface rupturing that require special design of the endangered pipeline section, only direct evidence of such activity can provide reliable input data for crossing design with relevant accuracy of fault location, amount and direction of displacement. Only traces of surface faults displacing Late Pleistocene - Holocene sediments and/or geomorphic features are considered as direct evidence of fault activity. Just

  17. Heterogeneity in signaled active avoidance learning: substantive and methodological relevance of diversity in instrumental defensive responses to threat cues

    PubMed Central

    Galatzer-Levy, Isaac R.; Moscarello, Justin; Blessing, Esther M.; Klein, JoAnna; Cain, Christopher K.; LeDoux, Joseph E.

    2014-01-01

    Individuals exposed to traumatic stressors follow divergent patterns including resilience and chronic stress. However, researchers utilizing animal models that examine learned or instrumental threat responses thought to have translational relevance for Posttraumatic Stress Disorder (PTSD) and resilience typically use central tendency statistics that assume population homogeneity. This approach potentially overlooks fundamental differences that can explain human diversity in response to traumatic stressors. The current study tests this assumption by identifying and replicating common heterogeneous patterns of response to signaled active avoidance (AA) training. In this paradigm, rats are trained to prevent an aversive outcome (shock) by performing a learned instrumental behavior (shuttling between chambers) during the presentation of a conditioned threat cue (tone). We test the hypothesis that heterogeneous trajectories of threat avoidance provide more accurate model fit compared to a single mean trajectory in two separate studies. Study 1 conducted 3 days of signaled AA training (n = 81 animals) and study 2 conducted 5 days of training (n = 186 animals). We found that four trajectories in both samples provided the strongest model fit. Identified populations included animals that acquired and retained avoidance behavior on the first day (Rapid Avoiders: 22 and 25%); those who never successfully acquired avoidance (Non-Avoiders; 20 and 16%); a modal class who acquired avoidance over 3 days (Modal Avoiders; 37 and 50%); and a population who demonstrated a slow pattern of avoidance, failed to fully acquire avoidance in study 1 and did acquire avoidance on days 4 and 5 in study 2 (Slow Avoiders; 22.0 and 9%). With the exception of the Slow Avoiders in Study 1, populations that acquired demonstrated rapid step-like increases leading to asymptotic levels of avoidance. These findings indicate that avoidance responses are heterogeneous in a way that may be informative for

  18. 33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Off Delaware Bay: Two-Way Traffic... 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...

  19. 33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Off Delaware Bay: Two-Way Traffic... 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...

  20. 33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Off Delaware Bay: Two-Way Traffic... 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...

  1. 33 CFR 167.173 - Off Delaware Bay: Two-Way Traffic Route.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Off Delaware Bay: Two-Way Traffic... 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...

  2. 78 FR 31576 - Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... a complaint filed on behalf of BriarTek IP, Inc. (``BriarTek'') of Alexandria, Virginia. 77 FR 58579... COMMISSION Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and... United States after importation of certain two-way global satellite communication devices, system...

  3. Primary Students' Proficiency and Achievement: The Difference Two-Way Immersion Programs Can Make

    ERIC Educational Resources Information Center

    Kaptain, Holly Janelle

    2010-01-01

    Chapter 3: This study investigated the effects of a new, Spanish two-way immersion program on first through third grade students' English and Spanish proficiency. All students were from an urban, high-poverty community in the Midwest that is English dominant, in a predominantly Anglo state. English-speakers in the two-way immersion program score…

  4. 77 FR 58579 - Certain Two-Way Global Satellite Communication Devices, System and Components Thereof...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... COMMISSION Certain Two-Way Global Satellite Communication Devices, System and Components Thereof; Institution...-way global satellite communication devices, system and components thereof by reason of infringement of... after importation of certain two-way global satellite communication devices, system and...

  5. An Experimental Two-Way Video Teletraining System: Design, Development and Evaluation.

    ERIC Educational Resources Information Center

    Simpson, Henry; And Others

    1991-01-01

    Describes the design, development, and evaluation of an experimental two-way video teletraining (VTT) system by the Navy that consisted of two classrooms linked by a land line to enable two-way audio/video communication. Trends in communication and computer technology for training are described, and a cost analysis is included. (12 references)…

  6. 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…

  7. Avoidance and activation as keys to depression: adaptation of the Behavioral Activation for Depression Scale in a Spanish sample.

    PubMed

    Barraca, Jorge; Pérez-Alvarez, Marino; Lozano Bleda, José Héctor

    2011-11-01

    In this paper we present the adaptation of the Behavioral Activation for Depression Scale (BADS), developed by Kanter, Mulick, Busch, Berlin, and Martell (2007), in a Spanish sample. The psychometric properties were tested in a sample of 263 participants (124 clinical and 139 non-clinical). The results show that, just as in the original English version, the Spanish BADS is a valid and internally consistent scale. Construct validity was examined by correlation with the BDI-II, AAQ, ATQ, MCQ-30, STAI and EROS. Factor analysis justified the four-dimensions of the original instrument (Activation, Avoidance/Rumination, Work/School Impairment and Social Impairment), although with some differences in the factor loadings of the items. Further considerations about the usefulness of the BADS in the clinical treatment of depressed patients are also suggested. PMID:22059343

  8. Functional brain activation during retrieval of visceral pain-conditioned passive avoidance in the rat.

    PubMed

    Wang, Zhuo; Bradesi, Sylvie; Charles, Jonathan R; Pang, Raina D; Maarek, Jean-Michel I; Mayer, Emeran A; Holschneider, Daniel P

    2011-12-01

    This study assessed functional brain activation in rats during expectation of visceral pain. Male rats were trained in step-down passive avoidance (PA) for 2 days. Upon stepping down from a platform, conditioned animals received noxious colorectal distension delivered through a colorectal balloon, whereas the balloon in control rats remained uninflated. On day 3, PA behavior was assessed while [(14)C]-iodoantipyrine was infused intravenously, followed by immediate euthanasia. Regional cerebral blood flow-related tissue radioactivity (rCBF) was analyzed by statistical parametric mapping using 3-dimensional brains reconstructed from autoradiographic brain slice images. Associated with retrieved PA behavior, conditioned rats compared with control subjects showed increases in rCBF in sensory (anterior insula, somatosensory cortex), limbic/paralimbic regions (anterior cingulate, prelimbic cortex, amygdala), all regions previously reported to show activation during acute visceral pain. Increases in rCBF were also noted in the dorsal hippocampus, nucleus accumbens, and caudate putamen, regions associated with retrieval of PA. Organization of the underlying brain network was further delineated by functional connectivity analysis. This revealed in conditioned rats a strongly and positively connected corticostriatal cluster (cingulate, prelimbic cortex, caudate putamen). The amygdala and cerebellar hemispheres formed another positively connected cluster, which was negatively connected with the corticostriatal cluster, suggesting corticolimbic modulation. Prelimbic cortex, nucleus accumbens, and anterior insula emerged in conditioned animals as hubs. Our results show that during retrieval of PA, brain areas implicated in PA expression as well as those implicated in acute visceral pain processing were recruited, in line with findings from human brain imaging studies on pain expectation. PMID:21944154

  9. Memory retrieval of inhibitory avoidance requires histamine H1 receptor activation in the hippocampus.

    PubMed

    Fabbri, Roberta; Furini, Cristiane Regina Guerino; Passani, Maria Beatrice; Provensi, Gustavo; Baldi, Elisabetta; Bucherelli, Corrado; Izquierdo, Ivan; de Carvalho Myskiw, Jociane; Blandina, Patrizio

    2016-05-10

    Retrieval represents a dynamic process that may require neuromodulatory signaling. Here, we report that the integrity of the brain histaminergic system is necessary for retrieval of inhibitory avoidance (IA) memory, because rats depleted of histamine through lateral ventricle injections of α-fluoromethylhistidine (a-FMHis), a suicide inhibitor of histidine decarboxylase, displayed impaired IA memory when tested 2 d after training. a-FMHis was administered 24 h after training, when IA memory trace was already formed. Infusion of histamine in hippocampal CA1 of brain histamine-depleted rats (hence, amnesic) 10 min before the retention test restored IA memory but was ineffective when given in the basolateral amygdala (BLA) or the ventral medial prefrontal cortex (vmPFC). Intra-CA1 injections of selective H1 and H2 receptor agonists showed that histamine exerted its effect by activating the H1 receptor. Noteworthy, the H1 receptor antagonist pyrilamine disrupted IA memory retrieval in rats, thus strongly supporting an active involvement of endogenous histamine; 90 min after the retention test, c-Fos-positive neurons were significantly fewer in the CA1s of a-FMHis-treated rats that displayed amnesia compared with in the control group. We also found reduced levels of phosphorylated cAMP-responsive element binding protein (pCREB) in the CA1s of a-FMHis-treated animals compared with in controls. Increases in pCREB levels are associated with retrieval of associated memories. Targeting the histaminergic system may modify the retrieval of emotional memory; hence, histaminergic ligands might reduce dysfunctional aversive memories and improve the efficacy of exposure psychotherapies. PMID:27118833

  10. Intracranial self-stimulation facilitates active-avoidance retention and induces expression of c-Fos and Nurr1 in rat brain memory systems.

    PubMed

    Aldavert-Vera, Laura; Huguet, Gemma; Costa-Miserachs, David; Ortiz, Sandra Pena de; Kádár, Elisabeth; Morgado-Bernal, Ignacio; Segura-Torres, Pilar

    2013-08-01

    Intracranial self-stimulation (ICSS), a special form of deep brain stimulation in which subjects self-administered electrical stimulation in brain reward areas as the lateral hypothalamus, facilitates learning and memory in a wide variety of tasks. Assuming that ICSS improves learning and memory increasing the activation of memory-related brain areas, the present work examined whether rats receiving an ICSS treatment immediately after the acquisition session of a two-way active avoidance conditioning (TWAA) show both an improved retention and a pattern of increased c-Fos and Nurr1 protein expression in the amygdala, hippocampus, dorsal striatum and/or lateral hypothalamus. The response of both activity-induced IEGs to ICSS was examined not only as markers of neural activation, but because of their reported role in the neural plasticity occurring during learning and memory formation. Results showed that the TWAA conditioning alone increased the expression of the two analysed IEGs in several hippocampal areas, and TWAA retention increased Nurr1 expression in amygdala. ICSS treatment increased the number of c-Fos and Nurr1 positive cells in almost all the brain regions studied when it was measured 70min, but not 48h, after the stimulation. Post-training ICSS treatment, as expected, facilitated the 48h retention of the conditioning. It is noteworthy that in CA3 conditioning and ICSS separately increased c-Fos expression, but this increasing was greater when both, conditioning and ICSS, were combined. Present results suggest that rapid and transient increased expression of these two synaptic plasticity and memory related IEGs in some hippocampal areas, such as CA3, could mediate the facilitative effects of ICSS on learning and memory consolidation. PMID:23624190

  11. 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. PMID:26922874

  12. Performance Improvement of Two-way Quantum Key Distribution by Using a Heralded Noiseless Amplifier

    NASA Astrophysics Data System (ADS)

    Li, Chenyang; Miao, Ruihang; Gong, Xinbao; Guo, Ying; He, Guangqiang

    2016-04-01

    We show the successful use of a heralded noiseless linear amplifier on the detection stage in the two-way continuous-variable quantum key distribution to improve the performance. Due to the excess noise, the secret-key rate of the two-way protocol becomes negative for a certain distance of transmission. The use of a heralded noiseless linear amplifier increases this distance by the equivalent of 20 log10 g dB of losses, and it also helps the two-way protocol tolerate more excess noise.

  13. 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

  14. 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. PMID:24454687

  15. Performance Analysis of Two-Way OFDM Relay Systems with Ordered Subcarrier Pairing

    NASA Astrophysics Data System (ADS)

    Yang, Wendong; Wang, Kaihua; Cai, Yueming; Yang, Weiwei; Tu, Jia

    2014-05-01

    In this paper, we first prove the optimality of ordered subcarrier pairing (OSP) in two-way orthogonal frequency division multiplexing (OFDM) relay systems. The probability distribution function (PDF) and the cumulative distribution function (CDF) of the signal-to-noise ratio (SNR) is then derived for each subcarrier pair of the two-way links over Rayleigh fading channels. Furthermore, we analyze the performance of the systems including outage probability, symbol error rate (SER) and capacity. Monte Carlo simulations validate our analysis.

  16. On the relative performance of one-way and two-way grid nesting

    NASA Astrophysics Data System (ADS)

    Harris, Lucas M.

    Most mesoscale models can be run with either one-way ("parasitic") or two-way ("interactive") grid nesting. This paper presents results from a linear 1D shallow-water model and from 3D simulations of a multicell thunderstorm and of trapped lee waves to determine whether the choice of nesting method can have a significant impact on the solution. In the shallow-water model, two-way nesting was found to be generally superior to one-way nesting. The increased reflection for longer-wavelength disturbances in the one-way case is due to a phase difference between the coarse- and nested-grid solutions at the nested-grid boundary that accumulates because of the difference in numerical phase speeds between the grids. Reflections for two-way nesting may be estimated from the difference in numerical group velocities between the coarse and nested grids, which only becomes large for waves that are poorly-resolved on the coarse grid. The only situation in which one-way nesting performs better than two-way is when very poorly-resolved waves strike the nest boundary; in these cases, using a filter on the coarse-grid values within the sponge zone of an otherwise conventional sponge boundary condition can greatly reduce the reflections caused by two-way nesting. The results were more equivocal for the 3D simulations. Two-way nesting clearly produced smaller precipitation errors than did one-way nesting in the multicell simulations, due to the lack of mismatch errors between the coarse- and nested-grid solutions in the two-way simulations. In the trapped lee-wave simulations, two-way nesting produced lower overall errors than did one-way nesting when a simple interpolation BC was used, but larger errors when the sponge BC was used.

  17. 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. PMID:26368863

  18. A dynamic balance between gene activation and repression regulates the shade avoidance response in Arabidopsis

    PubMed Central

    Sessa, Giovanna; Carabelli, Monica; Sassi, Massimiliano; Ciolfi, Andrea; Possenti, Marco; Mittempergher, Francesca; Becker, Jorg; Morelli, Giorgio; Ruberti, Ida

    2005-01-01

    Plants grown under dense canopies perceive through the phytochrome system a reduction in the ratio of red to far-red light as a warning of competition, and this triggers a series of morphological changes to avoid shade. Several phytochrome signaling intermediates acting as positive regulators of accelerated elongation growth and induction of flowering in shade avoidance have been identified. Here we report that a negative regulatory mechanism ensures that in the presence of far-red-rich light an exaggerated plant response does not occur. Strikingly, this unpredicted negative regulatory mechanism is centrally involved in the attenuation of virtually all plant responses to canopy shade. PMID:16322556

  19. A dynamic balance between gene activation and repression regulates the shade avoidance response in Arabidopsis.

    PubMed

    Sessa, Giovanna; Carabelli, Monica; Sassi, Massimiliano; Ciolfi, Andrea; Possenti, Marco; Mittempergher, Francesca; Becker, Jorg; Morelli, Giorgio; Ruberti, Ida

    2005-12-01

    Plants grown under dense canopies perceive through the phytochrome system a reduction in the ratio of red to far-red light as a warning of competition, and this triggers a series of morphological changes to avoid shade. Several phytochrome signaling intermediates acting as positive regulators of accelerated elongation growth and induction of flowering in shade avoidance have been identified. Here we report that a negative regulatory mechanism ensures that in the presence of far-red-rich light an exaggerated plant response does not occur. Strikingly, this unpredicted negative regulatory mechanism is centrally involved in the attenuation of virtually all plant responses to canopy shade. PMID:16322556

  20. Two way assessment of other physical work demands while measuring the whole body vibration magnitude

    NASA Astrophysics Data System (ADS)

    Tiemessen, Ivo J. H.; Hulshof, Carel T. J.; Frings-Dresen, Monique H. W.

    2008-03-01

    Direct observation, instead of using self-administered questionnaires might give more reliable and specific information about physical work demands at the workplace. This information is of use in a population already at risk of developing low back pain (LBP) due to whole body vibration (WBV) exposure. The aims of this study are to assess the WBV exposure in an exposed population and to assess other physical work demands in two ways, by direct observation and with the use of a self-administered questionnaire. We therefore assessed the WBV magnitude and 5 WBV-related physical work demands by using the PalmTrac system and a self-administered questionnaire in a group of drivers ( N=10). The main findings are 7 out of 10 drivers are exceeding the EU action value. About 50% of the drivers under-estimated the time 'bending', 60% the time 'walking+standing' and 60% over-estimated the time when 'lifting.' We concluded that 7 drivers from this group are at risk of developing LBP and substantial differences exists for the 5 physical work demands comparing the PalmTrac method with the questionnaire. Direct observational assessment in WBV measurements yields extra information. This is useful for preventive activities necessary as drivers are exceeding the EU action value.

  1. Temporal and spatial strategies in an active place avoidance task on Carousel: a study of effects of stability of arena rotation speed in rats

    PubMed Central

    Stuchlík, Aleš

    2015-01-01

    The active place avoidance task is a dry-arena task used to assess spatial navigation and memory in rodents. In this task, a subject is put on a rotating circular arena and avoids an invisible sector that is stable in relation to the room. Rotation of the arena means that the subject’s avoidance must be active, otherwise the subject will be moved in the to-be-avoided sector by the rotation of the arena and a slight electric shock will be administered. The present experiment explored the effect of variable arena rotation speed on the ability to avoid the to-be-avoided sector. Subjects in a group with variable arena rotation speed learned to avoid the sector with the same speed and attained the same avoidance ability as rats in a group with a stable arena rotation speed. Only a slight difference in preferred position within the room was found between the two groups. No difference was found between the two groups in the dark phase, where subjects could not use orientation cues in the room. Only one rat was able to learn the avoidance of the to-be-avoided sector in this phase. The results of the experiment suggest that idiothetic orientation and interval timing are not crucial for learning avoidance of the to-be-avoided sector. However, idiothetic orientation might be sufficient for avoiding the sector in the dark. PMID:26417540

  2. Temporal and spatial strategies in an active place avoidance task on Carousel: a study of effects of stability of arena rotation speed in rats.

    PubMed

    Bahník, Štěpán; Stuchlík, Aleš

    2015-01-01

    The active place avoidance task is a dry-arena task used to assess spatial navigation and memory in rodents. In this task, a subject is put on a rotating circular arena and avoids an invisible sector that is stable in relation to the room. Rotation of the arena means that the subject's avoidance must be active, otherwise the subject will be moved in the to-be-avoided sector by the rotation of the arena and a slight electric shock will be administered. The present experiment explored the effect of variable arena rotation speed on the ability to avoid the to-be-avoided sector. Subjects in a group with variable arena rotation speed learned to avoid the sector with the same speed and attained the same avoidance ability as rats in a group with a stable arena rotation speed. Only a slight difference in preferred position within the room was found between the two groups. No difference was found between the two groups in the dark phase, where subjects could not use orientation cues in the room. Only one rat was able to learn the avoidance of the to-be-avoided sector in this phase. The results of the experiment suggest that idiothetic orientation and interval timing are not crucial for learning avoidance of the to-be-avoided sector. However, idiothetic orientation might be sufficient for avoiding the sector in the dark. PMID:26417540

  3. Security of two-way continuous-variable quantum key distribution with source noise

    NASA Astrophysics Data System (ADS)

    Wang, Tianyi; Yu, Song; Zhang, Yi-Chen; Gu, Wanyi; Guo, Hong

    2014-11-01

    We investigate the security of reverse reconciliation two-way continuous-variable quantum key distribution with source noise at both legitimate sides. Because the source noise originates from imperfect devices, we ascribe it to the legitimate sides rather than the eavesdropper. The trusted model consists of a thermal noise injected into a beam splitter. The expressions of secret key rate are derived against collective entangling cloner attacks for homodyne and heterodyne detections. Simulation results show that by applying the trusted model, the security bound of the reverse reconciliation two-way protocols can be tightened, while the advantage over one-way protocols still maintains.

  4. Two-way Gaussian quantum cryptography against coherent attacks in direct reconciliation

    NASA Astrophysics Data System (ADS)

    Ottaviani, Carlo; Mancini, Stefano; Pirandola, Stefano

    2015-12-01

    We consider a two-way quantum cryptographic protocol with coherent states assuming direct reconciliation. A detailed security analysis is performed considering a two-mode coherent attack, which represents the residual eavesdropping once the parties have reduced the general attack by applying symmetric random permutations. In this context we provide a general analytical expression for the key rate, discussing the impact of the residual two-mode correlations on the security of the scheme. In particular, we identify the optimal eavesdropping against two-way quantum communication, which is given by a two-mode coherent attack with symmetric and separable correlations.

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

    SciTech Connect

    Lu Hua; Fung, Chi-Hang Fred; Ma Xiongfeng; Cai Qingyu

    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 general attacks.

  6. 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

  7. The two-way relationship between ionospheric outflow and the ring current

    NASA Astrophysics Data System (ADS)

    Welling, D. T.; Jordanova, V. K.; Glocer, A.; Toth, G.; Liemohn, M. W.; Weimer, D. R.

    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 Adaptive 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 noncoupled 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.

  8. The two-way relationship between ionospheric outflow and the ring current

    SciTech Connect

    Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex; Toth, Gabor; Liemohn, Michael W.; Weimer, Dan R.

    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 Adaptive 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.

  9. The two-way relationship between ionospheric outflow and the ring current

    DOE PAGESBeta

    Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex; Toth, Gabor; Liemohn, Michael W.; Weimer, Dan R.

    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

  10. Active Power Rescheduling for Avoiding Voltage Collapse Using Modified Bare Bones Particle Swarm Optimization

    NASA Astrophysics Data System (ADS)

    Arya, Rajesh; Purey, Pradeep

    2016-06-01

    MW-generation rescheduling is being considered for voltage stability improvement under stressed operating condition. At times it can avoid voltage collapse. This paper describes an algorithm for determination of optimum MW-generation participation pattern for static voltage stability margin enhancement. The optimum search direction has been obtained by employing modified bare born particle swarm optimization technique. Optimum search direction is based on maximization of distance to point of collapse in generation space. Developed algorithm has been implemented on a standard 25 bus test system. Results obtained have been compared with those obtained using standard particle swarm optimization.

  11. Active Power Rescheduling for Avoiding Voltage Collapse Using Modified Bare Bones Particle Swarm Optimization

    NASA Astrophysics Data System (ADS)

    Arya, Rajesh; Purey, Pradeep

    2015-06-01

    MW-generation rescheduling is being considered for voltage stability improvement under stressed operating condition. At times it can avoid voltage collapse. This paper describes an algorithm for determination of optimum MW-generation participation pattern for static voltage stability margin enhancement. The optimum search direction has been obtained by employing modified bare born particle swarm optimization technique. Optimum search direction is based on maximization of distance to point of collapse in generation space. Developed algorithm has been implemented on a standard 25 bus test system. Results obtained have been compared with those obtained using standard particle swarm optimization.

  12. 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.

  13. Study on stress characteristics of Francis hydraulic turbine runner based on two-way FSI

    NASA Astrophysics Data System (ADS)

    Zhu, W. R.; Xiao, R. F.; Yang, W.; Liu, J.; Wang, F. J.

    2012-11-01

    In recent years, cracking phenomenon occurs in many large-sized turbines both nationally and internationally, which has threatened the stable operation of hydraulic turbines. Consequently, Stress characteristics calculation and analysis of a Francis hydraulic turbine runner by application of fluid-structure interaction (FSI) technology become significantly important. In order to introduce two-way coupling technology to hydraulic machinery, two-way FSI technology is applied in this article to calculate and analyze stress characteristics. Through coordinate system transformation, the continuity equations and Navier-Stokes equations in the Cartesian coordinates system are firstly transformed to ALE coordinates system. The fluid field control equations are then constructed and discrete equations can be obtained by using flow-condition-based interpolation (FBIC-C). The structure static mechanics equations used are established in rotation coordinate system, and modeled with the finite method. Two-way coupling is computed by using iteration method. The fluid equations and structure equations are iterated until coupling coefficients converge. According to structure result, the maximum stress, displacement as well as its location can be found. As a result, the most easily wear position can be discovered which provides valuable basis for optimized design and stable operation of Francis hydraulic turbines. After comparing the results with that of one-way coupling, it is discovered that displacements is the key factors which affects the results of one-way and two-way coupling.

  14. Language Choice & Language Power: Children's Use of Korean & English in a Two-Way Immersion Program

    ERIC Educational Resources Information Center

    Lee, Soyong

    2014-01-01

    In this article, the author explores the phenomenon of children's language choice and language use in a Korean-English two-way immersion (TWI) program. She does so by drawing on situations in which the children spoke of the principles guiding their choice of languages, and instances in which they voluntarily adopted Korean as the means of…

  15. 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…

  16. 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…

  17. A Systematic Approach to Training Faculty To Teach via a Two-Way Interactive Television System.

    ERIC Educational Resources Information Center

    Thoms, Karen Jarrett

    This paper addresses a systematic approach to training faculty to teach via two-way interactive television (ITV). The following ten training modules are presented: (1) Introduction to the ITV System, including terminology and ITV history/development; (2) Making ITV Work for You, including syllabus construction, ITV equipment, and…

  18. 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 comparison…

  19. Rural Communities Communicating: The Emergence of Two-Way Interactive Video in Southwestern, Rural, Small Schools.

    ERIC Educational Resources Information Center

    Sullivan, Michael; And Others

    In three southwestern states, grassroots movements of citizens, educators, and local businesses developed and implemented two-way interactive television projects in their schools and communities. A descriptive multiple case study design was used to examine six project sites in New Mexico, Texas, and Oklahoma. Research questions were categorized in…

  20. Race, Power, and (In)equity within Two-Way Immersion Settings

    ERIC Educational Resources Information Center

    Scanlan, Martin; Palmer, Deborah

    2009-01-01

    Two-way immersion schools provide a promising model for service delivery to students who are English language learners. With the goals of bilingualism, academic excellence, and cross cultural appreciation, these schools are designed to build bridges across linguistically heterogeneous student bodies. Yet while empirical evidence demonstrates that…

  1. 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…

  2. Trends in Two-Way Immersion Education. A Review of the Research.

    ERIC Educational Resources Information Center

    Howard, Elizabeth R.; Sugarman, Julie; Christian, Donna

    Two-way immersion (TWI) is an instructional approach that integrates native English speakers and native speakers of another language (usually Spanish) and provides instruction to both groups of students in both languages. While the model has been in existence in the United States for almost 40 years, the most dramatic growth has been seen over the…

  3. Two-Way Immersion Education in Germany: Bridging the Linguistic Gap

    ERIC Educational Resources Information Center

    Meier, Gabriela Sylvia

    2010-01-01

    A PhD literature review in the field of two-way immersion (TWI) education revealed that German TWI programmes are hardly ever mentioned in English-language publications. There have been several TWI programmes in Germany since the 1960s with an increase in number and language combinations since the 1990s. This article provides an overview of German…

  4. Implementing Two-Way Immersion Programs in Secondary Schools. Educational Practice Report 5.

    ERIC Educational Resources Information Center

    Montone, Christopher L.; Loeb, Michael I.

    Elementary two-way immersion (TWI) programs continue to proliferate throughout the United States, but the number of successfully implemented secondary TWI programs remains small. Many districts with TWI cohorts that are reaching the upper elementary grades must now make complex decisions about whether and how to extend their programs into middle…

  5. 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, and…

  6. 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

  7. Improving Bilingual Service Delivery in Catholic Schools through Two-Way Immersion

    ERIC Educational Resources Information Center

    Scanlan, Martin; Zehrbach, Gareth

    2010-01-01

    Catholic elementary schools underserve Latino students, especially those who are bilingual. This paper presents a conceptual argument for Catholic elementary schools to improve this by pursuing the two-way immersion model of bilingual service delivery in Spanish and English. The argument is presented in three stages. First, we show that Catholic…

  8. Evaluation of Model Selection Strategies for Cross-Level Two-Way Differential Item Functioning Analysis

    ERIC Educational Resources Information Center

    Patarapichayatham, Chalie; Kamata, Akihito; Kanjanawasee, Sirichai

    2012-01-01

    Model specification issues on the cross-level two-way differential item functioning model were previously investigated by Patarapichayatham et al. (2009). Their study clarified that an incorrect model specification can easily lead to biased estimates of key parameters. The objective of this article is to provide further insights on the issue by…

  9. Languages across Borders: Social Network Development in an Adolescent Two-Way Dual-Language Program

    ERIC Educational Resources Information Center

    Kibler, Amanda K.; Atteberry, Allison; Hardigree, Christine N.; Salerno, April S.

    2015-01-01

    Background/Context: Two-way dual-language programs have become an increasingly popular educational model in the United States for language minority and majority speakers, with a small but growing number of programs at the high school level. Little is known, however, about how adolescents' social networks develop in the contexts of these programs.…

  10. Two-Way Bilingual Immersion Programs: Toward a More Inclusive Agenda in Bilingual Education.

    ERIC Educational Resources Information Center

    Reyes, Sharon Adelman

    2001-01-01

    Examines essential components of quality two-way bilingual immersion programs. Discusses language acquisition research underlying context-embedded content-area instruction in a second language; research on the benefits of bilingualism in terms of academic, cognitive, and metalinguistic development; and the link between bilingualism and positive…

  11. Emerging Literacy in a Two-Way Bilingual First Grade Classroom.

    ERIC Educational Resources Information Center

    Kuhlman, Natalie A.; And Others

    A study investigated the emerging journal-writing skills of 16 monolingual Spanish-speaking Mexican Americans and 10 monolingual English-speaking first-graders in San Diego County, California, in a whole-language, two-way bilingual classroom. The research looked for developmental stages in writing in the primary language, similarities or…

  12. Two-Way Bilingual Education: Students Learning through Two Languages. Final Report.

    ERIC Educational Resources Information Center

    Christian, Donna; Montone, Chris; Carranza, Isolda; Lindholm, Kathryn; Proctor, Patrick

    The report presents results of a study of elementary and secondary school two-way bilingual immersion programs that focused on the program and contextual factors affecting student learning, student and teacher language use in the classroom, and teaching strategies used to promote target language use and increase language proficiency. The study…

  13. 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…

  14. 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…

  15. 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…

  16. Parental Motivation, Attitudes, Support, and Commitment in a Southern Californian Two-Way Immersion Program

    ERIC Educational Resources Information Center

    Giacchino-Baker, Rosalie; Piller, Bonnie

    2006-01-01

    This article reports a study of parental motivation, attitudes, support, and commitment for the second year of the two-way immersion (TWI) program at an elementary school in San Bernardino, California. Findings include the unique aspects of border communities; similarities and differences between Spanish-language and English-language participants;…

  17. Mental Health of Two-Way Migrants: From Puerto Rico to the United States and Return.

    ERIC Educational Resources Information Center

    Prewitt Diaz, Joseph O.; Draguns, Juris G.

    The mental health needs of two-way migrants from Puerto Rico to the United States and back again are discussed in this paper. Four factors affecting Puerto Rican migrants are outlined. First, the relationship between migration and stress is considered. Often, it is noted, in migrating away from stressful economic conditions, the Puerto Rican…

  18. Advanced two-way satellite frequency transfer by carrier-phase and carrier-frequency measurements

    NASA Astrophysics Data System (ADS)

    Fujieda, Miho; Gotoh, Tadahiro; Amagai, Jun

    2016-06-01

    Carrier-phase measurement is one of the ways to improve the measurement resolution of two-way satellite frequency transfer. We introduce two possible methods for carrier-phase measurement: direct carrier-phase detection identified by Two-Way Carrier-Phase (TWCP) and the use of carrier-frequency information identified by Two-Way Carrier Frequency (TWCF). We performed the former using an arbitrary waveform generator and an analog-to-digital sampler and the latter using a conventional modem. The TWCF measurement using the modem had a resolution of 10-13 and the result agreed with that obtained by GPS carrier-phase frequency transfer in a 1500 km baseline. The measurement accuracy may have been limited by the poor frequency resolution of the modem; however, the TWCF measurement was able to improve the stability of conventional two-way satellite frequency transfer. Additionally, we show that the TWCP measurement system has the potential to achieve a frequency stability of 10-17.

  19. A Bayesian Solution for Two-Way Analysis of Variance. ACT Technical Bulletin No. 8.

    ERIC Educational Resources Information Center

    Lindley, Dennis V.

    The standard statistical analysis of data classified in two ways (say into rows and columns) is through an analysis of variance that splits the total variation of the data into the main effect of rows, the main effect of columns, and the interaction between rows and columns. This paper presents an alternative Bayesian analysis of the same…

  20. Two-Way Bilingual Education: Students Learning through Two Languages. Educational Practice Report: 12.

    ERIC Educational Resources Information Center

    Christian, Donna

    Since the mid-1980s two-way bilingual education programs have attracted renewed interest as an effective way to educate both language-minority and language-majority students. This report, which describes and assesses the current state of such programs in the United States, is based on data collected from 169 schools during the 1991-92, 1992-93,…

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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

  3. The Florida Teletraining Project: Military Training via Two-Way Compressed Video.

    ERIC Educational Resources Information Center

    Bramble, William J.; Martin, Barbara L.

    1995-01-01

    The Florida Teletraining Project tested the feasibility of using community colleges for training military personnel in the Reserve Components. Five interactive video courses were produced, delivered, and evaluated. The project demonstrated the potential of two-way video teletraining for military personnel. (AEF)

  4. 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. PMID:3359256

  5. Training bottlenose dolphins to overcome avoidance of environmental enrichment objects in order to stimulate play activities.

    PubMed

    Neto, Márcia P; Silveira, Miguel; Dos Santos, Manuel E

    2016-05-01

    Enrichment programs may contribute to the quality of life and stress reduction in bottlenose dolphins (Tursiops truncatus) kept in zoos and aquaria. The results of these programs are generally positive in terms of welfare, but the magnitude of their effects may vary greatly between individuals of the same species, especially when the enrichment plans are based on the introduction of manipulative objects. Some animals will interact spontaneously with novel objects, even without food rewards and in the absence of the trainers, while others show no interest or even aversion toward the objects. To determine if formal training can improve these conditions, we measured the effects of an operant conditioning program in the manipulation of objects by dolphins that initially avoided them. This program took place between April and October 2013 at Zoomarine Portugal. Subjects were two female and two male bottlenose dolphins (adults with ages from 17 to 35 years) that after a preliminary analysis showed avoidance or low interest in the manipulation of various toys. The level of interaction with introduced enrichment objects was observed before and after formal training to explore the toys (sixteen 20-min observation sessions per animal "before" and "after training"). In all subjects, an index of interest in object manipulation, in the absence of trainers, increased significantly after the application of the training techniques. The results show that an initial reinforcement program focused on the manipulation of toys may overcome resistance, improving the effects of environmental enrichment plans, and it is a potentially useful strategy to increase the welfare of some captive animals. Zoo Biol. 35:210-215, 2016. © 2016 Wiley Periodicals, Inc. PMID:26969822

  6. Active faults crossing trunk pipeline routes: some important steps to avoid disaster

    NASA Astrophysics Data System (ADS)

    Besstrashnov, V. M.; Strom, A. L.

    2011-05-01

    Assessment of seismic strong motion hazard produced by earthquakes originating within causative fault zones allows rather low accuracy of localisation of these structures that can be provided by indirect evidence of fault activity. In contrast, the relevant accuracy of localisation and characterisation of active faults, capable of surface rupturing, can be achieved solely by the use of direct evidence of fault activity. This differentiation requires strict definition of what can be classified as "active fault" and the normalisation of methods used for identification and localisation of active faults crossing oil and natural gas trunk pipelines.

  7. Avoiding Ticks

    MedlinePlus

    ... Avoiding ticks On people On pets In the yard Removing a tick Symptoms of tickborne illness Geographic ... ticks on your pets Preventing ticks in the yard File Formats Help: How do I view different ...

  8. 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-of-train devices. 232.405 Section 232.405 Transportation Other Regulations Relating to Transportation... Design and performance standards for two-way end-of-train devices. Two-way end-of-train devices shall...

  9. General existence of locally distinguishable maximally entangled states only with two-way classical communication

    PubMed Central

    Tian, Guojing; Wu, Xia; Cao, Ya; Gao, Fei; Wen, Qiaoyan

    2016-01-01

    It is known that there exist two locally operational settings, local operations with one-way and two-way classical communication. And recently, some sets of maximally entangled states have been built in specific dimensional quantum systems, which can be locally distinguished only with two-way classical communication. In this paper, we show the existence of such sets is general, through constructing such sets in all the remaining quantum systems. Specifically, such sets including p or n maximally entangled states will be built in the quantum system of (np − 1) ⊗ (np − 1) with n ≥ 3 and p being a prime number, which completes the picture that such sets do exist in every possible dimensional quantum system. PMID:27440087

  10. General existence of locally distinguishable maximally entangled states only with two-way classical communication.

    PubMed

    Tian, Guojing; Wu, Xia; Cao, Ya; Gao, Fei; Wen, Qiaoyan

    2016-01-01

    It is known that there exist two locally operational settings, local operations with one-way and two-way classical communication. And recently, some sets of maximally entangled states have been built in specific dimensional quantum systems, which can be locally distinguished only with two-way classical communication. In this paper, we show the existence of such sets is general, through constructing such sets in all the remaining quantum systems. Specifically, such sets including p or n maximally entangled states will be built in the quantum system of (np - 1) ⊗ (np - 1) with n ≥ 3 and p being a prime number, which completes the picture that such sets do exist in every possible dimensional quantum system. PMID:27440087

  11. 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.

  12. 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.

  13. 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. PMID:26476193

  14. Cysteamine and pantethine effects on passive avoidance behavior, shuttle box learning, open-field activity, striatal catecholamines and somatostatin.

    PubMed

    Vécsei, L; Widerlöv, E; Ekman, R; Alling, C

    1989-01-01

    The effects of cysteamine and pantethine were compared on different behavioral tests and neurochemical parameters in rats. Cysteamine, administered in high dose (3.90 mM/kg s.c.), decreased the locomotor and rearing activities of rats, while it slightly but not significantly increased the avoidance latency in a passive avoidance test. Pantethine, 24 hr after its administration, significantly increased the dihydroxyphenyl acetic acid (DOPAC) levels in the striatum. Cysteamine slightly reduced the DOPAC level without influencing the catecholamine levels in this brain area. The striatal somatostatin concentration was reduced 24 hr after the administration of cysteamine, while pantethine did not influence it. After repeated daily injections of pantethine, the drug facilitated the shuttle box learning process and increased the intertrial and open-field activities of the animals. Cysteamine only slightly increased the locomotion and rearing and did not influence the shuttle box learning. Both pantethine and cysteamine slowed the rate of the "body weight increase" of the animals when compared to a saline-treated group. These findings suggest that the locomotor activation induced by pantethine 24 hr after its administration plays an important role in its behavioral effects. It might be that the striatal dopaminergic transmission, modified by administration of pantethine, plays some role in the higher locomotor activity induced by the substance. PMID:2570553

  15. Geostationary satellite position determination for common-view two-way time transfer measurements

    NASA Technical Reports Server (NTRS)

    Zhuang, Qixiang; Douglas, Robert J.

    1992-01-01

    In common-view two-way time transfer, each earth station receives an unwanted return signal from its own transmission as well as the desired signal from the other earth station. National Institute of Standards and Technology (NIST), the National Research Council (NRC), and the U.S. Naval Observatory (USNO) have been cooperating in a three-corner common-view two-way time transfer experiment. Some systematic effects are known to depend on the position of the satellite (Sagnac effect and the cross-correlation pulling of the pseudo-random codes). A method is presented for deriving accurate satellite ranges from each of three stations doing common-view two-way satellite time transfer measurements, when one (and only one) station also takes ranging measurements on its 'unwanted return signal' for a brief period. The method is applied to determine the variations in position of the satellite used over the course of the NIST/NRC/USNO SBS-3 experiment, with ranging data taken at NRC, where no additional hardware was required to automate the process. The fit and extrapolation which are employed in this method have an estimated precision of 2 m. If the delays of SBS-3 satellite KU band transponder and earth station equipment were measured accurately as well as the tropospheric refractions were well modeled and corrected, we would expect a ranging accuracy of 2.5 m and satellite positioning accuracy would be 200 m (latitude) 50 m (longitude) and 20 m (height above ellipsoid).

  16. 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

  17. Engineering a portable riboswitch-LacP hybrid device for two-way gene regulation.

    PubMed

    Jin, Ye; Huang, Jian-Dong

    2011-10-01

    Riboswitches are RNA-based regulatory devices that mediate ligand-dependent control of gene expression. However, there has been limited success in rationally designing riboswitches. Moreover, most previous riboswitches are confined to a particular gene and only perform one-way regulation. Here, we used a library screening strategy for efficient creation of ON and OFF riboswitches of lacI on the chromosome of Escherichia coli. We then engineered a riboswitch-LacP hybrid device to achieve portable gene control in response to theophylline and IPTG. Moreover, this device regulated target expression in a 'two-way' manner: the default state of target expression was ON; the expression was switched off by adding theophylline and restored to the ON state by adding IPTG without changing growth medium. We showcased the portability and two-way regulation of this device by applying it to the small RNA CsrB and the RpoS protein. Finally, the use of the hybrid device uncovered an inhibitory role of RpoS in acetate assimilation, a function which is otherwise neglected using conventional genetic approaches. Overall, this work establishes a portable riboswitch-LacP device that achieves sequential OFF-and-ON gene regulation. The two-way control of gene expression has various potential scientific and biotechnological applications and helps reveal novel gene functions. PMID:21803790

  18. Damage assessment of two-way bending RC slabs subjected to blast loadings.

    PubMed

    Jia, Haokai; Yu, Ling; 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

  19. [Influence of chronic melipramine administration abolition on locomotion and defensive conditioned reflexes in passive and active avoidance in rats].

    PubMed

    Orlova, N V; Folomkina, A A; Koshtoiants, O Kh; Bazian, A S

    2005-01-01

    The chronic (21 days duration) administration of tricyclic antidepressant melipramine of Wistar rats strain (15 mg/kg daily, intraperitoneally) evoked weight loss of animals. The 7 days after melipramine abolition its sedative effect was observed in the "open field" test by decrease of locomotion and the number of boles. The 7 and 14 days after melipramine abolition the difference between control and melipramine treated animals in passive and active avoidance learning and memory not found. The experimental results comparison with the literature data show, that chronic melipramine administration of intact animals evokes a sedative state. This conclusion does not contradict to idea of punishment function of brain serotoninergic system. PMID:15828425

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

    DOE PAGESBeta

    Benafan, O.; Padula, S. A.; Noebe, R. D.; Sisneros, T. A.; Vaidyanathan, R.

    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' deformation twinning, and dislocationmore » 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

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

    NASA Astrophysics Data System (ADS)

    Benafan, O.; Padula, S. A.; Noebe, R. D.; Sisneros, T. A.; Vaidyanathan, R.

    2012-11-01

    Deformation of a B19' martensitic, polycrystalline Ni49.9Ti50.1 (at. %) shape memory alloy 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 situ neutron 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' deformation 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.

  2. Dual-Responsive Lipid Nanotubes: Two-Way Morphology Control by pH and Redox Effects.

    PubMed

    Unsal, Hande; Schmidt, Judith; Talmon, Yeshayahu; Yildirim, Leyla Tatar; Aydogan, Nihal

    2016-05-31

    Lipid nanotubes are the preferred structures for many applications, especially biological ones, and thus have attracted much interest recently. However, there is still a significant need for developing more lipid nanotubes that are reversibly controllable to improve their functionality and usability. Here, we presented a two-way reversible morphology control of the nanotubes formed by the recently designed molecule AQUA (C25H29NO4). Because of its special design, the AQUA has both pH-sensitive and redox-active characters provided by the carboxylic acid and anthraquinone groups. Upon chemical reduction, the nanotubes turned into thinner ribbons, and this structural transformation was significantly reversible. The reduction of the AQUA nanotubes also switched the nanotubes from electrically conductive to insulative. Nanotube morphology can additionally be altered by decreasing the pH below the pKa value of the AQUA, at ∼4.9. Decreasing the pH caused the gradual unfolding of the nanotubes, and the interlayer distance in the nanotube's walls increased. This morphological change was fast and reversible at a wide pH range, including the physiological pH. Thus, the molecular design of the AQUA allowed for an unprecedented two-way and reversible morphology control with both redox and pH effects. These unique features make AQUA a very promising candidate for many applications, ranging from electronics to controlled drug delivery. PMID:27148756

  3. Accurate calculation of Stokes drag for point-particle tracking in two-way coupled flows

    NASA Astrophysics Data System (ADS)

    Horwitz, J. A. K.; Mani, A.

    2016-08-01

    In this work, we propose and test a method for calculating Stokes drag applicable to particle-laden fluid flows where two-way momentum coupling is important. In the point-particle formulation, particle dynamics are coupled to fluid dynamics via a source term that appears in the respective momentum equations. When the particle Reynolds number is small and the particle diameter is smaller than the fluid scales, it is common to approximate the momentum coupling source term as the Stokes drag. The Stokes drag force depends on the difference between the undisturbed fluid velocity evaluated at the particle location, and the particle velocity. However, owing to two-way coupling, the fluid velocity is modified in the neighborhood of a particle, relative to its undisturbed value. This causes the computed Stokes drag force to be underestimated in two-way coupled point-particle simulations. We develop estimates for the drag force error as function of the particle size relative to the grid size. Because the disturbance field created by the particle contaminates the surrounding fluid, correctly calculating the drag force cannot be done solely by direct interpolation of the fluid velocity. Instead, we develop a correction method that calculates the undisturbed fluid velocity from the computed disturbed velocity field by adding an estimate of the velocity disturbance created by the particle. The correction scheme is tested for a particle settling in an otherwise quiescent fluid and is found to reduce the error in computed settling velocity by an order of magnitude compared with common interpolation schemes.

  4. One way and two way VHF ranging system performance for tracking and data relay applications

    NASA Technical Reports Server (NTRS)

    Bryan, J. W.; Filippi, C. A.

    1972-01-01

    The trajectory of an orbiting spacecraft is determined from an orbit determination program. Two inputs to this program, among others, are the range and range rate relative to some known location. The arithmetic and measurement errors in the determinations of the range, range rate, and range differences were identified and evaluated. These uncertainties are tabulated for one way and two way systems. A comparison of the measurement error contributions illustrate the predominance of thermal noise effects under low power budget conditions, with the other error sources becoming relevent for the high power budget case. The evaluated uncertainties are summarized as root sum squared noise and bias errors.

  5. Detecting short-term responses to weekend recreation activity: desert bighorn sheep avoidance of hiking trails

    USGS Publications Warehouse

    Longshore, Kathleen; Lowrey, Chris; Thompson, Daniel B.

    2013-01-01

    To study potential effects of recreation activity on habitat use of desert bighorn sheep (Ovis canadensis nelsoni), we placed Global Positioning System collars on 10 female bighorn sheep within the Wonderland of Rocks–Queen Mountain region of Joshua Tree National Park (JOTR), California, USA, from 2002 to 2004. Recreation use was highest from March to April and during weekends throughout the year. Daily use of recreation trails was highest during midday. By comparing habitat use (slope, ruggedness, distance to water, and distance to recreation trails) of female bighorn sheep on weekdays versus weekends, we were able to detect short-term shifts in behavior in response to recreation. In a logistic regression of bighorn sheep locations versus random locations for March and April, female locations at midday (1200 hours) were significantly more distant from recreation trails on weekends compared with weekdays. Our results indicate that within this region of JOTR, moderate to high levels of human recreation activity may temporarily exclude bighorn females from their preferred habitat. However, the relative proximity of females to recreation trails during the weekdays before and after such habitat shifts indicates that these anthropogenic impacts were short-lived. Our results have implications for management of wildlife on public lands where the co-existence of wildlife and recreational use is a major goal.

  6. Temperature- and Touch-Sensitive Neurons Couple CNG and TRPV Channel Activities to Control Heat Avoidance in Caenorhabditis elegans

    PubMed Central

    Liu, Shu; Schulze, Ekkehard; Baumeister, Ralf

    2012-01-01

    Background Any organism depends on its ability to sense temperature and avoid noxious heat. The nematode Caenorhabditis elegans responds to noxious temperatures exceeding ∼35°C and also senses changes in its environmental temperature in the range between 15 and 25°C. The neural circuits and molecular mechanisms involved in thermotaxis have been successfully studied, whereas details of the thermal avoidance behavior remain elusive. In this work, we investigate neurological and molecular aspects of thermonociception using genetic, cell biological and physiological approaches. Methodology/Principal Findings We show here that the thermosensory neurons AFD, in addition to sensing temperature within the range within which the animals can thrive, also contribute to the sensation of noxious temperatures resulting in a reflex-like escape reaction. Distinct sets of interneurons are involved in transmitting thermonociception and thermotaxis, respectively. Loss of AFD is partially compensated by the activity of a pair of multidendritic, polymodal neurons, FLP, whereas laser ablation of both types of neurons abrogated the heat response in the head of the animals almost completely. A third pair of heat sensory neurons, PHC, is situated in the tail. We find that the thermal avoidance response requires the cell autonomous function of cGMP dependent Cyclic Nucleotide-Gated (CNG) channels in AFD, and the heat- and capsaicin-sensitive Transient Receptor Potential Vanilloid (TRPV) channels in the FLP and PHC sensory neurons. Conclusions/Significance Our results identify distinct thermal responses mediated by a single neuron, but also show that parallel nociceptor circuits and molecules may be used as back-up strategies to guarantee fast and efficient responses to potentially detrimental stimuli. PMID:22448218

  7. Multiple phase screen calculation of two-way spherical wave propagation in the ionosphere

    NASA Astrophysics Data System (ADS)

    Knepp, Dennis L.

    2016-04-01

    This paper presents a numerical solution to the parabolic wave equation for spherical wave propagation in a disturbed ionosphere. The solution uses the Fourier/split step approach where the propagation medium is modeled using multiple phase-changing screens separated by free space. The phase screens can consist of deterministic or random components describing spatial scales of any size. This solution consists of realizations of the signal (i.e., the ionospheric transfer function) after two-way propagation from a transmitter, through the medium to a target, and back. The transmitter and target can be comprised of multiple, independent point scatterers. The solution is applicable to many propagation problems including synthetic aperture radar and is not subject to the small-scene limitation, where all scatterers in the scene experience identical propagation conditions. Several examples are given illustrating some features of the solution including reciprocity, relationship between one- and two-way (monostatic and bistatic) scintillation index, and reflection from a large target.

  8. Turbulent phase noise on asymmetric two-way ground-satellite coherent optical links

    NASA Astrophysics Data System (ADS)

    Robert, Clélia; Conan, Jean-Marc; Wolf, Peter

    2015-10-01

    Bidirectional ground-satellite laser links suffer from turbulence-induced scintillation and phase distortion. We study how turbulence impacts on coherent detection capacity and on the associated phase noise that restricts clock transfer precision. We evaluate the capacity to obtain a two-way cancellation of atmospheric effects despite the asymmetry between up and down link that limits the link reciprocity. For ground-satellite links, the asymmetry is induced by point-ahead angle and possibly the use, for the ground terminal, of different transceiver diameters, in reception and emission. The quantitative analysis is obtained thanks to refined end-to-end simulations under realistic turbulence and wind conditions as well as satellite cinematic. Simulations make use of the reciprocity principle to estimate both down and up link performance from wave-optics propagation of descending plane waves. These temporally resolved simulations allow characterising the coherent detection in terms of time series of heterodyne efficiency for different system parameters. We show Tip/Tilt correction on ground is mandatory at reception for the down link and as a pre-compensation of the up link. Good correlation between up and down phase noise is obtained even with asymmetric apertures of the ground transceiver and in spite of pointing ahead angle. The reduction to less than 1 rad2 of the two-way differential phase noise is very promising for clock transfer.

  9. 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.

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

    SciTech Connect

    Sun Shihai; Jiang Musheng; Liang Linmei

    2011-06-15

    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.

  11. Two-Way Partial Immersion Program, F. S. Key Elementary School. Units of Study--Grades 1-4. Curriculum Guide, Units of Study.

    ERIC Educational Resources Information Center

    Von Vacano, Marcela; And Others

    The curriculum guide for a Spanish two-way partial immersion program in the Francis Scott Key Elementary School (Arlington, Virginia) is designed as a reference for parents and teachers. It presents information, instructional objectives, and activities in the form of integrated instructional units for grades K-4. Introductory sections outline: the…

  12. Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO

    NASA Technical Reports Server (NTRS)

    Duffy, James B.

    1993-01-01

    The purpose of the Advanced Transportation System Study (ATSS) task area 1 study effort is to examine manned launch vehicle booster concepts and two-way cargo transfer and return vehicle concepts to determine which of the many proposed concepts best meets NASA's needs for two-way transportation to low earth orbit. The study identified specific configurations of the normally unmanned, expendable launch vehicles (such as the National Launch System family) necessary to fly manned payloads. These launch vehicle configurations were then analyzed to determine the integrated booster/spacecraft performance, operations, reliability, and cost characteristics for the payload delivery and return mission. Design impacts to the expendable launch vehicles which would be required to perform the manned payload delivery mission were also identified. These impacts included the implications of applying NASA's man-rating requirements, as well as any mission or payload unique impacts. The booster concepts evaluated included the National Launch System (NLS) family of expendable vehicles and several variations of the NLS reference configurations to deliver larger manned payload concepts (such as the crew logistics vehicle (CLV) proposed by NASA JSC). Advanced, clean sheet concepts such as an F-1A engine derived liquid rocket booster (LRB), the single stage to orbit rocket, and a NASP-derived aerospace plane were also included in the study effort. Existing expendable launch vehicles such as the Titan 4, Ariane 5, Energia, and Proton were also examined. Although several manned payload concepts were considered in the analyses, the reference manned payload was the NASA Langley Research Center's HL-20 version of the personnel launch system (PLS). A scaled up version of the PLS for combined crew/cargo delivery capability, the HL-42 configuration, was also included in the analyses of cargo transfer and return vehicle (CTRV) booster concepts. In addition to strictly manned payloads, two-way cargo

  13. Double criticality and the two-way Boussinesq equation in stratified shallow water hydrodynamics

    NASA Astrophysics Data System (ADS)

    Bridges, Thomas J.; Ratliff, Daniel J.

    2016-06-01

    Double criticality and its nonlinear implications are considered for stratified N-layer shallow water flows with N = 1, 2, 3. Double criticality arises when the linearization of the steady problem about a uniform flow has a double zero eigenvalue. We find that there are two types of double criticality: non-semisimple (one eigenvector and one generalized eigenvector) and semi-simple (two independent eigenvectors). Using a multiple scales argument, dictated by the type of singularity, it is shown that the weakly nonlinear problem near double criticality is governed by a two-way Boussinesq equation (non-semisimple case) and a coupled Korteweg-de Vries equation (semisimple case). Parameter values and reduced equations are constructed for the examples of two-layer and three-layer stratified shallow water hydrodynamics.

  14. Two-way coupling of Presto v2.8 and CTH v8.1.

    SciTech Connect

    Bruner, Christopher William Stuteville; Bishop, Joseph E.; Crawford, David A.; Edwards, Harold Carter

    2008-07-01

    A loose two-way coupling of SNL's Presto v2.8 and CTH v8.1 analysis code has been developed to support the analysis of explosive loading of structures. Presto is a Lagrangian, three-dimensional explicit, transient dynamics code in the SIERRA mechanics suite for the analysis of structures subjected to impact-like loads. CTH is a hydro code for modeling complex multi-dimensional, multi-material problems that are characterized by large deformations and/or strong shocks. A fundamental assumption in this loose coupling is that the compliance of the structure modeled with Presto is significantly smaller than the compliance of the surrounding medium (e.g. air) modeled with CTH. A current limitation of the coupled code is that the interaction between CTH and thin structures modeled in Presto (e.g. shells) is not supported. Research is in progress to relax this thin-structure limitation.

  15. Intelsat two-way time transfer experiments between Japan, Korea and Taiwan

    SciTech Connect

    Engelkemier, B.; Imamura, K.; Takahashi, F.

    1994-12-31

    This paper describes the first two-way time transfer experiments using Intelsat Ku-band satellites in eastern Asia performed by Communications Research Laboratory (CRL: Japan), Korea Research Institute of Standard and Science (KRISS: Korea) and Telecommunication Laboratory (TL: Taiwan) in 1992. The experiments are based on the recommendation of Conference Generale des Poids et Mesures (CGPM) in 1987. Also they are based on the international cooperation program between CRL and KRISS, and institute-level cooperation between CRL and TL. The experiments attained the short-term precision better than 1 ns, which is much better than conventional GPS time transfer. Long-term precision was not so good as short-term one. We discuss the reasons of the long-term instabilities. We can also established the procedures to use Intelsat satellites under the support of Intelsat Headquarters and each countries` common carrier agents.

  16. Symmetry breaking in optimal timing of traffic signals on an idealized two-way street

    NASA Astrophysics Data System (ADS)

    Panaggio, Mark J.; Ottino-Löffler, Bertand J.; Hu, Peiguang; Abrams, Daniel M.

    2013-09-01

    Simple physical models based on fluid mechanics have long been used to understand the flow of vehicular traffic on freeways; analytically tractable models of flow on an urban grid, however, have not been as extensively explored. In an ideal world, traffic signals would be timed such that consecutive lights turned green just as vehicles arrived, eliminating the need to stop at each block. Unfortunately, this “green-wave” scenario is generally unworkable due to frustration imposed by competing demands of traffic moving in different directions. Until now this has typically been resolved by numerical simulation and optimization. Here, we develop a theory for the flow in an idealized system consisting of a long two-way road with periodic intersections. We show that optimal signal timing can be understood analytically and that there are counterintuitive asymmetric solutions to this signal coordination problem. We further explore how these theoretical solutions degrade as traffic conditions vary and automotive density increases.

  17. A two-way interaction between the Hainan plume and the Manila subduction zone

    NASA Astrophysics Data System (ADS)

    Mériaux, Catherine A.; Duarte, João. C.; Schellart, Wouter P.; Mériaux, Anne-Sophie

    2015-07-01

    The interaction between mantle plumes and subducting slabs is well accepted, but the influence of slabs on plumes has more often been portrayed than the reverse. Here we present three-dimensional upper mantle laboratory models in which a compositional plume rises underneath a subducting plate. Slab/plume buoyancy flux ratios ranged between 7 and 18. The models exhibit a two-way interaction. While the plume conduit increasingly tilts away from the trench as a result of slab rollback-induced toroidal mantle flow, the slab subduction rate decreases as a function of the amount of plume buoyancy opposing that of the slab, which gets subducted beneath the slab. We propose that our models apply to the Hainan/Manila system and explain the recently imaged tilt of the Hainan plume by the Manila slab-induced mantle return flow. The Hainan plume could lessen the Manila subduction rate from 8 Ma into the future.

  18. An Upconversion Nanoparticle with Orthogonal Emissions Using Dual NIR Excitations for Controlled Two-way Photoswitching

    PubMed Central

    Lai, Jinping; Zhang, Yixiao; Pasquale, Nicholas

    2015-01-01

    Developing multicolor upconversion nanoparticles (UCNPs) with the capability of regulating their emission wavelengths in the UV to visible range in response to external stimuli can offer more dynamic platforms for applications in high resolution bio-imaging, multicolor barcoding and driving multiple important photochemical reactions, such as photoswitching. In this communication, we have rationally designed single crystal core-shell structured UCNPs which are capable of orthogonal UV and visible emissions in response to two distinct NIR excitations at 808 and 980 nm. The orthogonal excitation-emission properties of such UCNPs, as well as their ability to utilize low power excitation, which attenuates any local heating from the lasers, endows the UCNPs with great potential for applications in materials and biological settings. As a proof of concept, the use of this UCNP for the efficient regulation of the two-way photoswitching of spiropyran by using dual wavelengths of NIR irradiation has been demonstrated. PMID:25349100

  19. Two-way coupling between Vesuvius eruptions and southern Apennine earthquakes, Italy, by elastic stress transfer

    USGS Publications Warehouse

    Nostro, C.; Stein, R.S.; Cocco, M.; Belardinelli, M.E.; Marzocchi, W.

    1998-01-01

    During the past 1000 years, eruptions of Vesuvius have often been accompanied by large earthquakes in the Apennines 50-60 km to the northeast. Statistical investigations had shown that earthquakes often preceded eruptions, typically by less than a decade, but did not provide a physical explanation for the correlation. Here, we explore elastic stress interaction between earthquakes and eruptions under the hypothesis that small stress changes can promote events when the Apennine normal faults and the Vesuvius magma body are close to failure. We show that earthquakes can promote eruptions by compressing the magma body at depth and opening suitably oriented near-surface conduits. Voiding the magma body in turns brings these same normal faults closer to Coulomb failure, promoting earthquakes. Such a coupling is strongest if the magma reservoir is a dike oriented normal to the regional extension axis, parallel to the Apennines, and the near-surface conduits and fissures are oriented normal to the Apennines. This preferred orientation suggests that the eruptions issuing from such fissures should be most closely linked in time to Apennine earthquakes. Large Apennine earthquakes since 1400 are calculated to have transferred more stress to Vesuvius than all but the largest eruptions have transferred to Apennine faults, which may explain why earthquakes more commonly lead than follow eruptions. A two-way coupling may thus link earthquakes and Vesuvius eruptions along a 100-km-long set of faults. We test the statistical significance of the earthquake-eruption correlation in the two-way coupling zone, and find a correlation significant at the 95% confidence level.

  20. Towards positivity preservation for monolithic two-way solid-fluid coupling

    NASA Astrophysics Data System (ADS)

    Patkar, Saket; Aanjaneya, Mridul; Lu, Wenlong; Lentine, Michael; Fedkiw, Ronald

    2016-05-01

    We consider complex scenarios involving two-way coupled interactions between compressible fluids and solid bodies under extreme conditions where monolithic, as opposed to partitioned, schemes are preferred for maintaining stability. When considering such problems, spurious numerical cavitation can be quite common and have deleterious consequences on the flow field stability, accuracy, etc. Thus, it is desirable to devise numerical methods that maintain the positivity of important physical quantities such as density, internal energy and pressure. We begin by showing that for an arbitrary flux function, one can put conditions on the time step in order to preserve positivity by solving a linear equation for density fluxes and a quadratic equation for energy fluxes. Our formulation is independent of the underlying equation of state. After deriving the method for forward Euler time integration, we further extend it to higher order accurate Runge-Kutta methods. Although the scheme works well in general, there are some cases where no lower bound on the size of the allowable time step exists. Thus, to prevent the size of the time step from becoming arbitrarily small, we introduce a conservative flux clamping scheme which is also positivity preserving. Exploiting the generality of our formulation, we then design a positivity preserving scheme for a semi-implicit approach to time integration that solves a symmetric positive definite linear system to determine the pressure associated with an equation of state. Finally, this modified semi-implicit approach is extended to monolithic two-way solid-fluid coupling problems for modeling fluid structure interactions such as those generated by blast waves impacting complex solid objects.

  1. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines.

    PubMed

    López-Cruz, Roberto I; Crocker, Daniel E; Gaxiola-Robles, Ramón; Bernal, Jaime A; Real-Valle, Roberto A; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements. PMID:27375492

  2. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines

    PubMed Central

    López-Cruz, Roberto I.; Crocker, Daniel E.; Gaxiola-Robles, Ramón; Bernal, Jaime A.; Real-Valle, Roberto A.; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements. PMID:27375492

  3. 77 FR 37734 - Technical Standard Order (TSO) C-122a, Equipment That Prevent Blocked Channels Used in Two-Way...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-22

    ... Channels Used in Two-Way Radio Communications Due to Simultaneous Transmissions AGENCY: Federal Aviation..., Equipment That Prevent Blocked Channels Used in Two-Way Radio Communications Due to Simultaneous... means being used to address blocked channels caused by simultaneous transmissions. Issued in...

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

    PubMed

    Hao, Shijie; Liu, Yinong; Ren, Yang; Jiang, Daqiang; Yang, Feng; Cong, Daoyong; Wang, Yandong; Cui, Lishan

    2016-06-29

    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 ultralarge elastic strains are loaded inside a shape memory alloy (SMA) matrix to form a continuous array of nanobias 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 as high as that (∼500 MPa) found in reported two-way SMAs. Upon cooling, the composite shows an actuation stress of 134 MPa and a mechanical work output of 1.08 × 10(6) J/m(3), which are about three and five times higher than those of reported two-way SMAs, respectively. It was revealed that the massive number of Nb nanoribbons in the 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 a small volume and simple construct works well with the miniaturization and simplification of actuators. PMID:27276656

  5. 78 FR 21629 - Certain Two-Way Global Satellite Communication Devices, System and Components Thereof Issuance of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    .... of Alexandria, Virginia. 77 FR 58579-80. The complaint alleges violations of section 337 of the... COMMISSION Certain Two-Way Global Satellite Communication Devices, System and Components Thereof Issuance of... importation, and the sale within the United States after importation of certain two-way global...

  6. Building and Destroying Students' "Academic Identities": The Power of Discourse in a Two-Way Immersion Classroom

    ERIC Educational Resources Information Center

    Palmer, Deborah K.

    2008-01-01

    Two-way immersion is a model for bilingual education designed to help language-minority students develop additive bilingualism while at the same time offering language-majority students a chance to learn a second language. There is a great deal of rhetoric around two-way immersion that claims these programs aim to improve overall equity among…

  7. 77 FR 51045 - Certain Two-Way Global Satellite Communication Devices, System and Components Thereof; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ... COMMISSION Certain Two-Way Global Satellite Communication Devices, System and Components Thereof; Notice of... Commission has received a complaint entitled Certain Two-Way Global Satellite Communication Devices, System... satellite communication devices, systems. The complaint names as respondents Delorme Publishing Company...

  8. Manipulation of D2 receptors with quinpirole and sulpiride affects locomotor activity before spatial behavior of rats in an active place avoidance task.

    PubMed

    Stuchlik, Ales; Rehakova, Lenka; Rambousek, Lukas; Svoboda, Jan; Vales, Karel

    2007-06-01

    Dopamine-mediated neurotransmission is widely studied with respect to motivation, motor activity and cognitive processes. The aim of the present study was to evaluate the role of D2 receptors in the behavior of rats in the active allothetic place avoidance (AAPA) task. D2 receptor agonist quinpirole and antagonist sulpiride were administered intraperitoneally 20min prior to behavioral testing. Administration of quinpirole led to dose-dependent increase of locomotion; the spatial efficiency was spared across the dose range studied (0.05-1.0mg/kg). In contrast, sulpiride decreased locomotor activity at a dose not influencing spatial efficiency (60mg/kg); the highest dose of sulpiride (100mg/kg) caused a deficit in both locomotor and spatial behaviors. The results suggest a relatively lesser importance of D2 receptors for spatial efficiency in the AAPA task, with a predominant influence of D2 receptor ligands on motor activity. PMID:17360063

  9. International two-way satellite time transfers using INTELSAT space segment and small Earth stations

    NASA Astrophysics Data System (ADS)

    Veenstra, Lester B.

    1990-05-01

    The satellite operated by the International Telecommunications Satellite Organization (INTELSAT) provides new and unique capabilities for the coordinates of international time scales on a world wide basis using the two-way technique. A network of coordinated clocks using small earth stations collocated with the scales is possible. Antennas as small as 1.8 m at K-band and 3 m at C-band transmitting powers of less than 1 W will provide signals with time jitters of less than 1 ns existing spread spectrum modems. One way time broadcasting is also possible, under the INTELSAT INTELNET system, possibly using existing international data distribution (press and financial) systems that are already operating spread spectrum systems. The technical details of the satellite and requirements on satellite earth stations are given. The resources required for a regular operational international time transfer service are analyzed with respect to the existing international digital service offerings of the INTELSAT Business Service (IBS) and INTELNET. Coverage areas, typical link budgets, and a summary of previous domestic and international work using this technique are provided. Administrative procedures for gaining access to the space segment are outlined. Contact information for local INTELSAT signatories is listed.

  10. Improved signal detection for two-way wireless relaying networks under imperfect time synchronisation

    NASA Astrophysics Data System (ADS)

    O El Astal, Mohammed Taha; Olivier, Jan Corné

    2014-12-01

    Most research on two-way wireless relaying networks (TWRNs) assumes perfect time synchronisation between the terminals and among the relays. This is, however, difficult to accomplish as the terminals and relays are randomly located. The lack of synchronisation causes inter-symbol interference which introduces a serious impairment and negatively impacts the network's performance. In this article, an enhanced interference cancellation (EIC)-based detector is proposed to mitigate the experienced performance degradation while maintaining low complexity. It uses an innovative iterative approach and also benefits of interference components of currently detected symbols using a modified maximum likelihood (ML) scheme. As a result, it shows significant performance improvement compared to the conventional detector under different conditions of imperfect synchronisation. In addition, two existing interference cancellation detectors that are originally proposed for one-way WRNs are extended to TWRNs, even though the timing error among the terminals is a unique issue for TWRNs and never occurs in one-way networks. Unlike the existing literature, the proposed detectors apply to networks with an arbitrary number of multiple-antenna relays. Numerical simulation is provided in terms of bit error rate, to show the improvement in performance when compared to the conventional detector. Moreover, it is shown that the EIC detector outperforms the extended detectors and provides 3 to 4 dB gain under moderate condition of imperfect synchronisation.

  11. Lensfree on-chip high-resolution imaging using two-way lighting, and its limitations

    NASA Astrophysics Data System (ADS)

    Adachi, Yasuhiko; Tamaki, Tokuhiko; Motomura, Hideto; Kato, Yoshihisa

    2016-03-01

    A high-magnification image of a biological sample can generally be obtained by an optical microscope with an objective lens, moving the image sensor with a sub-pixel shift and the subsequent image processing for super-resolution. However, to obtain a high-resolution image, a large number of images will be required for the super-resolution, and thus it is difficult to achieve real-time operation, and the field-of-view (FOV) is not sufficiently wide. The currently proposed digital holography technique places a sample on the image sensor and captures the interference fringe (hologram) to reconstruct a 3D high-resolution image in a computer. This technique ensures the features of a wide FOV, whereas the high resolution obtained by image processing cannot ensure real-time operation, because it requires recursive calculations of light propagation and adequate computer resources. To realize wide FOV and the real-time operation at the same time, we have developed a new technique: Lensfree on-chip high-resolution imaging using two-way lighting. High-resolution image is immediately obtained by image processing of the low-resolution images of the samples. This makes it possible to ensure a wide FOV, a deep depth of focus without the need for focus adjustment, and a continuously expanding operation. We also discuss the limitations of the high resolution.

  12. Calibration System of Internal Delay Difference for Two-way Satellite Time Transfer

    NASA Astrophysics Data System (ADS)

    Fujieda, Miho; Imae, Michito; Suzuyama, Tomonari; Aida, Masanori; Maeno, Hideo; Tung, Lam Quoc

    Two Way Satellite Time and Frequency Transfer (TWSTFT) enables us to perform time transfer precisely, for atmospheric and geometric delays between the earth station and the satellite are almost canceled because of the path reciprocity. However, the delays in the uplink path and the downlink path of the earth station cannot cancel due to the different signal paths. The delay difference makes the absolute value of the time difference unknown, while the fluctuation in the delay difference degrades the stability of the time transfer. We have developed a delay-difference calibration system using a multi-channel TWSTFT modem. Because the signals for the calibration are processed with the received time-transfer signals from other stations, not only a short-term variation but also a secular change in the delay difference can be measured. It is found that the diurnal variation of the delay difference becomes a few hundred pico-second even if the low noise amplifier works in the temperature-controlled box. As for the time transfer result between two hydrogen masers, its stability was improved by the correction of the delay difference. We confirmed the calibration system was important to improve the precision of TWSTFT.

  13. Practical security analysis of two-way quantum-key-distribution protocols based on nonorthogonal states

    NASA Astrophysics Data System (ADS)

    Henao, C. Ivan; Serra, Roberto M.

    2015-11-01

    Within the broad research scenario of quantum secure communication, two-way quantum key distribution (TWQKD) is a relatively new proposal for sharing secret keys that is not yet fully explored. We analyze the security of TWQKD schemes that use qubits prepared in nonorthogonal states to transmit the key. Investigating protocols that employ an arbitrary number of bases for the channel preparation, we show, in particular, that the security of the LM05 protocol cannot be improved by the use of more than two preparation bases. We also provide an alternative proof of unconditional security for a deterministic TWQKD protocol recently proposed in Beaudry et al., Phys. Rev. A 88, 062302 (2013), 10.1103/PhysRevA.88.062302. In addition, we introduce a deterministic protocol named "TWQKD six-state" and compute an analytical lower bound (which can be tightened) for the maximum amount of information that an eavesdropper could extract in this case. An interesting advantage of our approach to the security analysis of TWQKD is the great simplicity and transparency of the derivations.

  14. Two-way traffic of glycoside hydrolase family 18 processive chitinases on crystalline chitin

    NASA Astrophysics Data System (ADS)

    Igarashi, Kiyohiko; Uchihashi, Takayuki; Uchiyama, Taku; Sugimoto, Hayuki; Wada, Masahisa; Suzuki, Kazushi; Sakuda, Shohei; Ando, Toshio; Watanabe, Takeshi; Samejima, Masahiro

    2014-06-01

    Processivity refers to the ability of synthesizing, modifying and degrading enzymes to catalyse multiple successive cycles of reaction with polymeric substrates without disengaging from the substrates. Since biomass polysaccharides, such as chitin and cellulose, often form recalcitrant crystalline regions, their degradation is highly dependent on the processivity of degrading enzymes. Here we employ high-speed atomic force microscopy to directly visualize the movement of two processive glycoside hydrolase family 18 chitinases (ChiA and ChiB) from the chitinolytic bacterium Serratia marcescens on crystalline β-chitin. The half-life of processive movement and the velocity of ChiA are larger than those of ChiB, suggesting that asymmetric subsite architecture determines both the direction and the magnitude of processive degradation of crystalline polysaccharides. The directions of processive movements of ChiA and ChiB are observed to be opposite. The molecular mechanism of the two-way traffic is discussed, including a comparison with the processive cellobiohydrolases of the cellulolytic system.

  15. International two-way satellite time transfers using INTELSAT space segment and small Earth stations

    NASA Technical Reports Server (NTRS)

    Veenstra, Lester B.

    1990-01-01

    The satellite operated by the International Telecommunications Satellite Organization (INTELSAT) provides new and unique capabilities for the coordinates of international time scales on a world wide basis using the two-way technique. A network of coordinated clocks using small earth stations collocated with the scales is possible. Antennas as small as 1.8 m at K-band and 3 m at C-band transmitting powers of less than 1 W will provide signals with time jitters of less than 1 ns existing spread spectrum modems. One way time broadcasting is also possible, under the INTELSAT INTELNET system, possibly using existing international data distribution (press and financial) systems that are already operating spread spectrum systems. The technical details of the satellite and requirements on satellite earth stations are given. The resources required for a regular operational international time transfer service are analyzed with respect to the existing international digital service offerings of the INTELSAT Business Service (IBS) and INTELNET. Coverage areas, typical link budgets, and a summary of previous domestic and international work using this technique are provided. Administrative procedures for gaining access to the space segment are outlined. Contact information for local INTELSAT signatories is listed.

  16. Two-way self-consistent coupling of HEIDI in SWMF

    NASA Astrophysics Data System (ADS)

    Ilie, R.; Liemohn, M. W.; Toth, G.

    2013-12-01

    In this study we present results from the two-way coupling between the kinetic Hot Electron and Ion Drift Integrator (HEIDI) model and the Space Weather Modeling Framework (SWMF). HEIDI solves the time dependent, gyration and bounced averaged kinetic equation for the phase space density of different ring current species and computes full pitch angle distributions for all local times and radial distances. This model was generalized to accommodate an arbitrary magnetic field and, through the coupling with SWMF, it obtains the magnetic field description along with the plasma distribution at the model boundaries from the Block Adaptive Tree Solar Wind Roe Upwind Scheme (BATS-R-US) magnetohydrodynamics (MHD) model within the SWMF. Electric field self-consistency is assured by the passing of convection potentials from the Ridley Ionosphere Model (RIM) within SWMF. Our study tests the various levels of coupling between the 3 models, highlighting the roles that the magnetic field, plasma sheet conditions and the cross polar cap potential play in the formation and evolution of the ring current. The results of the self-consistent coupling between HEIDI, BATSRUS and RIM during disturbed conditions emphasize the importance of a kinetic self-consistent approach to the description of the geospace.

  17. Two-way bistable out-of-plane actuator using Ti/SiO2 bilayer

    NASA Astrophysics Data System (ADS)

    Yu, Kevin; Michael, Aron; Kwok, Chee Yee

    2005-02-01

    A novel two-way bistable bimorph bridge actuator for out of plane deflection is reported in this paper. The device has a 1200μm long, 50μm wide and 4μm thick composite bimorph beam consists of PECVD SiO2 and titanium layers. The end supports of the beam consist of 2 pairs of spring and are provided by 2 pairs of long titanium 'legs" alongside the beam. 10mW and 4mW in the beam and legs for 3ms respectively is needed for 50 micron of out-of-plane deflection travel. By applying the appropriate joule heating sequence to the device, it is possible to snap the buckled beam upward or downward between two equilibrium states. An analytical and simulation models of heat transfer and tunable snapping are developed for the system. This paper presents the working principal, analysis, simulations of the device. The actuator will be used to move a micromirror, located at the centre of beam, for optical switching. This novel mechanism can have useful application in relays, optical switching and threshold sensors.

  18. Two-way shape memory behavior of semi-crystalline elastomer under stress-free condition

    NASA Astrophysics Data System (ADS)

    Qian, Chen; Dong, Yubing; Zhu, Yaofeng; Fu, Yaqin

    2016-08-01

    Semi-crystalline shape memory polymers exhibit two-way shape memory effect (2W-SME) under constant stresses through crystallization-induced elongation upon cooling and melting-induced constriction upon heating. The applied constant stress influenced the prediction and usability of 2W-SME in practical applications without any external force. Here the reversible shape transition in EVA-shaped memory polymer was quantitative analyzed under a suitable temperature range and external stress-free condition. The fraction of reversible strain increased with increasing upper temperature (T high) within the temperature range and reached the maximum value of 13.62% at 70 °C. However, reversible strain transition was almost lost when T high exceeded 80 °C because of complete melting of crystalline scaffold, known as the latent recrystallization template. The non-isothermal annealing of EVA 2W-SMP under changing circulating temperatures was confirmed. Moreover, the orientation of crystallization was retained at high temperatures. These findings may contribute to design an appropriate shape memory protocol based on application-specific requirements.

  19. Application of high-precision two-way ranging to Galileo Earth-1 encounter navigation

    NASA Technical Reports Server (NTRS)

    Pollmeier, V. M.; Thurman, S. W.

    1992-01-01

    The application of precision two-way ranging to orbit determination with relatively short data arcs is investigated for the Galileo spacecraft's approach to its first Earth encounter (December 8, 1990). Analysis of previous S-band (2.3-GHz) ranging data acquired from Galileo indicated that under good signal conditions submeter precision and 10-m ranging accuracy were achieved. It is shown that ranging data of sufficient accuracy, when acquired from multiple stations, can sense the geocentric angular position of a distant spacecraft. A range data filtering technique, in which explicit modeling of range measurement bias parameters for each station pass is utilized, is shown to largely remove the systematic ground system calibration errors and transmission media effects from the Galileo range measurements, which would otherwise corrupt the angle-finding capabilities of the data. The accuracy of the Galileo orbit solutions obtained with S-band Doppler and precision ranging were found to be consistent with simple theoretical calculations, which predicted that angular accuracies of 0.26-0.34 microrad were achievable. In addition, the navigation accuracy achieved with precision ranging was marginally better than that obtained using delta-differenced one-way range (delta DOR), the principal data type that was previously used to obtain spacecraft angular position measurements operationally.

  20. Granular Computing Approach to Two-Way Learning Based on Formal Concept Analysis in Fuzzy Datasets.

    PubMed

    Xu, Weihua; Li, Wentao

    2016-02-01

    The main task of granular computing (GrC) is about representing, constructing, and processing information granules. Information granules are formalized in many different approaches. Different formal approaches emphasize the same fundamental facet in different ways. In this paper, we propose a novel GrC method of machine learning by using formal concept description of information granules. Based on information granules, the model and mechanism of two-way learning system is constructed in fuzzy datasets. It is addressed about how to train arbitrary fuzzy information granules to become necessary, sufficient, and necessary and sufficient fuzzy information granules. Moreover, an algorithm of the presented approach is established, and the complexity of the algorithm is analyzed carefully. Finally, to interpret and help understand the theories and algorithm, a real-life case study is considered and experimental evaluation is performed by five datasets from the University of California-Irvine, which is valuable for applying these theories to deal with practical issues. PMID:25347892

  1. LASSO, two-way, and GPS time comparisons: A (very) preliminary status report

    NASA Technical Reports Server (NTRS)

    Veillet, Christian J. L.; Feraudy, D.; Torre, J. M.; Mangin, J. F.; Grudler, P.; Baumont, Francoise S.; Gaignebet, Jean C.; Hatat, J. L.; Hanson, Wayne; Clements, A.

    1990-01-01

    The first results are presented on the time transfer experiments between TUG (Graz, Austria) and OCA (Grasse, France) using common view Global Positioning System (GPS) and two-way stations at both sites. The present data, providing arms of the clock offsets of 2 to 3 nanoseconds for a three month period, have to be further analyzed before any conclusions on the respective precision and accuracy of these techniques can be drawn. Two years after its start, the Laser Synchronization from Stationary Orbit (LASSO) experiment is finally giving its first results at TUG and OCA. The first analysis of three common sessions permitted researchers to conclude that the LASSO package on board Meteosat P2 is working satisfactorily, and that time transfer using this method should provide clock offsets at better than 1 nanosecond precision, and clock rates at better than 10(exp -12) s/s in a 5 to 10 minutes session. A new method for extracting this information from the raw data sent by LASSO should enhance the performances of this experiment, exploiting the stability of the on-board oscillator.

  2. Two way fluid structure interaction analysis of a valveless micropump by CFD

    NASA Astrophysics Data System (ADS)

    Cǎlimǎnescu, Ioan; Dumitrache, Constantin L.; Grigorescu, Lucian

    2015-02-01

    In the microfluid control system, a valve-less micropump is a necessary component. It has the ability to pump a wide variety of fluids automatically and accurately on a micro scale. The dynamic characteristics of a valve-less micropump influence the performance of the microfluid control system. Consequently, it is of great importance to be able to accurately predict the dynamic characteristics of micropumps for appropriate design and usage of the microfluid control system. In this paper, we describe a corrugated diaphragm valveless micropump approached from the Computational Fluid Dynamics point of view in which the Fluid Structure Interaction is based on the Two Way principle, meaning that the diaphragm is moving and the fluid (water like fluid) is sucked from the inlet and pushed back to the outlet using the nozzle effect. The technical solution of micropumps without valves is a very clever idea to replace the custom valves with nozzles, with the same effect but virtually without any components beside the inlet and the outlet nozzles. The paperwork is demonstrating via a complex simulation involving the structural-fluid interaction the nozzle effects and the functioning of this kind of micropumps.

  3. Active and Avoidant Coping and Coping Efficacy as Mediators of the Relation of Maternal Involvement to Depressive Symptoms among Urban Adolescents

    ERIC Educational Resources Information Center

    Mosher, Catherine E.; Prelow, Hazel M.

    2007-01-01

    Our study tested an extension of the social resource model in an urban sample of 129 African American and 114 European American adolescents. Maternal involvement was positively related to the use of active and avoidant coping strategies among youth of both ethnicities. Additionally, use of active coping strategies was related to greater coping…

  4. Lesions of anterior thalamic nuclei impair acquisition of new and changing of preoperatively learnt active avoidance stereotypes.

    PubMed

    Klingberg, F; Klingberg, H

    1988-01-01

    Six-month-old male Long-Evans rats reproduced their preoperatively learnt active avoidance responses (CAR) in a Y-maze and in a jump test box after bilateral symmetric lesions of thalamic anterior ventral (AV) and anterior medial (AM) nuclei without significant changes. However, when the test sequence was changed in a way that transitions from high success probability (low error probability) to low success probability (high error probability) were taken into account, then problems with time limit and increased punishments were not overcome by lesioned rats. Transitions in the opposite direction were better mastered. All AV-AM rats were unable to acquire a new CAR stereotype in a W-like maze in which the first phase had a low success probability. Rats without lesions were rarely influenced by various test sequences. The lesioned rats showed purely arrest behaviour and did not develop learned helplessness in successless sessions and were transiently hyperactive in the open field test. The data support the hypothesis that the anterior thalamic nuclei as part of the Papez circuit participate in the analysis of success probability and preferent consolidation of correct responses, when stereotype behaviour has to be changed. PMID:3240299

  5. 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

  6. Two-way WKB Approximation Applied to GPR - COST Action TU1208

    NASA Astrophysics Data System (ADS)

    Prokopovich, Igor; Popov, Alexei; Marciniak, Marian; Pajewski, Lara

    2016-04-01

    The main goal of subsurface radio wave probing consists in reconstruction of the shape and the electrical properties of buried objects in material media. For this purpose the knowledge of the laws of EM pulse excitation and propagation in non-uniform subsurface medium is required, as well as the methods and algorithms of solving the inverse problem. Two ways of treating this problem exist. On the one hand, one can describe EM wave propagation by solving the Maxwell's equations with finite difference methods implemented in computer codes. However, when solving inverse problems, pure numerical algorithms require huge amount of calculation and, as a consequence, long calculation time. In this respect, more promising are analytical approaches. Here, we apply couple wave theory ("two-way WKB" approximation) to the problem of subsurface wave propagation. The derived formulas can be used in GPR design and for fast data processing of the experimental data. We start from the 1D model problem of GPR probing. Classical WKB method [1] allows one to describe wave propagation through non-uniform media with slowly varying dielectric permittivity. A principal shortcoming of this approximation is that it does not take into account backward reflection from permittivity gradients. Consequently, WKB method as such can not be used for the purposes of GPR sounding. An extension of this approximation consists in solving two coupled WKB-type equations by iterations. This approach properly describes backward reflections and provides good accuracy in a wide frequency range [2]. In our previous work [3] a time-domain counterpart of the Bremmer-Brekhovkikh approximation has been derived and applied to a 1D inverse problem of subsurface medium probing by an ultra-wide band EM pulse. In order to convert this approach into a practical GPR algorithm, a more realistic model is required: 2D or 3D propagation from a localized source with the effects of wave divergence and refraction taken into

  7. The two-way time synchronization system via a satellite voice channel

    NASA Astrophysics Data System (ADS)

    Heng-Qiu, Zheng; Ren-Huan, Zhang; Yong-Hui, Hu

    1994-05-01

    A newly developed two-way time synchronization system is described in this paper. The system uses one voice channel at a SCPC satellite digital communication earth station, whose bandwidth is only 45 kHz, thus saving satellite resources greatly. The system is composed of one master station and one or several, up to sixty-two, secondary stations. The master and secondary stations are equipped with the same equipment, including a set of timing equipment, a synthetic data terminal for time synchronizing, and a interface unit between the data terminal and the satellite earth station. The synthetic data terminal for time synchronization also has an IRIG-B code generator and a translator. The data terminal of master station is the key part of whole system. The system synchronization process is full automatic, which is controlled by the master station. Employing an autoscanning technique and conversational mode, the system accomplishes the following tasks: linking up liaison with each secondary station in turn, establishing a coarse time synchronization, calibrating date (years, months, days) and time of day (hours, minutes, seconds), precisely measuring the time difference between local station and the opposite station, exchanging measurement data, statistically processing the data, rejecting error terms, printing the data, calculating the clock difference and correcting the phase, thus realizing real-time synchronization from one point to multiple points. We also designed an adaptive phase circuit to eliminate the phase ambiguity of the PSK demodulator. The experiments have shown that the time synchronization accuracy is better than 2 mu S. The system has been put into regular operation.

  8. Dynamic stress analysis of sewage centrifugal pump impeller based on two-way coupling method

    NASA Astrophysics Data System (ADS)

    Pei, Ji; Yuan, Shouqi; Yuan, Jianping

    2014-03-01

    Current research on the operational reliability of centrifugal pumps has mainly focused on hydrodynamic instability. However, the interaction between the fluid and structure has not been sufficiently considered; this interaction can cause vibration and dynamic stress, which can affect the reliability. In this study, the dynamic stresses in a single-blade centrifugal pump impeller are analysed under different operating conditions; the two-way coupling method is used to calculate the fluid-structure interaction. Three-dimensional unsteady Reynolds-averaged Navier-Stokes equations are solved with the SST k-ω turbulence model for the fluid in the whole flow passage, while transient structure dynamic analysis is used with the finite element method for the structure side. The dynamic stresses in the rotor system are computed according to the fourth strength theory. The stress results show that the highest stress is near the loose bearing and that the equivalent stress increases with the flow rate because the dynamic stresses are closely related to the pressure load. The stress distributions on the blade pressure side, suction side, leading edge, and trailing edge are each analysed for different flow rates; the highest stress distribution is found on the pressure side. On the blade pressure side, a relatively large stress is found near the trailing edge and hub side. Based on these results, a stress distribution prediction method is proposed for centrifugal pumps, which considers the interaction between the fluid and structure. The method can be used to check the dynamic stress at different flow rates when optimising the pump design to increase the pump reliability.

  9. Stability improvement of an operational two-way satellite time and frequency transfer system

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Jiun; Fujieda, Miho; Takiguchi, Hiroshi; Tseng, Wen-Hung; Tsao, Hen-Wai

    2016-04-01

    To keep national time accurately coherent with coordinated universal time, many national metrology institutes (NMIs) use two-way satellite time and frequency transfer (TWSTFT) to continuously measure the time difference with other NMIs over an international baseline. Some NMIs have ultra-stable clocks with stability better than 10-16. However, current operational TWSTFT can only provide frequency uncertainty of 10-15 and time uncertainty of 1 ns, which is inadequate. The uncertainty is dominated by the short-term stability and the diurnals, i.e. the measurement variation with a period of one day. The aim of this work is to improve the stability of operational TWSTFT systems without additional transmission, bandwidth or increase in signal power. A software-defined receiver (SDR) comprising a high-resolution correlator and successive interference cancellation associated with open-loop configuration as the TWSTFT receiver reduces the time deviation from 140 ps to 73 ps at averaging time of 1 h, and occasionally suppresses diurnals. To study the source of the diurnals, TWSTFT is performed using a 2  ×  2 earth station (ES) array. Consequently, some ESs sensitive to temperature variation are identified, and the diurnals are significantly reduced by employing insensitive ESs. Hence, the operational TWSTFT using the proposed SDR with insensitive ESs achieves time deviation to 41 ps at 1 h, and 80 ps for averaging times from 1 h to 20 h.

  10. The two-way time synchronization system via a satellite voice channel

    NASA Technical Reports Server (NTRS)

    Heng-Qiu, Zheng; Ren-Huan, Zhang; Yong-Hui, HU

    1994-01-01

    A newly developed two-way time synchronization system is described in this paper. The system uses one voice channel at a SCPC satellite digital communication earth station, whose bandwidth is only 45 kHz, thus saving satellite resources greatly. The system is composed of one master station and one or several, up to sixty-two, secondary stations. The master and secondary stations are equipped with the same equipment, including a set of timing equipment, a synthetic data terminal for time synchronizing, and a interface unit between the data terminal and the satellite earth station. The synthetic data terminal for time synchronization also has an IRIG-B code generator and a translator. The data terminal of master station is the key part of whole system. The system synchronization process is full automatic, which is controlled by the master station. Employing an autoscanning technique and conversational mode, the system accomplishes the following tasks: linking up liaison with each secondary station in turn, establishing a coarse time synchronization, calibrating date (years, months, days) and time of day (hours, minutes, seconds), precisely measuring the time difference between local station and the opposite station, exchanging measurement data, statistically processing the data, rejecting error terms, printing the data, calculating the clock difference and correcting the phase, thus realizing real-time synchronization from one point to multiple points. We also designed an adaptive phase circuit to eliminate the phase ambiguity of the PSK demodulator. The experiments have shown that the time synchronization accuracy is better than 2 mu S. The system has been put into regular operation.

  11. Two-way interaction between plume and slab: The Hainan-Manila example

    NASA Astrophysics Data System (ADS)

    Mériaux, Catherine; Duarte, João; Schellart, Wouter

    2015-04-01

    Three-dimensional upper-mantle laboratory models consisting of a compositional plume that is initiated underneath an entirely dynamically driven dense plate fixed at the surface along its trailing edge exhibit a two-way interaction between plume and slab. The slab influence on the plume is driven by the induced mantle flow generated by the plate motion, which includes a sinking and a retreating phase. Slab/Plume buoyancy flux ratios ranged between 7 and 18. In all models, the plume is being swept away from the slab during its rise, and once it has reached the surface, its head spreads towards the trench as a gravity current while its conduit keeps being deflected away. The plume influence on the slab is seen later, when the slab in its retreat gets closer to the plume. The plume buoyancy spreading under the slab then weakens the subduction rate. The degree to which the subduction rate is lessened is conditioned by the level of asymmetry, which the slab may develop along its free edge during its impact at the bottom surface. A lasting symmetric plate causes maximum disturbance of the plume to the slab retreat rate, while plate asymmetry alleviates the plume influence as the plume buoyancy is no longer trapped underneath the plate in its centreline but can escape sideways. Our laboratory model configuration applies to the Hainan plume and Manila subduction system. The geophysical and seismic observations showing the existence of a NW-SE tilting plume-like mantle low-velocity structure in the crust and in the mantle beneath the north Hainan Island-Leizhou Peninsula basalt province are explained by slab rollback induced toroidal mantle flow from the Manila subduction zone. On the basis of our models, it can be foreseen that the Hainan plume is to spread out under the Manila slab towards the mantle wedge in the future, which could lessen the Manila subduction rate.

  12. Quantifying the safety effects of horizontal curves on two-way, two-lane rural roads.

    PubMed

    Gooch, Jeffrey P; Gayah, Vikash V; Donnell, Eric T

    2016-07-01

    The objective of this study is to quantify the safety performance of horizontal curves on two-way, two-lane rural roads relative to tangent segments. Past research is limited by small samples sizes, outdated statistical evaluation methods, and unreported standard errors. This study overcomes these drawbacks by using the propensity scores-potential outcomes framework. The impact of adjacent curves on horizontal curve safety is also explored using a cross-sectional regression model of only horizontal curves. The models estimated in the present study used eight years of crash data (2005-2012) obtained from over 10,000 miles of state-owned two-lane rural roads in Pennsylvania. These data included information on roadway geometry (e.g., horizontal curvature, lane width, and shoulder width), traffic volume, roadside hazard rating, and the presence of various low-cost safety countermeasures (e.g., centerline and shoulder rumble strips, curve and intersection warning pavement markings, and aggressive driving pavement dots). Crash prediction is performed by means of mixed effects negative binomial regression using the explanatory variables noted previously, as well as attributes of adjacent horizontal curves. The results indicate that both the presence of a horizontal curve and its degree of curvature must be considered when predicting the frequency of total crashes on horizontal curves. Both are associated with an increase in crash frequency, which is consistent with previous findings in the literature. Mixed effects negative binomial regression models for total crash frequency on horizontal curves indicate that the distance to adjacent curves is not statistically significant. However, the degree of curvature of adjacent curves in close proximity (within 0.75 miles) was found to be statistically significant and negatively correlated with crash frequency on the subject curve. This is logical, as drivers exiting a sharp curve are likely to be driving slower and with more

  13. Ten weeks of physical-cognitive-mindfulness training reduces fear-avoidance beliefs about work-related activity: Randomized controlled trial.

    PubMed

    Jay, Kenneth; Brandt, Mikkel; Jakobsen, Markus Due; Sundstrup, Emil; Berthelsen, Kasper Gymoese; Schraefel, Mc; Sjøgaard, Gisela; Andersen, Lars L

    2016-08-01

    People with chronic musculoskeletal pain often experience pain-related fear of movement and avoidance behavior. The Fear-Avoidance model proposes a possible mechanism at least partly explaining the development and maintenance of chronic pain. People who interpret pain during movement as being potentially harmful to the organism may initiate a vicious behavioral cycle by generating pain-related fear of movement accompanied by avoidance behavior and hyper-vigilance.This study investigates whether an individually adapted multifactorial approach comprised of biopsychosocial elements, with a focus on physical exercise, mindfulness, and education on pain and behavior, can decrease work-related fear-avoidance beliefs.As part of a large scale 10-week worksite randomized controlled intervention trial focusing on company initiatives to combat work-related musculoskeletal pain and stress, we evaluated fear-avoidance behavior in 112 female laboratory technicians with chronic neck, shoulder, upper back, lower back, elbow, and hand/wrist pain using the Fear-Avoidance Beliefs Questionnaire at baseline, before group allocation, and again at the post intervention follow-up 10 weeks later.A significant group by time interaction was observed (P < 0.05) for work-related fear-avoidance beliefs. The between-group difference at follow-up was -2.2 (-4.0 to -0.5), corresponding to a small to medium effect size (Cohen's d = 0.30).Our study shows that work-related, but not leisure time activity-related, fear-avoidance beliefs, as assessed by the Fear-avoidance Beliefs Questionnaire, can be significantly reduced by 10 weeks of physical-cognitive-mindfulness training in female laboratory technicians with chronic pain. PMID:27559939

  14. Examining Interior Grid Nudging Techniques Using Two-Way Nesting in the WRF Model for Regional Climate Modeling

    EPA Science Inventory

    This study evaluates interior nudging techniques using the Weather Research and Forecasting (WRF) model for regional climate modeling over the conterminous United States (CONUS) using a two-way nested configuration. NCEP–Department of Energy Atmospheric Model Intercomparison Pro...

  15. A two-way street: bridging implementation science and cultural adaptations of mental health treatments

    PubMed Central

    2013-01-01

    to what extent treatments and/or context should be customized to enhance the implementation of evidence-based treatments across settings and populations. Developing a two-way street between these two fields can provide a better avenue for moving the best available treatments into practice and for helping to reduce racial and ethnic disparities in mental health care. PMID:23958445

  16. Velocity model construction, uncertainty evaluation, and two-way travel time to sediment thickness conversion

    NASA Astrophysics Data System (ADS)

    Li, Q.; Shimeld, J.; Dickie, K.; Dehler, S. A.; Desroches, K.

    2013-12-01

    Sediment thickness determinations play a key role in positioning the most seaward fixed points of the outer limits of continental shelves for coastal states. Seismic reflection surveying is an invaluable technique for estimating the sediment thickness required for the positioning. However, such seismic reflection surveying records the two way travel time (twtt) of vertically incident seismic waves. An accurate seismic velocity model is required for the conversion between twtt and sediment thickness. In this approach, a velocity model is constructed, its uncertainty is evaluated, and twtt is converted to sediment thickness. All of these procedures are programmed for batch and script processing. First, a slowness (the inverse of velocity) function, which is based on the solid sediment compaction theory, is selected and it is fitted using all available velocity observations using the reduced major axis (RMA) method, which can minimize errors from both velocity and depth observations. Second, the velocity uncertainty is estimated using a bootstrapping method by simulating a non-replace re-sampling procedure; thus it is also used in the estimation of sediment thickness uncertainty that is caused by velocity model errors. Moreover, with the constructed velocity model, conversion from sediment depth to twtt is resolved analytically and the conversion from twtt to depth is completed by solving a nonlinear equation with Newton iteration method, having approved convergence efficiency and a predefined accuracy (0.1 m). Finally, all these processes have been implemented in C# and JavaScript for integration with GeoFrame file format (seismic horizon interpretation) or embedded in any document with power batch processing and flexible verification facilities. As an example, publicly available velocity observations in the Labrador Sea region are used in the construction of a velocity model and the evaluation of velocity and sediment thickness uncertainty. The conversion between

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

    SciTech Connect

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

    2010-12-03

    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 Polar 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

  18. 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

  19. Deletion of striatal adenosine A(2A) receptor spares latent inhibition and prepulse inhibition but impairs active avoidance learning.

    PubMed

    Singer, Philipp; Wei, Catherine J; Chen, Jiang-Fan; Boison, Detlev; Yee, Benjamin K

    2013-04-01

    Following early clinical leads, the adenosine A(2A)R receptor (A(2A)R) has continued to attract attention as a potential novel target for treating schizophrenia, especially against the negative and cognitive symptoms of the disease because of A(2A)R's unique modulatory action over glutamatergic in addition to dopaminergic signaling. Through (i) the antagonistic interaction with the dopamine D(2) receptor, and (ii) the regulation of glutamate release and N-methyl-d-aspartate receptor function, striatal A(2A)R is ideally positioned to fine-tune the dopamine-glutamate balance, the disturbance of which is implicated in the pathophysiology of schizophrenia. However, the precise function of striatal A(2A)Rs in the regulation of schizophrenia-relevant behavior is poorly understood. Here, we tested the impact of conditional striatum-specific A(2A)R knockout (st-A(2A)R-KO) on latent inhibition (LI) and prepulse inhibition (PPI) - behavior that is tightly regulated by striatal dopamine and glutamate. These are two common cross-species translational tests for the assessment of selective attention and sensorimotor gating deficits reported in schizophrenia patients; and enhanced performance in these tests is associated with antipsychotic drug action. We found that neither LI nor PPI was significantly affected in st-A(2A)R-KO mice, although a deficit in active avoidance learning was identified in these animals. The latter phenotype, however, was not replicated in another form of aversive conditioning - namely, conditioned taste aversion. Hence, the present study shows that neither learned inattention (as measured by LI) nor sensory gating (as indexed by PPI) requires the integrity of striatal A(2A)Rs - a finding that may undermine the hypothesized importance of A(2A)R in the genesis and/or treatment of schizophrenia. PMID:23276608

  20. High-Efficiency Ka-Band Waveguide Two-Way Asymmetric Power Combiner

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.; Simons, R. N.; Freeman, J. C.; Chevalier, C. T.

    2011-01-01

    NASA is planning a number of Space Exploration, Earth Observation and Space Science missions where Ka-band solid-state power amplifiers (SSPAs) could have a role. Monolithic microwave integrated circuit (MMIC) based SSPAs with output powers on the order of 10 W at Ka-band frequencies would be adequate to satisfy the data transmission rate requirements at the distances involved. MMICs are a type of integrated circuit fabricated on a GaAs wafer, which operates at micro wave frequencies and performs the function of signal amplification. The highest power Ka-band (31.8 to 32.3 GHz) SSPA to have flown in space had an output power of 2.6 W with an overall efficiency of 14.3 percent. This SSPA was built around discrete GaAs pHEMT (high electron mobility transistor) devices and flew aboard the Deep Space One spacecraft. State-of-the-art GaAs pHEMT-based MMIC power amplifiers (PAs) can deliver RF power at Ka-band frequencies anywhere from 3 W with a power added efficiency (PAE) of 32 percent to 6 W with a PAE of 26 percent. However, to achieve power levels higher than 6 W, the output of several MMIC PAs would need to be combined using a high-efficiency power combiner. Conventional binary waveguide power combiners, based on short-slot and magic-T circuits, require MMIC PAs with identical amplitude and phase characteristics for high combining efficiency. However, due to manufacturing process variations, the output powers of the MMIC PAs tend to be unequal, and hence the need to develop unequal power combiners. A two-way asymmetric magic-T based power combiner for MMIC power amplifiers, which can take in unequal inputs, has been successfully designed, fabricated, and characterized over NASA s Deep Space Network (DSN) frequency range of 31.8 to 32.3 GHz. The figure is a transparent view of the a sym - metric combiner that shows the 4-port configuration and the internal structure. The rod, post, and iris are positioned by design to achieve the desired asymmetric power ratio

  1. 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…

  2. Effects of Inter-Particle Collisions and Two-Way Coupling on Particle Deposition Velocity in a Turbulent Channel Flow

    NASA Astrophysics Data System (ADS)

    Nasr, Hojjat; Ahmadi, Goodarz; McLaughlin, John

    2010-11-01

    This study was concerned with the effect of particle-particle collisions and two-way coupling on the particle deposition velocity in a turbulent channel flow. The time history of the instantaneous turbulent velocity vector was generated by the two-way coupled direct numerical simulation (DNS) of the Navier-Stokes equation via a pseudospectral method. The particle equation of motion included the Stokes drag, the Saffman lift, and the gravitational forces. The effect of particles on the flow was included in the analysis via a feedback force that acted on the fluid on the computational grid points. Several simulations for different particle relaxation times and particle mass loading were performed, and the effects of the inter-particle collisions and two-way coupling on the particle deposition velocity, fluid and particle fluctuating velocities, particle normal mean velocity, and particle concentration were determined. It was found that when particle-particle collisions were included in the computation, the particle deposition velocity increased. When the particle collision was neglected but the particle-fluid two-way coupling was accounted for, the particle deposition velocity decreased slightly. For the four-way coupling case, when both inter-particle collisions and two-way coupling effects were taken into account, the particle deposition velocity increased. Comparisons of the present simulation results with the available experimental data and earlier numerical results are also presented.

  3. Two-Way Integration of WRF and CCSM for Regional Climate Simulations

    SciTech Connect

    Lin, Wuyin; Zhang, Minghua; He, Juanxiong; Jiao, Xiangmin; Chen, Ying; Colle, Brian; Vogelmann, Andrew M.; Liu, Ping; Khairoutdinov, Marat; Leung, Ruby

    2013-07-12

    Under the support of the DOE award DE-SC0004670, we have successfully developed an integrated climate modeling system by nesting Weather Research and Forecasting (WRF) model within the Community Climate System Model (CCSM) and the ensuing new generation Community Earth System Model (CESM). The integrated WRF/CESM system is intended as one method of global climate modeling with regional simulation capabilities. It allows interactive dynamical regional downscaling in the computational flow of present or future global climate simulations. This capability substantially simplifies the process of dynamical downscaling by avoiding massive intermediate model outputs at high frequency that are typically required for offline regional downscaling. The inline coupling also has the advantage of higher temporal resolution for the interaction between regional and global model components. With the aid of the inline coupling, a capability has also been developed to ingest other global climate simulations (by CESM or other models), which otherwise may not have necessary intermediate outputs for regional downscaling, to realize their embedded regional details. It is accomplished by relaxing the global atmospheric state of the integrated model to that of the source simulations with an appropriate time scale. This capability has the potential to open a new venue for ensemble regional climate simulations using a single modeling system. Furthermore, this new modeling system provides an effective modeling framework for the studies of physical and dynamical feedbacks of regional weather phenomena to the large scale circulation. The projected uses of this capability include the research of up-scaling effect of regional weather system, and its use as an alternative physical representation of sub-scale processes in coarser-resolution climate models.

  4. Carrier-Doppler-based real-time two way satellite frequency transfer and its application in BeiDou system

    NASA Astrophysics Data System (ADS)

    Liu, Zengjun; Gong, Hang; Yang, Wenke; Zhu, Xiangwei; Ou, Gang

    2014-09-01

    Two-way satellite time and frequency transfer (TWSTFT) method is valuable for precise time and frequency transfer. The frequency could be directly transferred by utilizing two-way carrier Doppler measurement. This method requires each station observing both its own and associated station’s transponder signals transferred by satellite. In BeiDou system (BDS), the reference station and the field station construct a two-way link via a GEO satellite, and the field station sends pseudorange and carrier phase information to the reference station by transmission signal, in order to achieve real time TWSTFT. This paper analyzes the theory of carrier Doppler based TWSTFT (called CD-TWSTFT), and validates it by using on line data of BDS. The results demonstrated that the performance of CD TWSTFT is much better than code based TWSTFT in short-term frequency transfer and almost same at long-term frequency transfer.

  5. 21 CFR Appendix E to Subpart A of... - Elements To Be Considered in Developing a Two-Way Alert System

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL DEVICE PRODUCT... Alert System E Appendix E to Subpart A of Part 26 Food and Drugs FOOD AND DRUG ADMINISTRATION... Considered in Developing a Two-Way Alert System 1. Documentation —Definition of a crisis/emergency and...

  6. Adjusting for Unequal Variances when Comparing Means in One-Way and Two-Way Fixed Effects ANOVA Models.

    ERIC Educational Resources Information Center

    Wilcox, Rand R.

    1989-01-01

    Two methods of handling unequal variances in the two-way fixed effects analysis of variance (ANOVA) model are described. One is based on an improved Wilcox (1988) method for the one-way model, and the other is an extension of G. S. James' (1951) second order method. (TJH)

  7. Appearance of the two-way shape-memory effect in a nitinol spring subjected to temperature and deformation cycling

    NASA Astrophysics Data System (ADS)

    Manjavidze, A. G.; Barnov, V. A.; Jorjishvili, L. I.; Sobolevskaya, S. V.

    2008-03-01

    The properties of a cylindrical spiral spring of nitinol (shape-memory alloy) are studied. When this spring is used as a working element in a rotary martensitic engine, the appearance of the two-way shape-memory effect in it is shown to decrease the engine operation efficiency.

  8. Teaching Practices and Language Use in Two-Way Dual Language Immersion Programs in a Large Public School District

    ERIC Educational Resources Information Center

    Li, Jennifer; Steele, Jennifer; Slater, Robert; Bacon, Michael; Miller, Trey

    2016-01-01

    Many educators and policy makers look to two-way dual language immersion as one of the most promising options to close achievement gaps for English learners. However, the programs' effectiveness depends on the quality of their implementation. This article reports on a large-scale study of the implementation of dual language immersion across a…

  9. English and Spanish "Para Un Futuro"--Or Just English? Immigrant Family Perspectives on Two-Way Immersion

    ERIC Educational Resources Information Center

    Dorner, Lisa Marie

    2010-01-01

    This article considers immigrants' perspectives on language immersion education. Data are drawn from a longitudinal research project that examined one suburban school district's construction of a two-way immersion (TWI), bilingual education policy. Analyses focus on 18 months of participant observation with six Mexican immigrant families who had…

  10. 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. PMID:25126485

  11. Perceived Impact of Two-Way Dual Immersion Programs on Latino Students' Relationships in Their Families and Communities

    ERIC Educational Resources Information Center

    Block, Nicholas C.

    2012-01-01

    This study examined how participation of Latino students in two-way dual immersion versus mainstream programs might have impacted students' relationships with Spanish-speaking adults, thus affecting contexts for students to develop resiliency. Participants were parents of 90 fifth- and sixth-grade students (initially English proficient [EP] as…

  12. Two-way coupling of the global EMAC and the regional COSMO model using the Modular Earth Submodel System (MESSy)

    NASA Astrophysics Data System (ADS)

    Kerkweg, Astrid; Hofmann, Christiane; Glaeser, Gregor; Joeckel, Patrick

    2015-04-01

    Based on the well established one-way on-line coupling of the regional chemistry climate model COSMO/MESSy to the global EMAC (ECHAM5/MESSy for Atmospheric Chemistry) model, a two-way coupling of these two models is developed within the MiKlip (decadal predictions) subproject FLAGSHIP (Feedback of a Limited-Area model to the Global Scale implemented for HIndcasts and Projections). By means of the two-way coupling, smaller scale processes resolved in the COSMO model are fed back to the global scale. Expectably, this improves the representation of processes on the global scale. The technical implementation of the two-way coupling includes a number of challenges, especially the ECHAM and the COSMO model are models of different types: The global ECHAM model has a spectral core and solves the hydrostatic equations of motion, while the regional COSMO model is a non-hydrostatic grid point model. While the coupling of passive tracers and the humidity fields functions well in our test cases, the dynamical coupling proves to be an extra challenge, especially due to the pressure based vertical grid and the spectral core of the model. Here, we report the current status of the two-way coupling and show first results for idealised test cases.

  13. “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...

  14. Two-Way Cable Television: An Evaluation of Community Uses in Reading, Pennsylvania. Summary of the Final Report.

    ERIC Educational Resources Information Center

    Moss, Mitchell L., Ed.

    The project described in this final report was designed to test and evaluate the impact of two-way cable television (CTV) on the delivery of public services to senior citizens in Reading, Pennsylvania. The experimental design, evaluative framework, and costs of establishing the system are presented, as well as the results of a before-and-after…

  15. Two-Way Cable Television: An Evaluation of Community Uses in Reading, Pennsylvania. Final Report. Volume 1.

    ERIC Educational Resources Information Center

    Moss, Mitchell L., Ed.

    The findings of an experiment designed to test and evaluate the impact of two-way cable television (CTV), located in three neighborhood communication centers in Reading, Pennsylvania, on the delivery of public services to senior citizens, indicated that CTV can effectively serve the information needs and preferences of all urban citizens as well…

  16. The School Administrator's Primer on Distance Learning: Two-Way Interactive Television (I-TV) via Fiber Optics.

    ERIC Educational Resources Information Center

    Hobbs, Vicki M.; And Others

    This guide is intended to provide assistance to educators interested in developing two-way interactive television networks, addressing the educational and cost issues of this technology. Interactive television (I-TV) offers smaller or rural schools the opportunity to offer a comprehensive program within budgetary restraints. I-TV refers to the…

  17. Teacher and Student Language Practices and Ideologies in a Third-Grade Two-Way Dual Language Program Implementation

    ERIC Educational Resources Information Center

    Henderson, Kathryn I.; Palmer, Deborah K.

    2015-01-01

    This article provides an in-depth exploration of the language ecologies of two classrooms attempting to implement a two-way dual language (TWDL) program and its mediating conditions. Drawing on ethnographic methods and a sociocultural understanding of language, we examined both teachers' and students' language ideologies and language practices,…

  18. Taking a Closer Look at Latino Parents at One Spanish-English Two-Way Immersion Charter School

    ERIC Educational Resources Information Center

    Whiting, Erin; Feinauer, Erika; VanDerwerken, Douglas

    2012-01-01

    Scholars who work with Latino/as in the USA have long been calling for a more nuanced understanding of the heterogeneity of the US-based Latino population. Two-way Immersion (TWI) bilingual education programmes are an interesting context in which to examine the Latino parent communities in the USA. Overall, the language enrichment nature of TWI…

  19. Home Language and Literacy Practices of Parents at One Spanish-English Two-Way Immersion Charter School

    ERIC Educational Resources Information Center

    Feinauer, Erika; Whiting, Erin Feinauer

    2014-01-01

    This study looks at how parents in one Spanish-English two-way immersion (TWI) charter school report their participation in various home language and literacy practices. Parent groups, based on a cluster analysis, highlight the heterogeneity of Latino parents at the school while acknowledging the commonalities as well. Four parent groups emerged…

  20. It's all about talking: two-way communication between proteasomal and lysosomal degradation pathways via ubiquitin.

    PubMed

    Liebl, Martina P; Hoppe, Thorsten

    2016-08-01

    Selective degradation of proteins requires a fine-tuned coordination of the two major proteolytic pathways, the ubiquitin-proteasome system (UPS) and autophagy. Substrate selection and proteolytic activity are defined by a plethora of regulatory cofactors influencing each other. Both proteolytic pathways are initiated by ubiquitylation to mark substrate proteins for degradation, although the size and/or topology of the modification are different. In this context E3 ubiquitin ligases, ensuring the covalent attachment of activated ubiquitin to the substrate, are of special importance. The regulation of E3 ligase activity, competition between different E3 ligases for binding E2 conjugation enzymes and substrates, as well as their interplay with deubiquitylating enzymes (DUBs) represent key events in the cross talk between the UPS and autophagy. The coordination between both degradation routes is further influenced by heat shock factors and ubiquitin-binding proteins (UBPs) such as p97, p62, or optineurin. Mutations in enzymes and ubiquitin-binding proteins or a general decline of both proteolytic systems during aging result in accumulation of damaged and aggregated proteins. Thus further mechanistic understanding of how UPS and autophagy communicate might allow therapeutic intervention especially against age-related diseases. PMID:27225656

  1. Actin polymerization or myosin contraction: two ways to build up cortical tension for symmetry breaking.

    PubMed

    Carvalho, Kevin; Lemière, Joël; Faqir, Fahima; Manzi, John; Blanchoin, Laurent; Plastino, Julie; Betz, Timo; Sykes, Cécile

    2013-01-01

    Cells use complex biochemical pathways to drive shape changes for polarization and movement. One of these pathways is the self-assembly of actin filaments and myosin motors that together produce the forces and tensions that drive cell shape changes. Whereas the role of actin and myosin motors in cell polarization is clear, the exact mechanism of how the cortex, a thin shell of actin that is underneath the plasma membrane, can drive cell shape changes is still an open question. Here, we address this issue using biomimetic systems: the actin cortex is reconstituted on liposome membranes, in an 'outside geometry'. The actin shell is either grown from an activator of actin polymerization immobilized at the membrane by a biotin-streptavidin link, or built by simple adsorption of biotinylated actin filaments to the membrane, in the presence or absence of myosin motors. We show that tension in the actin network can be induced either by active actin polymerization on the membrane via the Arp2/3 complex or by myosin II filament pulling activity. Symmetry breaking and spontaneous polarization occur above a critical tension that opens up a crack in the actin shell. We show that this critical tension is reached by growing branched networks, nucleated by the Arp2/3 complex, in a concentration window of capping protein that limits actin filament growth and by a sufficient number of motors that pull on actin filaments. Our study provides the groundwork to understanding the physical mechanisms at work during polarization prior to cell shape modifications. PMID:24062578

  2. Teachers Avoiding Learners' Avoidance: Is It Possible?

    ERIC Educational Resources Information Center

    Tadayyon, Maedeh; Zarrinabadi, Nourollah; Ketabi, Saeed

    2016-01-01

    Dealing with learners who prefer to take the back seat and avoid classroom participation can be every teacher's nightmare. This lack of participation may cause teacher frustration, and possibly the only way to reduce this lack of participation is to access the concept of avoidance strategy. Avoidance strategy is the abandonment of a classroom task…

  3. Immune Interactions with Pathogenic and Commensal Fungi: A Two-Way Street

    PubMed Central

    Underhill, David M.; Pearlman, Eric

    2016-01-01

    We are exposed to a wide spectrum of fungi including innocuous environmental organisms, opportunistic pathogens, commensal organisms, and fungi that can actively and explicitly cause disease. Much less is understood about effective host immunity to fungi than is generally known about immunity to bacterial and viral pathogens. Innate and adaptive arms of the immune system are required for effective host defense against Candida, Aspergillus, Cryptococcus, and others, with specific elements of the host response regulating specific types of fungal infections (e.g., mucocutaneous versus systemic). Here we will review themes and controversies that are currently shaping investigation of antifungal immunity (primarily to Candida and Aspergillus) and will also examine the emerging field of the role of fungi in the gut microbiome. PMID:26588778

  4. Avoidable waste management costs

    SciTech Connect

    Hsu, K.; Burns, M.; Priebe, S.; Robinson, P.

    1995-01-01

    This report describes the activity based costing method used to acquire variable (volume dependent or avoidable) waste management cost data for routine operations at Department of Energy (DOE) facilities. Waste volumes from environmental restoration, facility stabilization activities, and legacy waste were specifically excluded from this effort. A core team consisting of Idaho National Engineering Laboratory, Los Alamos National Laboratory, Rocky Flats Environmental Technology Site, and Oak Ridge Reservation developed and piloted the methodology, which can be used to determine avoidable waste management costs. The method developed to gather information was based on activity based costing, which is a common industrial engineering technique. Sites submitted separate flow diagrams that showed the progression of work from activity to activity for each waste type or treatability group. Each activity on a flow diagram was described in a narrative, which detailed the scope of the activity. Labor and material costs based on a unit quantity of waste being processed were then summed to generate a total cost for that flow diagram. Cross-complex values were calculated by determining a weighted average for each waste type or treatability group based on the volume generated. This study will provide DOE and contractors with a better understanding of waste management processes and their associated costs. Other potential benefits include providing cost data for sites to perform consistent cost/benefit analysis of waste minimization and pollution prevention (WMIN/PP) options identified during pollution prevention opportunity assessments and providing a means for prioritizing and allocating limited resources for WMIN/PP.

  5. 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. PMID:26970577

  6. Two-way communication with neural networks in vivo using focused light

    PubMed Central

    Wilson, Nathan R.; Schummers, James; Runyan, Caroline A.; Yan, Sherry; Chen, Robert F.; Deng, Yuting; Sur, Mriganka

    2014-01-01

    Neuronal networks process information in a distributed, spatially heterogeneous fashion that transcends the layout of electrodes. In contrast, directed and steerable light offers the potential to engage specific cells on demand. We present a unified framework for adapting microscopes to use light for simultaneous in vivo stimulation and recording of cells at fine spatiotemporal resolutions. We utilize straightforward optics to lock onto networks in vivo, steer light to activate circuit elements, and simultaneously record from other cells. We then actualize this “free” augmentation on both an “open” two-photon microscope, and a leading commercial one. Following this protocol, setup of the system takes a few days and the result is a non-invasive interface to brain dynamics based on directed light, at a network resolution that was not previously possible and which will further improve with the rapid advance in development of optical reporters and effectors. This protocol is for physiologists who are competent with computers and wish to extend hardware and software to interface more fluidly with neuronal networks. PMID:23702834

  7. Efficiency of two-way weirs and prepositioned electrofishing for sampling potamodromous fish migrations

    USGS Publications Warehouse

    Favrot, Scott D.; Kwak, Thomas J.

    2016-01-01

    Potamodromy (i.e., migration entirely in freshwater) is a common life history strategy of North American lotic fishes, and efficient sampling methods for potamodromous fishes are needed to formulate conservation and management decisions. Many potamodromous fishes inhabit medium-sized rivers and are mobile during spawning migrations, which complicates sampling with conventional gears (e.g., nets and electrofishing). We compared the efficiency of a passive migration technique (resistance board weirs) and an active technique (prepositioned areal electrofishers; [PAEs]) for sampling migrating potamodromous fishes in Valley River, a southern Appalachian Mountain river, from March through July 2006 and 2007. A total of 35 fish species from 10 families were collected, 32 species by PAE and 19 species by weir. Species richness and diversity were higher for PAE catch, and species dominance (i.e., proportion of assemblage composed of the three most abundant species) was higher for weir catch. Prepositioned areal electrofisher catch by number was considerably higher than weir catch, but biomass was lower for PAE catch. Weir catch decreased following the spawning migration, while PAEs continued to collect fish. Sampling bias associated with water velocity was detected for PAEs, but not weirs, and neither gear demonstrated depth bias in wadeable reaches. Mean fish mortality from PAEs was five times greater than that from weirs. Catch efficiency and composition comparisons indicated that weirs were effective at documenting migration chronology, sampling nocturnal migration, and yielding samples unbiased by water velocity or habitat, with low mortality. Prepositioned areal electrofishers are an appropriate sampling technique for seasonal fish occupancy objectives, while weirs are more suitable for quantitatively describing spawning migrations. Our comparative results may guide fisheries scientists in selecting an appropriate sampling gear and regime for research, monitoring

  8. 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. PMID:27544875

  9. 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.

  10. 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).

  11. Differential neuromodulation of acquisition and retrieval of avoidance learning by the lateral habenula and ventral tegmental area.

    PubMed

    Shumake, Jason; Ilango, Anton; Scheich, Henning; Wetzel, Wolfram; Ohl, Frank W

    2010-04-28

    Several studies suggest an opponent functional relationship between the lateral habenula (LHb) and the ventral tegmental area (VTA). Previous work has linked LHb activation to the inhibition of dopaminergic neurons during loss of reward, as well as to deficits in escape and avoidance learning. We hypothesized that a dopamine signal might underlie the negative reinforcement of avoidance responses and that LHb activation could block this signal and thereby cause avoidance deficits. To test this idea, we implanted stimulating electrodes in either the VTA or LHb of gerbils engaged in two-way active avoidance learning, a task that shows learning-associated dopamine changes and that is acquired faster following LHb lesions. We delivered brief electrical brain stimulation whenever the animal performed a correct response, i.e., when the successful avoidance of foot shock was hypothesized to trigger an intrinsic reward signal. During the acquisition phase, VTA stimulation improved avoidance performance, while LHb stimulation impaired it. VTA stimulation appeared to improve both acquisition and asymptotic performance of the avoidance response, as VTA-stimulated animals reached above-normal performance but reverted to normal responding when stimulation was discontinued. The effects of LHb stimulation during avoidance acquisition were long lasting and persisted even after stimulation was discontinued. However, when given after successful acquisition of avoidance behavior, LHb stimulation had no effect, indicating that LHb stimulation specifically impaired avoidance acquisition without affecting memory retrieval or motivation or ability to perform the avoidance response. These results demonstrate opponent roles of LHb and VTA during acquisition but not during retrieval of avoidance learning. PMID:20427648

  12. Actuator Response of Improved Two-Way Memory TiNi Wires Evaluated by Weight Fraction Diagrams

    NASA Astrophysics Data System (ADS)

    Urbina, C.; De la Flor, S.; Gispert-Guirado, F.; Ferrando, F.

    2014-05-01

    This paper experimentally studies the improvement in the actuator response of TiNi shape memory wires brought about by thermal treatments. Heat-treated TiNi wires were thermally cycled at zero stress before being trained by constant stress to develop the two-way shape memory effect. Subsequently, the work output of these two-way memory TiNi shape memory alloys are measured during repeated thermomechanical cycling under various levels of constant stress. Changes in the phase transformation behavior in two-way memory and thermomechanically cycled TiNi shape memory alloy wires are quantified by x-ray diffraction as a function of temperature. The weight fraction diagrams of TiNi wires thermally cycled at zero stress before they were trained suggests that during constant stress training they develop a lower quantity of R-phase than samples that have not been thermally cycled at zero stress before being trained. This gives thermally cycled TiNi samples higher levels of transformation strain and work output during thermomechanical cycling than samples that have not been thermally cycled before training. These results suggest that for the best material performance—that is, significant transformation strain and, consequently, substantial work output—the TiNi wire should be thermally cycled at zero stress before training.

  13. Two Ways to Lead

    ERIC Educational Resources Information Center

    Cody, Anthony

    2013-01-01

    One popular approach to teacher leadership is to identify certain teachers as particularly successful, then have others learn from them. Collaborative leadership, in contrast, looks at leadership as a quality that anyone can have. In this model, the goal is not to figure out who is best. Instead, teachers share their unique talents and interests…

  14. Disclosure Two Ways.

    PubMed

    Bernstein, Erin B

    2015-01-01

    This article is an initial attempt to compare the pre-abortion disclosure mandates that have proliferated in the two decades since the Court decided Planned Parenthood v. Casey with laws that, in the context of assisted reproduction and reproductive health, require specific disclosures beyond a state's baseline informed consent requirements. While some scholars have characterized pre-abortion disclosure laws as sui generis, they share some important common features with disclosure mandates in the context of oocyte donation and other reproductive health procedures. This article suggests that in critiquing pre-abortion disclosure mandates, scholars and advocates should be careful to differentiate the use of disclosure laws in general from uses where the government interest conveys a moral preference against a particular procedure. PMID:26242945

  15. 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

  16. Pyrazine analogs are active components of wolf urine that induce avoidance and fear-related behaviors in deer

    PubMed Central

    Osada, Kazumi; Miyazono, Sadaharu; Kashiwayanagi, Makoto

    2014-01-01

    Our previous studies indicated that a cocktail of pyrazine analogs, identified in wolf urine, induced avoidance and fear behaviors in mice. The effects of the pyrazine cocktail on Hokkaido deer (Cervus nippon yesoensis) were investigated in field bioassays at a deer park in Hokkaido, Japan. A set of feeding bioassay trials tested the effects of the pyrazine cocktail odor on the behavior of the deer located around a feeding area in August and September 2013. This odor effectively suppressed the approach of the deer to the feeding area. In addition, the pyrazine cocktail odor provoked fear-related behaviors, such as “tail-flag”, “flight” and “jump” actions, of the deer around the feeding area. This study is the first experimental demonstration that the pyrazine analogs in wolf urine have robust and continual fearful aversive effects on ungulates as well as mice. The pyrazine cocktail might be suitable for a chemical repellent that could limit damage to forests and agricultural crops by wild ungulates. PMID:25177281

  17. Modelling two-way interactions between atmospheric pollution and weather using high-resolution GEM-MACH

    NASA Astrophysics Data System (ADS)

    Makar, Paul; Gong, Wanmin; Pabla, Balbir; Cheung, Philip; Milbrandt, Jason; Gravel, Sylvie; Moran, Michael; Gilbert, Samuel; Zhang, Junhua; Zheng, Qiong

    2013-04-01

    The Global Environmental Multiscale (GEM) model is the source of the Canadian government's operational numerical weather forecast guidance, and GEM-MACH is the Canadian operational air-quality forecast model. GEM-MACH comprises GEM and the 'Modelling Air-quality and Chemistry' module, a gas-phase, aqueous-phase and aerosol chemistry and microphysics subroutine package called from within GEM's physics module. The present operational GEM-MACH model is "on-line" (both chemistry and meteorology are part of the same modelling structure) but is not fully coupled (weather variables are provided as inputs to the chemistry, but the chemical variables are not used to modify the weather). In this work, we describe modifications made to GEM-MACH as part of the 2nd phase of the Air Quality Model Evaluation International Initiative, in order to bring the model to a fully coupled status and present the results of initial tests comparing uncoupled and coupled versions of the model to observations for a high-resolution forecasting system. Changes to GEM's cloud microphysics and radiative transfer packages were carried out to allow two-way coupling. The cloud microphysics package used here is the Milbrandt-Yau 2-moment (MY2) bulk microphysics scheme, which solves prognostic equations for the total droplet number concentration and the mass mixing ratios of six hydrometeor categories. Here, we have replaced the original cloud condensation nucleation parameterization of MY2 (empirically relating supersaturation and CCN number) with the aerosol activation scheme of Abdul-Razzak and Ghan (2002). The latter scheme makes use of the particle size and speciation distribution of GEM-MACH's chemistry code as well as meteorological inputs to predict the number of aerosol particles activated to form cloud droplets, which is then used in the MY2 microphysics. The radiative transfer routines of GEM assume a default constant concentration aerosol profile between the surface and 1500m, and a single

  18. 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

  19. 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

  20. The activation and blockage of CRF type 2 receptors of the medial amygdala alter elevated T-maze inhibitory avoidance, an anxiety-related response.

    PubMed

    Alves, Stephanie W E; Portela, Natasha C; Silva, Mariana S; Céspedes, Isabel C; Bittencourt, Jackson C; Viana, Milena B

    2016-05-15

    Previous results show that the activation of CRF type 1 (CRFR1) receptors of the medial amygdala (MeA) induces anxiogenic-like effects. The present study investigates the role played by medial amygdala CRF type 2 receptors (CRFR2) in the modulation of anxiety and panic-related responses. Male Wistar rats were administered into the MeA with the CRFR2 agonist urocortin 2 (0.5 e 1.0μg/0.2μl, experiment 1) or with the CRFR2 antagonist astressin 2-B (60ng/0.2μl, experiment 2) and 10min later tested in the elevated T-maze (ETM) for inhibitory avoidance and escape measurements. In clinical terms, these responses have been respectively related to generalized anxiety and panic disorder. In a third experiment, the effects of the combined treatment with urocortin 2 (1.0μg/0.2μl) and a sub-effective dose of astressin 2-B (30ng/0.2μl) were also investigated. All animals were tested in an open field, immediately after the ETM, for locomotor activity assessment. Results showed that urocortin 2, in the highest dose administered (1.0μg/0.2μl), facilitated ETM avoidance, an anxiogenic-like effect. Astressin 2-B, also in the highest dose (60ng/0.2μl), significantly decreased avoidance latencies, an anxiolytic-like effect. The lower dose of astressin 2-B (30ng/0.2μl) did not induce anxiolytic-like effects but was able to counteract the anxiogenic-like effects of urocortin 2. None of the compounds administered altered escape responses or locomotor activity measurements. These results suggest that CRFR2 in the medial amygdala, as CRFR1, selectively modulate an anxiety-related response. PMID:26965566

  1. Comparing One-way and Two-way Coupled Hydrometeorological Forecasting Systems for Flood Forecasting in the Mediterranean Region

    NASA Astrophysics Data System (ADS)

    Givati, Amir; Gochis, David; Rummler, Thomas; Kunstmann, Harald; Yu, Wei

    2016-04-01

    A pair of hydro-meteorological modeling systems were calibrated and evaluated for the Ayalon basin in central Israel to assess the advantages and limitations of one-way versus two-way coupled modeling systems for flood prediction. The models used included the Hydrological Engineering Center-Hydrological Modeling System (HEC-HMS) model and the Weather Research and Forecasting (WRF) Hydro modeling system. The models were forced by observed, interpolated precipitation from rain-gauges within the basin, and with modeled precipitation from the WRF atmospheric model. Detailed calibration and evaluation was carried out for two major winter storms in January and December 2013. Then both modeling systems were executed and evaluated in an operational mode for the full 2014/2015 rainy season. Outputs from these simulations were compared to observed measurements from hydrometric stations at the Ayalon basin outlet. Various statistical metrics were employed to quantify and analyze the results: correlation, Root Mean Square Error (RMSE) and the Nash-Sutcliffe (NS) efficiency coefficient. Foremost, the results presented in this study highlight the sensitivity of hydrological responses to different sources of precipitation data, and less so, to hydrologic model formulation. With observed precipitation data both calibrated models closely simulated the observed hydrographs. The two-way coupled WRF/WRF-Hydro modeling system produced improved both the precipitation and hydrological simulations as compared to the one-way WRF simulations. Findings from this study suggest that the use of two-way atmospheric-hydrological coupling has the potential to improve precipitation and, therefore, hydrological forecasts for early flood warning applications. However more research needed in order to better understand the land-atmosphere coupling mechanisms driving hydrometeorological processes on a wider variety precipitation and terrestrial hydrologic systems.

  2. A two-way coupled mode formalism that satisfies energy conservation for impedance boundaries in underwater acoustics.

    PubMed

    Stotts, Steven A; Koch, Robert A

    2015-11-01

    This paper shows that energy conservation and the derivation of the two-way coupled mode range equations can be extended in three dimensions to complex mode functions and eigenvalues. Furthermore, the energy in the coupled mode formulation is conserved for finite thickness fluid ocean waveguides with a penetrable bottom boundary beneath any range dependence. The derivations rely on completeness and a modified orthonormality statement. The mode coupling coefficients are specified solely and explicitly by the waveguide range dependence. The statement of energy conservation is applied to a numerical coupled mode calculation. PMID:26627810

  3. Error tolerance of two-basis quantum-key-distribution protocols using qudits and two-way classical communication

    SciTech Connect

    Nikolopoulos, Georgios M.; Ranade, Kedar S.; Alber, Gernot

    2006-03-15

    We investigate the error tolerance of quantum cryptographic protocols using d-level systems. In particular, we focus on prepare-and-measure schemes that use two mutually unbiased bases and a key-distillation procedure with two-way classical communication. For arbitrary quantum channels, we obtain a sufficient condition for secret-key distillation which, in the case of isotropic quantum channels, yields an analytic expression for the maximally tolerable error rate of the cryptographic protocols under consideration. The difference between the tolerable error rate and its theoretical upper bound tends slowly to zero for sufficiently large dimensions of the information carriers.

  4. Advanced transportation system study: Manned launch vehicle concepts for two way transportation system payloads to LEO. Program cost estimates document

    NASA Technical Reports Server (NTRS)

    Duffy, James B.

    1993-01-01

    This report describes Rockwell International's cost analysis results of manned launch vehicle concepts for two way transportation system payloads to low earth orbit during the basic and option 1 period of performance for contract NAS8-39207, advanced transportation system studies. Vehicles analyzed include the space shuttle, personnel launch system (PLS) with advanced launch system (ALS) and national launch system (NLS) boosters, foreign launch vehicles, NLS-2 derived launch vehicles, liquid rocket booster (LRB) derived launch vehicle, and cargo transfer and return vehicle (CTRV).

  5. Avoiding Infusion Confusion Kindergarten through 3rd Grade. A Practical Handbook for Infusing Environmental Activities into Your Classroom.

    ERIC Educational Resources Information Center

    Hayden, Harvey; And Others

    To some educators, infusing environmental education into different subject areas at different levels may seem like an insurmountable task. This handbook was developed to take the guesswork out of this process and alleviate the fear and confusion that may result. It was designed to assist with infusing awareness and attitude activities into the…

  6. Avoiding Infusion Confusion 4th through 6th Grades. A Practical Handbook for Infusing Environmental Activities into Your Classroom.

    ERIC Educational Resources Information Center

    Hayden, Harvey; And Others

    To some educators, infusing environmental education into different subject areas at different levels may seem like an insurmountable task. This handbook was developed to take the guesswork out of this process and alleviate the fear and confusion that may result. It was designed to assist with infusing knowledge and attitude activities into the…

  7. Avoiding Infusion Confusion 7th through 9th Grades. A Practical Handbook for Infusing Environmental Activities into Your Classroom.

    ERIC Educational Resources Information Center

    Hayden, Harvey; And Others

    To some educators, infusing environmental education into different subject areas at different levels may seem like an insurmountable task. This handbook was developed to take the guesswork out of this process and alleviate the fear and confusion that may result. It was designed to assist with infusing knowledge, skill and attitude activities into…

  8. Unpredictable chronic stress decreases inhibitory avoidance learning in Tuebingen long-fin zebrafish: stronger effects in the resting phase than in the active phase.

    PubMed

    Manuel, Remy; Gorissen, Marnix; Zethof, Jan; Ebbesson, Lars O E; van de Vis, Hans; Flik, Gert; van den Bos, Ruud

    2014-11-01

    Zebrafish (Danio rerio Hamilton) are increasingly used as a model to study the effects of chronic stress on brain and behaviour. In rodents, unpredictable chronic stress (UCS) has a stronger effect on physiology and behaviour during the active phase than during the resting phase. Here, we applied UCS during the daytime (active phase) for 7 and 14 days or during the night-time (resting phase) for 7 nights in an in-house-reared Tuebingen long-fin (TLF) zebrafish strain. Following UCS, inhibitory avoidance learning was assessed using a 3 day protocol where fish learn to avoid swimming from a white to a black compartment where they will receive a 3 V shock. Latencies of entering the black compartment were recorded before training (day 1; first shock) and after training on day 2 (second shock) and day 3 (no shock, tissue sampling). Fish whole-body cortisol content and expression levels of genes related to stress, fear and anxiety in the telencephalon were quantified. Following 14 days of UCS during the day, inhibitory avoidance learning decreased (lower latencies on days 2 and 3); minor effects were found following 7 days of UCS. Following 7 nights of UCS, inhibitory avoidance learning decreased (lower latency on day 3). Whole-body cortisol levels showed a steady increase compared with controls (100%) from 7 days of UCS (139%), to 14 days of UCS (174%) to 7 nights of UCS (231%), suggestive of an increasing stress load. Only in the 7 nights of UCS group did expression levels of corticoid receptor genes (mr, grα, grβ) and of bdnf increase. These changes are discussed as adaptive mechanisms to maintain neuronal integrity and prevent overload, and as being indicative of a state of high stress load. Overall, our data suggest that stressors during the resting phase have a stronger impact than during the active phase. Our data warrant further studies on the effect of UCS on stress axis-related genes, especially grβ; in mammals this receptor has been implicated in

  9. Survey of the Influence of the Width of Urban Branch Roads on the Meeting of Two-Way Vehicle Flows.

    PubMed

    Chen, Qun; Zhao, Yunan; Pan, Shuangli; Wang, Yan

    2016-01-01

    Branch roads, which are densely distributed in cities, allow for the flow of local traffic and provide connections between the city and outlying areas. Branch roads are typically narrow, and two-way traffic flows on branch roads are thus affected when vehicles traveling in opposite directions meet. This study investigates the changes in the velocities of vehicles when they meet on two-way branch roads. Various widths of branch roads were selected, and their influence on traffic flows was investigated via a video survey. The results show that, depending on the average vehicle velocity, branch roads require different widths to prevent a large decrease in velocity when vehicles meet. When the velocity on a branch road is not high (e.g., the average velocity without meeting is approximately 6 m/s), appropriately increasing the road width will notably increase the meeting velocity. However, when the velocity is high (e.g., the average velocity without meeting is greater than 10 m/s), there is a large decrease in velocity when meeting even if the road surface is wide (6.5 m). This study provides a basis for selecting the width of urban branch roads and the simulation of bidirectional traffic on such roads. PMID:26881427

  10. Simulation and Analysis of Autonomous Time Synchronization Based on Asynchronism Two-way Inter-satellite Link

    NASA Astrophysics Data System (ADS)

    Fang, L.; Yang, X. H.; Sun, B. Q.; Qin, W. J.; Kong, Y.

    2013-09-01

    The measurement of the inter-satellite link is one of the key techniques in the autonomous operation of satellite navigation system. Based on the asynchronism inter-satellite two-way measurement mode in GPS constellation, the reduction formula of the inter-satellite time synchronization is built in this paper. Moreover, the corrective method of main systematic errors is proposed. Inter-satellite two-way time synchronization is simulated on the basis of IGS (International GNSS Service) precise ephemeris. The impacts of the epoch domestication of asynchronism inter-satellite link pseudo-range, the initial orbit, and the main systematic errors on satellite time synchronization are analyzed. Furthermore, the broadcast clock error of each satellite is calculated by the ``centralized'' inter-satellite autonomous time synchronization. Simulation results show that the epoch domestication of asynchronism inter-satellite link pseudo-range and the initial orbit have little impact on the satellite clock errors, and thus they needn't be taken into account. The errors caused by the relativistic effect and the asymmetry of path travel have large impact on the satellite clock errors. These should be corrected with theoretical formula. Compared with the IGS precise clock error, the root mean square of the broadcast clock error of each satellite is about 0.4 ns.

  11. Impact of turbulent phase noise on frequency transfer with asymmetric two-way ground-satellite coherent optical links

    NASA Astrophysics Data System (ADS)

    Robert, Clélia; Conan, Jean-Marc; Wolf, Peter

    2016-06-01

    Bidirectional ground-satellite laser links suffer from turbulence-induced scintillation and phase distortion. We study how turbulence impacts on coherent detection capacity and on the associated phase noise that restricts clock transfer precision. We evaluate the capacity to obtain a two-way cancellation of atmospheric effects despite the asymmetry between up and down link that limits the link reciprocity. For ground-satellite links, the asymmetry is induced by point-ahead angle and possibly the use, for the ground terminal, of different transceiver diameters, in reception and emission. The quantitative analysis is obtained thanks to refined end- to-end simulations under realistic turbulence and wind conditions as well as satellite cinematic. These temporally resolved simulations allow characterizing the coherent detection in terms of time series of heterodyne efficiency for different system parameters. We show that Tip/Tilt correction on ground is mandatory at reception for the down link and as a pre-compensation of the up link. Good correlation between up and down phase noise is obtained even with asymmetric apertures of the ground transceiver and in spite of pointing ahead angle. The reduction to less than 1 rad2 of the two-way differential phase noise is very promising for clock comparisons.

  12. Survey of the Influence of the Width of Urban Branch Roads on the Meeting of Two-Way Vehicle Flows

    PubMed Central

    Chen, Qun; Zhao, Yunan; Pan, Shuangli; Wang, Yan

    2016-01-01

    Branch roads, which are densely distributed in cities, allow for the flow of local traffic and provide connections between the city and outlying areas. Branch roads are typically narrow, and two-way traffic flows on branch roads are thus affected when vehicles traveling in opposite directions meet. This study investigates the changes in the velocities of vehicles when they meet on two-way branch roads. Various widths of branch roads were selected, and their influence on traffic flows was investigated via a video survey. The results show that, depending on the average vehicle velocity, branch roads require different widths to prevent a large decrease in velocity when vehicles meet. When the velocity on a branch road is not high (e.g., the average velocity without meeting is approximately 6 m/s), appropriately increasing the road width will notably increase the meeting velocity. However, when the velocity is high (e.g., the average velocity without meeting is greater than 10 m/s), there is a large decrease in velocity when meeting even if the road surface is wide (6.5 m). This study provides a basis for selecting the width of urban branch roads and the simulation of bidirectional traffic on such roads. PMID:26881427

  13. Joint terminals and relay optimization for two-way power line information exchange systems with QoS constraints

    NASA Astrophysics Data System (ADS)

    Wu, Xiaolin; Rong, Yue

    2015-12-01

    The quality-of-service (QoS) criteria (measured in terms of the minimum capacity requirement in this paper) are very important to practical indoor power line communication (PLC) applications as they greatly affect the user experience. With a two-way multicarrier relay configuration, in this paper we investigate the joint terminals and relay power optimization for the indoor broadband PLC environment, where the relay node works in the amplify-and-forward (AF) mode. As the QoS-constrained power allocation problem is highly non-convex, the globally optimal solution is computationally intractable to obtain. To overcome this challenge, we propose an alternating optimization (AO) method to decompose this problem into three convex/quasi-convex sub-problems. Simulation results demonstrate the fast convergence of the proposed algorithm under practical PLC channel conditions. Compared with the conventional bidirectional direct transmission (BDT) system, the relay-assisted two-way information exchange (R2WX) scheme can meet the same QoS requirement with less total power consumption.

  14. Development of a Detailed Stress Map of Oklahoma for Avoidance of Potentially Active Faults When Siting Wastewater Injection Wells

    NASA Astrophysics Data System (ADS)

    Alt, R. C., II; Zoback, M. D.

    2014-12-01

    We report progress on a project to create a detailed map of in situ stress orientations and relative magnitudes throughout the state of Oklahoma. It is well known that the past 5 years has seen a remarkable increase in seismicity in much of the state, potentially related to waste water injection. The purpose of this project is to attempt to utilize detailed knowledge of the stress field to identify which pre-existing faults could be potentially active in response to injection-related pore pressure increases. Over 50 new stress orientations have been obtained, principally utilizing wellbore image data provided by the oil and gas industry. These data reveal a very uniform ENE direction of maximum compressive stress through much of the state. As earthquake focal plane mechanisms indicate strike-slip faulting, the stress orientation data indicate which pre-existing faults are potentially active. The data are consistent with slip on the near-vertical, NE-trending fault associated with at least one of the M 5+ earthquakes in the Prague, OK sequence in 2011. If successful, it would demonstrate that combining detailed information about pre-existing faults and the current stress field could be used to guide the siting of injection wells so as to decrease the potential for injection-related seismicity.

  15. 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 ...

  16. A two-way clustering framework to identify disparities in multimorbidity patterns of mental and physical health conditions among Australians.

    PubMed

    Ng, S K

    2015-11-20

    Multimorbidity is present in more than one quarter of the population in Australia, and its prevalence increases with age. Greater multimorbidity burden among individuals is always associated with poor health-related outcomes, including quality of life, health service utilization and mortality, among others. It is thus significant to identify the heterogeneity in multimorbidity patterns in the community and determine the impact of multimorbidity on individual health outcomes. In this paper, I propose a two-way clustering framework to identify clusters of most significant non-random comorbid health conditions and disparities in multimorbidity patterns among individuals. This framework can establish a clustering-based approach to determine the association between multimorbidity patterns and health-related outcomes and to calculate a multimorbidity score for each individual. The proposed method is illustrated using simulated data and a national survey data set of mental health and wellbeing in Australia. PMID:26032906

  17. Bi- and uni-photon entanglement in two-way cascaded fiber-coupled atom-cavity systems

    NASA Astrophysics Data System (ADS)

    Mirza, Imran M.

    2015-08-01

    We theoretically investigate the two-photon entanglement in fiber-coupled, two-way cascaded atom-cavity systems. In particular, we demonstrate that, it is possible to generate two-photon entanglement in both weak coupling (atom-cavity coupling rate | g | smaller than the cavity leakage rate κ) and strong coupling regimes (κ < | g |) in this system, when both atoms start off in an excited state. By employing the quantum trajectory method, we characterize the two-photon entanglement in terms of von-Neumann entropy and show that the amount of entanglement exceed considerably (almost double) when κ > | g |. We also quantified the amount of entanglement when instead of two excitations there is a single excitation in the system in the beginning.

  18. Use of 64 kbits/s digital channel for image transmission: Using low scan two-way video

    NASA Astrophysics Data System (ADS)

    Rahko, K.; Hongyan, L.; Kley, M.; Peuhkuri, M.; Rahko, M.

    1993-09-01

    At the seminar 'Competition in Telecommunications in Finland' on September 3rd, 1993, a test of two-way transferring an image by using 64 kbits/s digital channel was carried out. With the help of the Helsinki Telephone Company, a portrait was transferred to the lecture hall by using Vistacom Videophones, Nokia and Siemens ISDN exchange, as well as Nokia's and Siemens' user terminal equipment. It was shown on a screen through a video projector, so all visitors could see it. For human factors in telecommunications studies, every attendee was asked to give comments about the transferring quality. The report presents the results of the survey and a brief assessment of the technology.

  19. Comparison of two-way satellite time transfer and GPS common-view time transfer between OCA and TUG

    NASA Technical Reports Server (NTRS)

    Kirchner, Dieter; Thyr, U.; Ressler, H.; Robnik, R.; Grudler, P.; Baumont, Francoise S.; Veillet, Christian; Lewandowski, Wlodzimierz W.; Hanson, W.; Clements, A.

    1992-01-01

    For about one year the time scales UTC(OCA) and UTC(TUG) were compared by means of GPS and two-way satellite time transfer. At the end of the experiment both links were independently 'calibrated' by measuring the differential delays of the GPS receivers and of the satellite earth stations by transportation of a GPS receiver and of one of the satellite terminals. The results obtained by both methods differ by about 3 ns, but reveal a seasonal variation of about 8 ns peak-to-peak which is likely the result of a temperature-dependence of the delays of the GPS receivers used. For the comparison of both methods the stabilities of the timescales are of great importance. Unfortunately, during the last three months of the experiment a less stable clock had to be used for the generation of UTC(TUG).

  20. Automated delay measurement system for an Earth station for Two-Way Satellite Time and Frequency Transfer

    NASA Technical Reports Server (NTRS)

    Dejong, Gerrit; Polderman, Michel C.

    1995-01-01

    The measurement of the difference of the transmit and receive delays of the signals in a Two-Way Satellite Time and Frequency Transfer (TWSTFT) Earth station is crucial for its nanosecond time transfer capability. Also, the monitoring of the change of this delay difference with time, temperature, humidity, or barometric pressure is important for improving the TWSTFT capabilities. An automated system for this purpose has been developed from the initial design at NMi-VSL. It calibrates separately the transmit and receive delays in cables, amplifiers, upconverters and downconverters, and antenna feeds. The obtained results can be applied as corrections to the TWSTFT measurement when, before and after a measurement session, a calibration session is performed. Preliminary results obtained at NMi-VSL will be shown. Also, if available, the results of a manual version of the system that is planned to be circulated in Sept. 1994 together with a USNO portable station on a calibration trip to European TWSTFT Earth stations.

  1. Time variable gravity retrieval and treatment of temporal aliasing using optical two-way links between GALILEO and LEO satellites

    NASA Astrophysics Data System (ADS)

    Hauk, Markus; Pail, Roland; Murböck, Michael; Schlicht, Anja

    2016-04-01

    For the determination of temporal gravity fields satellite missions such as GRACE (Gravity Recovery and Climate Experiment) or CHAMP (Challenging Minisatellite Payload) were used in the last decade. These missions improved the knowledge of atmospheric, oceanic and tidal mass variations. The most limiting factor of temporal gravity retrieval quality is temporal aliasing due to the undersampling of high frequency signals, especially in the atmosphere and oceans. This kind of error causes the typical stripes in spatial representations of global gravity fields such as from GRACE. As part of the GETRIS (Geodesy and Time Reference in Space) mission, that aims to establish a geodetic reference station and precise time- and frequency reference in space by using optical two-way communication links between geostationary (GEO) and low Earth orbiting (LEO) satellites, a possible future gravity field mission can be set up. By expanding the GETRIS space segment to the global satellite navigation systems (GNSS) the optical two-way links also connect the GALILEO satellites among themselves and to LEO satellites. From these links between GALILEO and LEO satellites gravitational information can be extracted. In our simulations inter-satellite links between GALILEO and LEO satellites are used to determine temporal changes in the Earth's gravitational field. One of the main goals of this work is to find a suitable constellation together with the best analysis method to reduce temporal aliasing errors. Concerning non-tidal aliasing, it could be shown that the co-estimation of short-period long-wavelength gravity field signals, the so-called Wiese approach, is a powerful method for aliasing reduction (Wiese et al. 2013). By means of a closed loop mission simulator using inter-satellite observations as acceleration differences along the line-of-sight, different mission scenarios for GALILEO-LEO inter-satellite links and different functional models like the Wiese approach are analysed.

  2. Comparison of hydro-environmental impacts for ebb-only and two-way generation for a Severn Barrage

    NASA Astrophysics Data System (ADS)

    Ahmadian, Reza; Falconer, Roger A.; Bockelmann-Evans, Bettina

    2014-10-01

    Marine renewable energy is playing an increasing significant role in many parts of the world, mainly due to a rise in the awareness of climate change, and its detrimental effects, and the increasing cost of natural resources. The Severn Estuary, located between South West England and South Wales, has a tidal range of up to 14 m which makes it the second highest tidal range in the world. There are a number of barrage proposals amongst various marine renewable energy schemes proposed to be built in the estuary. The Cardiff-Weston STPG (Severn Tidal Power Group) Barrage, which would be one of the world's largest tidal renewable energy schemes if built, is one of the most publicised schemes to-date. This barrage would generate about 17 TWh/annum of power, which is approximately 5% of the UK's electricity consumption, whilst causing significant hydro-environmental and ecological impact on the estuary. This study mainly focuses on investigating the hydro-environmental impacts of the STPG barrage for the option of two-way generation, and compares this with the commonly investigated option of ebb-only generation. The impacts of the barrage were modelled by implementing a linked 1-D/2-D hydro-environmental model, with the capability of modelling several key environmental processes. The model predictions show that the hydro-environmental impacts of the barrage on the Severn Estuary and Bristol Channel, such as changes in the maximum velocity and reduction in suspended sediment and bacteria levels, were less significant for the two-way generation scheme when compared with the corresponding impacts for ebb-only generation.

  3. Consistent inter-individual differences in common marmosets (Callithrix jacchus) in Boldness-Shyness, Stress-Activity, and Exploration-Avoidance.

    PubMed

    Šlipogor, Vedrana; Gunhold-de Oliveira, Tina; Tadić, Zoran; Massen, Jorg J M; Bugnyar, Thomas

    2016-09-01

    The study of animal personality, defined as consistent inter-individual differences in correlated behavioral traits stable throughout time and/or contexts, has recently become one of the fastest growing areas in animal biology, with study species ranging from insects to non-human primates. The latter have, however, only occasionally been tested with standardized experiments. Instead their personality has usually been assessed using questionnaires. Therefore, this study aimed to test 21 common marmosets (Callithrix jacchus) living in three family groups, in five different experiments, and their corresponding controls. We found that behavioral differences between our animals were not only consistent over time, but also across different contexts. Moreover, the consistent behaviors formed a construct of four major non-social personality components: Boldness-Shyness in Foraging, Boldness-Shyness in Predation, Stress-Activity, and Exploration-Avoidance. We found no sex or age differences in these components, but our results did reveal differences in Exploration-Avoidance between the three family groups. As social environment can have a large influence on behavior of individuals, our results may suggest group-level similarity in personality (i.e., "group personality") in common marmosets, a species living in highly cohesive social groups. Am. J. Primatol. 78:961-973, 2016. © 2016 Wiley Periodicals, Inc. PMID:27286098

  4. Consistent inter‐individual differences in common marmosets (Callithrix jacchus) in Boldness‐Shyness, Stress‐Activity, and Exploration‐Avoidance

    PubMed Central

    Gunhold‐de Oliveira, Tina; Tadić, Zoran; Massen, Jorg J.M.; Bugnyar, Thomas

    2016-01-01

    The study of animal personality, defined as consistent inter‐individual differences in correlated behavioral traits stable throughout time and/or contexts, has recently become one of the fastest growing areas in animal biology, with study species ranging from insects to non‐human primates. The latter have, however, only occasionally been tested with standardized experiments. Instead their personality has usually been assessed using questionnaires. Therefore, this study aimed to test 21 common marmosets (Callithrix jacchus) living in three family groups, in five different experiments, and their corresponding controls. We found that behavioral differences between our animals were not only consistent over time, but also across different contexts. Moreover, the consistent behaviors formed a construct of four major non‐social personality components: Boldness‐Shyness in Foraging, Boldness‐Shyness in Predation, Stress‐Activity, and Exploration‐Avoidance. We found no sex or age differences in these components, but our results did reveal differences in Exploration‐Avoidance between the three family groups. As social environment can have a large influence on behavior of individuals, our results may suggest group‐level similarity in personality (i.e., “group personality”) in common marmosets, a species living in highly cohesive social groups. Am. J. Primatol. 78:961–973, 2016. © 2016 The Authors. American Journal of Primatology published by Wiley Periodicals, Inc. PMID:27286098

  5. Managing the Risk of Triggered Seismicity: Can We Identify (and Avoid) Potentially Active Faults? - A Practical Case Study in Oklahoma

    NASA Astrophysics Data System (ADS)

    Zoback, M. D.; Alt, R. C., II; Walsh, F. R.; Walters, R. J.

    2014-12-01

    It is well known that throughout the central and eastern U.S. there has been a marked increase in seismicity since 2009, at least some of which appears to increased wastewater injection. No area has seen a greater increase in seismicity than Oklahoma. In this paper, we utilize newly available information on in situ stress orientation and relative magnitudes, the distribution of high volume injection wells and knowledge of the intervals used for waste water disposal to identify the factors potentially contributing to the occurrence of triggered seismicity. While there are a number of sites where in situ stress data has been successfully used to identify potentially active faults, we are investigating whether this methodology can be implemented throughout a state utilizing the types of information frequently available in areas of oil and gas development. As an initial test of this concept, we have been compiling stress orientation data from wells throughout Oklahoma provided by private industry. Over fifty new high quality data points, principally drilling-induced tensile fractures observed in image logs, result in a greatly improved understanding of the stress field in much of the state. A relatively uniform ENE direction of maximum compressive stress is observed, although stress orientations (and possibly relative stress magnitudes) differ in the southern and southwestern parts of the state. The proposed methodology can be tested in the area of the NE-trending fault that produced the M 5+ earthquakes in the Prague, OK sequence in 2011, and the Meers fault in southwestern OK, that produced a M~7 reverse faulting earthquake about 1100 years ago. This methodology can also be used to essentially rule out slip on other major faults in the area, such as the ~N-S trending Nemaha fault system. Additional factors leading to the occurrence of relatively large triggered earthquakes in Oklahoma are 1) the overall increase in injection volumes throughout the state in recent

  6. 49 CFR 232.407 - Operations requiring use of two-way end-of-train devices; prohibition on purchase of...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Operations requiring use of two-way end-of-train...-TRAIN DEVICES End-of-Train Devices § 232.407 Operations requiring use of two-way end-of-train devices... solely for the purpose of identifying those operations subject to the requirements for the use of...

  7. A Qualitative Analysis of the Benefits and Limitations of Using Two-Way Conferencing Technology to Supervise Preservice Teachers in Remote Locations

    ERIC Educational Resources Information Center

    Falconer, Karin Binner; Lignugaris/Kraft, Benjamin

    2002-01-01

    The purpose of this inquiry was to describe the benefits and limitations of using two-way audio/video conferencing technology in a preservice teacher training program located in a remote area. Two-way conferencing technology was introduced on a trial basis to assist in the supervision of practicum students and student teachers in remote university…

  8. Two-way hydro-mechanical coupling is required not to underestimate fault fluid flow in numerical simulations

    NASA Astrophysics Data System (ADS)

    Tillner, Elena; Nakaten, Benjamin; Kempka, Thomas

    2015-04-01

    -MP and coupled to the hydro-mechanical simulator FLAC3D through hydraulic property changes as a function of volumetric strain increments. Numerical simulations are based on one-way and two-way coupling procedures. The one-way coupling considers pore pressure calculated by the multiphase flow as input to the hydro-mechanical simulator without any feedback. The two-way coupling procedure includes a feedback from the hydro-mechanical simulator to the multiphase flow simulator using the parameters porosity and permeability accompanied by a capillary pressure correction. Results of the comparison of both coupling procedures outlines that a two-way coupling is required when fault fluid flow is assessed by numerical simulations, since hydraulic flow properties may change by several orders of magnitudes inducing significant migration pathways at faults under given conditions. Hence, in such cases one-way coupling tends to underestimate fault fluid flow. [1] Tillner E, Kempka T, Nakaten B, Kühn M. Brine migration through fault zones: 3D numerical simulations for a prospective CO2 storage site in Northeast Germany. Int J Greenh Gas Con 2013; 19: 689-703. doi: 10.1016/j.ijggc.2013.03.012. [2] Röhmann L, Tillner E, Magri F, Kühn M, Kempka T. Fault Reactivation and Ground Surface Uplift Assessment at a Prospective German CO2 Storage Site. Energy Procedia 2013; 40: 437-446. doi: 10.1016/j.egypro.2013.08.050.

  9. Downward Wave Coupling Changes in Response to Future Climate Change, Two Way Atmosphere/Ocean Coupling and QBO

    NASA Astrophysics Data System (ADS)

    Wellyanto Lubis, Sandro; Matthes, Katja; Harnik, Nili; Omrani, Nour-Eddine

    2014-05-01

    Wave reflection in the stratosphere can impact the troposphere via a well-defined, high latitude meridional waveguide that is bounded above by a vertical reflecting surface. Such wave reflection is known as downward wave coupling (DWC). Recent studies have shown that stratospheric ozone affects DWC, affecting wave propagation and subsequent wave-mean flow interaction in the Southern Hemisphere. However the factors controlling DWC in the Northern Hemisphere are still unclear. There is new evidence that the frequency of Major Stratospheric Warming (MSW) is significantly influenced by the QBO and two-way ocean/ atmosphere interaction. However the resulting impact on DWC has thus far not been investigated. Here we examine the impact of future climate change, two way atmosphere/ ocean coupling, and the QBO on wave geometry and DWC using different CESM-WACCM model experiments. A transient simulation of present and future climate (1955-2099), with green house gases (GHG) and ozone depleting substances (ODS) following the RCP 8.5 scenario, shows the largest reduction in the DWC over last few decades of the simulation. This reduction is associated with an absence of the vertical reflecting surface and statistically insignificant downward wave reflection. Comparison to an experiment with GHG/ODS fixed at 1960s levels, shows no indication of DWC-changes. The lack of a DWC response is associated with insignificant changes of the background wind states, whose vertical structure directly impacts the DWC. The comparison of this experiment with simulations with and without QBO nudging shows that the QBO strengthens the DWC. This can be explained by the fact that our nonQBO simulation has a permanent, strong QBO-like east phase, which dampens the DWC. Comparison of experiments with dynamically-coupled and fixed SSTs shows that the background zonal wind is strengthened significantly when the ocean/atmosphere interaction is removed. However, no apparent strengthening of DWC is seen

  10. Avoidant personality disorder

    MedlinePlus

    ... Names Personality disorder - avoidant References American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, VA: American Psychiatric Publishing. 2013. ...

  11. Two-way shift of wavelength in holographic sensing of organic vapor in nanozeolites dispersed acrylamide photopolymer.

    PubMed

    Mao, Dongyao; Geng, Yaohui; Liu, Hongpeng; Zhou, Ke; Xian, Lihong; Yu, Dan

    2016-08-10

    Holographic sensing of alcohol organic vapor is characterized in detail at transmission and reflection geometries in Y nanozeolites dispersed acrylamide photopolymer. The two-way shift of the diffraction spectrum and its temporal evolution with various vapor concentrations are measured. Obvious blueshifts of diffraction spectrum peaks are observed and analyzed in two recording geometries. The competition mechanism between decreasing the average refractive index and swelling the grating fringe space is proposed for exploring the wavelength shift mechanism. In the reflection grating, as organic vapor increases, the redshift after the blueshift of the wavelength peaks are observed clearly. We further demonstrate the significance of this competition mechanism. In the low concentration region, at transmission <700  ppm and reflection <400  ppm in nanozeolites dispersed polymer, the blueshift of the wavelength is a significant factor in identifying an organic vapor with a low refractive index. These experimental results provide a probability for improving the applicability of a holographic sensor. This work can accelerate the development of the holographic sensing strategy and provide a novel identification method for organic vapor. PMID:27534461

  12. 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.

  13. Two-way communication between SecY and SecA suggests a Brownian ratchet mechanism for protein translocation.

    PubMed

    Allen, William John; Corey, Robin Adam; Oatley, Peter; Sessions, Richard Barry; Baldwin, Steve A; Radford, Sheena E; Tuma, Roman; Collinson, Ian

    2016-01-01

    The essential process of protein secretion is achieved by the ubiquitous Sec machinery. In prokaryotes, the drive for translocation comes from ATP hydrolysis by the cytosolic motor-protein SecA, in concert with the proton motive force (PMF). However, the mechanism through which ATP hydrolysis by SecA is coupled to directional movement through SecYEG is unclear. Here, we combine all-atom molecular dynamics (MD) simulations with single molecule FRET and biochemical assays. We show that ATP binding by SecA causes opening of the SecY-channel at long range, while substrates at the SecY-channel entrance feed back to regulate nucleotide exchange by SecA. This two-way communication suggests a new, unifying 'Brownian ratchet' mechanism, whereby ATP binding and hydrolysis bias the direction of polypeptide diffusion. The model represents a solution to the problem of transporting inherently variable substrates such as polypeptides, and may underlie mechanisms of other motors that translocate proteins and nucleic acids. PMID:27183269

  14. Two-way self-consistent simulation of the inner magnetosphere driven by realistic electric and magnetic fields

    NASA Astrophysics Data System (ADS)

    Ilie, Raluca; Liemohn, Michael; Toth, Gabor

    2014-05-01

    The geomagnetic storm of August 6, 2011 is examined using the two-way self consistent coupling between the kinetic Hot Electron and Ion Drift Integrator (HEIDI) model, the Block Adaptive Tree Solar Wind Roes-Type Scheme (BATS-R-US) MHD model and the Ridley Ionospheric Model (RIM) through the Space Weather Modeling Framework (SWMF). HEIDI solves the time dependent, gyration and bounce-averaged kinetic equation for the phase space density of different ring current species and computes full pitch angle distributions for all local times and radial distances. This model was generalized to accommodate arbitrary magnetic fields and through the coupling with the SWMF it obtains magnetic field description along with plasma distribution at the model boundaries from the BATS-R-US model within the SWMF. Electric field self-consistency is assured by the passing of convection potentials from the Ridley Ionosphere Model (RIM) within SWMF. Our study tests the various levels of coupling between the three models, highlighting the role the magnetic field, plasma sheet conditions and the cross polar cap potential play in the formation and evolution of the ring current. We use the results of the coupled HEIDI, BATSRUS and RIM models during disturbed conditions to study the importance of a kinetic self-consistent approach to the description of geospace.

  15. Correcting velocity and volume-fraction calculations in two-way-coupled, particle-laden-flow simulations

    NASA Astrophysics Data System (ADS)

    Ireland, Peter; Capecelatro, Jesse; Fox, Rodney; Desjardins, Olivier

    2015-11-01

    In many flows, the motion of the carrier phase is altered by the presence of inertial particles. To alleviate the computational demands associated with resolving the boundary layers around these particles, volume-filtering is often applied to the underlying flow field, and model equations are solved for the forces on the particles. These model equations involve terms which depend on the fluid properties at the particle center in the absence of the disturbance induced by the particle (i.e., the `undisturbed fluid properties'). In a two-way-coupled simulation, however, we generally only have access to fluid properties after the particle-induced disturbance (i.e., the `disturbed fluid properties'). Using the disturbed fluid properties in the particle model equations leads to an under-prediction of the drag on the particles and an over-prediction of the particle settling velocity. We introduce analytical corrections to alleviate this issue for low particle Reynolds numbers, allowing us to recover undisturbed fluid properties from the disturbed fluid field, and thereby providing more accurate calculations of the particle velocity and drag. We show comparisons between the results with and without the corrections in both uniform Stokes flows and cluster-induced turbulent flows.

  16. 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.

  17. Two-way molecular ligation for efficient conversion of monomeric hepatitis B virus DNA constructs into tandem dimers.

    PubMed

    Zong, Li; Qin, Yanli; Jia, Haodi; Zhou, Huailiang; Chen, Chaoyang; Qiao, Ke; Zhang, Jiming; Wang, Yongxiang; Li, Jisu; Tong, Shuping

    2016-07-01

    Replication of the 3.2-kb hepatitis B virus (HBV) genome is driven by the covalently closed circular (ccc) DNA in the nucleus, from which four classes of co-terminal RNAs are transcribed. Genome replication requires just the 3.5-kb pregenomic RNA, which is terminally redundant. Cloning the full-length HBV genome into a vector disrupts its continuity, thus preventing genome replication at the step of pregenomic RNA transcription. This can be overcome by converting the monomeric construct into a tandem dimer, yet the need to ligate two molecules of the HBV genome with vector DNA makes it inefficient and even unsuccessful. To overcome this problem we partially digested the monomeric construct with the unique restriction enzyme used for cloning, and dephosphorylated the linearized monomer before its ligation with another copy of the HBV genome. Alternatively, the monomer was linearized at another unique restriction site inside the HBV genome, followed by its dephosphorylation and ligation with another copy of the HBV genome linearized at the same site. These approaches of two-way molecular ligation greatly improved the efficiency of dimer formation with about 50% of the bacterial colonies screened harboring tandem dimers. PMID:27025357

  18. Determination of turbine runner dynamic behaviour under operating condition by a two-way staggered fluid-structureinteraction method

    NASA Astrophysics Data System (ADS)

    Dompierre, F.; Sabourin, M.

    2010-08-01

    This paper presents the application of the two-way fluid-structure interaction method introduced by ANSYS to calculate the dynamic behaviour of a Francis turbine runner under operating condition. This time-dependant calculation directly takes into account characteristics of the flow and particularly the pressure fluctuations caused by the rotor-stator interaction. This formulation allows the calculation of the damping forces of the whole system implicitly. Thereafter, the calculated dynamic stress can be used for a fatigue analysis. A verification of the mechanical and fluid simulations used as input for the fluid-structure interaction calculation is first performed. Subsequently, a connection of these two independent simulations is made. A validation according to the hydraulic conditions is made with the measurements from the scale model testing. Afterwards, the static displacement of the runner under the hydraulic load is compared with the results of a classical static analysis for verification purposes. Finally, the natural frequencies deduced by the post-processing of the dynamic portion of the runner displacement with respect to time are compared with the natural frequencies obtained from a classical acoustic modal analysis. All comparisons show a good agreement with experimental data or results obtained with conventional methods.

  19. Two-way communication between SecY and SecA suggests a Brownian ratchet mechanism for protein translocation

    PubMed Central

    Allen, William John; Corey, Robin Adam; Oatley, Peter; Sessions, Richard Barry; Radford, Sheena E; Tuma, Roman; Collinson, Ian

    2016-01-01

    The essential process of protein secretion is achieved by the ubiquitous Sec machinery. In prokaryotes, the drive for translocation comes from ATP hydrolysis by the cytosolic motor-protein SecA, in concert with the proton motive force (PMF). However, the mechanism through which ATP hydrolysis by SecA is coupled to directional movement through SecYEG is unclear. Here, we combine all-atom molecular dynamics (MD) simulations with single molecule FRET and biochemical assays. We show that ATP binding by SecA causes opening of the SecY-channel at long range, while substrates at the SecY-channel entrance feed back to regulate nucleotide exchange by SecA. This two-way communication suggests a new, unifying 'Brownian ratchet' mechanism, whereby ATP binding and hydrolysis bias the direction of polypeptide diffusion. The model represents a solution to the problem of transporting inherently variable substrates such as polypeptides, and may underlie mechanisms of other motors that translocate proteins and nucleic acids. DOI: http://dx.doi.org/10.7554/eLife.15598.001 PMID:27183269

  20. Avoidable mortality in Lithuania.

    PubMed Central

    Gaizauskiene, A; Gurevicius, R

    1995-01-01

    STUDY OBJECTIVE--The study aimed to analyse avoidable mortality in Lithuania as an index of the quality of health care and to assess trends in avoidable mortality from 1970-90. SETTING AND PARTICIPANTS--All deaths of Lithuanian residents aged between 0 and 64 years between 1970 and 1990 were analysed. MEASUREMENTS AND MAIN RESULTS--Twenty seven per cent of all deaths in this age group were avoidable. Avoidable deaths were grouped into preventable and treatable ones. Treatable causes of death accounted for 54%, and preventable, 46% of avoidable mortality. Time trends showed that general mortality and mortality from avoidable causes of death in this age group were almost stable between 1970 and 1990. Mortality from treatable causes of death fell, while deaths from preventable causes increased. The results in the preventable group were greatly affected by deaths from malignant neoplasms of trachea, bronchus, and lungs. Differences were noted between the sexes in total mortality as well as in avoidable mortality. CONCLUSIONS--Avoidable causes of death are relatively common and, consequently, they are of practical importance for public health and studies of the health care quality in Lithuania. Reorganisation of health care is to be carried out and considerable emphasis will be placed on health education, promotion, and prevention, as primary prevention measures have not been effective thus far. PMID:7629464

  1. Avoiding Statistical Mistakes

    ERIC Educational Resources Information Center

    Strasser, Nora

    2007-01-01

    Avoiding statistical mistakes is important for educators at all levels. Basic concepts will help you to avoid making mistakes using statistics and to look at data with a critical eye. Statistical data is used at educational institutions for many purposes. It can be used to support budget requests, changes in educational philosophy, changes to…

  2. Increased Physical Activity and Fitness above the 50(th) Percentile Avoid the Threat of Older Adults Becoming Institutionalized: A Cross-sectional Pilot Study.

    PubMed

    Pereira, Catarina; Fernandes, Jorge; Raimundo, Armando; Biehl-Printes, Clarissa; Marmeleira, José; Tomas-Carus, Pablo

    2016-02-01

    The objective of this study was to analyze the impact of physical fitness and physical activity on the threat of older adults without cognitive impairment becoming institutionalized. This cross-sectional study involved 195 non-institutionalized (80.1 ± 4.4 years) and 186 institutionalized (83.8 ± 5.2years) participants. Cognitive impairment was assessed using Mini-Mental State Examination, measures of physical fitness were determined by the Senior Fitness Test, and physical activity was assessed using the International Physical Activity Questionnaire. Multivariate binary logistic analysis selected four main determinants of institutionalization in both genders: The likelihood of becoming institutionalized increased by +18.6% for each additional year of age, whereas it decreased by -24.8% by each fewer kg/m(2) in body mass index (BMI), by -0.9% for each additional meter performed in the aerobic endurance test, and by -2.0% for each additional 100 metabolic equivalent of task (MET)-min/week of physical activity expenditure (p < 0.05). Values ≤50(th) percentile (age ≥81 years, BMI ≥26.7 kg/m(2), aerobic endurance ≤367.6 meters, and physical activity ≤693 MET-min/week) were computed using receiver operating characteristics analysis as cutoffs discriminating institutionalized from non-institutionalized older adults. The performance of physical activity, allied to an improvement in physical fitness (mainly BMI and aerobic endurance), may avoid the threat of institutionalization of older adults without cognitive impairment only if they are above the 50(th) percentile. The following parameters are highly recommended: Expending ≥693 MET-min/week on physical activity, having a BMI ≤26.7 kg/m(2), and being able to walk ≥367.6 meters in the aerobic endurance test, especially above the age of 80 years. The discovery of this trigger justifies the development of physical activity programs targeting the pointed cutoffs in old and very old adults

  3. Two-way coupling of a global Hall magnetohydrodynamics model with a local implicit particle-in-cell model

    NASA Astrophysics Data System (ADS)

    Daldorff, Lars K. S.; Tóth, Gábor; Gombosi, Tamas I.; Lapenta, Giovanni; Amaya, Jorge; Markidis, Stefano; Brackbill, Jeremiah U.

    2014-07-01

    Computational models based on a fluid description of the plasma, such as magnetohydrodynamic (MHD) and extended magnetohydrodynamic (XMHD) codes are highly efficient, but they miss the kinetic effects due to the assumptions of small gyro radius, charge neutrality, and Maxwellian thermal velocity distribution. Kinetic codes can properly take into account the kinetic effects, but they are orders of magnitude more expensive than the fluid codes due to the increased degrees of freedom. If the fluid description is acceptable in a large fraction of the computational domain, it makes sense to confine the kinetic model to the regions where kinetic effects are important. This coupled approach can be much more efficient than a pure kinetic model. The speed up is approximately the volume ratio of the full domain relative to the kinetic regions assuming that the kinetic code uses a uniform grid. This idea has been advocated by [1] but their coupling was limited to one dimension and they employed drastically different grid resolutions in the fluid and kinetic models. We describe a fully two-dimensional two-way coupling of a Hall MHD model BATS-R-US with an implicit Particle-in-Cell (PIC) model iPIC3D. The coupling can be performed with identical grid resolutions and time steps. We call this coupled computational plasma model MHD-EPIC (MHD with Embedded PIC regions). Our verification tests show that MHD-EPIC works accurately and robustly. We show a two-dimensional magnetosphere simulation as an illustration of the potential future applications of MHD-EPIC.

  4. A single-dose, two-way crossover, bioequivalence study of dexmethylphenidate HCl with and without food in healthy subjects.

    PubMed

    Teo, Steve K; Scheffler, Michael R; Wu, Anfan; Stirling, David I; Thomas, Steve D; Stypinski, Daria; Khetani, Vikram D

    2004-02-01

    Attention deficit hyperactivity disorder (ADHD) in children is effectively treated by racemic oral methylphenidate (dl-MPH). The d-isomer (d-MPH) has been developed as an improved treatment for ADHD since only half the racemic dose is used. This study, performed in healthy subjects, assessed the effect of food on the pharmacokinetics of dexmethylphenidate hydrochloride (d-MPH HCl) in a single dose (2 x 10-mg tablets), two-way crossover with d-MPH administered to subjects in both a fasting state or after a high-fat breakfast. There were no serious or unexpected adverse events during the course of this study, with most events reported in comparable numbers of fed and fasted subjects. The bioequivalence of d-MPH was similar with or without food, with 90% confidence intervals of 88.2% to 104.6% and 105.9% to 118.2% for ln(C(max)) and ln[(AUC(0-infinity))], respectively. There was a marginal but statistically significant 1-hour increase in t(max) in the fed versus fasted state, reflecting an absorption delay. The rate of formation of the major metabolite, d-ritalinic acid (d-RA), was marginally decreased ( approximately 14%) after food. The extent of exposure to d-RA was similar (within 1.2%) between both treatments. There was a marginal but statistically significant difference in mean t(max) for d-RA between fed and fasted conditions, with peak concentration occurring 1.5 hours later after d-MPH administration with food. There was no measurable in vivo chiral inversion of d-MPH to l-MPH in plasma. In addition, the metabolism of d-MPH was stereospecific as d-MPH only produced d-RA. In summary, food had no substantial effect on the bioavailability of d-MPH, with an equivalent rate and extent of exposure obtained. Therefore, d-MPH can be administered without regard to food intake. PMID:14747426

  5. A hybrid surface layer parameterization scheme for the two-way fully coupled atmosphere-ocean wave system WEW

    NASA Astrophysics Data System (ADS)

    Katsafados, Petros; Papadopoulos, Anastasios; Varlas, George; Korres, Gerasimos

    2015-04-01

    The two-way fully coupled atmosphere-ocean wave system WEW has been recently developed in order to study the factors that contribute to the air-sea interaction processes and feedbacks. The coupled system consists of two components: the atmospheric component which is based on the Workstation Eta non-hydrostatic limited area model and the ocean-wave component which is based on the fourth generation OpenMP (OMP) version of the WAM model. The WEW has been already evaluated in a number of high-impact weather and sea state events where generally a more realistic representation of the momentum exchanges in the ocean wind-wave system has been shown However, the new developed wind-wave parameterization scheme reduces both the near surface wind speed and the significant wave height as a response to the increased aerodynamic drag considered by the atmospheric model over rough sea surfaces. Such behavior is mainly attributed to the surface layer parameterization scheme of the atmospheric component which is based on the Mellor-Yamada-Janjic (MYJ) scheme. It is noted that this scheme has been adjusted to support independent atmospheric simulations. Therefore, we proceed to develop a new hybrid surface layer parameterization based on the MYJ and the Janssen schemes that operate in the atmospheric and ocean wave components of the WEW, respectively. In this case the roughness length depends on the wave age instead of the Charnock parameter following the formulation proposed by Vickers and Mahrt. The spatial variability of the wave age is estimated at each ocean wave component time step and it is directly provided to the MYJ scheme. The parameterization of the viscous sublayer and the universal functions for the estimation of the near surface wind speed have been also revised accordingly. In this study, a test version of the new hybrid scheme of WEW has been statistically evaluated against a number of buoys and satellite retrievals over the Mediterranean Sea in a case study of high

  6. Two-way multi-band optical/IR transmission measurements in the Persian Gulf coastal region

    NASA Astrophysics Data System (ADS)

    de Jong, Arie N.; Fritz, Peter J.

    2005-10-01

    The atmospheric conditions in the Persian Gulf region are significantly different from other places in the world. The particle size distribution may vary daily and during the day. The aerosols can contribute to the amount of rainfall over land, important for the nations around the Gulf. In 2004 NASNGSFC and NRL (Naval Research Laboratory) introduced a proposal to improve the modelling of aerosol transport for the Persian Gulf area. The proposal included a measurement campaign in the UAE (United Arabian Emirates), held in the summer/fall of 2004, sponsored by the DWRS (Department of Water Resources Studies) in Abu Dhabi: UAEz (Unified Aerosol Experiment in the UAE). In this campaign NASA installed a number of multi-spectral sun-photometers at various locations in the UAE (http://aeronet.gsfc.nasa.gov). NRL installed ground based and airborne particle samplers. In addition, TNO (the Netherlands) installed its multi-band opticaUIR transmissometer, in order to collect horizontal, path-integrated transmission data. This device provides additional information on the scattering behaviour of the aerosols compared to the other instruments, which either integrate scattering over the full vertical path (the NASA sun-photometers, providing the Aerosol Optical Depth (AOD)) or sample the particles in-situ (the NRL particle samplers, providing size distribution and composition). This paper deals with our transmission measurement set-up, which was located in a coastal area near Abu Dhabi. This location allowed the investigation of the local variability of the atmospheric conditions: from desert dust to pollution, such as fossil fuel and biomass burning, depending on the wind direction. For logistic reasons a set-up was chosen with a retro-reflector. This choice implies consequences for the calibration procedure and measurement accuracy, which are discussed in detail. Also the effects of path-inhomogeneity and scintillation for such a two-way set-up are considered. Results are

  7. Responses to two-way selection on growth in mass-spawned F1 progeny of Argopecten irradians concentricus (Say)

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Liu, Jin; Li, Yanhong; Zhu, Xiaowen; Liu, Zhigang

    2014-03-01

    In the present study, the effect of one-generation divergent selection on the growth and survival of the bay scallop ( Argopecten irradians concentricus) was examined to evaluate the efficacy of a selection program currently being carried out in Beibu Bay in the South China Sea. A total of 146 adult scallops were randomly selected from the same cultured population of A. i. concentricus, and divided into two groups in shell length (anterior-posterior measurement): large (4.91-6.02 cm, n=74) and small (3.31-4.18 cm, n=72). At the same time, a control group was also randomly sampled (4.21-4.88 cm, n =80). Mass-spawned F 1 progenies from the three size groups were obtained and reared under identical conditions at all growth phases. The effects of two-way (or upward-downward) selection on fertilization rate, hatching rate, survival rate, daily growth in shell length and body weight were assessed in the three size groups. Results show that significant differences ( P<0.01) were found in hatching rate, survival rate and daily growth of F1 progenies, but not in fertilization rate ( P>0.05), among the three groups. The hatching rate, survival rate and daily growth of the progeny of large-sized parents were greater than those of the control group ( P<0.05), which in turn were larger than those of small-sized group ( P<0.05). Responses to selection by shell length and body weight were 0.32 ± 0.04 cm and 2.18 ± 0.05 g, respectively, for the upward selection, and -0.14 ± 0.03 cm and -2.77 ± 0.06 g, respectively, for the downward selection. The realized heritability estimates of shell length and body weight were 0.38 ± 0.06 cm and 0.22 ± 0.07 g for the upward selection, and 0.24 ± 0.06 cm and 0.37 ± 0.09 g for the downward selection, respectively. The change in growth by bidirectional selection suggests that high genetic variation may be present in the cultured bay scallop population in China.

  8. Avoiding Computer Viruses.

    ERIC Educational Resources Information Center

    Rowe, Joyce; And Others

    1989-01-01

    The threat of computer sabotage is a real concern to business teachers and others responsible for academic computer facilities. Teachers can minimize the possibility. Eight suggestions for avoiding computer viruses are given. (JOW)

  9. Long-Term Post-Stroke Changes Include Myelin Loss, Specific Deficits in Sensory and Motor Behaviors and Complex Cognitive Impairment Detected Using Active Place Avoidance

    PubMed Central

    Li, Jie; Ooi, Evelyn; Bloom, Jonathan; Poon, Carrie; Lax, Daniel; Rosenbaum, Daniel M.; Barone, Frank C.

    2013-01-01

    Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO) or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1) sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2) complex active place avoidance learning (APA) and simple passive avoidance retention (PA). Electroretinogram (ERG), hemispheric loss (infarction), hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue) staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001), sensory (p<0.001), beam balance performance (p<0.01) and hindlimb placement behavior (p<0.01). tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05) but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining). No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01) in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and can be

  10. Long-term post-stroke changes include myelin loss, specific deficits in sensory and motor behaviors and complex cognitive impairment detected using active place avoidance.

    PubMed

    Zhou, Jin; Zhuang, Jian; Li, Jie; Ooi, Evelyn; Bloom, Jonathan; Poon, Carrie; Lax, Daniel; Rosenbaum, Daniel M; Barone, Frank C

    2013-01-01

    Persistent neurobehavioral deficits and brain changes need validation for brain restoration. Two hours middle cerebral artery occlusion (tMCAO) or sham surgery was performed in male Sprague-Dawley rats. Neurobehavioral and cognitive deficits were measured over 10 weeks included: (1) sensory, motor, beam balance, reflex/abnormal responses, hindlimb placement, forepaw foot fault and cylinder placement tests, and (2) complex active place avoidance learning (APA) and simple passive avoidance retention (PA). Electroretinogram (ERG), hemispheric loss (infarction), hippocampus CA1 neuronal loss and myelin (Luxol Fast Blue) staining in several fiber tracts were also measured. In comparison to Sham surgery, tMCAO surgery produced significant deficits in all behavioral tests except reflex/abnormal responses. Acute, short lived deficits following tMCAO were observed for forelimb foot fault and forelimb cylinder placement. Persistent, sustained deficits for the whole 10 weeks were exhibited for motor (p<0.001), sensory (p<0.001), beam balance performance (p<0.01) and hindlimb placement behavior (p<0.01). tMCAO produced much greater and prolonged cognitive deficits in APA learning (maximum on last trial of 604±83% change, p<0.05) but only a small, comparative effect on PA retention. Hemispheric loss/atrophy was measured 10 weeks after tMCAO and cross-validated by two methods (e.g., almost identical % ischemic hemispheric loss of 33.4±3.5% for H&E and of 34.2±3.5% for TTC staining). No visual dysfunction by ERG and no hippocampus neuronal loss were detected after tMCAO. Fiber tract damage measured by Luxol Fast Blue myelin staining intensity was significant (p<0.01) in the external capsule and striatum but not in corpus callosum and anterior commissure. In summary, persistent neurobehavioral deficits were validated as important endpoints for stroke restorative research in the future. Fiber myelin loss appears to contribute to these long term behavioral dysfunctions and can be

  11. Avoided Crossing and Synchronization

    NASA Astrophysics Data System (ADS)

    Sekii, T.; Shibahashi, H.

    2013-12-01

    We examine avoided crossing of stellar pulsations in the nonlinear regime, where synchronization may occur, based on a simple model of weakly coupled van der Pol oscillators with close frequencies. For this simple case, avoided crossing is unaffected in the sense that there is a frequency difference between the symmetric and antisymmetric modes, but as a result of synchronization, unlike the linear oscillations case, the system can vibrate in only one of the modes.

  12. Operational Collision Avoidance

    NASA Technical Reports Server (NTRS)

    Guit, Bill

    2015-01-01

    This presentation will describe the early days of the EOS Aqua and Aura operational collision avoidance process. It will highlight EOS debris avoidance maneuvers, EOS high interest event statistic and A-Train systematic conjunctions and conclude with future challenges. This is related to earlier e-DAA (tracking number 21692) that an abstract was submitted to a different conference. Eric Moyer, ESMO Deputy Project Manager has reviewed and approved this presentation on May 6, 2015

  13. Zaprinast and Rolipram Enhances Spatial and Emotional Memory in the Elevated Plus Maze and Passive Avoidance Tests and Diminishes Exploratory Activity in Naive Mice

    PubMed Central

    Akar, Furuzan; Mutlu, Oguz; Celikyurt, Ipek Komsuoglu; Ulak, Guner; Erden, Faruk; Bektas, Emine; Tanyeri, Pelin

    2014-01-01

    Background Phosphodiesterase (PDE) inhibitors in the central nervous system have been shown to stimulate neuronal functions and increase neurogenesis in Alzheimer disease (AD) patients. Material/Methods The aim of this study was to investigate the effects of zaprinast, a PDE5 inhibitor, and rolipram, a PDE4 inhibitor, on learning and memory in elevated plus maze (EPM) and passive avoidance (PA) tests in naive mice. Male Balb-c mice received short-term treatment with zaprinast (3 and 10 mg/kg) and rolipram (0.05 and 0.1 mg/kg) before the acquisition trial of the EPM and PA tests. The exploratory activity of the animals was also investigated in the Hughes box test. Results Both zaprinast (10 mg/kg) and rolipram (0.1 mg/kg) significantly decreased second-day latency compared to the control group in the EPM test, while only rolipram (0.1 mg/kg) significantly increased second-day latency in the PA test. Both zaprinast (10 mg/kg) and rolipram (0.1 mg/kg) significantly decreased the number of entries to new areas and time spent in new areas in the Hughes box test. Conclusions Our study revealed that both zaprinast and rolipram enhanced spatial memory in EPM, while rolipram seemed to have more emotional memory-enhancing effects in the PA test compared to zaprinast. Both zaprinast and rolipram diminished exploratory activity in the Hughes box test, which can be attributed to the drugs’ anxiogenic effects. PMID:25057848

  14. Reactive Collision Avoidance Algorithm

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel; Acikmese, Behcet; Ploen, Scott; Hadaegh, Fred

    2010-01-01

    The reactive collision avoidance (RCA) algorithm allows a spacecraft to find a fuel-optimal trajectory for avoiding an arbitrary number of colliding spacecraft in real time while accounting for acceleration limits. In addition to spacecraft, the technology can be used for vehicles that can accelerate in any direction, such as helicopters and submersibles. In contrast to existing, passive algorithms that simultaneously design trajectories for a cluster of vehicles working to achieve a common goal, RCA is implemented onboard spacecraft only when an imminent collision is detected, and then plans a collision avoidance maneuver for only that host vehicle, thus preventing a collision in an off-nominal situation for which passive algorithms cannot. An example scenario for such a situation might be when a spacecraft in the cluster is approaching another one, but enters safe mode and begins to drift. Functionally, the RCA detects colliding spacecraft, plans an evasion trajectory by solving the Evasion Trajectory Problem (ETP), and then recovers after the collision is avoided. A direct optimization approach was used to develop the algorithm so it can run in real time. In this innovation, a parameterized class of avoidance trajectories is specified, and then the optimal trajectory is found by searching over the parameters. The class of trajectories is selected as bang-off-bang as motivated by optimal control theory. That is, an avoiding spacecraft first applies full acceleration in a constant direction, then coasts, and finally applies full acceleration to stop. The parameter optimization problem can be solved offline and stored as a look-up table of values. Using a look-up table allows the algorithm to run in real time. Given a colliding spacecraft, the properties of the collision geometry serve as indices of the look-up table that gives the optimal trajectory. For multiple colliding spacecraft, the set of trajectories that avoid all spacecraft is rapidly searched on

  15. Hippocampal-dependent memory in the plus-maze discriminative avoidance task: The role of spatial cues and CA1 activity.

    PubMed

    Leão, Anderson H F F; Medeiros, André M; Apolinário, Gênedy K S; Cabral, Alícia; Ribeiro, Alessandra M; Barbosa, Flávio F; Silva, Regina H

    2016-05-01

    The plus-maze discriminative avoidance task (PMDAT) has been used to investigate interactions between aversive memory and an anxiety-like response in rodents. Suitable performance in this task depends on the activity of the basolateral amygdala, similar to other aversive-based memory tasks. However, the role of spatial cues and hippocampal-dependent learning in the performance of PMDAT remains unknown. Here, we investigated the role of proximal and distal cues in the retrieval of this task. Animals tested under misplaced proximal cues had diminished performance, and animals tested under both misplaced proximal cues and absent distal cues could not discriminate the aversive arm. We also assessed the role of the dorsal hippocampus (CA1) in this aversive memory task. Temporary bilateral inactivation of dorsal CA1 was conducted with muscimol (0.05μg, 0.1μg, and 0.2μg) prior to the training session. While the acquisition of the task was not altered, muscimol impaired the performance in the test session and reduced the anxiety-like response in the training session. We also performed a spreading analysis of a fluorophore-conjugated muscimol to confirm selective inhibition of CA1. In conclusion, both distal and proximal cues are required to retrieve the task, with the latter being more relevant to spatial orientation. Dorsal CA1 activity is also required for aversive memory formation in this task, and interfered with the anxiety-like response as well. Importantly, both effects were detected by different parameters in the same paradigm, endorsing the previous findings of independent assessment of aversive memory and anxiety-like behavior in the PMDAT. Taken together, these findings suggest that the PMDAT probably requires an integration of multiple systems for memory formation, resembling an episodic-like memory rather than a pure conditioning behavior. Furthermore, the concomitant and independent assessment of emotionality and memory in rodents is relevant to elucidate

  16. Avoiding Sophomore Jinx.

    ERIC Educational Resources Information Center

    Fitzpatrick, James

    2002-01-01

    After the first year, new superintendents should take care to avoid the "sophomore jinx" by communicating effectively with the board president every week and with board members before meetings. Public engagement is also an integral part of a superintendent's job. (MLF)

  17. Pitcherpot: Avoiding Honeypot Detection

    NASA Astrophysics Data System (ADS)

    Panchal, Vinod K.; Bhatnagar, Pramod K.; Bhatnagar, Mitul

    This paper explores the various ways honeypots could be detected by the malicious attacker. This includes the different prevalent criteria and characteristics for honeypots generation & their weaknesses. Further this paper proposes a new way of implementation of a honeypot (Pitcher pots Systems) that effectively facilitate its identity avoidance and yet offers better ways to study the attacker.

  18. Myelin Avoids the JAM.

    PubMed

    Follis, Rose M; Carter, Bruce D

    2016-08-17

    In this issue of Neuron, Redmond et al. (2016) identify junction adhesion molecule 2 (JAM2) as an inhibitor of somatodendritic myelination in spinal cord neurons, thereby elucidating how myelin forms on axons but avoids dendrites and cell bodies. PMID:27537479

  19. Avoiding the "M" Word.

    ERIC Educational Resources Information Center

    Klinger, Donna

    2001-01-01

    Provides an overview of roundtable discussions by top business officers about how higher education can capitalize on strategic alliances. Describes how, by working with one another and with corporate partners, colleges and universities can avoid closing their doors or merging with stronger institutions. (EV)

  20. Plants to Avoid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge of poisonous plants is extremely important for home owners, gardeners, farmers, hunters, hikers, and the rest of the general public. Among the most important plants to avoid in the Delta Region are poison ivy, bull nettle, eastern black nightshade, Queen Ann’s lace, jimsonweed, and trumpe...

  1. Psychological Treatments to Avoid

    ERIC Educational Resources Information Center

    Thomason, Timothy C.

    2010-01-01

    Certain psychological treatments should be avoided, and a list of such treatments would provide valuable guidance for counselors, as well as potential clients. It is well established that some therapies are potentially dangerous, and some fringe therapies are highly unlikely to help clients beyond a placebo effect. This article provides an…

  2. Exploring Associations among Writing Self-Perceptions, Writing Abilities, and Native Language of English-Spanish Two-Way Immersion Students

    ERIC Educational Resources Information Center

    Neugebauer, Sabina R.; Howard, Elizabeth R.

    2015-01-01

    The current study, with 409 fourth graders in two-way immersion programs, explored the writing self-perceptions of native English and native Spanish speakers and the relationship between self-perceptions and writing performance. An adapted version of the Writer Self-Perception Scale (WSPS) was administered along with a writing task. Native English…

  3. Simulation of the Indirect Radiative Forcing of Climate Due to Aerosols by the Two-Way Coupled WRF-CMAQ over the Eastern United States

    EPA Science Inventory

    In this study, the shortwave cloud forcing (SWCF) and longwave cloud forcing (LWCF) are estimated with the newly developed two-way coupled WRF-CMAQ over the eastern United States. Preliminary indirect aerosol forcing has been successfully implemented in WRF-CMAQ. The comparisons...

  4. Middle-Class English Speakers in a Two-Way Immersion Bilingual Classroom: "Everybody Should Be Listening to Jonathan Right Now..."

    ERIC Educational Resources Information Center

    Palmer, Deborah K.

    2009-01-01

    Two-way bilingual immersion education, offered in a fast-growing number of primary schools in the United States, provides primary language maintenance to minority language speakers while simultaneously offering an enrichment "foreign" language immersion experience to English-speaking children in the same classroom, generally with the same teacher.…

  5. 49 CFR 232.407 - Operations requiring use of two-way end-of-train devices; prohibition on purchase of...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Operations requiring use of two-way end-of-train devices; prohibition on purchase of nonconforming devices. 232.407 Section 232.407 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS...

  6. The Development of Writing Skills in an Italian-English Two-Way Immersion Program: Evidence from First through Fifth Grade

    ERIC Educational Resources Information Center

    Montanari, Simona; Simón-Cereijido, Gabriela; Hartel, Antonella

    2016-01-01

    This study examines the writing skills of students in grades 1 to 5 of an Italian-English two-way immersion program. Narrative writing samples were collected in both languages and scored for content, organization, grammar, mechanics, vocabulary, text length, and overall total score. The results show that writing skills improved as a function of…

  7. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF-CMAQ: model description, development, evaluation and regional analysis

    EPA Science Inventory

    This study implemented first, second and glaciations aerosol indirect effects (AIE) on resolved clouds in the two-way coupled WRF-CMAQ modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ predicted aerosol distribu...

  8. Reasons for Enrollment at a Spanish-English Two-Way Immersion Charter School among Highly Motivated Parents from a Diverse Community

    ERIC Educational Resources Information Center

    Whiting, Erin F.; Feinauer, Erika

    2011-01-01

    This study builds on previous work to examine parent reasons for enrolling their children in a two-way immersion (TWI) charter school. This work goes beyond ethno linguistic background variables (language, ethnicity), to include other key variables such as education level, income, religion, household distance from school, and family structure.…

  9. Validation of the WRF-CMAQ Two-Way Model with Aircraft Data and High Resolution MODIS Data in the CA 2008 Wildfire Case

    EPA Science Inventory

    A new WRF-CMAQ two-way coupled model was developed to provide a pathway for chemical feedbacks from the air quality model to the meteorological model. The essence of this interaction is focused on the direct radiative effects of scattering and absorbing aerosols in the tropospher...

  10. A second anniversary operational review of the OmniTRACS(R): The first two-way mobile Ku-band satellite communications system

    NASA Technical Reports Server (NTRS)

    Jacobs, Irwin M.; Salmasi, Allen; Gilhousen, Klein S.; Weaver, Lindsay A., Jr.; Bernard, Thomas J.

    1990-01-01

    A novel two-way mobile satellite communications and vehicle position reporting system that is currently operational in the United States and Europe is described. The system characteristics and service operations are described in detail. Technical descriptions of the equipment and signal processing techniques are provided.

  11. A Widely Applicable Extension of the Random Effects Two-Way Layout: Its Definition and Statistical Analysis Based on Group Invariance

    ERIC Educational Resources Information Center

    Li, Heng

    2004-01-01

    A type of data layout that may be considered as an extension of the two-way random effects analysis of variance is characterized and modeled based on group invariance. The data layout seems to be suitable for several scenarios in psychometrics, including the one in which multiple measurements are taken on each of a set of variables, and the…

  12. A robust two-way switching control system for remote piloting and stabilization of low-cost quadrotor UAVs

    NASA Astrophysics Data System (ADS)

    Ripamonti, Francesco; Resta, Ferruccio; Vivani, Andrea

    2015-04-01

    The aim of this paper is to present two control logics and an attitude estimator for UAV stabilization and remote piloting, that are as robust as possible to physical parameters variation and to other external disturbances. Moreover, they need to be implemented on low-cost micro-controllers, in order to be attractive for commercial drones. As an example, possible applications of the two switching control logics could be area surveillance and facial recognition by means of a camera mounted on the drone: the high computational speed logic is used to reach the target, when the high-stability one is activated, in order to complete the recognition tasks.

  13. Absence of “Warm-Up” during Active Avoidance Learning in a Rat Model of Anxiety Vulnerability: Insights from Computational Modeling

    PubMed Central

    Myers, Catherine E.; Smith, Ian M.; Servatius, Richard J.; Beck, Kevin D.

    2014-01-01

    Avoidance behaviors, in which a learned response causes omission of an upcoming punisher, are a core feature of many psychiatric disorders. While reinforcement learning (RL) models have been widely used to study the development of appetitive behaviors, less attention has been paid to avoidance. Here, we present a RL model of lever-press avoidance learning in Sprague-Dawley (SD) rats and in the inbred Wistar Kyoto (WKY) rat, which has been proposed as a model of anxiety vulnerability. We focus on “warm-up,” transiently decreased avoidance responding at the start of a testing session, which is shown by SD but not WKY rats. We first show that a RL model can correctly simulate key aspects of acquisition, extinction, and warm-up in SD rats; we then show that WKY behavior can be simulated by altering three model parameters, which respectively govern the tendency to explore new behaviors vs. exploit previously reinforced ones, the tendency to repeat previous behaviors regardless of reinforcement, and the learning rate for predicting future outcomes. This suggests that several, dissociable mechanisms may contribute independently to strain differences in behavior. The model predicts that, if the “standard” inter-session interval is shortened from 48 to 24 h, SD rats (but not WKY) will continue to show warm-up; we confirm this prediction in an empirical study with SD and WKY rats. The model further predicts that SD rats will continue to show warm-up with inter-session intervals as short as a few minutes, while WKY rats will not show warm-up, even with inter-session intervals as long as a month. Together, the modeling and empirical data indicate that strain differences in warm-up are qualitative rather than just the result of differential sensitivity to task variables. Understanding the mechanisms that govern expression of warm-up behavior in avoidance may lead to better understanding of pathological avoidance, and potential pathways to modify these processes. PMID

  14. Design of two-way reversible bending actuator based on a shape memory alloy/shape memory polymer composite

    NASA Astrophysics Data System (ADS)

    Taya, Minoru; Liang, Yuanchang; Namli, Onur C.; Tamagawa, Hirohisa; Howie, Tucker

    2013-10-01

    The design of a reversible bending actuator based on a SMA/SMP composite is presented. The SMA/SMP composite is made of SMA NiTi wires with a bent ‘U’-shape in the austenite phase embedded in an epoxy SMP matrix which has a memorized flat shape. The bending motion is caused by heating the composite above TAf to activate the NiTi recovery. Upon cooling, the softening from the austenite to R-phase transformation results in a relaxation of the composite towards its original flat shape. In the three-point bending measurement the composite was able to exhibit a reversible deflection of 1.3 mm on a support with a 10 mm span. In addition, a material model for predicting the composite’s deflection is presented and predicts the experimental results reasonably well. The model also estimates the in-plane internal force and the degree of the SMA phase transformation.

  15. When threats foreign turn domestic: Two ways for distant realistic intergroup threats to carry over into local intolerance.

    PubMed

    Bouman, Thijs; van Zomeren, Martijn; Otten, Sabine

    2015-09-01

    In times of economic downturn, perceived realistic intergroup threats (e.g., labour competition) often dominate political and media discourse. Although local outgroups (e.g., local immigrants) can be experienced as sources of realistic threats, we propose that such threats can also be perceived to be caused by distant outgroups (e.g., European Union members perceiving Greece to threaten their economies) and that such distant threats can carry over into local intolerance (e.g., increasing intolerance towards local immigrant groups). We predicted and found in two studies that perceived distant realistic threats carried over into local intolerance via two different pathways. First, direct reactions towards the distant outgroup can generalize to culturally similar local outgroups (the group-based association pathway). Secondly, Study 2 indicated that when the distant threat was attributed to stereotypical outgroup traits (e.g., being lazy), distant realistic threats activated local realistic threats, which subsequently influenced local intolerance (the threat-based association pathway). Taken together, our studies indicate that perceived realistic threats foreign can turn domestic, but in two different ways. PMID:25491910

  16. 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.

  17. Highly specific role of hypocretin (orexin) neurons: differential activation as a function of diurnal phase, operant reinforcement vs. operant avoidance and light level

    PubMed Central

    McGregor, Ronald; Wu, Ming-Fung; Barber, Grace; Ramanathan, Lalini; Siegel, Jerome M.

    2011-01-01

    Hypocretin (Hcrt) cell loss is responsible for narcolepsy, but Hcrt's role in normal behavior is unclear. We found that Hcrt KO mice were unable to work for food or water reward during the light phase. However, they were unimpaired relative to wild type (WT) mice when working for reward during the dark phase or when working to avoid shock in the light or dark phases. In WT, expression of Fos in Hcrt neurons occurs only in the light phase when working for positive reinforcement. Expression was seen throughout the medio-lateral extent of the Hcrt field. Fos was not expressed when expected or unexpected, unearned rewards were presented, when working to avoid negative reinforcement, or when given or expecting shock, even though these conditions elicit maximal electroencephalographic (EEG) arousal. Fos was not expressed in the light phase when light was removed. This may explain the lack of light induced arousal in narcoleptics and its presence in normal individuals. This is the first demonstration of such specificity of arousal system function and has implications for understanding the motivational and circadian consequences of arousal system dysfunction. The current results also indicate that comparable and complementary specificities must exist in other “arousal” systems. PMID:22031892

  18. Avoiding dangerous climate change

    SciTech Connect

    Hans Joachim Schellnhuber; Wolfgang Cramer; Nebojsa Nakicenovic; Tom Wigley; Gary Yohe

    2006-02-15

    In 2005 the UK Government hosted the Avoiding Dangerous Climate Change conference to take an in-depth look at the scientific issues associated with climate change. This volume presents the most recent findings from the leading international scientists that attended the conference. The topics addressed include critical thresholds and key vulnerabilities of the climate system, impacts on human and natural systems, socioeconomic costs and benefits of emissions pathways, and technological options for meeting different stabilisation levels of greenhouse gases in the atmosphere. Contents are: Foreword from Prime Minister Tony Blair; Introduction from Rajendra Pachauri, Chairman of the IPCC; followed by 41 papers arranged in seven sections entitled: Key Vulnerabilities of the Climate System and Critical Thresholds; General Perspectives on Dangerous Impacts; Key Vulnerabilities for Ecosystems and Biodiversity; Socio-Economic Effects; Regional Perspectives; Emission Pathways; and Technological Options. Four papers have been abstracted separately for the Coal Abstracts database.

  19. Modeling the ocean and atmosphere during an extreme bora event in northern Adriatic using one-way and two-way atmosphere-ocean coupling

    NASA Astrophysics Data System (ADS)

    Ličer, M.; Smerkol, P.; Fettich, A.; Ravdas, M.; Papapostolou, A.; Mantziafou, A.; Strajnar, B.; Cedilnik, J.; Jeromel, M.; Jerman, J.; Petan, S.; Malačič, V.; Sofianos, S.

    2016-01-01

    We have studied the performances of (a) a two-way coupled atmosphere-ocean modeling system and (b) one-way coupled ocean model (forced by the atmosphere model), as compared to the available in situ measurements during and after a strong Adriatic bora wind event in February 2012, which led to extreme air-sea interactions. The simulations span the period between January and March 2012. The models used were ALADIN (Aire Limitée Adaptation dynamique Développement InterNational) (4.4 km resolution) on the atmosphere side and an Adriatic setup of Princeton ocean model (POM) (1°/30 × 1°/30 angular resolution) on the ocean side. The atmosphere-ocean coupling was implemented using the OASIS3-MCT model coupling toolkit. Two-way coupling ocean feedback to the atmosphere is limited to sea surface temperature. We have compared modeled atmosphere-ocean fluxes and sea temperatures from both setups to platform and CTD (conductivity, temperature, and depth) measurements from three locations in the northern Adriatic. We present objective verification of 2 m atmosphere temperature forecasts using mean bias and standard deviation of errors scores from 23 meteorological stations in the eastern part of Italy. We show that turbulent fluxes from both setups differ up to 20 % during the bora but not significantly before and after the event. When compared to observations, two-way coupling ocean temperatures exhibit a 4 times lower root mean square error (RMSE) than those from one-way coupled system. Two-way coupling improves sensible heat fluxes at all stations but does not improve latent heat loss. The spatial average of the two-way coupled atmosphere component is up to 0.3 °C colder than the one-way coupled setup, which is an improvement for prognostic lead times up to 20 h. Daily spatial average of the standard deviation of air temperature errors shows 0.15 °C improvement in the case of coupled system compared to the uncoupled. Coupled and uncoupled circulations in the northern

  20. TWO-WAY FREEZE VALVE

    DOEpatents

    Lantz, K.D.; Clark, P.M.

    1960-01-01

    A valve for closing off the flow of radioactive and corrosive gases and liquids or mixtures thereof and forming a leak tight barrier is described. This valve has no mechanical moving parts which would require design to close tolerances and retention of the usual seal tighthess. Instead, there is provided a cavity in which a fusible metal is contained. Heating and cooling are provided to exercise control over the state of the metal. Baffle chambers are utilized to separate the molten fusible metal from the gas or liquid which is being passed through and return the molten metal to its cavity.

  1. A Two-Way Spinoff

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Gougeon Brothers, Inc. successfully applied their boat building expertise to a NASA problem in wind turbine development. NASA and the department of Energy began experimenting with large wind turbine machines as an energy alternative to fossil fuels. During the development of a first generation wind turbine generator known as MOD-OA, Lewis Research Center faced the problem of supersize rotor blades made of metal that kept failing under stress. Using the techniques they had developed for fabricating wood composite structures, the Gougeon Brothers went on to build several sets of blades for the MOD-OA system; all worked successfully. Gougeon Brothers acquired new know-how during the course of studying rotor blade aerodynamics which they applied to their boat building. They developed the innovative "aerodynamic mast" for sailboats. Their mast, a strong, lightweight wood composite which needs no supporting rigging and is free to rotate with the wind, could cut a ship's fuel cost by as much as 40 percent.

  2. A Two-Way Spinoff.

    ERIC Educational Resources Information Center

    Aviation/Space, 1982

    1982-01-01

    A unusual technology transfer, involving sailboats and commercial wind energy systems, highlights space-related spinoffs for home, consumer, and recreational use. These include clothing for cooling athletes, high-intensity lighting, an advanced welding tool, and a water filter. (Author/JN)

  3. Two-Way Tether Gun

    NASA Technical Reports Server (NTRS)

    Sanger, George F.

    1994-01-01

    Safety-tether device enables crewmembers on spacecraft to retrieve crewmember drifting away from spacecraft. Alternatively, drifting crewmember who carries device uses it to grasp and return to spacecraft. Also used on Earth. For example, rescuer on vessel or pier uses it to retrieve and haul drowning or unconscious person to safety; drifting person or rescuer in water uses it to grasp and hold onto support.

  4. Measuring Experiential Avoidance in Adults: The Avoidance and Fusion Questionnaire

    ERIC Educational Resources Information Center

    Schmalz, Jonathan E.; Murrell, Amy R.

    2010-01-01

    To date, general levels of experiential avoidance are primarily measured by the Acceptance and Action Questionnaire-II (AAQ-II), but it includes items of questionable comprehensibility. The Avoidance and Fusion Questionnaire for Youth (AFQ-Y), previously validated as a measure of experiential avoidance with children and adolescents, was…

  5. Diet, nutrition, and avoidable cancer.

    PubMed Central

    Willett, W C

    1995-01-01

    In a 1981 review, Doll and Peto estimated that approximately 35% of cancer deaths in the United States were potentially avoidable by the modification of diet but that this percentage might be as low as 10% or as high as 70%. Since that time, the epidemiologic literature on diet and cancer has grown greatly, as has understanding of the mechanisms of carcinogenesis. In general, this expanded literature has not provided reason to alter the Doll and Peto estimate substantially. For colon cancer, evidence has accumulated that some of the international differences that were attributed to diet are probably due to physical activity. For breast cancer, the concept that fat intake per se is the primary reason for differences in rates among countries has not been supported by prospective studies. Although several lines of evidence suggest that caloric restriction and slow growth rates may contribute importantly to the low rates of breast cancer found outside Western countries, this may not translate directly to practical means of prevention. In contrast to breast cancer, more recent data have supported a causative role for red meat in the development of colon and prostate cancers, although perhaps not entirely due to its fat content. Whereas earlier thinking about nutrition and cancer emphasized the adverse effects of fat and other components in the diet, the most compelling evidence of the last decade has indicated the importance of protective factors, largely unidentified, in fruits and vegetables. Considering the more recent evidence, it is roughly estimated that about 32% of cancer may be avoidable by changes in diet; however, it now seems unlikely that less than 20% or more than 42% of cancer deaths would be avoidable by dietary change. PMID:8741778

  6. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  7. Modeling ocean response to an extreme Bora event in Northern Adriatic using one-way and two-way atmosphere-ocean coupling

    NASA Astrophysics Data System (ADS)

    Ličer, M.; Smerkol, P.; Fettich, A.; Ravdas, M.; Papapostolou, A.; Mantziafou, A.; Strajnar, B.; Cedilnik, J.; Jeromel, M.; Jerman, J.; Petan, S.; Malačič, V.; Sofianos, S.

    2015-07-01

    We study the performances of (a) fully two-way coupled atmosphere-ocean modeling system and (b) one-way coupled ocean model (forced by the atmospheric model hourly output), as compared to the available in situ (mooring and CTD) measurements during and after an strong Bora wind event in February 2012, which led to extreme air-sea interactions and record breaking seawater cooling and dense water formation in Northern Adriatic. The simulations span the period between January and March 2012. The models used were ALADIN (4.4 km resolution) on the atmospheric side and Adriatic setup of POM (1°/30 × 1°/30 angular resolution) on the ocean side. The atmosphere-ocean coupling was implemented using the OASIS3-MCT model coupling toolkit. We show, using in situ seawater temperature measurements, that the two-way atmosphere-ocean coupling improves the ocean response to Bora because it captures transient Bora-induced cooling better than the one-way coupled version of the ocean model. We show that this difference stems mainly from an underestimation of air-sea temperature difference in one-way coupled system during the Bora episode, leading to an underestimation of sensible heat losses from the ocean in the one-way coupled system. We show these losses exhibit significant impact on baroclinic circulation on synoptic timescales. We use CTD observations in the Gulf of Trieste to show that when compared to the one-way setup, the two-way coupled system produces a similar estimation of salinities and density anomalies before the Bora episode, but a significantly better estimation of these quantities afterwards.

  8. MEST- avoid next extinction

    NASA Astrophysics Data System (ADS)

    Cao, Dayong

    2012-11-01

    Asteroid 2011 AG5 will impact on Earth in 2040. (See Donald K. Yoemans, ``Asteroid 2011 AG5 - A Reality Check,'' NASA-JPL, 2012) In 2011, The author say: the dark hole will take the dark comet to impact our solar system in 20 years, and give a systemic model between the sun and its companion-dark hole to explain why were there periodicity mass extinction on earth. (see Dayong Cao, BAPS.2011.CAL.C1.7, BAPS.2011.DFD.LA.24, BAPS.2012.APR.K1.78 and BAPS.2011.APR.K1.17) The dark Asteroid 2011 AG5 (as a dark comet) is made of the dark matter which has a space-time (as frequence-amplitude square) center- a different systemic model from solar systemic model. It can asborb the space-time and wave. So it is ``dark.'' When many dark matters hit on our earth, they can break our atom structure and our genetic code to trigger the Mass Extinction. In our experiments, consciousness can change the systematic model and code by a life-informational technology. So it can change the output signals of the solar cell. (see Dayong Cao, BAPS.2011.MAR.C1.286 and BAPS.2012.MAR.P33.14) So we will develop the genetic code of lives to evolution and sublimation, will use the dark matter to change the systemic model between dark hole and sun and will avoid next extinction.

  9. Collision avoidance sensor skin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The objective was to totally eliminate the possibility of a robot (or any mechanism for that matter) inducing a collision in space operations. We were particularly concerned that human beings were safe under all circumstances. This was apparently accomplished, and it is shown that GSFC has a system that is ready for space qualification and flight. However, it soon became apparent that much more could be accomplished with this technology. Payloads could be made invulnerable to collision avoidance and the blind spots behind them eliminated. This could be accomplished by a simple, non-imaging set of 'Capaciflector' sensors on each payload. It also is evident that this system could be used to align and dock the system with a wide margin of safety. Throughout, lighting problems could be ignored, and unexpected events and modeling errors taken in stride. At the same time, computational requirements would be reduced. This can be done in a simple, rugged, reliable manner that will not disturb the form factor of space systems. It will be practical for space applications. The lab experiments indicate we are well on the way to accomplishing this. Still, the research trail goes deeper. It now appears that the sensors can be extended to end effectors to provide precontact information and make robot docking (or any docking connection) very smooth, with minimal loads impacted back into the mating structures. This type of ability would be a major step forward in basic control techniques in space. There are, however, baseline and restructuring issues to be tackled. The payloads must get power and signals to them from the robot or from the astronaut servicing tool. This requires a standard electromechanical interface. Any of several could be used. The GSFC prototype shown in this presentation is a good one. Sensors with their attendant electronics must be added to the payloads, end effectors, and robot arms and integrated into the system.

  10. 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

  11. Computational modelling of the scaffold-free chondrocyte regeneration: a two-way coupling between the cell growth and local fluid flow and nutrient concentration.

    PubMed

    Hossain, Md Shakhawath; Bergstrom, D J; Chen, X B

    2015-11-01

    The in vitro chondrocyte cell culture process in a perfusion bioreactor provides enhanced nutrient supply as well as the flow-induced shear stress that may have a positive influence on the cell growth. Mathematical and computational modelling of such a culture process, by solving the coupled flow, mass transfer and cell growth equations simultaneously, can provide important insight into the biomechanical environment of a bioreactor and the related cell growth process. To do this, a two-way coupling between the local flow field and cell growth is required. Notably, most of the computational and mathematical models to date have not taken into account the influence of the cell growth on the local flow field and nutrient concentration. The present research aimed at developing a mathematical model and performing a numerical simulation using the lattice Boltzmann method to predict the chondrocyte cell growth without a scaffold on a flat plate placed inside a perfusion bioreactor. The model considers the two-way coupling between the cell growth and local flow field, and the simulation has been performed for 174 culture days. To incorporate the cell growth into the model, a control-volume-based surface growth modelling approach has been adopted. The simulation results show the variation of local fluid velocity, shear stress and concentration distribution during the culture period due to the growth of the cell phase and also illustrate that the shear stress can increase the cell volume fraction to a certain extent. PMID:25804699

  12. 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. PMID:27191832

  13. Neuroimaging the temporal dynamics of human avoidance to sustained threat.

    PubMed

    Schlund, Michael W; Hudgins, Caleb D; Magee, Sandy; Dymond, Simon

    2013-11-15

    Many forms of human psychopathology are characterized by sustained negative emotional responses to threat and chronic behavioral avoidance, implicating avoidance as a potential transdiagnostic factor. Evidence from both nonhuman neurophysiological and human neuroimaging studies suggests a distributed frontal-limbic-striatal brain network supports avoidance. However, our understanding of the temporal dynamics of the network to sustained threat that prompts sustained avoidance is limited. To address this issue, 17 adults were given extensive training on a modified free-operant avoidance task in which button pressing avoided money loss during a sustained threat period. Subsequently, subjects underwent functional magnetic resonance imaging while completing the avoidance task. In our regions of interest, we observed phasic, rather than sustained, activation during sustained threat in dorsolateral and inferior frontal regions, anterior and dorsal cingulate, ventral striatum and regions associated with emotion, including the amygdala, insula, substantia nigra and bed nucleus of the stria terminalis complex. Moreover, trait levels of experiential avoidance were negatively correlated with insula, hippocampal and amygdala activation. These findings suggest knowledge that one can consistently avoid aversive outcomes is not associated with decreased threat-related responses and that individuals with greater experiential avoidance exhibit reduced reactivity to initial threat. Implications for understanding brain mechanisms supporting human avoidance and psychological theories of avoidance are discussed. PMID:24095880

  14. Healthcare avoidance: a critical review.

    PubMed

    Byrne, Sharon K

    2008-01-01

    The purpose of this study is to provide a critical review and synthesis of theoretical and research literature documenting the impact of avoidance on healthcare behaviors, identify the factors that influence healthcare avoidance and delay in the adult population, and propose a direction for future research. The Theory of Reasoned Action, Theory of Planned Behavior, Theory of Care-Seeking Behavior, the Transtheoretical Model, and the Behavioral Model of Health Services Use/Utilization are utilized to elaborate on the context within which individual intention to engage in healthcare behaviors occurs. Research literature on the concept of healthcare avoidance obtained by using computerized searches of CINAHL, MEDLINE, PSYCH INFO, and HAPI databases, from 1995 to 2007, were reviewed. Studies were organized by professional disciplines. Healthcare avoidance is a common and highly variable experience. Multiple administrative, demographic, personal, and provider factors are related to healthcare avoidance, for example, distrust of providers and/or the science community, health beliefs, insurance status, or socioeconomic/income level. Although the concept is recognized by multiple disciplines, limited research studies address its impact on healthcare decision making. More systematic research is needed to determine correlates of healthcare avoidance. Such studies will help investigators identify patients at risk for avoidant behaviors and provide the basis for health-promoting interventions. Methodological challenges include identification of characteristics of individuals and environments that hinder healthcare behaviors, as well as, the complexity of measuring healthcare avoidance. Studies need to systematically explore the influence of avoidance behaviors on specific healthcare populations at risk. PMID:18758277

  15. Differential hippocampal neuron density between inbred Roman high- (low anxious) and low-avoidance (high anxious) rats.

    PubMed

    Garcia-Falgueras, A; Castillo-Ruiz, M M; Put, T; Tobeña, A; Fernández-Teruel, A

    2012-07-26

    The inbred Roman low- (RLA-I) and high-avoidance (RHA-I) rats used in this study were initially selected and bred for extremely poor vs. rapid acquisition of active two-way avoidance behavior in the shuttle box. As a result of the selection for divergent avoidance acquisition, clear behavioral differences have been found between RHA and RLA rats in a variety of tasks related to anxiety and conflict. In rats of these two strains/lines previous brain studies have been performed, specifically in the striatum, the mesencephalic dopaminergic areas and the prefrontal cortex, as these brain areas are the classical ones for their critical role in sensitization and may play a role in the well-characterized anxiety response. In this study we analyzed, in RHA and RLA groups (N=5 each), the density of NeuN neurons counterstained with toluidine blue in the cingulate cortex (subdivision 1) and the hippocampus (CA1, CA2 and CA3). A statistical difference was found in the density of neurons of CA1 and CA2 (p=0.047 in both) and in the total density of the hippocampus (p=0.009). Contrary to our expectations, significant strain differences for the density of neurons in the cingulate cortex were not found. The relationship between those differences in the hippocampus and the between-strain differences in anxiety and in learning processes depending on anxiety are discussed. PMID:22698586

  16. 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.

  17. A novel error detection due to joint CRC aided denoise-and-forward network coding for two-way relay channels.

    PubMed

    Cheng, Yulun; Yang, Longxiang

    2014-01-01

    In wireless two-way (TW) relay channels, denoise-and-forward (DNF) network coding (NC) is a promising technique to achieve spectral efficiency. However, unsuccessful detection at relay severely deteriorates the diversity gain, as well as end-to-end pairwise error probability (PEP). To handle this issue, a novel joint cyclic redundancy code (CRC) check method (JCRC) is proposed in this paper by exploiting the property of two NC combined CRC codewords. Firstly, the detection probability bounds of the proposed method are derived to prove its efficiency in evaluating the reliability of NC signals. On the basis of that, three JCRC aided TW DNF NC schemes are proposed, and the corresponding PEP performances are also derived. Numerical results reveal that JCRC aided TW DNF NC has similar PEP comparing with the separate CRC one, while the complexity is reduced to half. Besides, it demonstrates that the proposed schemes outperform the conventional one with log-likelihood ratio threshold. PMID:25247205

  18. The impact of coastal phytoplankton blooms on ocean-atmosphere thermal energy exchange: Evidence from a two-way coupled numerical modeling system

    NASA Astrophysics Data System (ADS)

    Jolliff, Jason K.; Smith, Travis A.; Barron, Charlie N.; deRada, Sergio; Anderson, Stephanie C.; Gould, Richard W.; Arnone, Robert A.

    2012-12-01

    A set of sensitivity experiments are performed with a two-way coupled and nested ocean-atmosphere forecasting system in order to deconvolve how dense phytoplankton stocks in a coastal embayment may impact thermal energy exchange processes. Monterey Bay simulations parameterizing solar shortwave transparency in the surface ocean as an invariant oligotrophic oceanic water type estimate consistently colder sea surface temperature (SST) than simulations utilizing more realistic, spatially varying shortwave attenuation terms based on satellite estimates of surface algal pigment concentration. These SST differences lead to an ∼88% increase in the cumulative turbulent thermal energy transfer from the ocean to the atmosphere over the three month simulation period. The result is a warmer simulated atmospheric boundary layer with respective local air temperature differences approaching ∼2°C. This study suggests that the retention of shortwave solar flux by ocean flora may directly impact even short-term forecasts of coastal meteorological variables.

  19. Exploring ecology through science terms: A computer-supported vocabulary supplement to the science curriculum in a two-way immersion program

    NASA Astrophysics Data System (ADS)

    Herrera, Francisco Javier, Jr.

    This study set out to examine how a web-based tool embedded with vocabulary strategies, as part of the science curriculum in a third grade two-way immersion classroom, would aid students' academic vocabulary development. Fourteen students (seven boys, seven girls; ten of which were English learners) participated in this study. Students utilized web pages as part of their science curriculum on the topic of ecology. The study documented students' use of the web pages as a data-gathering tool on the topic of ecology during science instruction. Students were video and audio taped as they explored the web pages. Results indicated that through the use of the intervention web pages students significantly improved their knowledge of academic English target words.

  20. Organising European technical documentation to avoid duplication.

    PubMed

    Donawa, Maria

    2006-04-01

    The development of comprehensive accurate and well-organised technical documentation that demonstrates compliance with regulatory requirements is a resource-intensive, but critically important activity for medical device manufacturers. This article discusses guidance documents and method of organising technical documentation that may help avoid costly and time-consuming duplication. PMID:16736662

  1. Chemical avoidance responses of fishes.

    PubMed

    Tierney, Keith B

    2016-05-01

    The hydrosphere is a repository for all of our waste and mistakes, be they sewage, garbage, process-affected waters, runoff, and gases. For fish living in environments receiving undesirable inputs, moving away seems an obvious way to avoid harm. While this should occur, there are numerous examples where it will not. The inability to avoid harmful environments may lead to sensory impairments that in turn limit the ability to avoid other dangers or locate benefits. For avoidance to occur, the danger must first be perceived, which may not happen if the fish is 'blinded' in some capacity. Second, the danger must be recognized for what it is, which may also not happen if the fish is cognitively confused or impaired. Third, it is possible that the fish may not be able to leave the area, or worse, learns to prefer a toxic environment. Concerning generating regulations around avoidance, there are two possibilities: that an avoidance threshold be used to set guidelines for effluent release with the intention of driving fishes away; the second is to set a contaminant concentration that would not affect the avoidance or attraction responses to other cues. With the complexities of the modern world in which we release diverse pollutants, from light to municipal effluents full of 1000s of chemicals, to the diversity present in ecosystems, it is impossible to have avoidance data on every stimulus-species combination. Nevertheless, we may be able to use existing avoidance response data to predict the likelihood of avoidance of untested stimuli. Where we cannot, this review includes a framework that can be used to direct new research. This review is intended to collate existing avoidance response data, provide a framework for making decisions in the absence of data, and suggest studies that would facilitate the prediction of risk to fish health in environments receiving intentional and unintentional human-based chemical inputs. PMID:26970365

  2. Performance Analysis of Power Saving Class of Type I for Voice Service in Two-Way Communication in IEEE 802.16e

    NASA Astrophysics Data System (ADS)

    Hwang, Eunju; Kim, Kyung Jae; Choi, Bong Dae

    In IEEE 802.16e, power saving is one of the important issues for battery-powered mobile stations (MSs). We present a performance analysis of power saving class (PSC) of type I in IEEE 802.16e standard for voice over Internet protocol (VoIP) service with silence suppression in two-way communication. On-off pattern of a voice user in two-way communication is characterized by the modified Brady model, which includes short silence gaps less than 200ms and talkspurt periods shorter than 15ms, and so differs from the Brady model. Our analysis of PSC I follows the standard-based procedure for the deactivation of the sleep mode, where a uplink packet arrival during a mutual silence period wakes up the MS immediately while a downlink packet arrival waits to be served until the next listening window. We derive the delay distribution of the first downlink packet arriving during a mutual silence period, and find the dropping probability of downlink packets since a voice packet drops if it is not transmitted within maximum delay constraint. In addition, we calculate the average power consumption under the modified Brady model. Analysis and simulation results show that the sleep mode operation for the MS with VoIP service yields 32 ∼ 39% reduction in the power consumption of the MS. Finally we obtain the optimal initial/final-sleep windows that yield the minimum average power consumption while satisfying QoS constraints on the packet dropping probability and the maximum delay.

  3. Two-Way Interpretation about Climate Change: Preliminary Results from a Study in Select Units of the United States National Park System

    NASA Astrophysics Data System (ADS)

    Forist, B. E.; Knapp, D.

    2014-12-01

    Much interpretation in units of the National Park System, conducted by National Park Service (NPS) rangers and partners today is done in a didactic, lecture style. This "one-way" communication runs counter to research suggesting that long-term impacts of park interpretive experiences must be established through direct connections with the visitor. Previous research in interpretation has suggested that interpretive experiences utilizing a "two-way" dialogue approach are more successful at facilitating long-term memories than "one-way" approaches where visitors have few, if any, opportunities to ask questions, offer opinions, or share interests and experiences. Long-term memories are indicators of connections to places and resources. Global anthropogenic change poses critical threats to NPS sites, resources, and visitor experiences. As climate change plays an ever-expanding role in public, political, social, economic, and environmental discourse it stands to reason that park visitors may also be interested in engaging in this discourse. Indeed, NPS Director Jonathan Jarvis stated in the agency's Climate Change Action Plan 2012 - 2014 that, "We now know through social science conducted in parks that our visitors are looking to NPS staff for honest dialogue about this critical issue." Researchers from Indiana University will present preliminary findings from a multiple park study that assessed basic visitor knowledge and the impact of two-way interpretation related to climate change. Observations from park interpretive program addressing climate change will be presented. Basic visitor knowledge of climate change impacts in the select parks as well as immediate and long-term visitor recollections will be presented. Select units of the National Park System in this research included Cape Cod National Seashore, Cape Hatteras National Seashore, North Cascades National Park, Shenandoah National Park, and Zion National Park.

  4. Mixing models for the two-way-coupling of CFD codes and zero-dimensional multi-zone codes to model HCCI combustion

    SciTech Connect

    Barths, H.; Felsch, C.; Peters, N.

    2008-11-15

    The objective of this work is the development of a consistent mixing model for the two-way-coupling of a CFD code and a multi-zone code based on multiple zero-dimensional reactors. The two-way-coupling allows for a computationally efficient modeling of HCCI combustion. The physical domain in the CFD code is subdivided into multiple zones based on three phase variables (fuel mixture fraction, dilution, and total enthalpy). Those phase variables are sufficient for the description of the thermodynamic state of each zone, assuming that each zone is at the same pressure. Each zone in the CFD code is represented by a corresponding zone in the zero-dimensional code. The zero-dimensional code solves the chemistry for each zone, and the heat release is fed back into the CFD code. The difficulty in facing this kind of methodology is to keep the thermodynamic state of each zone consistent between the CFD code and the zero-dimensional code after the initialization of the zones in the multi-zone code has taken place. The thermodynamic state of each zone (and thereby the phase variables) will change in time due to mixing and source terms (e.g., vaporization of fuel, wall heat transfer). The focus of this work lies on a consistent description of the mixing between the zones in phase space in the zero-dimensional code, based on the solution of the CFD code. Two mixing models with different degrees of accuracy, complexity, and numerical effort are described. The most elaborate mixing model (and an appropriate treatment of the source terms) keeps the thermodynamic state of the zones in the CFD code and the zero-dimensional code identical. The models are applied to a test case of HCCI combustion in an engine. (author)

  5. Mixing models for the two-way-coupling of CFD codes and zero-dimensional multi-zone codes to model HCCI combustion

    SciTech Connect

    Barths, H.; Felsch, C.; Peters, N.

    2009-01-15

    The objective of this work is the development of a consistent mixing model for the two-way-coupling of a CFD code and a multi-zone code based on multiple zero-dimensional reactors. The two-way-coupling allows for a computationally efficient modeling of HCCI combustion. The physical domain in the CFD code is subdivided into multiple zones based on three phase variables (fuel mixture fraction, dilution, and total enthalpy). Those phase variables are sufficient for the description of the thermodynamic state of each zone, assuming that each zone is at the same pressure. Each zone in the CFD code is represented by a corresponding zone in the zero-dimensional code. The zero-dimensional code solves the chemistry for each zone, and the heat release is fed back into the CFD code. The difficulty in facing this kind of methodology is to keep the thermodynamic state of each zone consistent between the CFD code and the zero-dimensional code after the initialization of the zones in the multi-zone code has taken place. The thermodynamic state of each zone (and thereby the phase variables) will change in time due to mixing and source terms (e.g., vaporization of fuel, wall heat transfer). The focus of this work lies on a consistent description of the mixing between the zones in phase space in the zero-dimensional code, based on the solution of the CFD code. Two mixing models with different degrees of accuracy, complexity, and numerical effort are described. The most elaborate mixing model (and an appropriate treatment of the source terms) keeps the thermodynamic state of the zones in the CFD code and the zero-dimensional code identical. The models are applied to a test case of HCCI combustion in an engine. (author)

  6. Neuroendocrine and behavioral responses during conditioned active and passive behavior in the defensive burying/probe avoidance paradigm: effects of ipsapirone.

    PubMed

    Korte, S M; Bouws, G A; Koolhaas, J M; Bohus, B

    1992-08-01

    Plasma epinephrine (E), norepinephrine (NE), and corticosterone (CORT) concentrations were determined in the rat before, during, and after a 15-min exposure to a nonelectrified probe on day after receiving electric shock (1.5 mA) through a probe mounted on the wall of the home cage. Rats displayed burying (active coping) if sawdust was provided on the floor and immobility (passive coping) if bedding was absent both during training and testing. The conditioned burying was accompanied by high plasma NE but low E and CORT concentrations, whereas immobility was associated with high CORT and low NE levels. A forced switch from the active to passive coping (training with and testing without sawdust) led to the highest rise in E concentration. The 5-HT1A agonist ipsapirone, with anxiolytic properties, dose-dependently (0.5 and 2.5 mg/kg, IV) reduced defensive burying behavior and increased the amount of time spent on feeding behavior in the presence of bedding material. Both plasma E and CORT levels were further elevated by the higher dose of ipsapirone. In the absence of bedding material, ipsapirone failed to affect immobility behavior, but it dose-dependently elevated the stress-induced increase in E, NE, and CORT concentrations. Accordingly, the behavioral anxiolytic action of the 5-HT1A agonist ipsapirone was restricted to active coping, whereas neuroendocrine activation by the drug was present in all conditions. It is suggested that the effects of ipsapirone on behavioral coping and neuroendocrine regulation are produced by different populations of 5-HT1A receptors in the brain. PMID:1355919

  7. Acquaintance Rape: Effective Avoidance Strategies.

    ERIC Educational Resources Information Center

    Levine-MacCombie, Joyce; Koss, Mary P.

    1986-01-01

    Determined that acknowledged and unacknowledged acquaintance rape victims and rape avoiders could be discriminated by situational variables and response strategies. Avoiders were less likely to have experienced passive or internalizing emotions at the time of the assault, perceived the assault as less violent, and were more likely to have utilized…

  8. 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. PMID:26461246

  9. Postcopulatory inbreeding avoidance in guppies.

    PubMed

    Fitzpatrick, J L; Evans, J P

    2014-12-01

    In many species, the negative fitness effects of inbreeding have facilitated the evolution of a wide range of inbreeding avoidance mechanisms. Although avoidance mechanisms operating prior to mating are well documented, evidence for postcopulatory mechanisms of inbreeding avoidance remain scarce. Here, we examine the potential for paternity biases to favour unrelated males when their sperm compete for fertilizations though postcopulatory inbreeding avoidance mechanisms in the guppy, Poecilia reticulata. To test this possibility, we used a series of artificial inseminations to deliver an equal number of sperm from a related (either full sibling or half sibling) and unrelated male to a female while statistically controlling for differences in sperm quality between rival ejaculates. In this way, we were able to focus exclusively on postcopulatory mechanisms of inbreeding avoidance and account for differences in sperm competitiveness between rival males. Under these carefully controlled conditions, we report a significant bias in paternity towards unrelated males, although this effect was only apparent when the related male was a full sibling. We also show that sperm competition generally favours males with highly viable sperm and thus that some variance in sperm competitiveness can be attributed to difference in sperm quality. Our findings for postcopulatory inbreeding avoidance are consistent with prior work on guppies, revealing that sperm competition success declines linearly with the level of relatedness, but also that such effects are only apparent at relatedness levels of full siblings or higher. These findings reveal that postcopulatory processes alone can facilitate inbreeding avoidance. PMID:25387854

  10. Vertical jumping and signaled avoidance

    PubMed Central

    Cándido, Antonio; Maldonado, Antonio; Vila, Jaime

    1988-01-01

    This paper reports an experiment intended to demonstrate that the vertical jumping response can be learned using a signaled-avoidance technique. A photoelectric cell system was used to record the response. Twenty female rats, divided equally into two groups, were exposed to intertrial intervals of either 15 or 40 s. Subjects had to achieve three successive criteria of acquisition: 3, 5, and 10 consecutive avoidance responses. Results showed that both groups learned the avoidance response, requiring increasingly larger numbers of trials as the acquisition criteria increased. No significant effect of intertrial interval was observed. PMID:16812559

  11. RecG protein and single-strand DNA exonucleases avoid cell lethality associated with PriA helicase activity in Escherichia coli.

    PubMed

    Rudolph, Christian J; Mahdi, Akeel A; Upton, Amy L; Lloyd, Robert G

    2010-10-01

    Replication of the Escherichia coli chromosome usually initiates at a single origin (oriC) under control of DnaA. Two forks are established and move away in opposite directions. Replication is completed when these meet in a broadly defined terminus area half way around the circular chromosome. RecG appears to consolidate this arrangement by unwinding D-loops and R-loops that PriA might otherwise exploit to initiate replication at other sites. It has been suggested that without RecG such replication generates 3' flaps as the additional forks collide and displace nascent leading strands, providing yet more potential targets for PriA. Here we show that, to stay alive, cells must have either RecG or a 3' single-stranded DNA (ssDNA) exonuclease, which can be exonuclease I, exonuclease VII, or SbcCD. Cells lacking all three nucleases are inviable without RecG. They also need RecA recombinase and a Holliday junction resolvase to survive rapid growth, but SOS induction, although elevated, is not required. Additional requirements for Rep and UvrD are identified and linked with defects in DNA mismatch repair and with the ability to cope with conflicts between replication and transcription, respectively. Eliminating PriA helicase activity removes the requirement for RecG. The data are consistent with RecG and ssDNA exonucleases acting to limit PriA-mediated re-replication of the chromosome and the consequent generation of linear DNA branches that provoke recombination and delay chromosome segregation. PMID:20647503

  12. Converging evidence of social avoidant behavior in schizophrenia from two approach-avoidance tasks.

    PubMed

    de la Asuncion, Javier; Docx, Lise; Sabbe, Bernard; Morrens, Manuel; de Bruijn, Ellen R A

    2015-10-01

    Many people with schizophrenia suffer from social impairments characterized by active social avoidance, which is related to social phobia common in schizophrenia, while motivational impairments can also result in passive social withdrawal. Although social avoidance is frequently reported in this population, this is the first study to directly compare approach-avoidance tendencies in schizophrenia patients (N = 37) and healthy controls (N = 29). Participants performed two tasks: a computerized approach-avoidance task (AAT) to assess response tendencies toward images of happy and angry faces with direct or averted gaze and a one-to-one personal space test (PST) to gauge more naturalistic approach-avoidance behaviors toward a real person bearing a neutral expression. The AAT results showed that both groups showed faster avoidance responses to angry faces and faster approach responses to happy faces with a direct gaze. Happy faces with averted gaze, however, resulted in faster avoidance responses in the patient group only. On the PST, the patients approached the experimenter less than healthy controls did. This measure of interpersonal distance was positively related to positive symptom severity. Delusions of reference and increased sensitivity to social rejection may explain the patients' avoidance tendencies in response to pictures of happy faces with averted gaze and in the presence of an actual person. The current findings demonstrate the importance of others adopting positive and unambiguous attitudes when interacting with schizophrenia patients to minimize behavioral avoidance patterns, which is particularly relevant for relatives and clinicians whose interactions with the patients are crucial to facilitating treatment and promoting healthy social relationships. PMID:26343605

  13. Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats

    PubMed Central

    Scariot, Pedro P. M.; Manchado-Gobatto, Fúlvia de Barros; Torsoni, Adriana S.; dos Reis, Ivan G. M.; Beck, Wladimir R.; Gobatto, Claudio A.

    2016-01-01

    Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home

  14. Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats.

    PubMed

    Scariot, Pedro P M; Manchado-Gobatto, Fúlvia de Barros; Torsoni, Adriana S; Dos Reis, Ivan G M; Beck, Wladimir R; Gobatto, Claudio A

    2016-01-01

    Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home

  15. Endless self-avoiding walks

    NASA Astrophysics Data System (ADS)

    Clisby, Nathan

    2013-06-01

    We introduce a self-avoiding walk model for which end-effects are completely eliminated. We enumerate the number of these walks for various lattices in dimensions two and three, and use these enumerations to study the properties of this model. We find that endless self-avoiding walks have the same connective constant as self-avoiding walks, and the same Flory exponent ν. However, there is no power law correction to the exponential number growth for this new model, i.e. the critical exponent γ = 1 exactly in any dimension. In addition, the number growth has no analytic corrections to scaling, and we have convincing numerical evidence to support the conjecture that the amplitude for the number growth is a universal quantity. The technique by which end-effects are eliminated may be generalized to other models of polymers such as interacting self-avoiding walks.

  16. 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

  17. Vision-based obstacle avoidance

    DOEpatents

    Galbraith, John

    2006-07-18

    A method for allowing a robot to avoid objects along a programmed path: first, a field of view for an electronic imager of the robot is established along a path where the electronic imager obtains the object location information within the field of view; second, a population coded control signal is then derived from the object location information and is transmitted to the robot; finally, the robot then responds to the control signal and avoids the detected object.

  18. Mosaic analysis of extended auricle1 (eta1) suggests that a two-way signaling pathway is involved in positioning the blade/sheath boundary in Zea mays.

    PubMed

    Osmont, Karen S; Sadeghian, Nasim; Freeling, Michael

    2006-07-01

    The maize leaf develops in a simple, stereotypical manner; therefore, it serves as a basic model to understand the processes involved in forming developmental boundaries. extended auricle1 (eta1) is a pleiotropic maize mutant that affects proximodistal leaf development. Mutant eta1 individuals display basipetal displacement of the blade/sheath boundary and the boundary between auricle and blade is not clearly delineated, leading to an undulating auricle. SEM analysis shows that eta1 is required for proper placement of the blade/sheath boundary on the adaxial leaf surface. Examination of vascular and cellular organization indicates that eta1 affects not only placement of the blade/sheath boundary, but also differentiation of cell types within the blade/sheath boundary. Genetic mosaic analysis was used to determine the effect of eta1 mutant tissue on wild-type leaf development and to resolve the site and timing of the Eta1+ gene product. Interestingly, sectors of eta1 tissue affect the placement of the blade/sheath boundary even in wild-type tissue. These results suggest that a two-way signaling pathway may be involved in the positioning of the blade/sheath boundary. Based on these data, we propose a model for Eta1+ function in the maize leaf. PMID:16684518

  19. Preliminary Comparison of Two-Way Satellite Time and Frequency Transfer and GPS Common-View Time Transfer During the INTELSAT Field Trial

    NASA Technical Reports Server (NTRS)

    Davis, John A.; Lewandowski, W.; DeYoung, James A.; Kirchner, Dieter; Hetzel, Peter; deJong, Gerrit; Soering, A.; Baumont, F.; Klepczynski, William; McKinley, Angela Davis; Parker, Thomas E.; Bartle, K. A.; Ressler, Hubert; Robnik, R.; Veenstra, L.

    1996-01-01

    For a decade and a half Global Positioning System (GPS) common-view time transfer has greatly served the needs of primary timing laboratories for regular intercomparisons of remote atomic clocks. However, GPS as a one-way technique has natural limits and may not meet all challenges of the comparison of the coming new generation of atomic clocks. Two-way satellite time and frequency transfer (TWSTFT) is a promising technique which may successfully complement GPS. For two years, regular TWSTFT's have been performed between eight laboratories situated in both Europe and North America, using INTELSAT satellites. This has enabled an extensive direct comparison to be made between these two high performance time transfer methods. The performance of the TWSTFT and GPS common view methods are compared over a number of time-transfer links. These links use a variety of time-transfer hardware and atomic clocks and have baselines of substantially different lengths. The relative merits of the two time-transfer systems are discussed.

  20. Some Operational Aspects of the International Two-Way Satellite Time and Frequency Transfer (TWSTFT) Experiment Using INTELSAT Satellites at 307 Degrees East

    NASA Technical Reports Server (NTRS)

    DeYoung, J. A.; McKinley, A.; Davis, J. A.; Hetzel, P.; Bauch, A.

    1996-01-01

    Eight laboratories are participating in an international two-way satellite time and frequency transfer (TWSTFT) experiment. Regular time and frequency transfers have been performed over a period of almost two years, including both European and transatlantic time transfers. The performance of the regular TWSTFT sessions over an extended period has demonstrated conclusively the usefulness of the TWSTFT method for routine international time and frequency comparisons. Regular measurements are performed three times per week resulting in a regular but unevenly spaced data set. A method is presented that allows an estimate of the values of delta (sub y)(gamma) to be formed from these data. In order to maximize efficient use of paid satellite time an investigation to determine the optimal length of a single TWSTFT session is presented. The optimal experiment length is determined by evaluating how long white phase modulation (PM) instabilities are the dominant noise source during the typical 300-second sampling times currently used. A detailed investigation of the frequency transfers realized via the transatlantic TWSTFT links UTC(USNO)-UTC(NPL), UTC(USNO)-UTC(PTB), and UTC(PTB)-UTC(NPL) is presented. The investigation focuses on the frequency instabilities realized, a three cornered hat resolution of the delta (sub y) (gamma) values, and a comparison of the transatlantic and inter-European determination of UTC(PTB)-UTC(NPL). Future directions of this TWSTFT experiment are outlined.

  1. Temperature-scanned magnetic resonance and the evidence of two-way transfer of a nitrogen nuclear spin hyperfine interaction in coupled NV-N pairs in diamond

    NASA Astrophysics Data System (ADS)

    Babunts, R. A.; Soltamova, A. A.; Tolmachev, D. O.; Soltamov, V. A.; Gurin, A. S.; Anisimov, A. N.; Preobrazhenskii, V. L.; Baranovi, P. G.

    2012-06-01

    New method for the detection of magnetic resonance signals versus temperature is developed on the basis of the temperature dependence of the spin Hamiltonian parameters of the paramagnetic system under investigation. The implementation of this technique is demonstrated on the nitrogen-vacancy (NV) centers in diamonds. Single NV defects and their ensembles are suggested to be almost inertialess temperature sensors. The hyperfine structure of the 14N nitrogen nuclei of the nitrogen-vacancy center appears to be resolved in the hyperfine structure characteristic of the hyperfine interaction between NV and an N s center (substitutional nitrogen impurity) in the optically detected magnetic resonance spectra of the molecular NV-N s complex. Thus, we show that a direct evidence of the two-way transfer of a nitrogen nuclear spin hyperfine interaction in coupled NV-N s pairs was observed. It is shown that more than 3-fold enhancement of the NV optically detected magnetic resonance signal can be achieved by using water as a collection optics medium.

  2. Two-Way Spatial Extrapolation and Validation on Ecological Patterns of Elaeocarpus Japonicus Between Main Watersheds in Huisun of Central Taiwan

    NASA Astrophysics Data System (ADS)

    Su, S. Y.; Lo, N. J.; Chang, W. I.; Huang, K. Y.

    2012-07-01

    Spatial extrapolation has become a sine qua non and an ad hoc major research focus in applied ecology in the latter half 20th century. Progressive innovations in data acquisition and processing technologies over the last few decades, especially in the fields of 3S (RS, GIS and GPS) and statistical modeling method, have greatly enhanced ecologists' capacity to face the challenge by enabling them to to describe patterns in nature over larger spatial scales and a greater level of details than ever before. Elaeocarpus japonicas (Japanese Elaeocarpus tree, JET) was selected for applying in the concurrent developed technology, such as ecological distribution modeling and ecological extrapolation. The GPS-located JET samples were introduced in a GIS for overlaying with five environmental layers (elevation, slope, aspect, terrain position and vegetation index derived from two-date SPOT-5 images) for ecological information extraction and model building. We created three sampling designs (SD), Tong-Feng samples for SD1, Kuan-Dau samples for SD2, and the merge of the two former datasets for SD3, according to watersheds, and the three SDs were used individually to test the extrapolation ability of predictive models. The results of the two-way extrapolation indicated it is hard to extend the predicted distribution patterns through different watersheds. The main reasons resulting in this outcome were the difference in microclimate and micro-terrain between these two watersheds. Consequently, the models built with SD3 were the more robust. The information of vegetation index in this study poorly improved the models, so we will adopt the hyperspectral data to overcome the shortage of the SPOT-5 images.

  3. Simulation of the Indian Summer Monsoon Using Comprehensive Atmosphere-land Interactions, in the Absence of Two-way Air-sea Interactions

    NASA Technical Reports Server (NTRS)

    Lim, Young-Kwon; Shin, D. W.; Cocke, Steven; Kang, Sung-Dae; Kim, Hae-Dong

    2011-01-01

    Community Land Model version 2 (CLM2) as a comprehensive land surface model and a simple land surface model (SLM) were coupled to an atmospheric climate model to investigate the role of land surface processes in the development and the persistence of the South Asian summer monsoon. Two-way air-sea interactions were not considered in order to identify the reproducibility of the monsoon evolution by the comprehensive land model, which includes more realistic vertical soil moisture structures, vegetation and 2-way atmosphere-land interactions at hourly intervals. In the monsoon development phase (May and June). comprehensive land-surface treatment improves the representation of atmospheric circulations and the resulting convergence/divergence through the improvements in differential heating patterns and surface energy fluxes. Coupling with CLM2 also improves the timing and spatial distribution of rainfall maxima, reducing the seasonal rainfall overestimation by approx.60 % (1.8 mm/d for SLM, 0.7 mm/dI for CLM2). As for the interannual variation of the simulated rainfall, correlation coefficients of the Indian seasonal rainfall with observation increased from 0.21 (SLM) to 0.45 (CLM2). However, in the mature monsoon phase (July to September), coupling with the CLM2 does not exhibit a clear improvement. In contrast to the development phase, latent heat flux is underestimated and sensible heat flux and surface temperature over India are markedly overestimated. In addition, the moisture fluxes do not correlate well with lower-level atmospheric convergence, yielding correlation coefficients and root mean square errors worse than those produced by coupling with the SLM. A more realistic representation of the surface temperature and energy fluxes is needed to achieve an improved simulation for the mature monsoon period.

  4. 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.

  5. 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.

  6. A collision avoidance system for a spaceplane manipulator arm

    NASA Technical Reports Server (NTRS)

    Sciomachen, Anna; Magnani, Piergiovanni

    1989-01-01

    Part of the activity in the area of collision avoidance related to the Hermes spaceplane is reported. A collision avoidance software system which was defined, developed and implemented in this project is presented. It computes the intersection between the solids representing the arm, the payload, and the objects. It is feasible with respect to the resources available on board, considering its performance.

  7. Regulating Cognitive Control through Approach-Avoidance Motor Actions

    ERIC Educational Resources Information Center

    Koch, Severine; Holland, Rob W.; van Knippenberg, Ad

    2008-01-01

    In two studies, the regulatory function of approach-avoidance cues in activating cognitive control processes was investigated. It was hypothesized that avoidance motor actions, relative to approach motor actions, increase the recruitment of cognitive resources, resulting in better performance on tasks that draw on these capacities. In Study 1,…

  8. 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

  9. Glyphosate Use Predicts ADHD Hospital Discharges in the Healthcare Cost and Utilization Project Net (HCUPnet): A Two-Way Fixed-Effects Analysis

    PubMed Central

    Fluegge, Keith R.; Fluegge, Kyle R.

    2015-01-01

    There has been considerable international study on the etiology of rising mental disorders, such as attention-deficit hyperactivity disorder (ADHD), in human populations. As glyphosate is the most commonly used herbicide in the world, we sought to test the hypothesis that glyphosate use in agriculture may be a contributing environmental factor to the rise of ADHD in human populations. State estimates for glyphosate use and nitrogen fertilizer use were obtained from the U.S. Geological Survey (USGS). We queried the Healthcare Cost and Utilization Project net (HCUPNET) for state-level hospitalization discharge data in all patients for all-listed ADHD from 2007 to 2010. We used rural-urban continuum codes from the USDA-Economic Research Service when exploring the effect of urbanization on the relationship between herbicide use and ADHD. Least squares dummy variable (LSDV) method and within method using two-way fixed effects was used to elucidate the relationship between glyphosate use and all-listed ADHD hospital discharges. We show that a one kilogram increase in glyphosate use, in particular, in one year significantly positively predicts state-level all-listed ADHD discharges, expressed as a percent of total mental disorders, the following year (coefficient = 5.54E-08, p<.01). A study on the effect of urbanization on the relationship between glyphosate and ADHD indicates that the relationship is marginally significantly positive after multiple comparison correction only in urban U.S. counties (p<.025). Furthermore, total glyphosate use is strongly positively associated with total farm use of nitrogen fertilizers from 1992 to 2006 (p<.001). We present evidence from the biomedical research literature of a plausible link among glyphosate, nitrogen dysbiosis and ADHD. Glyphosate use is a significant predictor of state hospitalizations for all-listed ADHD hospital discharges, with the effect concentrated in urban U.S. counties. This effect is seen even after controlling

  10. Glyphosate Use Predicts ADHD Hospital Discharges in the Healthcare Cost and Utilization Project Net (HCUPnet): A Two-Way Fixed-Effects Analysis.

    PubMed

    Fluegge, Keith R; Fluegge, Kyle R

    2015-01-01

    There has been considerable international study on the etiology of rising mental disorders, such as attention-deficit hyperactivity disorder (ADHD), in human populations. As glyphosate is the most commonly used herbicide in the world, we sought to test the hypothesis that glyphosate use in agriculture may be a contributing environmental factor to the rise of ADHD in human populations. State estimates for glyphosate use and nitrogen fertilizer use were obtained from the U.S. Geological Survey (USGS). We queried the Healthcare Cost and Utilization Project net (HCUPNET) for state-level hospitalization discharge data in all patients for all-listed ADHD from 2007 to 2010. We used rural-urban continuum codes from the USDA-Economic Research Service when exploring the effect of urbanization on the relationship between herbicide use and ADHD. Least squares dummy variable (LSDV) method and within method using two-way fixed effects was used to elucidate the relationship between glyphosate use and all-listed ADHD hospital discharges. We show that a one kilogram increase in glyphosate use, in particular, in one year significantly positively predicts state-level all-listed ADHD discharges, expressed as a percent of total mental disorders, the following year (coefficient = 5.54E-08, p<.01). A study on the effect of urbanization on the relationship between glyphosate and ADHD indicates that the relationship is marginally significantly positive after multiple comparison correction only in urban U.S. counties (p<.025). Furthermore, total glyphosate use is strongly positively associated with total farm use of nitrogen fertilizers from 1992 to 2006 (p<.001). We present evidence from the biomedical research literature of a plausible link among glyphosate, nitrogen dysbiosis and ADHD. Glyphosate use is a significant predictor of state hospitalizations for all-listed ADHD hospital discharges, with the effect concentrated in urban U.S. counties. This effect is seen even after controlling

  11. The Effects of Milnacipran on Sleep Disturbance in Fibromyalgia: A Randomized, Double-Blind, Placebo-Controlled, Two-Way Crossover Study

    PubMed Central

    Ahmed, Mansoor; Aamir, Rozina; Jishi, Zahra; Scharf, Martin B.

    2016-01-01

    Objective: This study examined the effects of milnacipran on polysomnographic (PSG) measures of sleep and subjective complaints in patients with fibromyalgia and disturbed sleep. Methods: This was a single-site, double-blind, placebo-controlled, two-period crossover PSG study. Eligible subjects (aged 28–72 y) were randomized (1:1) to milnacipran (100 mg/d) or placebo for crossover period 1, and vice versa for period 2. Each crossover period comprised a dose-escalation and dose-maintenance phase, with a 2-w taper/washout between periods. In-laboratory PSGs were collected at baseline, and at the end of each treatment period. The primary endpoints were the difference in PSG-recorded wake after sleep onset (WASO), number of awakenings after sleep onset (NAASO), and sleep efficiency (SE) between 4 w of maintenance treatment with milnacipran and placebo. Other PSG measures, subject-rated sleep, fatigue, physical functioning, and pain were assessed. Post hoc analysis was performed in subjects showing at least 25% reduction in pain from baseline in the Brief Pain Inventory Score (responders). Results: Of 19 subjects randomized, 15 completed both periods. Subjects treated with milnacipran showed no significant improvements in WASO and NAASO, but showed reduced SE (p = 0.049). Milnacipran did not show significant improvement in other PSG parameters or subjective endpoints. Two thirds of completers met responder criteria and additionally showed a significant improvement in daily effect of pain (p = 0.043) and subjective sleep quality (p = 0.040). Conclusion: The data suggest that milnacipran is not sedating in most patients with fibromyalgia and improvements in sleep are likely a result of pain improvement. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT01234675 Citation: Ahmed M, Aamir R, Jishi Z, Scharf MB. The effects of milnacipran on sleep disturbance in fibromyalgia: a randomized, double-blind, placebo-controlled, two-way crossover study. J Clin Sleep

  12. 4-Aminoethylamino-emodin – a novel potent inhibitor of GSK-3β– acts as an insulin-sensitizer avoiding downstream effects of activated β-catenin

    PubMed Central

    Gebhardt, Rolf; Lerche, Katja S; Götschel, Frank; Günther, Robert; Kolander, Jens; Teich, Lars; Zellmer, Sebastian; Hofmann, Hans-Jörg; Eger, Kurt; Hecht, Andreas; Gaunitz, Frank

    2010-01-01

    Abstract Glycogen synthase kinase-3β (GSK-3β) is a key target and effector of downstream insulin signalling. Using comparative protein kinase assays and molecular docking studies we characterize the emodin-derivative 4-[N-2-(aminoethyl)-amino]-emodin (L4) as a sensitive and potent inhibitor of GSK-3β with peculiar features. Compound L4 shows a low cytotoxic potential compared to other GSK-3β inhibitors determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay and cellular ATP levels. Physiologically, L4 acts as an insulin-sensitizing agent that is able to enhance hepatocellular glycogen and fatty acid biosynthesis. These functions are particularly stimulated in the presence of elevated concentrations of glucose and in synergy with the hormone action at moderate but not high insulin levels. In contrast to other low molecular weight GSK-3β inhibitors (SB216763 and LiCl) or Wnt-3α-conditioned medium, however, L4 does not induce reporter and target genes of activated β-catenin such as TOPflash, Axin2 and glutamine synthetase. Moreover, when present together with SB216763 or LiCl, L4 counteracts expression of TOPflash or induction of glutamine synthetase by these inhibitors. Because L4 slightly activates β-catenin on its own, these results suggest that a downstream molecular step essential for activation of gene transcription by β-catenin is also inhibited by L4. It is concluded that L4 represents a potent insulin-sensitizing agent favouring physiological effects of insulin mediated by GSK-3β inhibition but avoiding hazardous effects such as activation of β-catenin-dependent gene expression which may lead to aberrant induction of cell proliferation and cancer. PMID:19228266

  13. Avoiding unfavourable outcomes in liposuction

    PubMed Central

    Khanna, Atul; Filobbos, George

    2013-01-01

    The origin of liposuction can be traced to an adverse event by Dujarrier in 1921 when he used a uterine curette to remove fat from the knees of a ballerina ending in an amputation secondary to damage of the femoral artery. The history of liposuction since then has been one of avoiding complications and optimising outcome. After this adverse event, liposuction was abandoned until the 1960's when Schrudde revived the practice using small stab incisions and sharp curettage with the secondary suction to aspirate the freed tissue. This technique was associated with a high incidence of complications especially seroma and skin necrosis. Illouz then replaced the curette with a blunt cannula connected to vacuum pump thus avoiding the complications of a sharp curette. Despite the presence of various techniques for liposuction, suction assisted liposuction (SAL) is still the standard technique of liposuction. This article aims to discuss literature regarding the various aspects of liposuction (SAL) and to highlight the salient points in the literature and in the senior author's experience in order to avoid unfavourable outcomes in liposuction. A literature review on avoiding complication is in liposuction including some of the seminal papers on liposuction. Liposuction is generally a safe procedure with reproducible outcome. Just like any surgical procedure it should be treated with the utmost care. Illouz published 10 commandments for liposuction in 1989 and we review these commandments to demonstrate how liposuction has evolved. PMID:24501475

  14. Biochar aging reduces earthworm avoidance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar, a black carbon substance produced by the pyrolysis of organic feedstocks, has been used in many soil improvement strategies ranging from nutrient addition to sequestration of C. Simple toxicity studies and laboratory preference/avoidance assays are recommended but results rarely reported. ...

  15. Avoiding plagiarism in academic writing.

    PubMed

    Anderson, Irene

    Plagiarism means taking the work of another and presenting it as one's own, resulting in potential upset for the original author and disrepute for the professions involved. This article aims to explore the issue of plagiarism and some mechanisms for detection and avoidance. PMID:19186631

  16. Accessory cells with a veiled morphology and movement pattern generated from monocytes after avoidance of plastic adherence and of NADPH oxidase activation. A comparison with GM-CSF/IL-4-induced monocyte-derived dendritic cells.

    PubMed

    Ruwhof, Cindy; Canning, Martha O; Grotenhuis, Kristel; de Wit, Harm J; Florencia, Zenovia Z; de Haan-Meulman, Meeny; Drexhage, Hemmo A

    2002-07-01

    Veiled cells (VC) present in afferent lymph transport antigen from the periphery to the draining lymph nodes. Although VC in lymph form a heterogeneous population, some of the cells clearly belong on morphological grounds to the Langerhans cell (LC)/ dendritic cell (DC) series. Here we show that culturing monocytes for 24 hrs while avoiding plastic adherence (polypropylene tubes) and avoiding the activation of NADPH oxidase (blocking agents) results in the generation of a population of veiled accessory cells. The generated VC were actively moving cells like lymph-borne VC in vivo. The monocyte (mo)-derived VC population existed of CD14(dim/-) and CD14(brighT) cells. Of these the CD14(dim/-) VC were as good in stimulating allogeneic T cell proliferation as immature DC (iDC) obtained after one week of adherent culture of monocytes in granulocyte-macrophage-colony stimulating factor (GM-CSF)/interleukin (IL)-4. This underscores the accessory cell function of the mo-derived CD14(dim/-) VC. Although the CD14(dim/-)VC had a modest expression of the DC-specific marker CD83 and were positive for S100, expression of the DC-specific markers CD1a, Langerin, DC-SIGN, and DC-LAMP were absent. This indicates that the here generated CD14(dim/-) VC can not be considered as classical LC/DC. It was also impossible to turn the CD14(dim/-) mo-derived VC population into typical DC by culture for one week in GM-CSF/IL-4 or LPS. In fact the cells died tinder such circumstances, gaining some macrophage characteristics before dying. The IL-12 production from mo-derived CD14(dim/-) VC was lower, whereas the production of IL-10 was higher as compared to iDC. Consequently the T cells that were stimulated by these mo-derived VC produced less IFN-gamma as compared with T cells stimulated by iDC. Our data indicate that it is possible to rapidly generate a population of CD14(dim/-) veiled accessory cells from monocytes. The marker pattern and cytokine production of these VC indicate that this

  17. Two-way coupled ice sheet-earth system simulations: Consequences of raising CO2 concentration for Greenland and the interacting climate system

    NASA Astrophysics Data System (ADS)

    Rodehacke, Christian; Vizcaino, Miren; Mikolajewicz, Uwe

    2013-04-01

    The observed distinct warming in the Arctic and the northward flow of tropical water masses seem to trigger enhanced melting of the Greenland ice sheet, which adds more fresh water into the ambient ocean. A continuation of the observed accelerated melting during the last decade would stabilize the water column in the adjacent deep water formation sides. With our fully coupled ice sheet-earth system model we approach the questions if this weakens the formation of deep water masses and reduces the thermohaline driven meridional overturning circulation (MOC). We have performed idealized future projections to investigate the response of the interaction under raising atmospheric carbon dioxide concentration with our two-way coupled ice sheet-earth system model system. We will present the building blocks of our fully coupled system, which includes a physical based calculation of the ice sheet's surface mass balance and ice sheet-ocean interaction; The ESM instead is subject to orographic changes and receives fresh water fluxes, for example. Since the behavior of an ice sheet in the near future is controlled by both the external forcing and by its initial conditions, we have performed Latin Hyper Cube (LHC) simulations with the ice sheet model over more than one glacial-interglacial cycle utilizing standard techniques to obtain a reasonable initial state. According to several quantities the best performing LHC member is exposed afterwards to boundary conditions determined from energy balance calculations again obtained from simulated forcing fields. Finally the fully coupled system is brought into a quasi-equilibrium under pre-industrial conditions before idealized scenarios have been started. In contrast to commonly used strategies, our coupled ice sheet inherits the memory of a glacial cycle simulations obtain exclusively from ESM fields. Furthermore we use a mass conserving scheme, do neither apply flux corrections nor utilize anomaly coupling. Under different CO2

  18. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF–CMAQ: model description, development, evaluation and regional analysis

    SciTech Connect

    Yu, S.; Mathur, R.; Pleim, J.; Wong, D.; Gilliam, R.; Alapaty, K.; Zhao, C.; Liu, X.

    2014-01-01

    This study implemented first, second and glaciation aerosol indirect effects (AIE) on resolved clouds in the two-way coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF–CMAQ) modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ-predicted aerosol distributions and WRF meteorological conditions. The performance of the newly developed WRF–CMAQ model, with alternate Community Atmospheric Model (CAM) and Rapid Radiative Transfer Model for GCMs (RRTMG) radiation schemes, was evaluated with observations from the Clouds and the See http://ceres.larc.nasa.gov/. Earth's Radiant Energy System (CERES) satellite and surface monitoring networks (AQS, IMPROVE, CASTNET, STN, and PRISM) over the continental US (CONUS) (12 km resolution) and eastern Texas (4 km resolution) during August and September of 2006. The results at the Air Quality System (AQS) surface sites show that in August, the normalized mean bias (NMB) values for PM2.5 over the eastern US (EUS) and the western US (WUS) are 5.3% (-0.1%) and 0.4% (-5.2%) for WRF–CMAQ/CAM (WRF–CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF–CMAQ/CAM (WRF–CMAQ/RRTMG) consistently underestimated the observed SO42- by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the Clean Air Status Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciated Trends Network (STN) sites, respectively. Both configurations (WRF–CMAQ/CAM, WRF–CMAQ/RRTMG) overestimated the observed mean organic carbon (OC), elemental carbon (EC) and and total carbon (TC) concentrations over the EUS in August at the IMPROVE sites. Both configurations generally underestimated the cloud field (shortwave cloud forcing, SWCF) over the CONUS in August due to the

  19. Aerosol indirect effect on the grid-scale clouds in the two-way coupled WRF-CMAQ: model description, development, evaluation and regional analysis

    NASA Astrophysics Data System (ADS)

    Yu, S.; Mathur, R.; Pleim, J.; Wong, D.; Gilliam, R.; Alapaty, K.; Zhao, C.; Liu, X.

    2014-10-01

    This study implemented first, second and glaciation aerosol indirect effects (AIE) on resolved clouds in the two-way coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF-CMAQ) modeling system by including parameterizations for both cloud drop and ice number concentrations on the basis of CMAQ-predicted aerosol distributions and WRF meteorological conditions. The performance of the newly developed WRF-CMAQ model, with alternate Community Atmospheric Model (CAM) and Rapid Radiative Transfer Model for GCMs (RRTMG) radiation schemes, was evaluated with observations from the Clouds and the See http://ceres.larc.nasa.gov/. Earth's Radiant Energy System (CERES) satellite and surface monitoring networks (AQS, IMPROVE, CASTNET, STN, and PRISM) over the continental US (CONUS) (12 km resolution) and eastern Texas (4 km resolution) during August and September of 2006. The results at the Air Quality System (AQS) surface sites show that in August, the normalized mean bias (NMB) values for PM2.5 over the eastern US (EUS) and the western US (WUS) are 5.3% (-0.1%) and 0.4% (-5.2%) for WRF-CMAQ/CAM (WRF-CMAQ/RRTMG), respectively. The evaluation of PM2.5 chemical composition reveals that in August, WRF-CMAQ/CAM (WRF-CMAQ/RRTMG) consistently underestimated the observed SO42- by -23.0% (-27.7%), -12.5% (-18.9%) and -7.9% (-14.8%) over the EUS at the Clean Air Status Trends Network (CASTNET), Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciated Trends Network (STN) sites, respectively. Both configurations (WRF-CMAQ/CAM, WRF-CMAQ/RRTMG) overestimated the observed mean organic carbon (OC), elemental carbon (EC) and and total carbon (TC) concentrations over the EUS in August at the IMPROVE sites. Both configurations generally underestimated the cloud field (shortwave cloud forcing, SWCF) over the CONUS in August due to the fact that the AIE on the subgrid convective clouds was not

  20. Estimating avoidable causes of cancer.

    PubMed Central

    Davis, D L; Muir, C

    1995-01-01

    Evidence that much cancer is preventable derives from observations of time trends and geographic patterns of cancer, birth cohort changes, high risks in groups with well-defined exposures, and experimental studies. In an effort to identify additional opportunities for reducing the impact of cancer on society, this conference assessed avoidable causes of cancer. The magnitude and extent of preventable causes of cancer are subjects of intense debate, with discrepancies often related to the use of different time frames and different weights for epidemiologic and toxicologic evidence. There is much agreement, however, about the exposures that increase risk, notably tobacco, alcohol, diet, radiation, medications, occupational exposures, general environmental exposures, and infectious agents. Interactions between carcinogenic exposures and genetic susceptibility are also important. Concerted efforts are needed to identify avoidable causes of cancer and to apply knowledge already obtained to reduce the cancer burden. PMID:8741803

  1. GEO Collision Avoidance using a Service Vehicle

    NASA Astrophysics Data System (ADS)

    Duncan, M.; Concha, M.

    2013-09-01

    Space Situational Awareness (SSA) is defined as the knowledge and characterization of all aspects of space. SSA is now a fundamental and critical component of space operations. The increased dependence on our space assets has in turn lead to a greater need for accurate, near real-time knowledge of all space activities. Key areas of SSA include improved tracking of small objects, determining the intent of maneuvering spacecraft, identifying all potential high risk conjunction events, and leveraging non-traditional sensors in support of the SSA mission. As the size of the space object population grows, the number of collision avoidance maneuvers grows. Moreover, as the SSA mission evolves to near real-time assessment and analysis, the need for new, more sophisticated collision avoidance methods are required. This paper demonstrates the utility of using a service vehicle to perform collision avoidance maneuver for GEO satellites. We present the planning and execution details required to successfully execute a maneuver; given the traditional conjunction analysis timelines. Various operational constraints and scenarios are considered as part of the demonstration. Development of the collision avoidance strategy is created using SpaceNav's collision risk management tool suite. This study aims to determine the agility required of any proposed servicing capability to provide collision avoidance within traditional conjunction analysis and collision avoidance operations timelines. Key trades and analysis items are given to be: 1. How do we fuse the spacecraft state data with the tracking data collected from the proximity sensor that resides on the servicing spacecraft? 2. How do we deal with the possibility that the collision threat for the event may change as the time to close approach is reduced? 3. Perform trade space of maneuver/thrust time versus achievable change in the spacecraft's orbit. 4. Perform trade space of proximity of service vehicle to spacecraft versus time

  2. 3D Two-way coupled TEHD analysis on the lubricating characteristics of thrust bearings in pump-turbine units by combining CFD and FEA

    NASA Astrophysics Data System (ADS)

    Zhai, Liming; Luo, Yongyao; Wang, Zhengwei; Liu, Xin

    2016-01-01

    The thermal elastic hydro dynamic (TEHD) lubrication analysis for the thrust bearing is usually conducted by combining Reynolds equation with finite element analysis (FEA). But it is still a problem to conduct the computation by combining computational fluid dynamics (CFD) and FEA which can simulate the TEHD more accurately. In this paper, by using both direct and separate coupled solutions together, steady TEHD lubrication considering the viscosity-temperature effect for a bidirectional thrust bearing in a pump-turbine unit is simulated combining a 3D CFD model for the oil film with a 3D FEA model for the pad and mirror plate. Cyclic symmetry condition is used in the oil film flow as more reasonable boundary conditions which avoids the oil temperature assumption at the leading and trailing edge. Deformations of the pad and mirror plate are predicted and discussed as well as the distributions of oil film thickness, pressure, temperature. The predicted temperature shows good agreement with measurements, while the pressure shows a reasonable distribution comparing with previous studies. Further analysis of the three-coupled-field reveals the reason of the high pressure and high temperature generated in the film. Finally, the influence of rotational speed of the mirror plate on the lubrication characteristics is illustrated which shows the thrust load should be balanced against the oil film temperature and pressure in optimized designs. This research proposes a thrust bearing computation method by combining CFD and FEA which can do the TEHD analysis more accurately.

  3. Bis(N-confused porphyrin) as a semirigid receptor with a chirality memory: a two-way host enantiomerization through point-to-axial chirality transfer.

    PubMed

    Chmielewski, Piotr J; Siczek, Marta; Stępień, Marcin

    2015-02-01

    The adduct formation of protonated bis(N-confused porphyrin) (BNCP, 3,3'-bis(meso-tetratolyl-2-aza-21-carbaporphyrin) with chiral anions, carboxylic acids, and alcohols was studied in solution by means of (1) H NMR and circular dichroism (CD) spectroscopic analysis and DFT methods. The addition of enantiopure guests to the acidified BNCP resulted in optical activity that vanished after neutralization. Pairs of the (1) H NMR-distinguishable diastereomers were formed when enantiopure guests were applied, although a single form was observed upon the addition of the racemic mixtures in each case. Unidirectional configuration change that led to diastereomeric excess was observed in several instances. Such an excess was memorized by metalation of the adducts with AgBF4 , thus resulting in optically active silver(III) complexes of BNCP with some enantiomeric excess. Absolute configurations of BNCP cations and bis(zinc) and bis(silver(III)) complexes were determined on the basis of time-dependent (TD)-DFT calculations of their CD spectra. It was shown that some of the chiral carboxylates induced opposite directions of enantiomerization of di- and tetracations or di-/tetracation and bis(zinc) complexes. The source of the optical activity of the equimolar diastereomeric mixture of adducts is discussed. PMID:25504541

  4. Autonomous hazard detection and avoidance

    NASA Technical Reports Server (NTRS)

    Pien, Homer

    1992-01-01

    During GFY 91, Draper Laboratory was awarded a task by NASA-JSC under contract number NAS9-18426 to study and evaluate the potential for achieving safe autonomous landings on Mars using an on-board autonomous hazard detection and avoidance (AHDA) system. This report describes the results of that study. The AHDA task had four objectives: to demonstrate, via a closed-loop simulation, the ability to autonomously select safe landing sites and the ability to maneuver to the selected site; to identify key issues in the development of AHDA systems; to produce strawman designs for AHDA sensors and algorithms; and to perform initial trade studies leading to better understanding of the effect of sensor/terrain/viewing parameters on AHDA algorithm performance. This report summarizes the progress made during the first year, with primary emphasis on describing the tools developed for simulating a closed-loop AHDA landing. Some cursory performance evaluation results are also presented.

  5. NASA satellite helps airliners avoid ozone concentrations

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Results from a test to determine the effectiveness of satellite data for helping airlines avoid heavy concentrations of ozone are reported. Information from the Total Ozone Mapping Spectrometer, aboard the Nimbus-7 was transmitted, for use in meteorological forecast activities. The results show: (1) Total Ozone Mapping Spectrometer profile of total ozone in the atmosphere accurately represents upper air patterns and can be used to locate meteorological activity; (2) route forecasting of highly concentrated ozone is feasible; (3) five research aircraft flights were flown in jet stream regions located by the Total Ozone Mapping Spectrometer to determine winds, temperatures, and air composition. It is shown that the jet stream is coincides with the area of highest total ozone gradient, and low total ozone amounts are found where tropospheric air has been carried along above the tropopause on the anticyclonic side of the subtropical jet stream.

  6. Tyr254 hydroxyl group acts as a two-way switch mechanism in the coupling of heterotropic and homotropic effects in Escherichia coli glucosamine-6-phosphate deaminase.

    PubMed

    Montero-Morán, G M; Horjales, E; Calcagno, M L; Altamirano, M M

    1998-05-26

    The involvement of tyrosine residues in the allosteric function of the enzyme glucosamine 6-phosphate deaminase from Escherichia coli was first proposed on the basis of a theoretical analysis of the sequence and demonstrated by spectrophotometric experiments. Two tyrosine residues, Tyr121 and Tyr254, were indicated as involved in the mechanism of cooperativity and in the allosteric regulation of the enzyme [Altamirano et al. (1994) Eur. J. Biochem. 220, 409-413]. Tyr121 replacement by threonine or tryptophan altered the symmetric character of the T --> R transition [Altamirano et al. (1995) Biochemistry 34, 6074-6082]. From crystallographic data of the R allosteric conformer, Tyr254 has been shown to be part of the allosteric pocket [Oliva et al. (1995) Structure 3, 1323-1332]. Although it is not directly involved in binding the allosteric activator, N-acetylglucosamine 6-phosphate, Tyr 254 is hydrogen bonded through its phenolic hydroxyl to the backbone carbonyl from residue 161 in the neighboring polypeptide chain. Kinetic and binding experiments with the mutant form Tyr254-Phe of the enzyme reveal that this replacement caused an uncoupling of the homotropic and heterotropic effects. Homotropic cooperativity diminished and the allosteric activation pattern changed from one of the K-type in the wild-type deaminase to a mixed K-V pattern. On the other hand, Tyr254-Trp deaminase is kinetically closer to a K-type enzyme and it has a higher catalytic efficiency than the wild-type protein. These results show that the interactions of Tyr254 are fundamental in coupling binding in the active site to events occurring in the allosteric pocket of E. coli glucosamine 6-P deaminase. PMID:9601045

  7. ACAT Ground Collision Avoidance Flight Tests Over

    NASA Video Gallery

    NASA's Dryden Flight Research Center has concluded flight tests of an Automatic Ground Collision Avoidance System (Auto GCAS) under the joint U.S. Air Force/NASA F-16D Automatic Collision Avoidance...

  8. Avoidant/Restrictive Food Intake Disorder

    MedlinePlus

    ... Professional Version Eating Disorders Definition of Eating Disorders Anorexia Nervosa Avoidant/Restrictive Food Intake Disorder Binge Eating ... they eat. Eating Disorders Definition of Eating Disorders Anorexia Nervosa Avoidant/Restrictive Food Intake Disorder Binge Eating ...

  9. Are You a Seeker or an Avoider?

    ERIC Educational Resources Information Center

    Berman, Mark L.

    2002-01-01

    Some workers may consistently try to avoid failure, responsibility, and negative feedback. Trainers can help by assessing organizational circumstances; assist avoiders in developing knowledge, skills, and positive attitudes; and locate employee assistance programs or counseling if needed. (JOW)

  10. Avoidance of strobe lights by zooplankton

    USGS Publications Warehouse

    Hamel, Martin J.; Richards, Nathan S.; Brown, Michael L.; Chipps, Steven R.

    2010-01-01

    Underwater strobe lights can influence the behavior and distribution of fishes and are increasingly used as a technique to divert fish away from water intake structures on dams. However, few studies examine how strobe lights may affect organisms other than targeted species. To gain insight on strobe lighting effects on nontarget invertebrates, we investigated whether underwater strobe lights influence zooplankton distributions and abundance in Lake Oahe, South Dakota. Zooplankton were collected using vertical tows at 3 discrete distances from an underwater strobe light to quantify the influence of light intensity on zooplankton density. Samples were collected from 3 different depth ranges (0–10 m, 10–20 m and 20–30 m) at <1 m, 15 m and ⩾100 m distance intervals away from the strobe light. Copepods represented 67.2% and Daphnia spp. represented 23.3% of all zooplankton sampled from 17 August to 15 September 2004. Night time zooplankton densities significantly decreased in surface waters when strobe lights were activated. Copepods exhibited the greatest avoidance patterns, while Daphnia avoidance varied throughout sampling depths. These results indicate that zooplankton display negative phototaxic behavior to strobe lights and that researchers must be cognizant of potential effects to the ecosystem such as altering predator–prey interactions or affecting zooplankton distribution and growth.

  11. Convective Weather Avoidance with Uncertain Weather Forecasts

    NASA Technical Reports Server (NTRS)

    Karahan, Sinan; Windhorst, Robert D.

    2009-01-01

    Convective weather events have a disruptive impact on air traffic both in terminal area and in en-route airspaces. In order to make sure that the national air transportation system is safe and efficient, it is essential to respond to convective weather events effectively. Traffic flow control initiatives in response to convective weather include ground delay, airborne delay, miles-in-trail restrictions as well as tactical and strategic rerouting. The rerouting initiatives can potentially increase traffic density and complexity in regions neighboring the convective weather activity. There is a need to perform rerouting in an intelligent and efficient way such that the disruptive effects of rerouting are minimized. An important area of research is to study the interaction of in-flight rerouting with traffic congestion or complexity and developing methods that quantitatively measure this interaction. Furthermore, it is necessary to find rerouting solutions that account for uncertainties in weather forecasts. These are important steps toward managing complexity during rerouting operations, and the paper is motivated by these research questions. An automated system is developed for rerouting air traffic in order to avoid convective weather regions during the 20- minute - 2-hour time horizon. Such a system is envisioned to work in concert with separation assurance (0 - 20-minute time horizon), and longer term air traffic management (2-hours and beyond) to provide a more comprehensive solution to complexity and safety management. In this study, weather is dynamic and uncertain; it is represented as regions of airspace that pilots are likely to avoid. Algorithms are implemented in an air traffic simulation environment to support the research study. The algorithms used are deterministic but periodically revise reroutes to account for weather forecast updates. In contrast to previous studies, in this study convective weather is represented as regions of airspace that pilots

  12. Termites eavesdrop to avoid competitors

    PubMed Central

    Evans, Theodore A.; Inta, Ra; Lai, Joseph C. S.; Prueger, Stefan; Foo, Nyuk Wei; Fu, Eugene Wei'en; Lenz, Michael

    2009-01-01

    Competition exclusion, when a single species dominates resources due to superior competitiveness, is seldom observed in nature. Termites compete for resources with deadly consequences, yet more than one species can be found feeding in the same wooden resource. This is especially surprising when drywood species, with colonies of a few hundred, are found cohabiting with subterranean species, with colonies of millions. Termites communicate vibro-acoustically and, as these signals can travel over long distances, they are vulnerable to eavesdropping. We investigated whether drywood termites could eavesdrop on vibration cues from subterranean species. We show, using choice experiments and recordings, that the drywood termite Cryptotermes secundus can distinguish its own species from the dominant competitor in the environment, the subterranean termite Coptotermes acinaciformis. The drywood termite was attracted to its own vibration cues, but was repelled by those of the subterranean species. This response increased with decreasing wood size, corresponding with both increased risk and strength of the cue. The drywood termites appear to avoid confrontation by eavesdropping on the subterranean termites; these results provide further evidence that vibro-acoustic cues are important for termite sensory perception and communication. PMID:19710058

  13. FVIII inhibitors: pathogenesis and avoidance

    PubMed Central

    2015-01-01

    The pathogenesis of inhibitory antibodies has been the focus of major scientific interest over the last decades, and several studies on underlying immune mechanisms and risk factors for formation of these antibodies have been performed with the aim of improving the ability to both predict and prevent their appearance. It seems clear that the decisive factors for the immune response to the deficient factor are multiple and involve components of both a constitutional and therapy-related nature. A scientific concern and obstacle for research in the area of hemophilia is the relatively small cohorts available for studies and the resulting risk of confounded and biased results. Careful interpretation of data is recommended to avoid treatment decisions based on a weak scientific platform. This review will summarize current concepts of the underlying immunological mechanisms and risk factors for development of inhibitory antibodies in patients with hemophilia A and discuss how these findings may be interpreted and influence our clinical management of patients. PMID:25712994

  14. Research Report: Variations on the Theme of Avoidance as Compensations during Unsuccessful Reading Performance

    ERIC Educational Resources Information Center

    Damico, Jack S.; Abendroth, Kathleen J.; Nelson, Ryan L.; Lynch, Karen E.; Damico, Holly L.

    2011-01-01

    This research report provides additional data, manifestations and discussion about avoidance strategies employed by a language-learning disabled student during reading activities. Rather than seeing avoidance as due to random distractions or oppositional behaviours, these data provide a rationale for viewing many types of avoidance as systematic…

  15. Incautiously Optimistic: Positively-Valenced Cognitive Avoidance in Adult ADHD

    PubMed Central

    Knouse, Laura E.; Mitchell, John T.

    2015-01-01

    Clinicians who conduct cognitive-behavioral therapy (CBT) targeting attention-deficit/hyperactivity disorder (ADHD) in adulthood have noted that their patients sometimes verbalize overly positive automatic thoughts and set overly optimistic goals. These cognitions are frequently related to failure to engage in compensatory behavioral strategies emphasized in CBT. In this paper, we offer a functional analysis of this problematic pattern, positively-valenced cognitive avoidance, and suggest methods for addressing it within CBT for adult ADHD. We propose that maladaptive positive cognitions function to relieve aversive emotions in the short-term and are therefore negatively reinforced but that, in the long-term, they are associated with decreased likelihood of active coping and increased patterns of behavioral avoidance. Drawing on techniques from Behavioral Activation (BA), we offer a case example to illustrate these concepts and describe step-by-step methods for clinicians to help patients recognize avoidant patterns and engage in more active coping. PMID:25908901

  16. The vomeronasal system mediates sick conspecific avoidance.

    PubMed

    Boillat, Madlaina; Challet, Ludivine; Rossier, Daniel; Kan, Chenda; Carleton, Alan; Rodriguez, Ivan

    2015-01-19

    Although sociability offers many advantages, a major drawback is the increased risk of exposure to contagious pathogens, like parasites, viruses, or bacteria. Social species have evolved various behavioral strategies reducing the probability of pathogen exposure. In rodents, sick conspecific avoidance can be induced by olfactory cues emitted by parasitized or infected conspecifics. The neural circuits involved in this behavior remain largely unknown. We observed that olfactory cues present in bodily products of mice in an acute inflammatory state or infected with a viral pathogen are aversive to conspecifics. We found that these chemical signals trigger neural activity in the vomeronasal system, an olfactory subsystem controlling various innate behaviors. Supporting the functional relevance of these observations, we show that preference toward healthy individuals is abolished in mice with impaired vomeronasal function. These findings reveal a novel function played by the vomeronasal system. PMID:25578906

  17. Avoidance of aluminum by rainbow trout

    SciTech Connect

    Exley, C.

    2000-04-01

    Aluminum is the principal toxicant in fish in acid waters. The ability to avoid Al, particularly at low concentrations, would confer a considerable ecological advantage, but previous research into avoidance of Al has produced mixed results. The author used a cylindrical perspex tank, 150 cm in length, to study avoidance of Al by rainbow trout fry. The fish avoided Al, and their response was dependent on pH. Avoidance that was demonstrated at pHs of 5.00, 5.50, 5.50, and 5.75 was abolished at a pH of 6.00. Fry avoided very low Al concentrations being sensitive to [Al] > 1.00 {micro}mol L{sup {minus}1} at a pH of 5.00. This unequivocal demonstration of avoidance by rainbow trout fry of Al may have important implications for the ecology of indigenous fish populations in surface waters impacted by acidic deposition.

  18. ITI-Signals and Prelimbic Cortex Facilitate Avoidance Acquisition and Reduce Avoidance Latencies, Respectively, in Male WKY Rats

    PubMed Central

    Beck, Kevin D.; Jiao, Xilu; Smith, Ian M.; Myers, Catherine E.; Pang, Kevin C. H.; Servatius, Richard J.

    2014-01-01

    As a model of anxiety disorder vulnerability, male Wistar-Kyoto (WKY) rats acquire lever-press avoidance behavior more readily than outbred Sprague-Dawley rats, and their acquisition is enhanced by the presence of a discrete signal presented during the inter-trial intervals (ITIs), suggesting that it is perceived as a safety signal. A series of experiments were conducted to determine if this is the case. Additional experiments investigated if the avoidance facilitation relies upon processing through medial prefrontal cortex (mPFC). The results suggest that the ITI-signal facilitates acquisition during the early stages of the avoidance acquisition process, when the rats are initially acquiring escape behavior and then transitioning to avoidance behavior. Post-avoidance introduction of the visual ITI-signal into other associative learning tasks failed to confirm that the visual stimulus had acquired the properties of a conditioned inhibitor. Shortening the signal from the entirety of the 3 min ITI to only the first 5 s of the 3 min ITI slowed acquisition during the first four sessions, suggesting the flashing light (FL) is not functioning as a feedback signal. The prelimbic (PL) cortex showed greater activation during the period of training when the transition from escape responding to avoidance responding occurs. Only combined PL + infralimbic cortex lesions modestly slowed avoidance acquisition, but PL-cortex lesions slowed avoidance response latencies. Thus, the FL ITI-signal is not likely perceived as a safety signal nor is it serving as a feedback signal. The functional role of the PL-cortex appears to be to increase the drive toward responding to the threat of the warning signal. Hence, avoidance susceptibility displayed by male WKY rats may be driven, in part, both by external stimuli (ITI signal) as well as by enhanced threat recognition to the warning signal via the PL cortex. PMID:25484860

  19. 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

  20. Creativity and Culture: A Two Way Interaction.

    ERIC Educational Resources Information Center

    Rudowicz, Elisabeth

    2003-01-01

    Discusses different manifestations of the impact of culture on creativity and reviews empirical studies. Makes the case that creative expression is a universal human phenomenon that is grounded in culture and has impact on culture itself. (SLD)

  1. Two-way unidirectional condenser microphone

    NASA Astrophysics Data System (ADS)

    Morita, A.; Mizoguchi, A.

    1984-03-01

    A microphone for digital use is described which has a flat frequency-response over a wide range, from 20 Hz to 20 kHz; high sensitivity; and a unidirectional pattern over the whole frequency range. The principal ratings of the microphone are tabulated.

  2. Instrumented Bolt Measures Load In Two Ways

    NASA Technical Reports Server (NTRS)

    Smith, D. E.; Melvick, G. R.; Klundt, T. J.; Everton, R. L.; Eggett, M.

    1995-01-01

    Bolt instrumented to allow both ultrasonic and strain-gauge measurements of tensile load in bolt during installation and use of bolt in structure. Bolt head design allows interface for ultrasonic transducer installed, while shallow chamfered circumferential groove on bolt shank contains four strain gauges at equal angular intervals wired as a full-bridge transducer.

  3. Feedback Is a Two-Way Street

    ERIC Educational Resources Information Center

    Tovani, Cris

    2012-01-01

    In this article, the author shares her experience that illustrates that the feedback students give is just as important as the feedback they get. For her, the idea that students giving her feedback was more powerful than her giving them feedback sounded too good to be true. If she could come up with a system to regularly collect feedback that did…

  4. Telecommunications: Avoiding the Black Hole.

    ERIC Educational Resources Information Center

    Riel, Margaret

    1993-01-01

    Careful planning is required for teachers to take full advantage of the cross-cultural learning opportunities afforded by electronic networks and telecommunications. Networking with more than one classroom and using a well-defined group project integral to other classroom activities are recommended. (EA)

  5. How microorganisms avoid phagocyte attraction.

    PubMed

    Bestebroer, Jovanka; De Haas, Carla J C; Van Strijp, Jos A G

    2010-05-01

    Microorganisms have developed several mechanisms to modulate the host immune system to increase their survival and propagation in the host. Their presence in the host is not only revealed by self-produced peptides but also through host-derived chemokines and active complement fragments. These so-called chemoattractants are recognized by G protein-coupled receptors (GPCRs) expressed on leukocyte cell membranes. Activation of GPCRs triggers leukocyte activation and guides their recruitment to the site of infection. Therefore, GPCRs play a central role in leukocyte trafficking leading to microbial clearance. It is therefore not surprising that microorganisms are able to sabotage this arm of the immune response. Different microorganisms have evolved a variety of tactics to modulate GPCR activation. Here, we review the mechanisms and proteins used by major human pathogens and less virulent microorganisms that affect GPCR signaling. While viruses generally produce receptor and chemoattractant mimics, parasites and bacteria such as Staphylococcus aureus, Streptococcus pyogenes, Porphyromonas gingivalis, and Bordetella pertussis secrete proteins that affect receptor signaling, directly antagonize receptors, cleave stimuli, and even prevent stimulus generation. As the large arsenal of GPCR modulators aids prolonged microbial persistence in the host, their study provides us a better understanding of microbial pathogenesis. PMID:20059549

  6. Generalization of socially transmitted and instructed avoidance

    PubMed Central

    Cameron, Gemma; Schlund, Michael W.; Dymond, Simon

    2015-01-01

    Excessive avoidance behavior, in which an instrumental action prevents an upcoming aversive event, is a defining feature of anxiety disorders. Left unchecked, both fear and avoidance of potentially threatening stimuli may generalize to perceptually related stimuli and situations. The behavioral consequences of generalization mean that aversive learning experiences with specific threats may lead to the inference that classes of related stimuli are threatening, potentially dangerous, and need to be avoided, despite differences in physical form. Little is known however about avoidance generalization in humans and the learning pathways by which it may be transmitted. In the present study, we compared two pathways to avoidance—instructions and social observation—on subsequent generalization of avoidance behavior, fear expectancy and physiological arousal. Participants first learned that one cue was a danger cue (conditioned stimulus, CS+) and another was a safety cue (CS−). Groups were then either instructed that a simple avoidance response in the presence of the CS+ cancelled upcoming shock (instructed-learning group) or observed a short movie showing a demonstrator performing the avoidance response to prevent shock (observational-learning group). During generalization testing, danger and safety cues were presented along with generalization stimuli that parametrically varied in perceptual similarity to the CS+. Reinstatement of fear and avoidance was also tested. Findings demonstrate, for the first time, generalization of socially transmitted and instructed avoidance: both groups showed comparable generalization gradients in fear expectancy, avoidance behavior and arousal. Return of fear was evident, suggesting that generalized avoidance remains persistent following extinction testing. The utility of the present paradigm for research on avoidance generalization is discussed. PMID:26150773

  7. Flight Tests Validate Collision-Avoidance System

    NASA Video Gallery

    Flights tests of a smartphone-assisted automatic ground collision avoidance system at NASA's Dryden Flight Research Center consistently commanded evasive maneuvers when it sensed that the unmanned ...

  8. 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

  9. Divergent effects of isolation rearing on prepulse inhibition, activity, anxiety and hippocampal-dependent memory in Roman high- and low-avoidance rats: A putative model of schizophrenia-relevant features.

    PubMed

    Oliveras, Ignasi; Sánchez-González, Ana; Piludu, Maria Antonietta; Gerboles, Cristina; Río-Álamos, Cristóbal; Tobeña, Adolf; Fernández-Teruel, Alberto

    2016-11-01

    Social isolation of rats induces a constellation of behavioral alterations known as "isolation syndrome" that are consistent with some of the positive and cognitive symptoms observed in schizophrenic patients. In the present study we have assessed whether isolation rearing of inbred Roman high-avoidance (RHA-I) and Roman low-avoidance (RLA-I) strains can lead to the appearance of some of the key features of the "isolation syndrome", such as prepulse inhibition (PPI) deficits, increased anxious behavior, hyperactivity and memory/learning impairments. Compared to RLA-I rats, the results show that isolation rearing (IR) in RHA-I rats has a more profound impact, as they exhibit isolation-induced PPI deficits, increased anxiety, hyperactivity and long-term reference memory deficits, while isolated RLA-I rats only exhibit deficits in a spatial working memory task. These results give further support to the validity of RHA-I rats as a genetically-based model of schizophrenia relevant-symptoms. PMID:27478139

  10. A large-scale assessment of two-way SNP interactions in breast cancer susceptibility using 46,450 cases and 42,461 controls from the breast cancer association consortium.

    PubMed

    Milne, Roger L; Herranz, Jesús; Michailidou, Kyriaki; Dennis, Joe; Tyrer, Jonathan P; Zamora, M Pilar; Arias-Perez, José Ignacio; González-Neira, Anna; Pita, Guillermo; Alonso, M Rosario; Wang, Qin; Bolla, Manjeet K; Czene, Kamila; Eriksson, Mikael; Humphreys, Keith; Darabi, Hatef; Li, Jingmei; Anton-Culver, Hoda; Neuhausen, Susan L; Ziogas, Argyrios; Clarke, Christina A; Hopper, John L; Dite, Gillian S; Apicella, Carmel; Southey, Melissa C; Chenevix-Trench, Georgia; Swerdlow, Anthony; Ashworth, Alan; Orr, Nicholas; Schoemaker, Minouk; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Andrulis, Irene L; Knight, Julia A; Glendon, Gord; Mulligan, Anna Marie; Bojesen, Stig E; Nordestgaard, Børge G; Flyger, Henrik; Nevanlinna, Heli; Muranen, Taru A; Aittomäki, Kristiina; Blomqvist, Carl; Chang-Claude, Jenny; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Wang, Xianshu; Olson, Janet E; Vachon, Celine; Purrington, Kristen; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Dunning, Alison M; Shah, Mitul; Guénel, Pascal; Truong, Thérèse; Sanchez, Marie; Mulot, Claire; Brenner, Hermann; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; Lindblom, Annika; Margolin, Sara; Hooning, Maartje J; Hollestelle, Antoinette; Collée, J Margriet; Jager, Agnes; Cox, Angela; Brock, Ian W; Reed, Malcolm W R; Devilee, Peter; Tollenaar, Robert A E M; Seynaeve, Caroline; Haiman, Christopher A; Henderson, Brian E; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Dumont, Martine; Soucy, Penny; Dörk, Thilo; Bogdanova, Natalia V; Hamann, Ute; Försti, Asta; Rüdiger, Thomas; Ulmer, Hans-Ulrich; Fasching, Peter A; Häberle, Lothar; Ekici, Arif B; Beckmann, Matthias W; Fletcher, Olivia; Johnson, Nichola; dos Santos Silva, Isabel; Peto, Julian; Radice, Paolo; Peterlongo, Paolo; Peissel, Bernard; Mariani, Paolo; Giles, Graham G; Severi, Gianluca; Baglietto, Laura; Sawyer, Elinor; Tomlinson, Ian; Kerin, Michael; Miller, Nicola; Marme, Federik; Burwinkel, Barbara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M; Lambrechts, Diether; Yesilyurt, Betul T; Floris, Giuseppe; Leunen, Karin; Alnæs, Grethe Grenaker; Kristensen, Vessela; Børresen-Dale, Anne-Lise; García-Closas, Montserrat; Chanock, Stephen J; Lissowska, Jolanta; Figueroa, Jonine D; Schmidt, Marjanka K; Broeks, Annegien; Verhoef, Senno; Rutgers, Emiel J; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Couch, Fergus J; Toland, Amanda E; Yannoukakos, Drakoulis; Pharoah, Paul D P; Hall, Per; Benítez, Javier; Malats, Núria; Easton, Douglas F

    2014-04-01

    Part of the substantial unexplained familial aggregation of breast cancer may be due to interactions between common variants, but few studies have had adequate statistical power to detect interactions of realistic magnitude. We aimed to assess all two-way interactions in breast cancer susceptibility between 70,917 single nucleotide polymorphisms (SNPs) selected primarily based on prior evidence of a marginal effect. Thirty-eight international studies contributed data for 46,450 breast cancer cases and 42,461 controls of European origin as part of a multi-consortium project (COGS). First, SNPs were preselected based on evidence (P < 0.01) of a per-allele main effect, and all two-way combinations of those were evaluated by a per-allele (1 d.f.) test for interaction using logistic regression. Second, all 2.5 billion possible two-SNP combinations were evaluated using Boolean operation-based screening and testing, and SNP pairs with the strongest evidence of interaction (P < 10(-4)) were selected for more careful assessment by logistic regression. Under the first approach, 3277 SNPs were preselected, but an evaluation of all possible two-SNP combinations (1 d.f.) identified no interactions at P < 10(-8). Results from the second analytic approach were consistent with those from the first (P > 10(-10)). In summary, we observed little evidence of two-way SNP interactions in breast cancer susceptibility, despite the large number of SNPs with potential marginal effects considered and the very large sample size. This finding may have important implications for risk prediction, simplifying the modelling required. Further comprehensive, large-scale genome-wide interaction studies may identify novel interacting loci if the inherent logistic and computational challenges can be overcome. PMID:24242184

  11. A large-scale assessment of two-way SNP interactions in breast cancer susceptibility using 46 450 cases and 42 461 controls from the breast cancer association consortium

    PubMed Central

    Milne, Roger L.; Herranz, Jesús; Michailidou, Kyriaki; Dennis, Joe; Tyrer, Jonathan P.; Zamora, M. Pilar; Arias-Perez, José Ignacio; González-Neira, Anna; Pita, Guillermo; Alonso, M. Rosario; Wang, Qin; Bolla, Manjeet K.; Czene, Kamila; Eriksson, Mikael; Humphreys, Keith; Darabi, Hatef; Li, Jingmei; Anton-Culver, Hoda; Neuhausen, Susan L.; Ziogas, Argyrios; Clarke, Christina A.; Hopper, John L.; Dite, Gillian S.; Apicella, Carmel; Southey, Melissa C.; Chenevix-Trench, Georgia; Swerdlow, Anthony; Ashworth, Alan; Orr, Nicholas; Schoemaker, Minouk; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Andrulis, Irene L.; Knight, Julia A.; Glendon, Gord; Mulligan, Anna Marie; Bojesen, Stig E.; Nordestgaard, Børge G.; Flyger, Henrik; Nevanlinna, Heli; Muranen, Taru A.; Aittomäki, Kristiina; Blomqvist, Carl; Chang-Claude, Jenny; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Wang, Xianshu; Olson, Janet E.; Vachon, Celine; Purrington, Kristen; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Dunning, Alison M.; Shah, Mitul; Guénel, Pascal; Truong, Thérèse; Sanchez, Marie; Mulot, Claire; Brenner, Hermann; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; Lindblom, Annika; Margolin, Sara; Hooning, Maartje J.; Hollestelle, Antoinette; Collée, J. Margriet; Jager, Agnes; Cox, Angela; Brock, Ian W.; Reed, Malcolm W.R.; Devilee, Peter; Tollenaar, Robert A.E.M.; Seynaeve, Caroline; Haiman, Christopher A.; Henderson, Brian E.; Schumacher, Fredrick; Le Marchand, Loic; Simard, Jacques; Dumont, Martine; Soucy, Penny; Dörk, Thilo; Bogdanova, Natalia V.; Hamann, Ute; Försti, Asta; Rüdiger, Thomas; Ulmer, Hans-Ulrich; Fasching, Peter A.; Häberle, Lothar; Ekici, Arif B.; Beckmann, Matthias W.; Fletcher, Olivia; Johnson, Nichola; dos Santos Silva, Isabel; Peto, Julian; Radice, Paolo; Peterlongo, Paolo; Peissel, Bernard; Mariani, Paolo; Giles, Graham G.; Severi, Gianluca; Baglietto, Laura; Sawyer, Elinor; Tomlinson, Ian; Kerin, Michael; Miller, Nicola; Marme, Federik; Burwinkel, Barbara; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Lambrechts, Diether; Yesilyurt, Betul T.; Floris, Giuseppe; Leunen, Karin; Alnæs, Grethe Grenaker; Kristensen, Vessela; Børresen-Dale, Anne-Lise; García-Closas, Montserrat; Chanock, Stephen J.; Lissowska, Jolanta; Figueroa, Jonine D.; Schmidt, Marjanka K.; Broeks, Annegien; Verhoef, Senno; Rutgers, Emiel J.; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Couch, Fergus J.; Toland, Amanda E.; Yannoukakos, Drakoulis; Pharoah, Paul D.P.; Hall, Per; Benítez, Javier; Malats, Núria; Easton, Douglas F.

    2014-01-01

    Part of the substantial unexplained familial aggregation of breast cancer may be due to interactions between common variants, but few studies have had adequate statistical power to detect interactions of realistic magnitude. We aimed to assess all two-way interactions in breast cancer susceptibility between 70 917 single nucleotide polymorphisms (SNPs) selected primarily based on prior evidence of a marginal effect. Thirty-eight international studies contributed data for 46 450 breast cancer cases and 42 461 controls of European origin as part of a multi-consortium project (COGS). First, SNPs were preselected based on evidence (P < 0.01) of a per-allele main effect, and all two-way combinations of those were evaluated by a per-allele (1 d.f.) test for interaction using logistic regression. Second, all 2.5 billion possible two-SNP combinations were evaluated using Boolean operation-based screening and testing, and SNP pairs with the strongest evidence of interaction (P < 10−4) were selected for more careful assessment by logistic regression. Under the first approach, 3277 SNPs were preselected, but an evaluation of all possible two-SNP combinations (1 d.f.) identified no interactions at P < 10−8. Results from the second analytic approach were consistent with those from the first (P > 10−10). In summary, we observed little evidence of two-way SNP interactions in breast cancer susceptibility, despite the large number of SNPs with potential marginal effects considered and the very large sample size. This finding may have important implications for risk prediction, simplifying the modelling required. Further comprehensive, large-scale genome-wide interaction studies may identify novel interacting loci if the inherent logistic and computational challenges can be overcome. PMID:24242184

  12. Details Of Collision-Avoidance Study

    NASA Technical Reports Server (NTRS)

    Chappell, Sheryl L.; Billings, Charles E.; Olsen, M. Christine; Scott, Barry C.; Tuttell, Robert J.; Kozon, Thomas E.

    1990-01-01

    Report provides background information on and detailed description of study of pilots' use of traffic-alert and collision-avoidance system (TCAS II) in simulated flights. Described in article, "Evaluation of an Aircraft-Collision-Avoidance System" (ARC-12367). Plans, forms, training narratives, scripts, questionnaires, and other information compiled.

  13. 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…

  14. How Do Speakers Avoid Ambiguous Linguistic Expressions?

    ERIC Educational Resources Information Center

    Ferreira, V.S.; Slevc, L.R.; Rogers, E.S.

    2005-01-01

    Three experiments assessed how speakers avoid linguistically and nonlinguistically ambiguous expressions. Speakers described target objects (a flying mammal, bat) in contexts including foil objects that caused linguistic (a baseball bat) and nonlinguistic (a larger flying mammal) ambiguity. Speakers sometimes avoided linguistic-ambiguity, and they…

  15. Recommendations for Sense and Avoid Policy Compliance

    NASA Technical Reports Server (NTRS)

    2005-01-01

    Since unmanned aircraft do not have a human on board, they need to have a sense and avoid capability that provides an "equivalent level of safety" (ELOS) to manned aircraft. The question then becomes - is sense and avoid ELOS for unmanned aircraft adequate to satisfy the requirements of 14 CFR 91.113? Access 5 has proposed a definition of sense and avoid, but the question remains as to whether any sense and avoid system can comply with 14 CFR 91.113 as currently written. The Access 5 definition of sense and avoid ELOS allows for the development of a sense and avoid system for unmanned aircraft that would comply with 14 CFR 91.113. Compliance is based on sensing and avoiding other traffic at an equivalent level of safety for collision avoidance, as manned aircraft. No changes to Part 91 are necessary, with the possible exception of changing "see" to "sense," or obtaining an interpretation from the FAA General Counsel that "sense" is equivalent to "see."

  16. Strategic Family Therapy of Avoidant Behavior.

    ERIC Educational Resources Information Center

    Burgess, Thomas A.; Hinkle, J. Scott

    1993-01-01

    Notes that Millon's biopsychosocial model asserts that socioenvironmental factors of parental or peer rejection may shape development of avoidant behavior but does not elaborate on how family system may perpetuate its existence once disorder has evolved. Presents brief overview of avoidant behavior and strategic family therapy case study.…

  17. A new collision avoidance model for pedestrian dynamics

    NASA Astrophysics Data System (ADS)

    Wang, Qian-Ling; Chen, Yao; Dong, Hai-Rong; Zhou, Min; Ning, Bin

    2015-03-01

    The pedestrians can only avoid collisions passively under the action of forces during simulations using the social force model, which may lead to unnatural behaviors. This paper proposes an optimization-based model for the avoidance of collisions, where the social repulsive force is removed in favor of a search for the quickest path to destination in the pedestrian’s vision field. In this way, the behaviors of pedestrians are governed by changing their desired walking direction and desired speed. By combining the critical factors of pedestrian movement, such as positions of the exit and obstacles and velocities of the neighbors, the choice of desired velocity has been rendered to a discrete optimization problem. Therefore, it is the self-driven force that leads pedestrians to a free path rather than the repulsive force, which means the pedestrians can actively avoid collisions. The new model is verified by comparing with the fundamental diagram and actual data. The simulation results of individual avoidance trajectories and crowd avoidance behaviors demonstrate the reasonability of the proposed model. Project supported by the National Natural Science Foundation of China (Grant Nos. 61233001 and 61322307) and the Fundamental Research Funds for Central Universities of China (Grant No. 2013JBZ007).

  18. Design of cross-linked semicrystalline poly(ε-caprolactone)-based networks with one-way and two-way shape-memory properties through Diels-Alder reactions.

    PubMed

    Raquez, Jean-Marie; Vanderstappen, Sophie; Meyer, Franck; Verge, Pierre; Alexandre, Michael; Thomassin, Jean-Michel; Jérôme, Christine; Dubois, Philippe

    2011-08-29

    Cross-linked poly(ε-caprolactone) (PCL)-based polyesterurethane (PUR) systems have been synthesized through Diels-Alder reactions by reactive extrusion. The Diels-Alder and retro-Diels-Alder reactions proved to be useful for enhancing the molecular motion of PCL-based systems, and therefore their crystallization ability, in the design of cross-linked semicrystalline polymers with one-way and two-way shape-memory properties. Successive reactions between α,ω-diol PCL (PCL(2) ), furfuryl alcohol, and methylene diphenyl 4,4'-diisocyanate straightforwardly afforded the α,ω-furfuryl PCL-based PUR systems, and subsequent Diels-Alder reactions with N,N-phenylenedimaleimide afforded the thermoreversible cycloadducts. The cross-linking density could be modulated by partially replacing PCL-diol with PCL-tetraol. Interestingly, the resulting PUR systems proved to be semicrystalline cross-linked polymers, the melting temperature of which (close to 45 °C) represented the switching temperature for their shape-memory properties. Qualitative and quantitative measurements demonstrated that these PUR systems exhibited one-way and two-way shape-memory properties depending on their cross-linking density. PMID:21744399

  19. Avoiding DEET through insect gustatory receptors

    PubMed Central

    Lee, Youngseok; Kim, Sang Hoon; Montell, Craig

    2010-01-01

    Summary DEET is the most widely used insect repellent worldwide. In Drosophila olfactory receptor neurons (ORNs), DEET is detected through a mechanism that employs the olfactory receptor, OR83b. However, it is controversial as to whether ORNs respond directly to DEET or whether DEET blocks the response to attractive odors. Here, we showed that DEET suppressed feeding behavior in Drosophila and this effect was mediated by gustatory receptor neurons (GRNs). DEET was potent in suppressing feeding as <0.1% DEET elicited aversive behavior. Inhibition of feeding by DEET required multiple gustatory receptors (GRs), which were expressed in inhibitory GRNs. DEET stimulated action potentials in GRNs that respond to aversive compounds, and this response was lost in Gr32a, Gr33a and Gr66a mutants. Since 0.02% DEET elicited action potentials, we conclude that DEET directly activates of GRNs. We suggest that the effectiveness of DEET in pest control owes to its dual action in inducing avoidance simultaneously via GRNs and ORNs. PMID:20797533

  20. Moving Obstacle Avoidance for Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Lin, Yucong

    There has been a vast increase in applications of Unmanned Aerial Vehicles (UAVs) in civilian domains. To operate in the civilian airspace, a UAV must be able to sense and avoid both static and moving obstacles for flight safety. While indoor and low-altitude environments are mainly occupied by static obstacles, risks in space of higher altitude primarily come from moving obstacles such as other aircraft or flying vehicles in the airspace. Therefore, the ability to avoid moving obstacles becomes a necessity for Unmanned Aerial Vehicles. Towards enabling a UAV to autonomously sense and avoid moving obstacles, this thesis makes the following contributions. Initially, an image-based reactive motion planner is developed for a quadrotor to avoid a fast approaching obstacle. Furthermore, A Dubin's curve based geometry method is developed as a global path planner for a fixed-wing UAV to avoid collisions with aircraft. The image-based method is unable to produce an optimal path and the geometry method uses a simplified UAV model. To compensate these two disadvantages, a series of algorithms built upon the Closed-Loop Rapid Exploratory Random Tree are developed as global path planners to generate collision avoidance paths in real time. The algorithms are validated in Software-In-the-Loop (SITL) and Hardware-In-the-Loop (HIL) simulations using a fixed-wing UAV model and in real flight experiments using quadrotors. It is observed that the algorithm enables a UAV to avoid moving obstacles approaching to it with different directions and speeds.

  1. Passive avoidence learning in the young rat.

    PubMed

    Blozovski, D; Cudennec, A

    1980-09-01

    A step-through locomotor passive avoidance task is described requiring the suppression of a spontaneous escape reaction from a cool toward a warm compartment in order to avoid an electric shock delivered in the warm side. We observed no lerning of this task at 9 days of age, a very low but significant level of acquisition at 11 days, a slow but progressive improvement of avoidance from the 13th until the 17th day when the adult capacity was achieved, and a marked increase in the rate between 17-20 days. PMID:7409331

  2. Isolation-hypoxia and re-oxygenation of the pallial cavity of female Crepipatella dilatata during estuarine salinity changes requires increased glyoxylase activity and antioxidant metabolism to avoid oxidative damage to female tissues and developing embryos.

    PubMed

    Cubillos, Víctor; Chaparro, Oscar; Segura, Cristian; Montory, Jaime; Cruces, Edgardo; Burritt, David

    2016-08-01

    The estuarine slipper limpet Crepipatella dilatata is a gastropod that can survive prolonged periods of low salinities (< 24 PSU) caused by tidal changes and/or prolonged periods of rain. During low salinity events, C. dilatata can isolate its body from the outside environment, by sealing its shell against the substrate on which it grows. Prolonged isolation periods from the surrounding environment can greatly lower available oxygen levels inside of the pallial cavity, impacting on the physiology of both females and their incubated encapsulated embryos. When salinity levels return to normal, isolation is terminated and the inflow of seawater results in re-oxygenation. In this study we show that when re-oxygenation of the pallial cavity takes place, oxidative damage, in the form of increased levels of lipid peroxides and protein carbonyls, occurs in both maternal tissues and in incubated embryos. To avoid terminal oxidative damage both females and their embryos increase their levels of the glyoxalase pathway enzymes (GLX-I and GLX-II) and general antioxidant metabolism (SOD, CAT, GR, GPOX and GST). As a result the levels of oxidative damage decline to basal levels within 24 h of reoxygenation. Thus the combination of isolation, a behavioural strategy, combined with encapsulation of embryos and a capacity to up regulate relatively rapidly the glyoxylase pathway and general antioxidant metabolism, play major roles in facilitating the survival of C. dilatata in the small estuaries of Southern Chile. PMID:27232979

  3. 6 Tips to Avoid Medication Mistakes

    MedlinePlus

    ... consumer www.fda.gov/consumer/updates/medtips062107.html 6 Tips to Avoid Medication Mistakes 1. Know the ... labels & follow directions 5. Keep your doctors informed 6. K eep a list of all your medications ...

  4. When Should a Mother Avoid Breastfeeding?

    MedlinePlus

    ... Address What's this? Submit What's this? Submit Button Breastfeeding Information for Families Breastfeeding Hotline The HHS Office ... Tweet Share Compartir When should a mother avoid breastfeeding? Health professionals agree that human milk provides the ...

  5. Many Manly Men Avoid Needed Health Care

    MedlinePlus

    ... fullstory_158551.html Many Manly Men Avoid Needed Health Care Gender stereotypes can have dangerous consequences, research suggests ... traditional masculine ideals were less likely to seek health care, more likely to downplay symptoms, and had worse ...

  6. Avoiding Anemia: Boost Your Red Blood Cells

    MedlinePlus

    ... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...

  7. Family Key to Helping Teens Avoid Obesity

    MedlinePlus

    ... 159681.html Family Key to Helping Teens Avoid Obesity Good relationship with parents, especially between fathers and ... develop healthy habits that may protect them against obesity, a new study suggests. The researchers also found ...

  8. Avoid the Consequences of High Blood Pressure

    MedlinePlus

    ... Tools & Resources Stroke More Avoid the Consequences of High Blood Pressure Infographic Updated:Jun 19,2014 View a downloadable version of this infographic High Blood Pressure • Home • About High Blood Pressure (HBP) • Why HBP ...

  9. Men, Avoid Impotence Drugs Before Surgery

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_157884.html Men, Avoid Impotence Drugs Before Surgery Let an anesthesia ... 21, 2016 MONDAY, March 21, 2016 (HealthDay News) -- Men should not take erectile dysfunction drugs such as ...

  10. The challenges for scientists in avoiding plagiarism.

    PubMed

    Fisher, E R; Partin, K M

    2014-01-01

    Although it might seem to be a simple task for scientists to avoid plagiarism and thereby an allegation of research misconduct, assessment of trainees in the Responsible Conduct of Research and recent findings from the National Science Foundation Office of Inspector General regarding plagiarism suggests otherwise. Our experiences at a land-grant academic institution in assisting researchers in avoiding plagiarism are described. We provide evidence from a university-wide multi-disciplinary course that understanding how to avoid plagiarism in scientific writing is more difficult than it might appear, and that a failure to learn the rules of appropriate citation may cause dire consequences. We suggest that new strategies to provide training in avoiding plagiarism are required. PMID:24785995

  11. Singularity avoidance and time in quantum gravity

    SciTech Connect

    Kreienbuehl, Andreas

    2009-06-15

    We consider the quantization of a Friedmann-Robertson-Walker universe. We derive a reduced square root Hamiltonian by choosing the scale factor as time variable and quantize the theory using Pauli matrices a la Dirac. From the resulting spinor equation we show that there is no semiclassical wave packet that avoids the big bang singularity. Our work raises the question concerning the relationship between the choice of time and singularity avoidance.

  12. The inhibitory avoidance discrimination task to investigate accuracy of memory

    PubMed Central

    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. PMID:25814942

  13. Beyond negligence: avoidability and medical injury compensation.

    PubMed

    Kachalia, Allen B; Mello, Michelle M; Brennan, Troyen A; Studdert, David M

    2008-01-01

    Disenchantment with the tort system and negligence standard in the United States is fueling interest in alternate compensation systems for medical injury. One possibility is experimentation with administrative "health courts," through which specialized adjudicators would utilize neutral experts to render compensability determinations. Compensation would be based not on negligence, but rather on a broader avoidable medical injury (avoidability) standard. Although considerable interest in health courts exists, stakeholders frequently express uncertainty about the meaning and operation of an avoidability standard. Three nations-Sweden, Denmark, and New Zealand-have long operated administrative schemes. We conducted interviews with administrators and stakeholders in these systems. Our goal was to garner lessons on how to operate a health court, and specifically, how to develop and apply alternate compensation criteria such as avoidability. This article reports our findings on the origins and operations of the systems, the evolution of their compensation criteria, and how these criteria are actually applied. We found that all three systems had their primary genesis in ensuring compensation for the injured, as opposed to sanctioning providers. All have abandoned the negligence standard. The Nordic systems use an avoidability standard, principally defined as injury that would not occur in the hands of the best practitioner. Their experience demonstrates that this definition is feasible to apply. New Zealand's recent move to a no-fault system sheds light on the benefits and drawbacks of a variety of compensation standards. Key lessons for successfully applying an alternate standard, such as avoidability, include a strict adherence to national precedent, the use of neutral and experienced experts, and a block on routine transfer of information from compensation investigations to disciplinary authorities. Importantly, all three nations are harnessing their systems' power to

  14. Adoptive immunotherapy with genetically engineered T cells: modification of the IgG1 Fc 'spacer' domain in the extracellular moiety of chimeric antigen receptors avoids 'off-target' activation and unintended initiation of an innate immune response.

    PubMed

    Hombach, A; Hombach, A A; Abken, H

    2010-10-01

    Chimeric antigen receptors (CARs, immunoreceptors) are frequently used to redirect T cells with pre-defined specificity, in particular towards tumour cells for use in adoptive immunotherapy of malignant diseases. Specific targeting is mediated by an extracellularly located antibody-derived binding domain, which is joined to the transmembrane and intracellular CD3ζ moiety for T-cell activation. Stable CAR expression in T cells, however, requires a spacer domain interposed between the binding and the transmembrane domain and which is commonly the constant IgG1 Fc domain. We here revealed that CARs with Fc spacer domain bind to IgG Fc gamma receptors (FcγRs), thereby unintentionally activating innate immune cells, including monocytes and natural killer (NK) cells, which consequently secrete high amounts of pro-inflammatory cytokines. Engineered T cells, on the other hand, are likewise activated by FcγR binding resulting in cytokine secretion and lysis of monocytes and NK cells independently of the redirected specificity. To reduce FcγR binding, we modified the spacer domain without affecting CAR expression and antigen binding. Engineered with the modified CAR, T cells are not activated in presence of FcγR(+) cells, thereby minimizing the risk of off-target activation while preserving their redirected targeting specificity. PMID:20555360

  15. The "Eye Avoidance" Hypothesis of Autism Face Processing.

    PubMed

    Tanaka, James W; Sung, Andrew

    2016-05-01

    Although a growing body of research indicates that children with autism spectrum disorder (ASD) exhibit selective deficits in their ability to recognize facial identities and expressions, the source of their face impairment is, as yet, undetermined. In this paper, we consider three possible accounts of the autism face deficit: (1) the holistic hypothesis, (2) the local perceptual bias hypothesis and (3) the eye avoidance hypothesis. A review of the literature indicates that contrary to the holistic hypothesis, there is little evidence to suggest that individuals with autism do perceive faces holistically. The local perceptual bias account also fails to explain the selective advantage that ASD individuals demonstrate for objects and their selective disadvantage for faces. The eye avoidance hypothesis provides a plausible explanation of face recognition deficits where individuals with ASD avoid the eye region because it is perceived as socially threatening. Direct eye contact elicits a increased physiological response as indicated by heightened skin conductance and amygdala activity. For individuals with autism, avoiding the eyes is an adaptive strategy, however, this approach interferes with the ability to process facial cues of identity, expressions and intentions, exacerbating the social challenges for persons with ASD. PMID:24150885

  16. Neural Correlates of Attentional Flexibility during Approach and Avoidance Motivation

    PubMed Central

    Calcott, Rebecca D.; Berkman, Elliot T.

    2015-01-01

    Dynamic, momentary approach or avoidance motivational states have downstream effects on eventual goal success and overall well being, but there is still uncertainty about how those states affect the proximal neurocognitive processes (e.g., attention) that mediate the longer-term effects. Attentional flexibility, or the ability to switch between different attentional foci, is one such neurocognitive process that influences outcomes in the long run. The present study examined how approach and avoidance motivational states affect the neural processes involved in attentional flexibility using fMRI with the aim of determining whether flexibility operates via different neural mechanisms under these different states. Attentional flexibility was operationalized as subjects’ ability to switch between global and local stimulus features. In addition to subjects’ motivational state, the task context was manipulated by varying the ratio of global to local trials in a block in light of recent findings about the moderating role of context on motivation-related differences in attentional flexibility. The neural processes involved in attentional flexibility differ under approach versus avoidance states. First, differences in the preparatory activity in key brain regions suggested that subjects’ preparedness to switch was influenced by motivational state (anterior insula) and the interaction between motivation and context (superior temporal gyrus, inferior parietal lobule). Additionally, we observed motivation-related differences the anterior cingulate cortex during switching. These results provide initial evidence that motivation-induced behavioral changes may arise via different mechanisms in approach versus avoidance motivational states. PMID:26000735

  17. Avoidance of hydrolyzed casein by mice

    PubMed Central

    Field, Kristin L.; Kimball, Bruce A.; Mennella, Julie A.; Beauchamp, Gary K.; Bachmanov, Alexander A.

    2008-01-01

    When casein, a milk protein, is hydrolyzed, it renders human foods that contain it (e.g., hypoallergenic infant formula, cheeses) distasteful to many people. This rejection of hydrolyzed casein (HC)-containing foods has recently been found to also occur in a non-human species (deer, Odocoileus spp.). Identifying other animals that avoid HC would facilitate understanding how and why HC-containing food is often rejected. This study determined whether HC-containing food is avoided by Mus musculus and whether consumption patterns were sensitive to testing conditions, specifically food form (powder, pellet or dough) and food access (ad libitum or 1.5 h/day following 6 h of food deprivation). Diets were offered in two-choice tests that paired an HC-containing food with an intact casein-containing alternative at seven protein concentrations (0%–50% w/w). Five experimental groups were tested under different combinations of food form and food access. Three groups (ad lib/powder, ad lib/pellet, and 1.5 h/pellet) avoided the HC diet starting at the 30% protein level. At the 40% and 50% protein levels, all groups showed strong avoidance of HC. Although testing conditions influenced total caloric intake and body weight gain, avoidance of HC at the highest concentrations was robust to the manipulations in experimental conditions. Our study suggests that mice may be a useful model for understanding the mechanisms of HC rejection. PMID:17900635

  18. Rape avoidance behavior among Slovak women.

    PubMed

    Prokop, Pavol

    2013-01-01

    Rape has been a recurrent adaptive problem for many species, including humans. Rape is costly to women in terms of disease transmission, partner abandonment, and unwanted pregnancy (among other costs). Therefore, behavioral strategies which allow women to avoid coercive men may have been favored by selection. In line with this evolutionary reasoning, the current research documented that physically stronger women and those in a committed romantic relationship reported more rape avoidance behavior. In addition, virgin women tended to perform more rape avoidance behavior compared with their non-virgin counterparts. Women with high conception risk perceived themselves as physically stronger, which may protect them against a potential rapist. Fear of unwanted pregnancy from rape decreased as age increased, reflecting higher fertility among younger participants. However, older women reported more rape avoidance behavior, which contradicts evolutionary predictions. The results provide some support for evolutionary hypotheses of rape avoidance behavior which suggest that woman's perception of rape is influenced by parental investment and perceived physical condition. PMID:23715617

  19. Integrated Collision Avoidance System for Air Vehicle

    NASA Technical Reports Server (NTRS)

    Lin, Ching-Fang (Inventor)

    2013-01-01

    Collision with ground/water/terrain and midair obstacles is one of the common causes of severe aircraft accidents. The various data from the coremicro AHRS/INS/GPS Integration Unit, terrain data base, and object detection sensors are processed to produce collision warning audio/visual messages and collision detection and avoidance of terrain and obstacles through generation of guidance commands in a closed-loop system. The vision sensors provide more information for the Integrated System, such as, terrain recognition and ranging of terrain and obstacles, which plays an important role to the improvement of the Integrated Collision Avoidance System.

  20. Autonomous Landing and Hazard Avoidance Technology (ALHAT)

    NASA Technical Reports Server (NTRS)

    Epp, Chirold

    2007-01-01

    This viewgraph presentation reviews the work towards technology that will result in an autonomous landing on the lunar surface, that will avoid the hazards of lunar landing. In October 2005, the Exploration Systems Mission Directorate at NASA Headquarters assigned the development of new technologies to support the return to the moon. One of these was Autonomous Precision Landing and Hazard Detection and Avoidance Technology now known as ALHAT ALHAT is a lunar descent and landing GNC technology development project led by Johnson Space Center (JSC) with team members from Langley Research Center (LaRC), Jet Propulsion Laboratory (JPL), Draper Laboratories (CSDL) and the Applied Physics Laboratory (APL)

  1. A collision avoidance system for workpiece protection

    SciTech Connect

    Schmitt, D.J.; Weber, T.M.; Novak, J.L.; Maslakowski, J.E.

    1995-04-01

    This paper describes an application of Sandia`s non-contact capacitive sensing technology for collision avoidance during the manufacturing of rocket engine thrust chambers. The collision avoidance system consists of an octagon shaped collar with a capacitive proximity sensor mounted on each face. The sensors produced electric fields which extend several inches from the face of the collar and detect potential collisions between the robot and the workpiece. A signal conditioning system processes the sensor output and provides varying voltage signals to the robot controller for stopping the robot.

  2. Collision avoidance for CTV: Requirements and capabilities

    NASA Astrophysics Data System (ADS)

    Nosek, Thomas; Rourke, Kenneth

    Collision avoidance must be ensured during Cargo Transfer Vehicle (CTV) operations near the space station. The design of the Collision Avoidance Maneuver (CAM) will involve analysis of CTV failure modes during rendezvous and proximity operations as well as analysis of possible problems external to the CTV, but that would require CTV to execute a CAM. In considering the requirements and design of the CAM for the CTV, the CAM design for the Orbital Maneuvering Vehicle (OMV) is a useful reference point from which some lessons can be learned and many CTV design options can be set forth.

  3. Collision avoidance for CTV: Requirements and capabilities

    NASA Technical Reports Server (NTRS)

    Nosek, Thomas; Rourke, Kenneth

    1991-01-01

    Collision avoidance must be ensured during Cargo Transfer Vehicle (CTV) operations near the space station. The design of the Collision Avoidance Maneuver (CAM) will involve analysis of CTV failure modes during rendezvous and proximity operations as well as analysis of possible problems external to the CTV, but that would require CTV to execute a CAM. In considering the requirements and design of the CAM for the CTV, the CAM design for the Orbital Maneuvering Vehicle (OMV) is a useful reference point from which some lessons can be learned and many CTV design options can be set forth.

  4. Telerobotics with whole arm collision avoidance

    SciTech Connect

    Wilhelmsen, K.; Strenn, S.

    1993-09-01

    The complexity of teleorbotic operations in a cluttered environment is exacerbated by the need to present collision information to the operator in an understandable fashion. In addition to preventing movements which will cause collisions, a system providing some form of virtual force reflection (VFR) is desirable. With this goal in mind, Lawrence Livermore National Laboratory (LLNL) has installed a kinematically master/slave system and developed a whole arm collision avoidance system which interacts directly with the telerobotic controller. LLNL has also provided a structure to allow for automated upgrades of workcell models and provide collision avoidance even in a dynamically changing workcell.

  5. Prepulse inhibition and latent inhibition deficits in Roman high-avoidance vs. Roman low-avoidance rats: Modeling schizophrenia-related features.

    PubMed

    Esnal, Aitor; Sánchez-González, Ana; Río-Álamos, Cristóbal; Oliveras, Ignasi; Cañete, Toni; Blázquez, Gloria; Tobeña, Adolf; Fernández-Teruel, Alberto

    2016-09-01

    The aim of the present study was to obtain further evidence supporting the validity of a new genetically-based rat model for the study of schizophrenia-relevant symptoms. The Roman high- (RHA-I) and low-avoidance (RLA-I) inbred rats have been psychogenetically selected for their rapid versus extremely poor acquisition of the two-way avoidance task in the shuttle box and present two well-differentiated profiles regarding several traits related to anxiety, impulsivity and sensitivity to (dopaminergic) psychostimulants. In this study we have tested animals from both strains in two behavioral paradigms that are related to schizophrenia, i.e. prepulse inhibition (PPI) and latent inhibition (LI) of fear-potentiated startle (FPS). The results show that while RLA-I rats display good PPI and LI to the context, RHA-Is show an impairment of PPI and no sign of an LI effect, which goes in the direction of the results obtained in schizophrenic patients. Therefore, although further behavioral and psychopharmacological work needs to be done, the present findings and previous studies carried out in our laboratory and others allow us to propose the RHA-I rat strain as a putative genetic rat model of differential schizophrenia-related features. PMID:27184235

  6. Self-avoiding walks adsorbed at a surface and subject to a force

    NASA Astrophysics Data System (ADS)

    Janse van Rensburg, E. J.; Whittington, S. G.

    2016-06-01

    We consider self-avoiding walks terminally attached to an impenetrable surface at which they can adsorb. We call the vertices farthest away from this plane the top vertices and we consider applying a force at the plane containing the top vertices. This force can be directed away from the adsorbing surface or towards it. In both cases we prove that the free energy (in the thermodynamic limit) is identical to the free energy when the force is applied at the last vertex. This means that the criterion determining the critical force—temperature curve is identical for the two ways in which the force is applied and the response to pushing the walk is also the same in the two cases. Dedicated to Tony Guttmann on the occasion of his 70th birthday.

  7. An Examination of Avoided Costs in Utah

    SciTech Connect

    Bolinger, Mark; Wiser, Ryan

    2005-01-07

    The Utah Wind Working Group (UWWG) believes there are currently opportunities to encourage wind power development in the state by seeking changes to the avoided cost tariff paid to qualifying facilities (QFs). These opportunities have arisen as a result of a recent renegotiation of Pacificorp's Schedule 37 tariff for wind QFs under 3 MW, as well as an ongoing examination of Pacificorp's Schedule 38 tariff for wind QFs larger than 3 MW. It is expected that decisions made regarding Schedule 38 will also impact Schedule 37. Through the Laboratory Technical Assistance Program (Lab TAP), the UWWG has requested (through the Utah Energy Office) that LBNL provide technical assistance in determining whether an alternative method of calculating avoided costs that has been officially adopted in Idaho would lead to higher QF payments in Utah, and to discuss the pros and cons of this method relative to the methodology recently adopted under Schedule 37 in Utah. To accomplish this scope of work, I begin by summarizing the current method of calculating avoided costs in Utah (per Schedule 37) and Idaho (the ''surrogate avoided resource'' or SAR method). I then compare the two methods both qualitatively and quantitatively. Next I present Pacificorp's four main objections to the use of the SAR method, and discuss the reasonableness of each objection. Finally, I conclude with a few other potential considerations that might add value to wind QFs in Utah.

  8. Inducer Design to Avoid Cavitation Instabilities

    NASA Astrophysics Data System (ADS)

    Kang, Donghyuk; Watanabe, Toshifumi; Yonezawa, Koichi; Horiguchi, Hironori; Kawata, Yutaka; Tsujimoto, Yoshinobu

    2010-06-01

    Three inducers were designed to avoid cavitation instabilities. This was accomplished by avoiding the interaction of tip cavity with the leading edge of the opposing blade. The first one applied extremely larger leading edge sweep, the second and third ones applied smaller incidence angle by reducing the inlet blade angle or increasing the design flow rate, respectively. The inducer with larger design flow rate has larger outlet blade angle to obtain sufficient pressure rise. The inducer with larger sweep could suppress the cavitation instabilities in wide ranges of cavitation number and flow rate, owing to weaker tip leakage vortex cavity with stronger disturbance by backflow vortices. The inducer with larger outlet blade angle could avoid the cavitation instabilities at higher flow rates owing to the extension of the tip cavity along the suction surface of the blade. The inducer with smaller inlet blade angle could avoid the cavitation instabilities at the flow rates larger than the design flow coefficient, owing to the occurrence of the cavity first in the blade passage and its extension upstream. The cavity shape and suction performance were reasonably simulated by three dimensional CFD computations under the steady cavitating condition, except for the backflow vortex cavity. The difference in the growth of cavity for each inducer is explained from the difference of the pressure distribution on the suction side of the blades.

  9. Teaching Preschool Children to Avoid Poison Hazards

    ERIC Educational Resources Information Center

    Dancho, Kelly A.; Thompson, Rachel H.; Rhoades, Melissa M.

    2008-01-01

    We evaluated the effectiveness of group safety training and in situ feedback and response interruption to teach preschool children to avoid consuming potentially hazardous substances. Three children ingested ambiguous substances during a baited baseline assessment condition and continued to ingest these substances following group safety training.…

  10. Freeze tolerance and avoidance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold acclimation is a multigenic, quantitative trait that involves biochemical and structural changes that effect the physiology of a plant. Mechanisms associated with freeze tolerance or freeze avoidance develop and are lost on an annual cycle. When conducting studies to characterize and determin...

  11. Perspectives in avoidance-preference bioassays

    SciTech Connect

    Steele, C.W.; Taylor, D.H.; Strickler-Shaw, S.

    1996-12-31

    Although behavioral endpoints are used in hazard assessment, establishment of water quality criteria and assessment of a contaminant`s hazard to aquatic life rely primarily on standard acute and chronic toxicity tests. Sublethal effects of pollutants should, however, be of major concern because more organisms experience sublethal rather than acutely or chronically lethal exposures of contaminants. The avoidance-preference approach to behavioral bioassays is very useful in screening pollutants for which the mechanisms of perception or response are largely unknown. The underlying philosophy of these studies is that an animal which perceives a chemical can be attracted or repulsed by it. No response is frequently assumed to indicate lack of perception. All three responses have broad ecological implications. The authors discuss the conditions required for performing avoidance-preference bioassays, as well as their sensitivities, advantages, and limitations. In this regard, a comparative approach is used in examining the results of avoidance-preference bioassays with zebrafish in two different apparatuses. Finally, they compare the results of avoidance-preference studies with other measures of the behavioral toxicity of lead to tadpoles.

  12. Working with Avoidant Children: A Clinical Challenge.

    ERIC Educational Resources Information Center

    Berson, Nancy; Meisburger, Diana

    1998-01-01

    Presents strategies for interviewing and assisting highly avoidant children who may be victims of maltreatment. Discusses factors inhibiting their self-disclosure, the importance of managing child safety, and establishing and maintaining rapport. Describes strategies including pacing the interview, empowering the child, and using distancing…

  13. Proactive strategies to avoid infectious disease

    PubMed Central

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

    2011-01-01

    Infectious disease exerts a large selective pressure on all organisms. One response to this has been for animals to evolve energetically costly immune systems to counter infection, while another—the focus of this theme issue—has been the evolution of proactive strategies primarily to avoid infection. These strategies can be grouped into three types, all of which demonstrate varying levels of interaction with the immune system. The first concerns maternal strategies that function to promote the immunocompetence of their offspring. The second type of strategy influences mate selection, guiding the selection of a healthy mate and one who differs maximally from the self in their complement of antigen-coding genes. The third strategy involves two classes of behaviour. One relates to the capacity of the organisms to learn associations between cues indicative of pathogen threat and immune responses. The other relates to prevention and even treatment of infection through behaviours such as avoidance, grooming, quarantine, medicine and care of the sick. In humans, disease avoidance is based upon cognition and especially the emotion of disgust. Human disease avoidance is not without its costs. There is a propensity to reject healthy individuals who just appear sick—stigmatization—and the system may malfunction, resulting in various forms of psychopathology. Pathogen threat also appears to have been a highly significant and unrecognized force in shaping human culture so as to minimize infection threats. This cultural shaping process—moralization—can be co-opted to promote human health. PMID:22042913

  14. The Advocacy or Avoidance of Only Children.

    ERIC Educational Resources Information Center

    Falbo, Toni

    A brief review of the psychological literature on the characteristics of only children is presented in order to determine if the one-child family should be avoided or advocated. The relevant literature is found to be limited in quantity and conceptualization of the only child. Previous literature is divided into three types of study: those with…

  15. Digital-Difference Processing For Collision Avoidance.

    NASA Technical Reports Server (NTRS)

    Shores, Paul; Lichtenberg, Chris; Kobayashi, Herbert S.; Cunningham, Allen R.

    1988-01-01

    Digital system for automotive crash avoidance measures and displays difference in frequency between two sinusoidal input signals of slightly different frequencies. Designed for use with Doppler radars. Characterized as digital mixer coupled to frequency counter measuring difference frequency in mixer output. Technique determines target path mathematically. Used for tracking cars, missiles, bullets, baseballs, and other fast-moving objects.

  16. Learn to Avoid or Overcome Leadership Obstacles

    ERIC Educational Resources Information Center

    D'Auria, John

    2015-01-01

    Leadership is increasingly recognized as an important factor in moving schools forward, yet we have been relatively random in how we prepare and support them. Four obstacles often block or diminish their effectiveness. Avoiding or overcoming each of these requires an underlying set of skills and knowledge that we believe can be learned and…

  17. Metacognitive evaluation in the avoidance of demand.

    PubMed

    Dunn, Timothy L; Lutes, David J C; Risko, Evan F

    2016-09-01

    In the current set of experiments our goal was to test the hypothesis that individuals avoid courses of action based on a kind of metacognitive evaluation of demand in a Demand Selection Task (DST). Individuals in Experiment 1 completed a DST utilizing visual stimuli known to yield a dissociation between performance and perceived demand. Patterns of demand avoidance followed that of perceived demand. Experiment 2 provided a replication of the aforementioned results, in addition to demonstrating a second dissociation between a peripheral physiological measure of demand (i.e., blink rates) and demand avoidance. Experiment 3 directly tested the assumption that individuals make use of a general metacognitive evaluation of task demand during selections. A DST was utilized in a forced-choice paradigm that required individuals to either select the most effortful, time demanding, or least accurate of 2 choices. Patterns of selections were similar across all rating dimensions, lending credit to this notion. Findings are discussed within a metacognitive framework of demand avoidance and contrasted to current theories. (PsycINFO Database Record PMID:27123679

  18. Disgust as a Disease-Avoidance Mechanism

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  19. Specific Language Impairment at Adolescence: Avoiding Complexity

    ERIC Educational Resources Information Center

    Tuller, Laurice; Henry, Celia; Sizaret, Eva; Barthez, Marie-Anne

    2012-01-01

    This study explores complex language in adolescents with specific language impairment (SLI) with the aim of finding out how aspects of language characteristic of typical syntactic development after childhood fare and, in particular, whether there is evidence that individuals with SLI avoid using structures whose syntactic derivation involves…

  20. The employment interview. Avoiding discriminatory questioning.

    PubMed

    Poteet, G W

    1984-04-01

    The potential for legal action against health care institutions for unlawful preemployment interviews has never been greater. This article shows how to avoid discriminatory questions when interviewing job applicants in the health care setting. The author presents guidelines for helping nursing administrators obtain necessary information without violating the basic rights of the potential employee. PMID:6561248