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Sample records for give ambiguous results

  1. Perceived ambiguity as a barrier to intentions to learn genome sequencing results

    PubMed Central

    Taber, Jennifer M.; Klein, William M.P.; Ferrer, Rebecca A.; Han, Paul K. J.; Lewis, Katie L.; Biesecker, Leslie G.; Biesecker, Barbara B.

    2015-01-01

    Many variants that could be returned from genome sequencing may be perceived as ambiguous—lacking reliability, credibility, or adequacy. Little is known about how perceived ambiguity influences thoughts about sequencing results. Participants (n=494) in an NIH genome sequencing study completed a baseline survey before sequencing results were available. We examined how perceived ambiguity regarding sequencing results and individual differences in medical ambiguity aversion and tolerance for uncertainty were associated with cognitions and intentions concerning sequencing results. Perceiving sequencing results as more ambiguous was associated with less favorable cognitions about results and lower intentions to learn and share results. Among participants low in tolerance for uncertainty or optimism, greater perceived ambiguity was associated with lower intentions to learn results for non-medically actionable diseases; medical ambiguity aversion did not moderate any associations. Results are consistent with the phenomenon of “ambiguity aversion” and may influence whether people learn and communicate genomic information. PMID:26003053

  2. Real-time PPP with undifferenced integer ambiguity resolution, experimental results

    NASA Astrophysics Data System (ADS)

    Laurichesse, Denis; Mercier, Flavien

    2010-05-01

    A method to solve the GPS zero-difference measurement equations with integer ambiguities has been recently introduced at CNES. When the method is applied to data from a global network of GPS receivers it provides a consistent set of satellite orbits and clocks, which have an ‘integer' property: phase residuals for any receiver computed using these orbits and clocks easily reveal integer ambiguities. The presentation focuses on the application of this novel approach to the computation of real-time orbits and clocks for the GPS constellation, and the benefit of using these products for real-time Precise Point Positioning (PPP) with integer ambiguity fixing of user receivers. In this method, real-time corrections to extrapolated IGS IGU orbits are estimated at the same time as all other relevant parameters by a Kalman filter which processes measurements from a world-wide stations network. The filter performs zero-difference ambiguity fixing in real-time. Two results are presented; the first with one month of raw data taken from the IGS, the second with raw data taken from the Internet in real-time using the NTRIP protocol. Relative to IGS final orbits, the 3-D precision of the real-time orbits is about 3 cm RMS. When these constellation orbits and clocks are used to perform real-time PPP for receivers outside of the reference network, the horizontal precision obtained using zero-difference integer ambiguity fixing is close to 1 cm RMS. This is about one order of magnitude better than standard solutions, which rely upon floating ambiguity fixing, close to the precision of RTK. We present several ‘site survey' type real-time experiments conducted at CNES that confirm these results. Advantages and drawbacks of this new integer-PPP method with respect to RTK are outlined. These topics include mainly the time to convergence, the baselines size and the associated precision. Some specific applications of this new method, especially those that cannot be obtained using a standard RTK method are proposed. Finally, ongoing and future work conducted at CNES on real-time applications is outlined. This work concerns mainly the development of a real-time integer PPP demonstrator. The goal and architecture of this demonstrator is presented, as well as the current development state and some preliminary results.

  3. Study Finds Charter Networks Give No Clear Edge on Results

    ERIC Educational Resources Information Center

    Shah, Nirvi

    2011-01-01

    The author reports on a national study of middle school students in 40 charter networks which finds that, when it comes to having an impact on student achievement, results vary and, overall, charter students do not learn dramatically more than their counterparts in regular public schools. The findings from the research group Mathematica and the

  4. Image Ambiguity and Fluency

    PubMed Central

    Jakesch, Martina; Leder, Helmut; Forster, Michael

    2013-01-01

    Ambiguity is often associated with negative affective responses, and enjoying ambiguity seems restricted to only a few situations, such as experiencing art. Nevertheless, theories of judgment formation, especially the processing fluency account, suggest that easy-to-process (non-ambiguous) stimuli are processed faster and are therefore preferred to (ambiguous) stimuli, which are hard to process. In a series of six experiments, we investigated these contrasting approaches by manipulating fluency (presentation duration: 10ms, 50ms, 100ms, 500ms, 1000ms) and testing effects of ambiguity (ambiguous versus non-ambiguous pictures of paintings) on classification performance (Part A; speed and accuracy) and aesthetic appreciation (Part B; liking and interest). As indicated by signal detection analyses, classification accuracy increased with presentation duration (Exp. 1a), but we found no effects of ambiguity on classification speed (Exp. 1b). Fifty percent of the participants were able to successfully classify ambiguous content at a presentation duration of 100 ms, and at 500ms even 75% performed above chance level. Ambiguous artworks were found more interesting (in conditions 50ms to 1000ms) and were preferred over non-ambiguous stimuli at 500ms and 1000ms (Exp. 2a - 2c, 3). Importantly, ambiguous images were nonetheless rated significantly harder to process as non-ambiguous images. These results suggest that ambiguity is an essential ingredient in art appreciation even though or maybe because it is harder to process. PMID:24040172

  5. Ambiguous genitalia

    MedlinePLUS

    ... the outer genitals do not have the typical appearance of either a boy or a girl. ... ambiguity varies. In very rare instances, the physical appearance may be fully developed as the opposite of ...

  6. Are ambiguity aversion and ambiguity intolerance identical? A neuroeconomics investigation.

    PubMed

    Tanaka, Yusuke; Fujino, Junya; Ideno, Takashi; Okubo, Shigetaka; Takemura, Kazuhisa; Miyata, Jun; Kawada, Ryosaku; Fujimoto, Shinsuke; Kubota, Manabu; Sasamoto, Akihiko; Hirose, Kimito; Takeuchi, Hideaki; Fukuyama, Hidenao; Murai, Toshiya; Takahashi, Hidehiko

    2014-01-01

    In recent years, there has been growing interest in understanding a person's reaction to ambiguous situations, and two similar constructs related to ambiguity, "ambiguity aversion" and "ambiguity intolerance," are defined in different disciplines. In the field of economic decision-making research, "ambiguity aversion" represents a preference for known risks relative to unknown risks. On the other hand, in clinical psychology, "ambiguity intolerance" describes the tendency to perceive ambiguous situations as undesirable. However, it remains unclear whether these two notions derived from different disciplines are identical or not. To clarify this issue, we combined an economic task, psychological questionnaires, and voxel-based morphometry (VBM) of structural brain magnetic resonance imaging (MRI) in a sample of healthy volunteers. The individual ambiguity aversion tendency parameter, as measured by our economic task, was negatively correlated with agreeableness scores on the self-reported version of the Revised NEO Personality Inventory. However, it was not correlated with scores of discomfort with ambiguity, one of the subscales of the Need for Closure Scale. Furthermore, the ambiguity aversion tendency parameter was negatively correlated with gray matter (GM) volume of areas in the lateral prefrontal cortex and parietal cortex, whereas ambiguity intolerance was not correlated with GM volume in any region. Our results suggest that ambiguity aversion, described in decision theory, may not necessarily be identical to ambiguity intolerance, referred to in clinical psychology. Cautious applications of decision theory to clinical neuropsychiatry are recommended. PMID:25698984

  7. Are ambiguity aversion and ambiguity intolerance identical? A neuroeconomics investigation

    PubMed Central

    Tanaka, Yusuke; Fujino, Junya; Ideno, Takashi; Okubo, Shigetaka; Takemura, Kazuhisa; Miyata, Jun; Kawada, Ryosaku; Fujimoto, Shinsuke; Kubota, Manabu; Sasamoto, Akihiko; Hirose, Kimito; Takeuchi, Hideaki; Fukuyama, Hidenao; Murai, Toshiya; Takahashi, Hidehiko

    2015-01-01

    In recent years, there has been growing interest in understanding a person's reaction to ambiguous situations, and two similar constructs related to ambiguity, ambiguity aversion and ambiguity intolerance, are defined in different disciplines. In the field of economic decision-making research, ambiguity aversion represents a preference for known risks relative to unknown risks. On the other hand, in clinical psychology, ambiguity intolerance describes the tendency to perceive ambiguous situations as undesirable. However, it remains unclear whether these two notions derived from different disciplines are identical or not. To clarify this issue, we combined an economic task, psychological questionnaires, and voxel-based morphometry (VBM) of structural brain magnetic resonance imaging (MRI) in a sample of healthy volunteers. The individual ambiguity aversion tendency parameter, as measured by our economic task, was negatively correlated with agreeableness scores on the self-reported version of the Revised NEO Personality Inventory. However, it was not correlated with scores of discomfort with ambiguity, one of the subscales of the Need for Closure Scale. Furthermore, the ambiguity aversion tendency parameter was negatively correlated with gray matter (GM) volume of areas in the lateral prefrontal cortex and parietal cortex, whereas ambiguity intolerance was not correlated with GM volume in any region. Our results suggest that ambiguity aversion, described in decision theory, may not necessarily be identical to ambiguity intolerance, referred to in clinical psychology. Cautious applications of decision theory to clinical neuropsychiatry are recommended. PMID:25698984

  8. Reducing values: dinitrosalicylate gives over-oxidation and invalid results whereas copper bicinchoninate gives no over-oxidation and valid results.

    PubMed

    McIntyre, Amanda P; Mukerjea, Rupendra; Robyt, John F

    2013-10-18

    A comparative study was made between two carbohydrate reducing value methods, a relatively old, highly alkaline, 3,5-dinitrosalicylic acid (DNSA) method and a relatively newer, low alkaline (pH 10.5), copper bicinchoninate (CuBic) method. Reducing values for a series of equimolar amounts of maltose-maltohexaose, isomaltose-isomaltohexaose, and cellobiose-cellohexaose were compared by the two methods. The DNSA method gave over-oxidation for equimolar amounts of all three of the oligosaccharide series. The amount of oxidation increased as the sizes of the oligosaccharides increased, giving inflated, inaccurate reducing values. The CuBic method gave constant reducing values, for equimolar amounts of the oligosaccharides, indicating that there was no over-oxidation, as the sizes of the oligosaccharides were increased. The two methods were used to determine the number average molecular weights (MWn) for six polysaccharides. The DNSA method was not able to determine the MWn for any of the polysaccharides tested due to the low sensitivity of the method, compared with the CuBic method that did not give over-oxidation and gave reasonable MWn values for all six of the polysaccharides tested. PMID:24021436

  9. Charitable Giving for HIV and AIDS: Results from a Canadian National Survey

    PubMed Central

    Allman, Dan; Calzavara, Liviana; Worthington, Catherine; Tyndall, Mark; Adrien, Alix; Walters, Melissa; White, Samantha; Jones, Marcella K.

    2014-01-01

    Background For the first time, a national survey of adults in Canada posed questions on charitable giving for HIV and AIDS. The objective of this analysis was to explore the behaviour and attitudes of this population in terms of charitable giving. Methods In 2011, individuals in Canada 16 years of age or older were recruited for a survey from an online panel supplemented by random digit dial telephone interviewing. The margin of error was +/−2.1 percentage points (95%). Chi-square tests were used to detect bivariate associations. A multivariate logistic regression model was fit to compare those who had donated to HIV and AIDS in the past 12 months with those who had donated to other disease or illness charities. Results 2,139 participated. 82.5% had donated to a charitable cause in the past 12 months. 22.2% had ever donated to HIV and AIDS, with 7.8% doing so in the past 12 months. Individuals who had donated to HIV and AIDS versus other disease or illness charities tended to be younger (p<0.05), single (p<0.005), more highly educated (p<0.001) and to self-identify as a member of a sexual minority group (p<0.001). Multivariate analysis revealed individuals who self-identified as a member of a sexual minority group were significantly much more likely to have donated to HIV and AIDS than to other disease or illness charities in the past 12 months (OR, 7.73; p<0.001; CI 4.32–13.88). Discussion Despite a generally philanthropic orientation, relatively few respondents had ever been involved in charitable giving for HIV and AIDS. Those who had could be understood relationally as individuals at closer social proximity to HIV and AIDS such as members of sexual minority groups. PMID:25153827

  10. The Ambiguity in Immunology

    PubMed Central

    Barnaba, Vincenzo; Paroli, Marino; Piconese, Silvia

    2012-01-01

    In the present article, we discuss the various ambiguous aspects of the immune system that render this complex biological network so highly flexible and able to defend the host from different external invaders. This ambiguity stems mainly from the property of the immune system to be both protective and harmful. Immunity cannot be fully protective without producing a certain degree of damage (immunopathology) to the host. The balance between protection and tissue damage is, therefore, critical for the establishment of immune homeostasis and protection. In this review, we will consider as ambiguous, various immunological tactics including: (a) the opposing functions driving immune responses, immune-regulation, and contra-regulation, as well as (b) the phenomenon of chronic immune activation as a result of a continuous cross-presentation of apoptotic T cells by dendritic cells. All these plans participate principally to maintain a state of chronic low-level inflammation during persisting infections, and ultimately to favor the species survival. PMID:22566903

  11. Fermionic entanglement ambiguity in noninertial frames

    SciTech Connect

    Montero, Miguel; Martin-Martinez, Eduardo

    2011-06-15

    We analyze an ambiguity in previous works on entanglement of fermionic fields in noninertial frames. This ambiguity, related to the anticommutation properties of field operators, leads to nonunique results when computing entanglement measures for the same state. We show that the ambiguity disappears when we introduce detectors, which are in any case necessary as a means to probe the field entanglement.

  12. Lexical ambiguity in sentence comprehension

    PubMed Central

    Mason, Robert A.; Just, Marcel Adam

    2009-01-01

    An event-related fMRI paradigm was used to investigate brain activity during the reading of sentences containing either a lexically ambiguous word or an unambiguous control word. Higher levels of activation occurred during the reading of sentences containing a lexical ambiguity. Furthermore, the activated cortical network differed, depending on: (1) whether the sentence contained a balanced (i.e., both meanings equally likely) or a biased (i.e., one meaning more likely than other meanings) ambiguous word; and, (2) the working memory capacity of the individual as assessed by reading span. The findings suggest that encountering a lexical ambiguity is dealt with by activating multiple meanings utilizing processes involving both hemispheres. When an early interpretation of a biased ambiguous word is later disambiguated to the subordinate meaning, the superior frontal cortex activates in response to the coherence break and the right inferior frontal gyrus and the insula activate, possibly to suppress the incorrect interpretation. Negative correlations between reading span scores and activation in the right hemisphere for both types of ambiguous words suggest that readers with lower spans are more likely to involve show right hemisphere involvement in the processing of the ambiguity. A positive correlation between reading span scores and insula activation appearing only for biased sentences disambiguated to the subordinate meaning indicates that individuals with higher spans were more likely to initially maintain both meanings and as a result had to suppress the unintended dominant meaning. PMID:17433891

  13. Quantum vs Classical Mechanics for a 'Simple' Dissociation Reaction. Should They Give the Same Results?

    NASA Astrophysics Data System (ADS)

    Holloway, Stephen

    1997-03-01

    When performing molecular dynamical simulations on light systems at low energies, there is always the risk of producing data that bear no similarity to experiment. Indeed, John Barker himself was particularly anxious about treating Ar scattering from surfaces using classical mechanics where it had been shown experimentally in his own lab that diffraction occurs. In such cases, the correct procedure is probably to play the trump card "... well of course, quantum effects will modify this so that....." and retire gracefully. For our particular interests, the tables are turned in that we are interested in gas-surface dynamical studies for highly quantized systems, but would be interested to know when it is possible to use classical mechanics in order that a greater dimensionality might be treated. For molecular dissociation and scattering, it has been oft quoted that the greater the number of degrees of freedom, the more appropriate is classical mechanics, primarily because of the mass averaging over the quantized dimensions. Is this true? We have been investigating the dissociation of hydrogen molecules at surfaces and in this talk I will present quantum results for dissociation and scattering, along with a novel method for their interpretation based upon adiabatic potential energy surfaces. Comparison with classical calculations will be made and conclusions drawn. a novel method for their interpretation based upon adiabatic potential energy surfaces

  14. SAR ambiguous range suppression.

    SciTech Connect

    Doerry, Armin Walter

    2006-09-01

    Pulsed Radar systems suffer range ambiguities, that is, echoes from pulses transmitted at different times arrive at the receiver simultaneously. Conventional mitigation techniques are not always adequate. However, pulse modulation schemes exist that allow separation of ambiguous ranges in Doppler space, allowing easy filtering of problematic ambiguous ranges.

  15. Vignettes of Ambiguity

    ERIC Educational Resources Information Center

    Gotz, Ignacio L.

    2010-01-01

    This article is an exploration of ambiguity as it appears in various guises in philosophical, social, political, and educational situations. Among these situations is the experience of exile. The exploration is conducted by means of literary anecdotes and real-life instances, hence the use of vignettes. The suggestion is made that ambiguity can be

  16. Vignettes of Ambiguity

    ERIC Educational Resources Information Center

    Gotz, Ignacio L.

    2010-01-01

    This article is an exploration of ambiguity as it appears in various guises in philosophical, social, political, and educational situations. Among these situations is the experience of exile. The exploration is conducted by means of literary anecdotes and real-life instances, hence the use of vignettes. The suggestion is made that ambiguity can be…

  17. Processing Coordination Ambiguity

    ERIC Educational Resources Information Center

    Engelhardt, Paul E.; Ferreira, Fernanda

    2010-01-01

    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based theories assume

  18. Processing Coordination Ambiguity

    ERIC Educational Resources Information Center

    Engelhardt, Paul E.; Ferreira, Fernanda

    2010-01-01

    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based theories assume…

  19. Two Cheers for Ambiguity.

    ERIC Educational Resources Information Center

    Holden, William

    Ambiguity can be enjoyed in statements without context, in unclear comparisons, in words often confused, and in casual disorders. In spite of the grammarians' efforts to "disambiguate," it is doubtful that any willful act or combination of acts can eliminate ambiguity, since language is a system of symbols which can stand for one thing or another.

  20. Effective ambiguity checking in biosequence analysis

    PubMed Central

    Reeder, Janina; Steffen, Peter; Giegerich, Robert

    2005-01-01

    Background Ambiguity is a problem in biosequence analysis that arises in various analysis tasks solved via dynamic programming, and in particular, in the modeling of families of RNA secondary structures with stochastic context free grammars. Several types of analysis are invalidated by the presence of ambiguity. As this problem inherits undecidability (as we show here) from the namely problem for context free languages, there is no complete algorithmic solution to the problem of ambiguity checking. Results We explain frequently observed sources of ambiguity, and show how to avoid them. We suggest four testing procedures that may help to detect ambiguity when present, including a just-in-time test that permits to work safely with a potentially ambiguous grammar. We introduce, for the special case of stochastic context free grammars and RNA structure modeling, an automated partial procedure for proving non-ambiguity. It is used to demonstrate non-ambiguity for several relevant grammars. Conclusion Our mechanical proof procedure and our testing methods provide a powerful arsenal of methods to ensure non-ambiguity. PMID:15967024

  1. Effects of ambiguous and unambiguous stimulus word differences on popular responses of schizophrenics.

    PubMed

    Penk, W E

    1978-10-01

    Tested that aspect of response interference theory that predicts that schizophrenics give fewer dominant and more competing responses for ambiguous, but not unambiguous, conditions. It was hypothesized that schizophrenics would evidence in a word association task greater gains, after treatment, in response popularity for ambiguous, but not for unambiguous, stimulus words. The prediction was assessed by administering a specially-constructed wordlist balanced for idiodynamic semantic sets (Moran, 1966). Results, from a pre- and posttest control group design, met predictions for 24 matched pairs of schizophrenics and neurotics: after 5 weeks of treatment, schizophrenics gained significantly in popular responses for ambiguous but not for unambiguous stimulus words, whereas neurotics did not gain significantly for either condition. Positive correlation for schizophrenics between ambiguous word response popularity gains in home and community adjustment as rated by a significant other coincided with expectations from response interference theory (Broen, 1968). PMID:711871

  2. Neural Correlates of Decision-Making Under Ambiguity and Conflict

    PubMed Central

    Pushkarskaya, Helen; Smithson, Michael; Joseph, Jane E.; Corbly, Christine; Levy, Ifat

    2015-01-01

    HIGHLIGHTS We use a simple gambles design in an fMRI study to compare two conditions: ambiguity and conflict.Participants were more conflict averse than ambiguity averse.Ambiguity aversion did not correlate with conflict aversion.Activation in the medial prefrontal cortex correlated with ambiguity level and ambiguity aversion.Activation in the ventral striatum correlated with conflict level and conflict aversion. Studies of decision making under uncertainty generally focus on imprecise information about outcome probabilities (“ambiguity”). It is not clear, however, whether conflicting information about outcome probabilities affects decision making in the same manner as ambiguity does. Here we combine functional magnetic resonance imaging (fMRI) and a simple gamble design to study this question. In this design the levels of ambiguity and conflict are parametrically varied, and ambiguity and conflict gambles are matched on expected value. Behaviorally, participants avoided conflict more than ambiguity, and attitudes toward ambiguity and conflict did not correlate across participants. Neurally, regional brain activation was differentially modulated by ambiguity level and aversion to ambiguity and by conflict level and aversion to conflict. Activation in the medial prefrontal cortex was correlated with the level of ambiguity and with ambiguity aversion, whereas activation in the ventral striatum was correlated with the level of conflict and with conflict aversion. These novel results indicate that decision makers process imprecise and conflicting information differently, a finding that has important implications for basic and clinical research. PMID:26640434

  3. Integer aperture ambiguity resolution based on difference test

    NASA Astrophysics Data System (ADS)

    Zhang, Jingyu; Wu, Meiping; Li, Tao; Zhang, Kaidong

    2015-07-01

    Carrier-phase integer ambiguity resolution (IAR) is the key to highly precise, fast positioning and attitude determination with Global Navigation Satellite System (GNSS). It can be seen as the process of estimating the unknown cycle ambiguities of the carrier-phase observations as integers. Once the ambiguities are fixed, carrier phase data will act as the very precise range data. Integer aperture (IA) ambiguity resolution is the combination of acceptance testing and integer ambiguity resolution, which can realize better quality control of IAR. Difference test (DT) is one of the most popular acceptance tests. This contribution will give a detailed analysis about the following properties of IA ambiguity resolution based on DT: 1. The sharpest and loose upper bounds of DT are derived from the perspective of geometry. These bounds are very simple and easy to be computed, which give the range for the critical values of DT.

  4. Lexical ambiguity resolution

    SciTech Connect

    Small, S.; Cottrell, G.; Tanenhaus, M.

    1987-01-01

    This book collects much of the best research currently available on the problem of lexical ambiguity resolution in the processing of human language. When taken out of context, sentences are usually ambiguous. When actually uttered in a dialogue or written in text, these same sentences often have unique interpretations. The inherent ambiguity of isolated sentences, becomes obvious in the attempt to write a computer program to understand them. Different views have emerged on the nature of context and the mechanisms by which it directs unambiguous understanding of words and sentences. These perspectives are represented and discussed. Eighteen original papers from a valuable source book for cognitive scientists in AI, psycholinguistics, neuropsychology, or theoretical linguistics.

  5. Weighting effects on Costas array ambiguity function

    NASA Astrophysics Data System (ADS)

    Dukeman, Mordechai; Hammer, Amnon

    An analysis of Hamming time, frequency and mixed weighting effects, on the ambiguity function of Costas arrays in pulse compression radars, is presented. The weighted ambiguity functions are derived both analytically and numerically by means of computer programs. Sidelobe and pedestal analysis for a special case and signal spectrum are given. The results obtained indicate that with adequate weighting, the sidelobes on the Doppler and delay axes may be reduced considerably, while preserving the ambiguity function thumbtack form and pedestal peak limits. The weighted sidelobe density remains largest near the origin.

  6. Ambiguity noise analysis of a SAR system

    NASA Astrophysics Data System (ADS)

    Tian, Haishan; Chang, Wenge; Li, Xiangyang

    2015-12-01

    The presence of range and azimuth (or Doppler) ambiguities in synthetic aperture radars (SARs) is well known. The ambiguity noise is related to the antenna pattern and the value of pulse repetition frequency (PRF). Because a new frequency modulated continuous wave (FMCW) SAR has the characters of low cost and small size, and the capacity of real-time signal processing, the antenna will likely vibrate or deform due to a lack of the stabilized platform. And the value of PRF cannot be much high because of the high computation burden for the real-time processing. The aim of this study is to access and improve the performance of a new FMCW SAR system based on the ambiguity noise. First, the quantitative analysis of the system's ambiguity noise level is performed; an antenna with low sidelobes is designed. The conclusion is that the range ambiguity noise is small; the azimuth ambiguity noise is somewhat increased, however, it is sufficiently small to have marginal influence on the image quality. Finally, the ambiguity noise level is measured using the imaging data from a Ku-band FMCW SAR. The results of this study show that the measured noise level coincides with the theoretical noise level.

  7. Resolution of quantifier scope ambiguities.

    PubMed

    Kurtzman, H S; MacDonald, M C

    1993-09-01

    Various processing principles have been suggested to be governing the resolution of quantifier scope ambiguities in sentences such as Every kid climbed a tree. This paper investigates structural principles, that is, those which refer to the syntactic or semantic positions of the quantified phrases. To test these principles, the preferred interpretations for three grammatical constructions were determined in a task in which participants made speeded judgments of whether a sentence following a doubly quantified sentence was a reasonable discourse continuation of the quantified sentence. The observed preferences cannot be explained by any single structural principle, but point instead to the interaction of several principles. Contrary to many proposals, there is little or no effect of a principle that assigns scope according to the linear order of the phrases. The interaction of principles suggests that alternative interpretations of the ambiguity may be initially considered in parallel, followed by selection of the single interpretation that best satisfies the principles. These results are discussed in relation to theories of ambiguity resolution at other levels of linguistic representation. PMID:8269698

  8. Facing ambiguous threats.

    PubMed

    Roberto, Michael A; Bohmer, Richard M J; Edmondson, Amy C

    2006-11-01

    On February 1, 2003, the world watched in horror as the Columbia space shuttle broke apart while reentering the earth's atmosphere, killing all seven astronauts. Some have argued that NASA's failure to respond with appropriate intensity to the so-called foam strike that led to the accident was evidence of irresponsible or incompetent management. The authors' research, however, suggests that NASA was exhibiting a natural, albeit unfortunate, pattern of behavior common in many organizations. The foam strike is a prime example of what the authors call an ambiguous threat-a signal that may or may not portend future harm. Ambiguous threats differ from threats with obvious causes-say, a fire in the building-for which the response is clear. They also differ from unmistakable threats that may lack straightforward response paths (such as the frightening oxygen-tank explosion aboard Apollo 13). However, when the warning sign is ambiguous and the threat's potential effect is unclear, managers may choose to ignore or discount the risk. Such an approach can be catastrophic. Firms that do a good job of dealing with ambiguous threats do not improvise during a crisis; rather, they apply a rigorous set of detection and response capabilities that they have developed and practiced beforehand. In this article, the authors outline how to put such capabilities in place long before a crisis strikes. First, companies need to hone their teamwork and rapid problem-solving skills through practice. Second, they must learn to recognize weak signals, amplify the threat, and encourage employees to ask disconcerting "what if" questions in a safe environment. Finally, they should explore possible responses to threats through quick, low-cost experimentation. PMID:17131567

  9. The Ambiguous Dying Syndrome

    ERIC Educational Resources Information Center

    Bern-Klug, Mercedes

    2004-01-01

    More than one-half of the 2.4 million deaths that will occur in the United States in 2004 will be immediately preceded by a time in which the likelihood of dying can best be described as "ambiguous." Many people die without ever being considered "dying" or "at the end of life." These people may miss out on the opportunity to close important

  10. Children do not exhibit ambiguity aversion despite intact familiarity bias

    PubMed Central

    Li, Rosa; Brannon, Elizabeth M.; Huettel, Scott A.

    2015-01-01

    The phenomenon of ambiguity aversion, in which risky gambles with known probabilities are preferred over ambiguous gambles with unknown probabilities, has been thoroughly documented in adults but never measured in children. Here, we use two distinct tasks to investigate ambiguity preferences of children (8- to 9-year-olds) and a comparison group of adults (19- to 27-year-olds). Across three separate measures, we found evidence for significant ambiguity aversion in adults but not in children and for greater ambiguity aversion in adults compared to children. As ambiguity aversion in adults has been theorized to result from a preference to bet on the known and avoid the unfamiliar, we separately measured familiarity bias and found that children, like adults, are biased towards the familiar. Our findings indicate that ambiguity aversion emerges across the course of development between childhood and adolescence, while a familiarity bias is already present in childhood. PMID:25601848

  11. Does ambiguity aversion influence the framing effect during decision making?

    PubMed

    Osmont, Anas; Cassotti, Mathieu; Agogu, Marine; Houd, Olivier; Moutier, Sylvain

    2015-04-01

    Decision-makers present a systematic tendency to avoid ambiguous options for which the level of risk is unknown. This ambiguity aversion is one of the most striking decision-making biases. Given that human choices strongly depend on the options' presentation, the purpose of the present study was to examine whether ambiguity aversion influences the framing effect during decision making. We designed a new financial decision-making task involving the manipulation of both frame and uncertainty levels. Thirty-seven participants had to choose between a sure option and a gamble depicting either clear or ambiguous probabilities. The results revealed a clear preference for the sure option in the ambiguity condition regardless of frame. However, participants presented a framing effect in both the risk and ambiguity conditions. Indeed, the framing effect was bidirectional in the risk condition and unidirectional in the ambiguity condition given that it did not involve preference reversal but only a more extreme choice tendency. PMID:25030206

  12. REDUCING AMBIGUITY IN THE FUNCTIONAL ASSESSMENT OF PROBLEM BEHAVIOR

    PubMed Central

    Rooker, Griffin W.; DeLeon, Iser G.; Borrero, Carrie S. W.; Frank-Crawford, Michelle A.; Roscoe, Eileen M.

    2015-01-01

    Severe problem behavior (e.g., self-injury and aggression) remains among the most serious challenges for the habilitation of persons with intellectual disabilities and is a significant obstacle to community integration. The current standard of behavior analytic treatment for problem behavior in this population consists of a functional assessment and treatment model. Within that model, the first step is to assess the behavior–environment relations that give rise to and maintain problem behavior, a functional behavioral assessment. Conventional methods of assessing behavioral function include indirect, descriptive, and experimental assessments of problem behavior. Clinical investigators have produced a rich literature demonstrating the relative effectiveness for each method, but in clinical practice, each can produce ambiguous or difficult-to-interpret outcomes that may impede treatment development. This paper outlines potential sources of variability in assessment outcomes and then reviews the evidence on strategies for avoiding ambiguous outcomes and/or clarifying initially ambiguous results. The end result for each assessment method is a set of best practice guidelines, given the available evidence, for conducting the initial assessment. PMID:26236145

  13. Precise Point Positioning with Partial Ambiguity Fixing.

    PubMed

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  14. Precise Point Positioning with Partial Ambiguity Fixing

    PubMed Central

    Li, Pan; Zhang, Xiaohong

    2015-01-01

    Reliable and rapid ambiguity resolution (AR) is the key to fast precise point positioning (PPP). We propose a modified partial ambiguity resolution (PAR) method, in which an elevation and standard deviation criterion are first used to remove the low-precision ambiguity estimates for AR. Subsequently the success rate and ratio-test are simultaneously used in an iterative process to increase the possibility of finding a subset of decorrelated ambiguities which can be fixed with high confidence. One can apply the proposed PAR method to try to achieve an ambiguity-fixed solution when full ambiguity resolution (FAR) fails. We validate this method using data from 450 stations during DOY 021 to 027, 2012. Results demonstrate the proposed PAR method can significantly shorten the time to first fix (TTFF) and increase the fixing rate. Compared with FAR, the average TTFF for PAR is reduced by 14.9% for static PPP and 15.1% for kinematic PPP. Besides, using the PAR method, the average fixing rate can be increased from 83.5% to 98.2% for static PPP, from 80.1% to 95.2% for kinematic PPP respectively. Kinematic PPP accuracy with PAR can also be significantly improved, compared to that with FAR, due to a higher fixing rate. PMID:26067196

  15. Giving office-based physicians electronic access to patients' prior imaging and lab results did not deter ordering of tests.

    PubMed

    McCormick, Danny; Bor, David H; Woolhandler, Stephanie; Himmelstein, David U

    2012-03-01

    Policy-based incentives for health care providers to adopt health information technology are predicated on the assumption that, among other things, electronic access to patient test results and medical records will reduce diagnostic testing and save money. To test the generalizability of findings that support this assumption, we analyzed the records of 28,741 patient visits to a nationally representative sample of 1,187 office-based physicians in 2008. Physicians' access to computerized imaging results (sometimes, but not necessarily, through an electronic health record) was associated with a 40-70 percent greater likelihood of an imaging test being ordered. The electronic availability of lab test results was also associated with ordering of additional blood tests. The availability of an electronic health record in itself had no apparent impact on ordering; the electronic access to test results appears to have been the key. These findings raise the possibility that, as currently implemented, electronic access does not decrease test ordering in the office setting and may even increase it, possibly because of system features that are enticements to ordering. We conclude that use of these health information technologies, whatever their other benefits, remains unproven as an effective cost-control strategy with respect to reducing the ordering of unnecessary tests. PMID:22392659

  16. Sexual function after surgical treatment for penile cancer: Which organ-sparing approach gives the best results?

    PubMed Central

    Sedigh, Omid; Falcone, Marco; Ceruti, Carlo; Timpano, Massimiliano; Preto, Mirko; Oderda, Marco; Kuehhas, Franklin; Sibona, Mattia; Gillo, Arianna; Gontero, Paolo; Rolle, Luigi; Frea, Bruno

    2015-01-01

    Introduction: We compared the postoperative sexual function of patients who underwent wide local excision (WLE) and glansectomy with urethral glanduloplasty for penile cancer. Methods: We retrospectively reviewed clinical data of 41 patients affected by superficial, localized penile cancer (?cT2a) between 2006 and 2013. Patients with severe erectile dysfunction and not interested in resuming an active sexual life were selected for penile partial amputation. Patients with preoperative satisfying erectile function and concerned about the preservation of their sexual potency were scheduled for WLE (Group A) or glansectomy with urethral glanduloplasty (Group B). Sexual function was assessed with the International Index of Erectile Function (IIEF) questionnaire and the Sex Encounter Profile (SEP). At 1 year, patients were asked to complete the questionnaires again and were questioned about their genital sensibility and ejaculatory reflex persistence. Postoperative complications were reported according to the Clavien-Dindo classification. Statistical analysis was performed by two-tailed test: Student t-test and chi-square. Results: Among the 41 patients enrolled, 12 underwent WLE (29.2%), 23 glansectomy with urethral glanduloplasty (56%) and 6 with penile partial amputation (14.6%). A decrease in postoperative IIEF was recorded in both groups, but was statistically significant only in Group B (p = 0.003). As for the SEP, while no significant changes were recorded postoperatively in Group A, a marked reduction was reported for Group B, with a statistically significant decrease in the possibility of achieving penetrative intercourse (p = 0.006) and in the perceived satisfaction during sexual activity (p = 0.004). Conclusions: WLE lead to better sexual outcomes and less postoperative complications as compared to glansectomy with urethral glanduloplasty. PMID:26279710

  17. Learning, Teaching and Ambiguity in Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Carr, Diane; Oliver, Martin; Burn, Andrew

    What might online communities and informal learning practices teach us about virtual world pedagogy? In this chapter we describe a research project in which learning practices in online worlds such as World of Warcraft and Second LifeTM (SL) were investigated. Working within an action research framework, we employed a range of methods to investigate how members of online communities define the worlds they encounter, negotiate the terms of participation, and manage the incremental complexity of game worlds. The implications of such practices for online pedagogy were then explored through teaching in SL. SL eludes simple definitions. Users, or "residents", of SL partake of a range of pleasures and activities - socialising, building, creating and exhibiting art, playing games, exploring, shopping, or running a business, for instance. We argue that the variable nature of SL gives rise to degrees of ambiguity. This ambiguity impacts on inworld social practices, and has significant implications for online teaching and learning.

  18. Situs ambiguous in a schoolchild.

    PubMed

    Tortajada, Miguel; Moreno, Miriam; Gracia, Miguel; Sanchis, Amparo

    2009-01-01

    We report the case of a 9-year-old child with asthma, atopic dermatitis and allergic rhinoconjunctivitis due to house dust mites, in whom a routine chest x-ray identified by chance abnormal organ position, such as the stomach located on the right side. Abdominal ultrasonography indicated a centralised liver, with polysplenia on the right side and an inferior cava vein located to the left of the aorta with no interruption. Ultrasonography did not show heart defects. Magnetic resonance imaging (MRI) of the abdomen was performed that showed a short pancreas, with no neck, body and tail in it, and a left inferior vena cava with normal outlet of the renal veins, and absence of the intrahepatic part of the inferior vena cava, that was replaced by the left hemiazygos vein. Spinal cord MRI revealed dorsal syringomelia. In view of the results obtained, the diagnosis of situs ambiguous was established. PMID:22121394

  19. P300 and Decision Making under Risk and Ambiguity

    PubMed Central

    Wang, Lei; Zheng, Jiehui; Huang, Shenwei; Sun, Haoye

    2015-01-01

    Our study aims to contrast the neural temporal features of early stage of decision making in the context of risk and ambiguity. In monetary gambles under ambiguous or risky conditions, 12 participants were asked to make a decision to bet or not, with the event-related potentials (ERPs) recorded meantime. The proportion of choosing to bet in ambiguous condition was significantly lower than that in risky condition. An ERP component identified as P300 was found. The P300 amplitude elicited in risky condition was significantly larger than that in ambiguous condition. The lower bet rate in ambiguous condition and the smaller P300 amplitude elicited by ambiguous stimuli revealed that people showed much more aversion in the ambiguous condition than in the risky condition. The ERP results may suggest that decision making under ambiguity occupies higher working memory and recalls more past experience while decision making under risk mainly mobilizes attentional resources to calculate current information. These findings extended the current understanding of underlying mechanism for early assessment stage of decision making and explored the difference between the decision making under risk and ambiguity. PMID:26539213

  20. The Ambiguity of the Child's "Voice" in Social Research

    ERIC Educational Resources Information Center

    Komulainen, Sirkka

    2007-01-01

    This article addresses the ambiguity of the child's "voice" in social research. Drawing on a recent research project on young children's communication difficulties, the author argues that the currently popular discourse on "listening to children" is beset with practical and ethical ambiguities that result from the "socialness" of human

  1. The Ambiguity of the Child's "Voice" in Social Research

    ERIC Educational Resources Information Center

    Komulainen, Sirkka

    2007-01-01

    This article addresses the ambiguity of the child's "voice" in social research. Drawing on a recent research project on young children's communication difficulties, the author argues that the currently popular discourse on "listening to children" is beset with practical and ethical ambiguities that result from the "socialness" of human…

  2. AmbiguityVis: Visualization of Ambiguity in Graph Layouts.

    PubMed

    Wang, Yong; Shen, Qiaomu; Archambault, Daniel; Zhou, Zhiguang; Zhu, Min; Yang, Sixiao; Qu, Huamin

    2016-01-01

    Node-link diagrams provide an intuitive way to explore networks and have inspired a large number of automated graph layout strategies that optimize aesthetic criteria. However, any particular drawing approach cannot fully satisfy all these criteria simultaneously, producing drawings with visual ambiguities that can impede the understanding of network structure. To bring attention to these potentially problematic areas present in the drawing, this paper presents a technique that highlights common types of visual ambiguities: ambiguous spatial relationships between nodes and edges, visual overlap between community structures, and ambiguity in edge bundling and metanodes. Metrics, including newly proposed metrics for abnormal edge lengths, visual overlap in community structures and node/edge aggregation, are proposed to quantify areas of ambiguity in the drawing. These metrics and others are then displayed using a heatmap-based visualization that provides visual feedback to developers of graph drawing and visualization approaches, allowing them to quickly identify misleading areas. The novel metrics and the heatmap-based visualization allow a user to explore ambiguities in graph layouts from multiple perspectives in order to make reasonable graph layout choices. The effectiveness of the technique is demonstrated through case studies and expert reviews. PMID:26390486

  3. Regularization ambiguities in loop quantum gravity

    NASA Astrophysics Data System (ADS)

    Perez, Alejandro

    2006-02-01

    One of the main achievements of loop quantum gravity is the consistent quantization of the analog of the Wheeler-DeWitt equation which is free of ultraviolet divergences. However, ambiguities associated to the intermediate regularization procedure lead to an apparently infinite set of possible theories. The absence of an UV problemthe existence of well-behaved regularization of the constraintsis intimately linked with the ambiguities arising in the quantum theory. Among these ambiguities is the one associated to the SU(2) unitary representation used in the diffeomorphism covariant point-splitting regularization of the nonlinear functionals of the connection. This ambiguity is labeled by a half-integer m and, here, it is referred to as the m ambiguity. The aim of this paper is to investigate the important implications of this ambiguity. We first study 2+1 gravity (and more generally BF theory) quantized in the canonical formulation of loop quantum gravity. Only when the regularization of the quantum constraints is performed in terms of the fundamental representation of the gauge group does one obtain the usual topological quantum field theory as a result. In all other cases unphysical local degrees of freedom arise at the level of the regulated theory that conspire against the existence of the continuum limit. This shows that there is a clear-cut choice in the quantization of the constraints in 2+1 loop quantum gravity. We then analyze the effects of the ambiguity in 3+1 gravity exhibiting the existence of spurious solutions for higher representation quantizations of the Hamiltonian constraint. Although the analysis is not complete in 3+1 dimensionsdue to the difficulties associated to the definition of the physical inner productit provides evidence supporting the definitions quantum dynamics of loop quantum gravity in terms of the fundamental representation of the gauge group as the only consistent possibilities. If the gauge group is SO(3) we find physical solutions associated to spin-two local excitations.

  4. The Ellipticity Distribution of Ambiguously Blended Objects

    NASA Astrophysics Data System (ADS)

    Dawson, William A.; Schneider, Michael D.; Tyson, J. Anthony; Jee, M. James

    2016-01-01

    Using overlapping fields with space-based Hubble Space Telescope and ground-based Subaru Telescope imaging we identify a population of blended galaxies that are blended to such a large degree that they are detected as single objects in the ground-based monochromatic imaging, which we label “ambiguous blends.” For deep imaging data, such as the depth targeted with the Large Synoptic Survey Telescope (LSST), the ambiguous blend population is both large (∼14%) and has a distribution of ellipticities that is different from that of unblended objects in a way that will likely be important for weak lensing measurements. Most notably, for a limiting magnitude of i ∼ 27 we find that ambiguous blending results in a ∼14% increase in shear noise (or an ∼12% decrease in the effective projected number density of lensed galaxies; neff) due to (1) larger intrinsic ellipticity dispersion, and (2) a scaling with the galaxy number density Ngal that is shallower than 1/\\sqrt{{N}{gal}}. For the LSST Gold Sample (i < 25.3) there is a ∼7% increase in shear noise (or ∼7% decrease in neff). More importantly than these increases in the shear noise, we find that the ellipticity distribution of ambiguous blends has an rms that is 13% larger than that of non-blended galaxies. Given the need of future weak lensing surveys to constrain the ellipticity distribution of galaxies to better than a percent in order to mitigate cosmic shear multiplicative biases, if it is unaccounted for, the different ellipticity distribution of ambiguous blends could be a dominant systematic.

  5. Ambiguous absence, ambiguous presence: a qualitative study of military reserve families in wartime.

    PubMed

    Faber, Anthony J; Willerton, Elaine; Clymer, Shelley R; MacDermid, Shelley M; Weiss, Howard M

    2008-04-01

    The "Global War on Terrorism" has resulted in reservists being deployed at an ever-increasing rate. However, because reservists and their families are unaccustomed to deployments, many families may experience boundary ambiguity, a state in which family members are uncertain in their perception about who is in or out of the family and who is performing which roles and tasks within the family. This qualitative description study examined boundary ambiguity in military reserve families over time. A sample of 34 reservists, spouses, and parents was interviewed 7 times within the 1st year of the reservists' return from Iraq. During deployment, all family members experienced boundary ambiguity. Gathering information and attending a family support group provided some relief for families. After the reservists returned, couples as well as those who had experienced additional life events or losses experienced the highest levels of boundary ambiguity. However, this boundary ambiguity dissipated over time, as families tended to restabilize once the reservists had returned to work and a routine had been established. PMID:18410209

  6. Coding of level of ambiguity within neural systems mediating choice

    PubMed Central

    Lopez-Paniagua, Dan; Seger, Carol A.

    2013-01-01

    Data from previous neuroimaging studies exploring neural activity associated with uncertainty suggest varying levels of activation associated with changing degrees of uncertainty in neural regions that mediate choice behavior. The present study used a novel task that parametrically controlled the amount of information hidden from the subject; levels of uncertainty ranged from full ambiguity (no information about probability of winning) through multiple levels of partial ambiguity, to a condition of risk only (zero ambiguity with full knowledge of the probability of winning). A parametric analysis compared a linear model in which weighting increased as a function of level of ambiguity, and an inverted-U quadratic models in which partial ambiguity conditions were weighted most heavily. Overall we found that risk and all levels of ambiguity recruited a common frontoparietalstriatal network including regions within the dorsolateral prefrontal cortex, intraparietal sulcus, and dorsal striatum. Activation was greatest across these regions and additional anterior and superior prefrontal regions for the quadratic function which most heavily weighs trials with partial ambiguity. These results suggest that the neural regions involved in decision processes do not merely track the absolute degree ambiguity or type of uncertainty (risk vs. ambiguity). Instead, recruitment of prefrontal regions may result from greater degree of difficulty in conditions of partial ambiguity: when information regarding reward probabilities important for decision making is hidden or not easily obtained the subject must engage in a search for tractable information. Additionally, this study identified regions of activity related to the valuation of potential gains associated with stimuli or options (including the orbitofrontal and medial prefrontal cortices and dorsal striatum) and related to winning (including orbitofrontal cortex and ventral striatum). PMID:24367286

  7. Giving behavior of millionaires.

    PubMed

    Smeets, Paul; Bauer, Rob; Gneezy, Uri

    2015-08-25

    This paper studies conditions influencing the generosity of wealthy people. We conduct incentivized experiments with individuals who have at least €1 million in their bank account. The results show that millionaires are more generous toward low-income individuals in a giving situation when the other participant has no power, than in a strategic setting, where the other participant can punish unfair behavior. Moreover, the level of giving by millionaires is higher than in any other previous study. Our findings have important implications for charities and financial institutions that deal with wealthy individuals. PMID:26261327

  8. Giving behavior of millionaires

    PubMed Central

    Smeets, Paul; Bauer, Rob; Gneezy, Uri

    2015-01-01

    This paper studies conditions influencing the generosity of wealthy people. We conduct incentivized experiments with individuals who have at least €1 million in their bank account. The results show that millionaires are more generous toward low-income individuals in a giving situation when the other participant has no power, than in a strategic setting, where the other participant can punish unfair behavior. Moreover, the level of giving by millionaires is higher than in any other previous study. Our findings have important implications for charities and financial institutions that deal with wealthy individuals. PMID:26261327

  9. To mind the mind: An event-related potential study of word class and semantic ambiguity

    PubMed Central

    Lee, Chia-lin; Federmeier, Kara D.

    2009-01-01

    The goal of this study was to jointly examine the effects of word class, word class ambiguity, and semantic ambiguity on the brain response to words in syntactically specified contexts. Four types of words were used: (1) word class ambiguous words with a high degree of semantic ambiguity (e.g., duck); (2) word class ambiguous words with little or no semantic ambiguity (e.g., vote); (3) word class unambiguous nouns (e.g., sofa); and (4) word class unambiguous verbs (e.g., eat). These words were embedded in minimal phrases that explicitly specified their word class: the for nouns (and ambiguous words used as nouns) and to for verbs (and ambiguous words used as verbs). Our results replicate the basic word class effects found in prior work (Federmeier, K.D., Segal, J.B., Lombrozo, T., Kutas, M., 2000. Brain responses to nouns, verbs and class ambiguous words in context. Brain, 123 (12), 25522566), including an enhanced N400 (250450ms) to nouns compared with verbs and an enhanced frontal positivity (300700 ms) to unambiguous verbs in relation to unambiguous nouns. A sustained frontal negativity (250900 ms) that was previously linked to word class ambiguity also appeared in this study but was specific to word class ambiguous items that also had a high level of semantic ambiguity; word class ambiguous items without semantic ambiguity, in contrast, were more positive than class unambiguous words in the early part of this time window (250500 ms). Thus, this frontal negative effect seems to be driven by the need to resolve the semantic ambiguity that is sometimes associated with different grammatical uses of a word class ambiguous homograph rather than by the class ambiguity per se. PMID:16516169

  10. Giving an insulin injection

    MedlinePLUS

    To give an insulin injection, you need to fill the right syringe with the right amount of medicine, decide where to give the ... of each medicine to give. The type of insulin should match the type of syringe: U-100 ...

  11. Lexical Access for Phonetic Ambiguities.

    ERIC Educational Resources Information Center

    Spencer, N. J.; Wollman, Neil

    1980-01-01

    Reports on research that (1) suggests that phonetically ambiguous pairs (ice cream/I scream) have been used inaccurately to illustrate contextual effects in word segmentation, (2) supports unitary rather than exhaustive processing, and (3) supports the use of the concepts of word frequency and listener expectations instead of top-down, multiple…

  12. Ambiguity Resolution in Lateralized Arabic

    ERIC Educational Resources Information Center

    Hayadre, Manar; Kurzon, Dennis; Peleg, Orna; Zohar, Eviatar

    2015-01-01

    We examined ambiguity resolution in reading in Arabic. Arabic is an abjad orthography and is morphologically similar to Hebrew. However, Arabic literacy occurs in a diglossic context, and its orthography is more visually complex than Hebrew. We therefore tested to see whether hemispheric differences will be similar or different from previous

  13. Lexical Access for Phonetic Ambiguities.

    ERIC Educational Resources Information Center

    Spencer, N. J.; Wollman, Neil

    1980-01-01

    Reports on research that (1) suggests that phonetically ambiguous pairs (ice cream/I scream) have been used inaccurately to illustrate contextual effects in word segmentation, (2) supports unitary rather than exhaustive processing, and (3) supports the use of the concepts of word frequency and listener expectations instead of top-down, multiple

  14. Text Association Analysis and Ambiguity in Text Mining

    NASA Astrophysics Data System (ADS)

    Bhonde, S. B.; Paikrao, R. L.; Rahane, K. U.

    2010-11-01

    Text Mining is the process of analyzing a semantically rich document or set of documents to understand the content and meaning of the information they contain. The research in Text Mining will enhance human's ability to process massive quantities of information, and it has high commercial values. Firstly, the paper discusses the introduction of TM its definition and then gives an overview of the process of text mining and the applications. Up to now, not much research in text mining especially in concept/entity extraction has focused on the ambiguity problem. This paper addresses ambiguity issues in natural language texts, and presents a new technique for resolving ambiguity problem in extracting concept/entity from texts. In the end, it shows the importance of TM in knowledge discovery and highlights the up-coming challenges of document mining and the opportunities it offers.

  15. GNSS carrier phase ambiguity resolution based on integrity restriction in ambiguity domain

    NASA Astrophysics Data System (ADS)

    Liu, Haiying; Chen, Zhiming; Ye, Weisong; Wang, Huinan

    2014-04-01

    Carrier phase ambiguity resolution of Global Navigation Satellite System (GNSS) is a key technology for high-precision navigation and positioning, and it is a challenge for applications which require both high accuracy and high integrity. This paper proposes efficient ambiguity resolution methods based on integrity restriction using Fixed Failure rate Ratio Test (FF-RT) and Doubly Non-central F-distribution Ratio Test (DNF-RT), and derives the related processing models and numerical algorithms compared with the traditional Ratio Test (RT) method. Firstly, the integer ambiguity resolution and validation procedures, especially the Least squares AMBiguity Decorrelation Adjustment (LAMBDA) estimation and RT validation are analyzed. Then the quality evaluation using success rate, the FF-RT method using Integer Aperture (IA) estimation and the NDF-RT method are proposed. Lastly, the simulation and analysis for LAMBDA using RT, FF-RT and DNF-RT methods are performed. Simulation results show that in case of unbiased scenario FF-RT and DNF-RT have similar performances, which are significantly better than RT. In case of biased scenario it is difficult for FF-RT to predict the biased success rate thus it should not be used for bias detection, while DNF-RT can detect biases in most cases except for the biases are approximate or equal to integer, which has the important benefit for early detection of potential threat to the position solution.

  16. How do speakers avoid ambiguous linguistic expressions?

    PubMed

    Ferreira, Victor S; Slevc, L Robert; Rogers, Erin S

    2005-07-01

    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 did so equally regardless of whether they also were about to describe foils. This suggests that comprehension processes can sometimes detect linguistic-ambiguity before producing it. However, once produced, speakers consistently avoided using the same linguistically ambiguous expression again for a different meaning. This suggests that production processes can successfully detect linguistic-ambiguity after-the-fact. Speakers almost always avoided nonlinguistic-ambiguity. Thus, production processes are especially sensitive to nonlinguistic- but not linguistic-ambiguity, with the latter avoided consistently only once it is already articulated. PMID:15996561

  17. Isoclinic Ambiguity Unwrapping of Circular Ring under Diametric Compression

    NASA Astrophysics Data System (ADS)

    Huang, M.-J.

    2010-06-01

    Isoclinic and isochromatic parameters in photoelastic analysis are formulated by arc tangent function of several phase shifting frames but for isochromatic calculation it is, in addition, in terms of isoclinic data also. Thus, any isoclinic phase ambiguity would also result in the phase inconsistencies of isochromatic calculation and cause unwrapping problems and difficulties. Many methods had been proposed to treat these kinds of isochromatic fringes but lots of treatments were needed for the correct retrieval. In this work, the isoclinic ambiguity problem is investigated and solved directly by a novel regional phase unwrapping technique. Once the isoclinic phase ambiguity problems are solved, a correct isoclinic result can be obtained. Then, substituting this result into the isochromatic formation yields an ambiguity free isochromatic phase map, which can be easily restored by any phase unwrapping algorithm. A stress frozen sample - circular ring under diametric compression verifies its effectiveness. Usually happened is that this kind of sample is with ambiguous isoclinic data which would cause phase ambiguities of the isochromatic formulation if not treated well first.

  18. [A neonate with ambiguous genitalia].

    PubMed

    Jansen, Burgo J; van Rijn, Rick R; van Trotsenburg, A S P Paul

    2015-01-01

    In a neonate with ambiguous genitalia, physical examination revealed a phallus. Ultrasonography showed a vagina and uterus, but no gonads. Because of severe undervirilisation in the presence of a uterus, probably due to 46,XY gonadal dysgenesis, parents were advised female sex assignment. When after a few weeks the phallus had increased in size, abdominal laparoscopy showed an underdeveloped uterus. Gonadal biopsy confirmed gonadal dysgenesis. Sex assignment was reconsidered and changed into the male gender. PMID:26200425

  19. Productive Ambiguity in the Learning of Mathematics

    ERIC Educational Resources Information Center

    Foster, Colin

    2011-01-01

    In this paper I take a positive view of ambiguity in the learning of mathematics. Following Grosholz (2007), I argue that it is not only the arts which exploit ambiguity for creative ends but science and mathematics too. By enabling the juxtaposition of multiple conflicting frames of reference, ambiguity allows novel connections to be made. I

  20. 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

  1. Generative Learning: Adults Learning within Ambiguity

    ERIC Educational Resources Information Center

    Nicolaides, Aliki

    2015-01-01

    This study explored the extent to which ambiguity can serve as a catalyst for adult learning. The purpose of this study is to understand learning that is generated when encountering ambiguity agitated by the complexity of liquid modernity. "Ambiguity," in this study, describes an encounter with an appearance of reality that is at first…

  2. Generative Learning: Adults Learning within Ambiguity

    ERIC Educational Resources Information Center

    Nicolaides, Aliki

    2015-01-01

    This study explored the extent to which ambiguity can serve as a catalyst for adult learning. The purpose of this study is to understand learning that is generated when encountering ambiguity agitated by the complexity of liquid modernity. "Ambiguity," in this study, describes an encounter with an appearance of reality that is at first

  3. 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…

  4. Which smokers are helped to give up smoking using transdermal nicotine patches? Results from a randomized, double-blind, placebo-controlled trial.

    PubMed Central

    Yudkin, P L; Jones, L; Lancaster, T; Fowler, G H

    1996-01-01

    BACKGROUND: Nicotine replacement therapy is effective in helping people to give up smoking. The three forms now available--transdermal patches, chewing gum and nasal spray--deliver nicotine at different rates and to different levels. Therefore, it might be expected that smokers with different characteristics, and at different levels of nicotine dependence, will be helped more by one or other method. AIM: The aim of the study was to examine whether the effectiveness of transdermal patches is related to nicotine dependence or to other smoker characteristics and to investigate factors predicting smoking cessation using patches. METHOD: Data from a randomized, double-blind, placebo-controlled trial of nicotine transdermal patches were analysed retrospectively. The trial, conducted in 1990-1992, involved 1686 patients recruited from 19 general practices in Oxfordshire. The main outcome measure was continuous smoking cessation from 8 to 52 weeks after the start of patch use, biochemically validated at 12, 24 and 52 weeks. The effectiveness of the patches was measured by the relative odds of sustained cessation using nicotine patches compared with placebo patches. RESULTS: Nicotine transdermal patches were more effective in smokers with moderate nicotine dependence [odds ratio (OR) 1.94; 95% confidence interval (CI) 1.24-3.04] than in mildly or highly dependent smokers (OR 0.98; 95% CI 0.58-1.65) (difference in ORs P < 0.05) and more effective in those aged 24-49 years (OR 1.89; 95% CI 1.24-2.87) than in older smokers aged 50-65 years (OR 0.88; 95% CI 0.49-1.59) (difference in ORs P < 0.05). Abstinence from smoking in the first week of the trial was the strongest predictor of sustained cessation and was more common among smokers using nicotine patches than those using placebo patches (33% of 842 compared with 22% of 844; P < 0.001). Of first-week abstainers, 25 and 28% of 277 and 182 in the nicotine and placebo groups, respectively, achieved sustained cessation compared with 4% of 565 and 2% of 662 first-week smokers. CONCLUSION: Nicotine transdermal patches were most effective for smokers with moderate nicotine dependence and for younger smokers. Early abstinence from smoking was the strongest predictor of sustained cessation. A week's trial of the patch proceeding to longer term use if abstinence is achieved may be an effective policy. PMID:8731618

  5. Interaction of bottom-up and top-down processes in the perception of ambiguous figures.

    PubMed

    Intait?, Monika; Noreika, Valdas; oli?nas, Alvydas; Falter, Christine M

    2013-08-30

    Ambiguous figures reverse their appearance during prolonged viewing and can be perceived in two (or more) available interpretations. Both physical stimulus manipulations and cognitive control influence the perception of ambiguous figures, but the underlying mechanisms remain poorly understood. In the current study, the perception of an ambiguous figure was manipulated by adaptation to unambiguous figures and/or placing the ambiguous figure into a context of unambiguous figures. Our results indicate that both adaptation and context can effectively modulate perception of the ambiguous figure. When manipulated together, adaptation and context processes showed additive effects upon the perception of the ambiguous figure implying the independent mechanisms. Thus, top-down and bottom-up processes seem to influence the perception of the ambiguous figures independently and neither seems to be uniquely responsible for the generation of perceptual changes. PMID:23851264

  6. [Grandchildren in family care giving for people with dementia: experiences and evaluations--results from a life-world-oriented study].

    PubMed

    Philipp-Metzen, H E

    2011-12-01

    Dementia often has a serious impact on family life in household care giving situations. The qualitative study in applied gerontology presented here focuses on the subjective experiences of grandchildren and the intergenerational relationships of the family members. It includes 15 in-depth retrospective interviews with young adults (11 female, 4 male). The theoretical background is a sociological life-world-oriented approach by Alfred Schtz. The grandchildren reported a wide range of experiences with positive and enriching incidents prevailing, e.g., individual and familial competence in care giving, increased contact between family members, i.e., so-called"family cohesion", improvements in the grandchildren's social responsibility, and their acquired knowledge of the needs of older people and of persons with dementia. Individual stress was experienced because of so-called "challenging behavior" by the grandparents (e.g., aggressive behavior) or family circumstances when the demands were too great.A third category includes those experiences which seem to be "taken for granted" and are regarded as insignificant by the grandchildren. Because this category encompasses many of the grandchildren's own care giving activities, the widespread assumption that dementia must always cause younger carers stress is not true in general. The data suggest that living in a family that has difficulties in coping with the situation might be more demanding than dealing with the behavior and psychological symptoms of dementia. The grandchildren should be given access to age-appropriate information about the disease and the ways to communicate effectively with their grandparent needing care. PMID:21909775

  7. Long-Duration Spaceflight Increases Depth Ambiguity of Reversible Perspective Figures.

    PubMed

    Clment, Gilles; Allaway, Heather C M; Demel, Michael; Golemis, Adrianos; Kindrat, Alexandra N; Melinyshyn, Alexander N; Merali, Tahir; Thirsk, Robert

    2015-01-01

    The objective of this study was to investigate depth perception in astronauts during and after spaceflight by studying their sensitivity to reversible perspective figures in which two-dimensional images could elicit two possible depth representations. Other ambiguous figures that did not give rise to a perception of illusory depth were used as controls. Six astronauts and 14 subjects were tested in the laboratory during three sessions for evaluating the variability of their responses in normal gravity. The six astronauts were then tested during four sessions while on board the International Space Station for 5-6 months. They were finally tested immediately after return to Earth and up to one week later. The reaction time decreased throughout the sessions, thus indicating a learning effect. However, the time to first percept reversal and the number of reversals were not different in orbit and after the flight compared to before the flight. On Earth, when watching depth-ambiguous perspective figures, all subjects reported seeing one three-dimensional interpretation more often than the other, i.e. a ratio of about 70-30%. In weightlessness this asymmetry gradually disappeared and after 3 months in orbit both interpretations were seen for the same duration. These results indicate that the perception of "illusory" depth is altered in astronauts during spaceflight. This increased depth ambiguity is attributed to the lack of the gravitational reference and the eye-ground elevation for interpreting perspective depth cues. PMID:26146839

  8. Long-Duration Spaceflight Increases Depth Ambiguity of Reversible Perspective Figures

    PubMed Central

    Clément, Gilles; Allaway, Heather C. M.; Demel, Michael; Golemis, Adrianos; Kindrat, Alexandra N.; Melinyshyn, Alexander N.; Merali, Tahir; Thirsk, Robert

    2015-01-01

    The objective of this study was to investigate depth perception in astronauts during and after spaceflight by studying their sensitivity to reversible perspective figures in which two-dimensional images could elicit two possible depth representations. Other ambiguous figures that did not give rise to a perception of illusory depth were used as controls. Six astronauts and 14 subjects were tested in the laboratory during three sessions for evaluating the variability of their responses in normal gravity. The six astronauts were then tested during four sessions while on board the International Space Station for 5–6 months. They were finally tested immediately after return to Earth and up to one week later. The reaction time decreased throughout the sessions, thus indicating a learning effect. However, the time to first percept reversal and the number of reversals were not different in orbit and after the flight compared to before the flight. On Earth, when watching depth-ambiguous perspective figures, all subjects reported seeing one three-dimensional interpretation more often than the other, i.e. a ratio of about 70–30%. In weightlessness this asymmetry gradually disappeared and after 3 months in orbit both interpretations were seen for the same duration. These results indicate that the perception of “illusory” depth is altered in astronauts during spaceflight. This increased depth ambiguity is attributed to the lack of the gravitational reference and the eye-ground elevation for interpreting perspective depth cues. PMID:26146839

  9. Combined GPS/GLONASS Precise Point Positioning with Fixed GPS Ambiguities

    PubMed Central

    Pan, Lin; Cai, Changsheng; Santerre, Rock; Zhu, Jianjun

    2014-01-01

    Precise point positioning (PPP) technology is mostly implemented with an ambiguity-float solution. Its performance may be further improved by performing ambiguity-fixed resolution. Currently, the PPP integer ambiguity resolutions (IARs) are mainly based on GPS-only measurements. The integration of GPS and GLONASS can speed up the convergence and increase the accuracy of float ambiguity estimates, which contributes to enhancing the success rate and reliability of fixing ambiguities. This paper presents an approach of combined GPS/GLONASS PPP with fixed GPS ambiguities (GGPPP-FGA) in which GPS ambiguities are fixed into integers, while all GLONASS ambiguities are kept as float values. An improved minimum constellation method (MCM) is proposed to enhance the efficiency of GPS ambiguity fixing. Datasets from 20 globally distributed stations on two consecutive days are employed to investigate the performance of the GGPPP-FGA, including the positioning accuracy, convergence time and the time to first fix (TTFF). All datasets are processed for a time span of three hours in three scenarios, i.e., the GPS ambiguity-float solution, the GPS ambiguity-fixed resolution and the GGPPP-FGA resolution. The results indicate that the performance of the GPS ambiguity-fixed resolutions is significantly better than that of the GPS ambiguity-float solutions. In addition, the GGPPP-FGA improves the positioning accuracy by 38%, 25% and 44% and reduces the convergence time by 36%, 36% and 29% in the east, north and up coordinate components over the GPS-only ambiguity-fixed resolutions, respectively. Moreover, the TTFF is reduced by 27% after adding GLONASS observations. Wilcoxon rank sum tests and chi-square two-sample tests are made to examine the significance of the improvement on the positioning accuracy, convergence time and TTFF. PMID:25237901

  10. On Ambiguities in SAR Design

    NASA Technical Reports Server (NTRS)

    Freeman, Anthony

    2006-01-01

    Ambiguities are an aliasing effect caused by the periodic sampling of the scene backscatter inherent to pulsed radar systems such as Synthetic Aperture radar (SAR). In this paper we take a fresh look at the relationship between SAR range and azimuth ambiguity constraints on the allowable pulse repetition frequency (PRF) and the antenna length. We show that for high squint angles smaller antennas may be feasible in some cases. For some applications, the ability to form a synthetic aperture at high squint angles is desirable, but the size of the antenna causes problems in the design of systems capable of such operation. This is because the SAR system design is optimized for a side-looking geometry. In two examples design examples we take a suboptimum antenna size and examine the performance in terms of azimuth resolution and swath width as a function of squint angle. We show that for stripmap SARs, the swath width is usually worse for off-boresight squint angles, because it is severely limited by range walk, except in cases where we relax the spatial resolution. We consider the implications for the design of modest-resolution, narrow swath, scanning SAR scatterometers .

  11. Evolution of phage with chemically ambiguous proteomes

    PubMed Central

    Bacher, Jamie M; Bull, James J; Ellington, Andrew D

    2003-01-01

    Background The widespread introduction of amino acid substitutions into organismal proteomes has occurred during natural evolution, but has been difficult to achieve by directed evolution. The adaptation of the translation apparatus represents one barrier, but the multiple mutations that may be required throughout a proteome in order to accommodate an alternative amino acid or analogue is an even more daunting problem. The evolution of a small bacteriophage proteome to accommodate an unnatural amino acid analogue can provide insights into the number and type of substitutions that individual proteins will require to retain functionality. Results The bacteriophage Q? initially grows poorly in the presence of the amino acid analogue 6-fluorotryptophan. After 25 serial passages, the fitness of the phage on the analogue was substantially increased; there was no loss of fitness when the evolved phage were passaged in the presence of tryptophan. Seven mutations were fixed throughout the phage in two independent lines of descent. None of the mutations changed a tryptophan residue. Conclusions A relatively small number of mutations allowed an unnatural amino acid to be functionally incorporated into a highly interdependent set of proteins. These results support the 'ambiguous intermediate' hypothesis for the emergence of divergent genetic codes, in which the adoption of a new genetic code is preceded by the evolution of proteins that can simultaneously accommodate more than one amino acid at a given codon. It may now be possible to direct the evolution of organisms with novel genetic codes using methods that promote ambiguous intermediates. PMID:14667253

  12. Adapting to an Uncertain World: Cognitive Capacity and Causal Reasoning with Ambiguous Observations

    PubMed Central

    Shou, Yiyun; Smithson, Michael

    2015-01-01

    Ambiguous causal evidence in which the covariance of the cause and effect is partially known is pervasive in real life situations. Little is known about how people reason about causal associations with ambiguous information and the underlying cognitive mechanisms. This paper presents three experiments exploring the cognitive mechanisms of causal reasoning with ambiguous observations. Results revealed that the influence of ambiguous observations manifested by missing information on causal reasoning depended on the availability of cognitive resources, suggesting that processing ambiguous information may involve deliberative cognitive processes. Experiment 1 demonstrated that subjects did not ignore the ambiguous observations in causal reasoning. They also had a general tendency to treat the ambiguous observations as negative evidence against the causal association. Experiment 2 and Experiment 3 included a causal learning task requiring a high cognitive demand in which paired stimuli were presented to subjects sequentially. Both experiments revealed that processing ambiguous or missing observations can depend on the availability of cognitive resources. Experiment 2 suggested that the contribution of working memory capacity to the comprehensiveness of evidence retention was reduced when there were ambiguous or missing observations. Experiment 3 demonstrated that an increase in cognitive demand due to a change in the task format reduced subjects tendency to treat ambiguous-missing observations as negative cues. PMID:26468653

  13. Preliminary study of tolerance of ambiguity of individuals reporting paranormal experiences.

    PubMed

    Houran, J

    1998-02-01

    This research tested the notion that poltergeist-like experiences reflect the need to explain anomalous personal experiences. Thus, it was hypothesized that percipients of poltergeists would score lower on tolerance of ambiguity than controls. Further, it was hypothesized that tolerance of ambiguity would negatively correlate with the number of different categories of poltergeist experience. 30 self-identified percipients of poltergeist-like phenomena and 30 self-identified nonpercipients of the paranormal were administered the Rydell-Rosen Ambiguity Tolerance Scale and Houran and Lange's Poltergeist Experiences Checklist. Results partially supported predictions. Percipients of the paranormal scored significantly lower on tolerance of ambiguity than nonpercipients, but scores on the experiences checklist did not significantly correlate with scores on tolerance of ambiguity. The results supported the main hypothesis but more detailed research is needed to clarify the roles of age and tolerance of ambiguity in the perception of anomalous phenomena. PMID:9520551

  14. Neural Correlates of Semantic Competition during Processing of Ambiguous Words

    PubMed Central

    Bilenko, Natalia Y.; Grindrod, Christopher M.; Myers, Emily B.; Blumstein, Sheila E.

    2010-01-01

    The current study investigated the neural correlates that underlie the processing of ambiguous words and the potential effects of semantic competition on that processing. Participants performed speeded lexical decisions on semantically related and unrelated prime-target pairs presented in the auditory modality. The primes were either ambiguous words (e.g., ball) or unambiguous words (e.g., athlete), and targets were either semantically related to the dominant (i.e., most frequent) meaning of the ambiguous prime word (e.g., soccer) or to the subordinate (i.e., less frequent) meaning (e.g., dance). Results showed increased activation in the bilateral inferior frontal gyrus (IFG) for ambiguous related compared to unambiguous related stimulus pairs, demonstrating that prefrontal areas are activated even in an implicit task where participants are not required to explicitly analyze the semantic content of the stimuli and to make an overt selection of a particular meaning based on this analysis. Additionally, increased activation was found in the left IFG and the left cingulate gyrus for subordinate meaning compared to dominant meaning conditions, suggesting that additional resources are recruited in order to resolve increased competition demands in accessing the subordinate meaning of an ambiguous word. PMID:18702579

  15. Possible ambiguities in the equation of state for neutron stars

    SciTech Connect

    Cheoun, Myung-Ki; Miyatsu, Tsuyoshi; Ryu, C. Y.; Deliduman, Cemsinan; Güngör, Can; Keleş, Vildan; Kajino, Toshitaka; Mathews, Grant J.

    2014-05-02

    We addressed possible ambiguities on the properties of neutron stars (NSs) estimated in theoretical sides. First, roles of hyperons inside the NS are discussed through various relativistic mean field (RMF) theories. In particular, the extension of SU(6) spin-flavor symmetry to SU(3) flavor symmetry is shown to give rise to the increase of hyperon threshold density, similarly to the Fock term effects in RMF theories. As a result, about 2.0 solar mass is obtained with the hyperons. Second, the effect by the modified f(R) gravity, which leaves a room for the dark energy in the Einstein equation to be taken into account, is discussed for the NS in a strong magnetic field (MF). Our results show that the modified gravity with the Kaluza-Klein electro-magnetism theory expanded in terms of a length scale parameter may reasonably describe the NS in strong MF, so called magnetar. Even the super-soft equation of state is shown to be revived by the modified f(R) gravity.

  16. Selection of optimum median-filter-based ambiguity removal algorithm parameters for NSCAT. [NASA scatterometer

    NASA Technical Reports Server (NTRS)

    Shaffer, Scott; Dunbar, R. Scott; Hsiao, S. Vincent; Long, David G.

    1989-01-01

    The NASA Scatterometer, NSCAT, is an active spaceborne radar designed to measure the normalized radar backscatter coefficient (sigma0) of the ocean surface. These measurements can, in turn, be used to infer the surface vector wind over the ocean using a geophysical model function. Several ambiguous wind vectors result because of the nature of the model function. A median-filter-based ambiguity removal algorithm will be used by the NSCAT ground data processor to select the best wind vector from the set of ambiguous wind vectors. This process is commonly known as dealiasing or ambiguity removal. The baseline NSCAT ambiguity removal algorithm and the method used to select the set of optimum parameter values are described. An extensive simulation of the NSCAT instrument and ground data processor provides a means of testing the resulting tuned algorithm. This simulation generates the ambiguous wind-field vectors expected from the instrument as it orbits over a set of realistic meoscale wind fields. The ambiguous wind field is then dealiased using the median-based ambiguity removal algorithm. Performance is measured by comparison of the unambiguous wind fields with the true wind fields. Results have shown that the median-filter-based ambiguity removal algorithm satisfies NSCAT mission requirements.

  17. Giving something back.

    PubMed

    Bromley, P; Ehrenreich, D

    1998-01-01

    The Taoist teachings of self-reflection, openness, and sharing of self illustrate the need for the seasoned professional to examine one's own practice and share with the greater professional community. Taoism incorporates interdependency and harmony for all systems and suggests that as individuals we rely on the well-being of the whole. Four specific methods provide meaningful ways to give back to the profession; networking, presenting, publishing, and professional association work. Implementing one or more of these methods promotes the profession's collegial spirit and facilitates one's own growth while giving to others. PMID:9543890

  18. Value transfer contributes to ambiguous-cue discrimination learning.

    PubMed

    Urcuioli, Peter J; Michalek, Sarah

    2007-08-01

    Pigeons learned two concurrent simultaneous discriminations in which the S- for one served as the S+ for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S- more often than the S+ on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S+ transfers to its companion S-, contributes to ambiguous-cue performances. PMID:17972729

  19. Authoritarianism, cognitive rigidity, and the processing of ambiguous visual information.

    PubMed

    Duncan, Lauren E; Peterson, Bill E

    2014-01-01

    Intolerance of ambiguity and cognitive rigidity are unifying aspects of authoritarianism as defined by Adorno, Frenkel-Brunswik, Levinson, and Sanford (1982/1950), who hypothesized that authoritarians view the world in absolute terms (e.g., good or evil). Past studies have documented the relationship between authoritarianism and intolerance of ambiguity and rigidity. Frenkel-Brunswik (1949) hypothesized that this desire for absolutism was rooted in perceptual processes. We present a study with three samples that directly tests the relationship between right wing authoritarianism (RWA) and the processing of ideologically neutral but ambiguous visual stimuli. As hypothesized, in all three samples we found that RWA was related to the slower processing of visual information that required participants to recategorize objects. In a fourth sample, RWA was unrelated to speed of processing visual information that did not require recategorization. Overall, results suggest a relationship between RWA and rigidity in categorization. PMID:25280165

  20. Scheme-scale ambiguity in analysis of QCD observable

    NASA Astrophysics Data System (ADS)

    Mirjalili, A.; A. Kniehl, B.

    2010-09-01

    The scheme-scale ambiguity that has plagued perturbative analysis in QCD remains on obstacle to making precise tests of the theory. Many attempts have been done to resolve the scale ambiguity. In this regard the BLM, EC, PMS and CORGI approaches are more distinct. We try to employ these methods to fix the scale ambiguity at NLO, NNLO and even in more higher order approximations. By optimizing the renormalization scale, there will be a possibility to predicate higher order terms. We present general results for predicted terms at any order, using different optimization methods. Some observable as specific examples will be used to indicate the validity of scale fixing to predicate the higher order terms.

  1. The Communicative Function of Ambiguity in Language

    ERIC Educational Resources Information Center

    Piantadosi, Steven T.; Tily, Harry; Gibson, Edward

    2012-01-01

    We present a general information-theoretic argument that all efficient communication systems will be ambiguous, assuming that context is informative about meaning. We also argue that ambiguity allows for greater ease of processing by permitting efficient linguistic units to be re-used. We test predictions of this theory in English, German, and…

  2. Ambiguous Words Are Harder to Learn

    ERIC Educational Resources Information Center

    Degani, Tamar; Tokowicz, Natasha

    2010-01-01

    Relatively little is known about the role of ambiguity in adult second-language learning. In this study, native English speakers learned Dutch-English translation pairs that either mapped in a one-to-one fashion (unambiguous items) in that a Dutch word uniquely corresponded to one English word, or mapped in a one-to-many fashion (ambiguous items),

  3. The Communicative Function of Ambiguity in Language

    ERIC Educational Resources Information Center

    Piantadosi, Steven T.; Tily, Harry; Gibson, Edward

    2012-01-01

    We present a general information-theoretic argument that all efficient communication systems will be ambiguous, assuming that context is informative about meaning. We also argue that ambiguity allows for greater ease of processing by permitting efficient linguistic units to be re-used. We test predictions of this theory in English, German, and

  4. Passive coherent location FPGA implementation of the cross ambiguity function

    NASA Astrophysics Data System (ADS)

    Kvasni?ka, Michal; He?mnek, Antonn; Kune, Michal; Pelant, Martin; Plek, Radek

    2006-02-01

    One of key problem in passive coherent location (PCL) is effective and accurate computation of the cross ambiguity function (CAF). This function is related to the direct signal and signals reflected from localized targets. PCL systems exploit high-power commercial transmitters of opportunity (FM, TV, etc.) to take advantage of lower frequencies, multistatic geometries and covert deployment. The transmitter does not have to cooperate with the receiver. The CAF represent power spectral density distribution of the cross-correlation between direct and reflected signals. It depends on mutual time delay and frequency shift of the input signals and is considerate as primary information for detection, localization and identification of the tracked targets. Regarding above mentioned reasons has to be important develop optimal (numerically effective and sufficiently accurate) implementation of the HW architecture based on FPGA for CAF computation, which will be suitable for future real-time PCL systems. As a first result which originates on the ongoing mutual cooperation between ERA a.s. and UTIA is design of the PC accelerator card for CAF computation based on Xilinx FPGA processor. The presented contribution gives overall information about used algorithms, FPGA accelerator card design and achieved performance. The future possibilities of the additional enhancements are discussed.

  5. Sequence data - Magnitude and implications of some ambiguities.

    NASA Technical Reports Server (NTRS)

    Holmquist, R.; Jukes, T. H.

    1972-01-01

    A stochastic model is applied to the divergence of the horse-pig lineage from a common ansestor in terms of the alpha and beta chains of hemoglobin and fibrinopeptides. The results are compared with those based on the minimum mutation distance model of Fitch (1972). Buckwheat and cauliflower cytochrome c sequences are analyzed to demonstrate their ambiguities. A comparative analysis of evolutionary rates for various proteins of horses and pigs shows that errors of considerable magnitude are introduced by Glx and Asx ambiguities into evolutionary conclusions drawn from sequences of incompletely analyzed proteins.

  6. Giving Students Feedback.

    ERIC Educational Resources Information Center

    Lowman, Joseph

    1987-01-01

    Some of the special challenges associated with evaluation and grading in the large class are discussed. Suggestions for evaluation methods include seeking clarity, reducing the stress of test administration, giving feedback, guarding against errors in record keeping, and returning exams efficiently and with respect. (MLW)

  7. Effect of ambiguities on SAR picture quality

    NASA Technical Reports Server (NTRS)

    Korwar, V. N.; Lipes, R. G.

    1978-01-01

    The degradation of picture quality in a high-resolution, large-swath SAR mapping system caused by speckle, additive white Gaussian noise and range and azimuthal ambiguities occurring because of the nonfinite antenna pattern produced by a square aperture antenna was studied and simulated. The effect of the azimuth antenna pattern was accounted for by calculating the azimuth ambiguity function. Range ambiguities were accounted for by adding, to each pixel of interest, appropriate pixels at a range separation corresponding to one pulse repetition period, but attenuated by the antenna pattern. It is concluded that azimuth ambiguities do not cause any noticeable degradation (for large time bandwidth product systems, at least) but range ambiguities might.

  8. A Two-Dimensional Variational Analysis Method for NSCAT Ambiguity Removal: Methodology, Sensitivity, and Tuning

    NASA Technical Reports Server (NTRS)

    Hoffman, R. N.; Leidner, S. M.; Henderson, J. M.; Atlas, R.; Ardizzone, J. V.; Bloom, S. C.; Atlas, Robert (Technical Monitor)

    2001-01-01

    In this study, we apply a two-dimensional variational analysis method (2d-VAR) to select a wind solution from NASA Scatterometer (NSCAT) ambiguous winds. 2d-VAR determines a "best" gridded surface wind analysis by minimizing a cost function. The cost function measures the misfit to the observations, the background, and the filtering and dynamical constraints. The ambiguity closest in direction to the minimizing analysis is selected. 2d-VAR method, sensitivity and numerical behavior are described. 2d-VAR is compared to statistical interpolation (OI) by examining the response of both systems to a single ship observation and to a swath of unique scatterometer winds. 2d-VAR is used with both NSCAT ambiguities and NSCAT backscatter values. Results are roughly comparable. When the background field is poor, 2d-VAR ambiguity removal often selects low probability ambiguities. To avoid this behavior, an initial 2d-VAR analysis, using only the two most likely ambiguities, provides the first guess for an analysis using all the ambiguities or the backscatter data. 2d-VAR and median filter selected ambiguities usually agree. Both methods require horizontal consistency, so disagreements occur in clumps, or as linear features. In these cases, 2d-VAR ambiguities are often more meteorologically reasonable and more consistent with satellite imagery.

  9. Processing Deliberate Ambiguity in Newspaper Headlines: Double Grounding

    ERIC Educational Resources Information Center

    Brone, Geert; Coulson, Seana

    2010-01-01

    Two experiments investigated the processing and appreciation of double grounding, a form of intentional ambiguity often used in the construction of headlines. For example, in "Russia takes the froth off Carlsberg results," the key element, "takes the froth off," is significant both metaphorically, where it refers to the detrimental impact of

  10. Processing Deliberate Ambiguity in Newspaper Headlines: Double Grounding

    ERIC Educational Resources Information Center

    Brone, Geert; Coulson, Seana

    2010-01-01

    Two experiments investigated the processing and appreciation of double grounding, a form of intentional ambiguity often used in the construction of headlines. For example, in "Russia takes the froth off Carlsberg results," the key element, "takes the froth off," is significant both metaphorically, where it refers to the detrimental impact of…

  11. Give unto others: genetically unrelated cotton-top tamarin monkeys preferentially give food to those who altruistically give food back.

    PubMed

    Hauser, Marc D; Chen, M Keith; Chen, Frances; Chuang, Emmeline

    2003-11-22

    Altruistic food giving among genetically unrelated individuals is rare in nature. The few examples that exist suggest that when animals give food to unrelated others, they may do so on the basis of mutualistic or reciprocally altruistic relationships. We present the results of four experiments designed to tease apart the factors mediating food giving among genetically unrelated cotton-top tamarins (Saguinus oedipus), a cooperatively breeding New World primate. In experiment 1 we show that individuals give significantly more food to a trained conspecific who unilaterally gives food than to a conspecific who unilaterally never gives food. The apparent contingency of the tamarins' food-giving behaviour motivated the design of experiments 2-4. Results from all three experiments show that altruistic food giving is mediated by prior acts of altruistic food giving by a conspecific. Specifically, tamarins do not give food to unrelated others when the food received in the past represents the by-product of another's selfish actions (experiments 2 and 3) or when a human experimenter gives them food (experiment 4) as did the unilateral altruist in experiment 1. By contrast, if one tamarin gives another food without obtaining any immediate benefit, then the recipient is more likely to give food in return. Overall, results show that tamarins altruistically give food to genetically unrelated conspecifics, discriminate between altruistic and selfish actions, and give more food to those who give food back. Tamarins therefore have the psychological capacity for reciprocally mediated altruism. PMID:14667352

  12. Give/Take

    Energy Science and Technology Software Center (ESTSC)

    2007-09-12

    Give and Take are set of companion utilities that allow a secure transfer of files from one user to another without exposing the files to third parties. The named files are copied to a spool area. The reciever can retrieve the files by running the "take" program. Ownership of the files remains with the giver until they are taken. Certain users may be limited to take files only from specific givers. For these users, filesmore » may only be taken from givers who are members of the gt-uid-group where uid is the UNIX id of the limited user.« less

  13. Typology of Ambiguity on Representation of Information Problem: An Exploratory Study.

    ERIC Educational Resources Information Center

    Kim, Yang-woo

    2003-01-01

    Develops a framework explaining the need to disambiguate user inquiries to improve information systems and services. Categorizes a set of questions according to ambiguity type. Discusses three aspects of retrieval systems and services, based on results of categorization: increasing user input to make initial queries less ambiguous; reducing search

  14. Can People Creative in Imagery Interpret Ambiguous Figures Faster than People Less Creative in Imagery?

    ERIC Educational Resources Information Center

    Riquelme, Hernan

    2002-01-01

    A study involving 47 Chinese managers investigated whether those who were creative in imagery were better at interpreting ambiguous figures. Results found managers who were creative in imagery were more capable in interpreting ambiguous figures and were quicker in their discoveries than managers less creative in imagery. (Contains references.)

  15. Fearing to give life.

    PubMed

    Wallace, B

    1992-01-01

    Fear of HIV infection and AIDS has contributed to the development of a global shortage, especially in Africa, of available blood for transfusions. Potential donors may be suspicious of the blood-giving process, that volunteer blood is sold, that those in need do not benefit, and of whether confidentiality will be maintained over their HIV status. Uncourteous and disaffected clinic workers have also contributed to donor erosion. Blood supplies must, however, be maintained in quantities adequate to meet patient needs around the world. With an over 90% probability of contracting HIV from 1 transfusion of infected blood, the importance of screening out potentially unsafe donors, recruiting from low risk populations, and discouraging high risk persons from donating should not be underestimated. To increase the available pool of willing and safe donors, sensitive and creative recruitment campaigns are suggested. Incentives which acknowledge donors' public spirit of giving, encouraging blood donations from prominent officials, and fostering regular education sessions from frequent donors are examples of potential strategies. Further, alternatives to transfusions should be encouraged where appropriate. Recruiters now target school-age youths in Zimbabwe and rural villagers in Rwanda as highly probably safe sources of blood. PMID:12284778

  16. Clock ambiguity and the emergence of physical laws

    SciTech Connect

    Albrecht, Andreas; Iglesias, Alberto

    2008-03-15

    The process of identifying a time variable in time-reparameterization invariant theories results in great ambiguities about the actual laws of physics described by a given theory. A theory set up to describe one set of physical laws can equally well be interpreted as describing any other laws of physics by making a different choice of time variable or clock. In this article we demonstrate how this 'clock ambiguity' arises and then discuss how one might still hope to extract specific predictions about the laws of physics even when the clock ambiguity is present. We argue that a requirement of quasiseparability should play a critical role in such an analysis. As a step in this direction, we compare the Hamiltonian of a local quantum field theory with a completely random Hamiltonian. We find that any random Hamiltonian (constructed in a sufficiently large space) can yield a 'good enough' approximation to a local field theory. Based on this result we argue that theories that suffer from the clock ambiguity may in the end provide a viable fundamental framework for physics in which locality can be seen as a strongly favored (or predicted) emergent behavior. We also speculate on how other key aspects of known physics such as gauge symmetries and Poincare invariance might be predicted to emerge in this framework.

  17. Resolving the ambiguity: Making sense of intrinsic disorder when PDB structures disagree.

    PubMed

    DeForte, Shelly; Uversky, Vladimir N

    2016-03-01

    Missing regions in X-ray crystal structures in the Protein Data Bank (PDB) have played a foundational role in the study of intrinsically disordered protein regions (IDPRs), especially in the development of in silico predictors of intrinsic disorder. However, a missing region is only a weak indication of intrinsic disorder, and this uncertainty is compounded by the presence of ambiguous regions, where more than one structure of the same protein sequence "disagrees" in terms of the presence or absence of missing residues. The question is this: are these ambiguous regions intrinsically disordered, or are they the result of static disorder that arises from experimental conditions, ensembles of structures, or domain wobbling? A novel way of looking at ambiguous regions in terms of the pattern between multiple PDB structures has been demonstrated. It was found that the propensity for intrinsic disorder increases as the level of ambiguity decreases. However, it is also shown that ambiguity is more likely to occur as the protein region is placed within different environmental conditions, and even the most ambiguous regions as a set display compositional bias that suggests flexibility. The results suggested that ambiguity is a natural result for many IDPRs crystallized under different conditions and that static disorder and wobbling domains are relatively rare. Instead, it is more likely that ambiguity arises because many of these regions were conditionally or partially disordered. PMID:26683124

  18. Ambiguities in spaceborne synthetic aperture radar systems

    NASA Technical Reports Server (NTRS)

    Li, F. K.; Johnson, W. T. K.

    1983-01-01

    An examination of aspects of spaceborne SAR time delay and Doppler ambiguities has led to the formulation of an accurate method for the evaluation of the ratio of ambiguity intensities to that of the signal, which has been applied to the nominal SAR system on Seasat. After discussing the variation of this ratio as a function of orbital latitude and attitude control error, it is shown that the detailed range migration-azimuth phase history of an ambiguity is different from that of a signal, so that the images of ambiguities are dispersed. Seasat SAR dispersed images are presented, and their dispersions are eliminated through an adjustment of the processing parameters. A method is also presented which uses a set of multiple pulse repetition sequences to determine the Doppler centroid frequency absolute values for SARs with high carrier frequencies and poor attitude measurements.

  19. Characterization of Ambiguity in Decision Making

    ERIC Educational Resources Information Center

    Yates, J. Frank; Zukowski, Lisa G.

    1976-01-01

    Describes a psychology experiment that investigated the effect of ambiguity on human decision-making behavior. (Available from Behavioral Science, University of Louisville, P.O. Box 1055, Louisville, KY 40201; $3.50 single copy.) (JG)

  20. Role Conflict and Ambiguity in Complex Organizations

    ERIC Educational Resources Information Center

    Rizzo, John R.; And Others

    1970-01-01

    Study describes the development and testing of questionnaire measures of role conflict and ambiguity. Analyses of responses of managers show these two constructs to be factorially identifiable and independent. (Author/KJ)

  1. Death: 'nothing' gives insight.

    PubMed

    Ettema, Eric J

    2013-08-01

    According to a widely accepted belief, we cannot know our own death--death means 'nothing' to us. At first sight, the meaning of 'nothing' just implies the negation or absence of 'something'. Death then simply refers to the negation or absence of life. As a consequence, however, death has no meaning of itself. This leads to an ontological paradox in which death is both acknowledged and denied: death is nothing. In this article, I investigate whether insight into the ontological paradox of the nothingness of death can contribute to a good end-of-life. By analysing Aquinas', Heidegger's and Derrida's understanding of death as nothingness, I explore how giving meaning to death on different ontological levels connects to, and at the same time provides resistance against, the harsh reality of death. By doing so, I intend to demonstrate that insight into the nothingness of death can count as a framework for a meaningful dealing with death. PMID:23054426

  2. Role ambiguity, employee gender, and workplace friendship.

    PubMed

    Chen, Chien-Yu; Mao, Hsiao-Yen; Hsieh, An-Tien

    2012-06-01

    The importance of workplace friendship is recognized by researchers and practitioners, but its antecedents with respect to work roles are not well understood. Employees' gender might moderate a relationship between work roles and friendships. Data from a survey of 221 international tourist hotel employees showed that a key aspect of job support, role ambiguity, was negatively related to having workplace friendships. However, employees' gender did not moderate this relationship. Role clarity (the opposite of role ambiguity) may facilitate workplace friendships. PMID:22897079

  3. Emolabeling effectively reduces the influence of ambiguous labeling on food packages among grocery store shoppers.

    PubMed

    Privitera, Gregory J; Brown, Caitlin J; Gillespie, James J

    2015-01-01

    Despite increased regulations and policy enforcement for nutrition labeling, ambiguous labels on food items can still have deleterious effects on consumer perceptions of health. The present study used a counterbalanced within-subjects design to test if emolabeling - the use of emoticons to convey health information (happy = healthy; sad = not healthy) - will reduce the effects of ambiguous labels on consumer perceptions of the healthfulness of a food item. 85 grocery store shoppers were shown nutrition labels for a low calorie (LC) and a high calorie (HC) food with/without emolabels, and with an ambiguous label that either implied the food was healthy or unhealthy. Results showed that emolabels reduced the effectiveness of ambiguous labels: consumers rated the LC food as healthier and the HC food as less healthy when emolabels were added. The results suggest that, if implemented, this image-based emolabeling system could possibly be an effective buffer against the use of ambiguous labeling by food manufacturers. PMID:25946913

  4. GNSS integer ambiguity validation based on posterior probability

    NASA Astrophysics Data System (ADS)

    Wu, Zemin; Bian, Shaofeng

    2015-10-01

    GNSS integer ambiguity validation is considered to be a challenge task for decades. Several kinds of validation tests are developed and widely used in these years, but theoretical basis is their weakness. Ambiguity validation theoretically is an issue of hypothesis test. In the frame of Bayesian hypothesis testing, posterior probability is the canonical standard that statistical decision should be based on. In this contribution, (i) we derive the posterior probability of the fixed ambiguity based on the Bayesian principle and modify it for practice ambiguity validation. (ii) The optimal property of the posterior probability test is proved based on an extended Neyman-Pearson lemma. Since validation failure rate is the issue users most concerned about, (iii) we derive the failure rate upper bound of the posterior probability test, so the user can use the posterior probability test either in the fixed posterior probability or in the fixed failure rate way. Simulated as well as real observed data are used for experimental validations. The results show that (i) the posterior probability test is the most effective within the R-ratio test, difference test, ellipsoidal integer aperture test and posterior probability test, (ii) the posterior probability test is computational efficient and (iii) the failure rate estimation for posterior probability test is useful.

  5. Recommendations for reducing ambiguity in written procedures.

    SciTech Connect

    Matzen, Laura E.

    2009-11-01

    Previous studies in the nuclear weapons complex have shown that ambiguous work instructions (WIs) and operating procedures (OPs) can lead to human error, which is a major cause for concern. This report outlines some of the sources of ambiguity in written English and describes three recommendations for reducing ambiguity in WIs and OPs. The recommendations are based on commonly used research techniques in the fields of linguistics and cognitive psychology. The first recommendation is to gather empirical data that can be used to improve the recommended word lists that are provided to technical writers. The second recommendation is to have a review in which new WIs and OPs and checked for ambiguities and clarity. The third recommendation is to use self-paced reading time studies to identify any remaining ambiguities before the new WIs and OPs are put into use. If these three steps are followed for new WIs and OPs, the likelihood of human errors related to ambiguity could be greatly reduced.

  6. Probability judgments under ambiguity and conflict

    PubMed Central

    Smithson, Michael

    2015-01-01

    Whether conflict and ambiguity are distinct kinds of uncertainty remains an open question, as does their joint impact on judgments of overall uncertainty. This paper reviews recent advances in our understanding of human judgment and decision making when both ambiguity and conflict are present, and presents two types of testable models of judgments under conflict and ambiguity. The first type concerns estimate-pooling to arrive at “best” probability estimates. The second type is models of subjective assessments of conflict and ambiguity. These models are developed for dealing with both described and experienced information. A framework for testing these models in the described-information setting is presented, including a reanalysis of a multi-nation data-set to test best-estimate models, and a study of participants' assessments of conflict, ambiguity, and overall uncertainty reported by Smithson (2013). A framework for research in the experienced-information setting is then developed, that differs substantially from extant paradigms in the literature. This framework yields new models of “best” estimates and perceived conflict. The paper concludes with specific suggestions for future research on judgment and decision making under conflict and ambiguity. PMID:26042081

  7. Event ambiguity fuels the effective spread of rumors

    NASA Astrophysics Data System (ADS)

    Xu, Jiuping; Zhang, Yi

    2015-08-01

    In this paper, a new rumor spreading model which quantifies a specific rumor spreading feature is proposed. The specific feature focused on is the important role the event ambiguity plays in the rumor spreading process. To study the impact of this event ambiguity on the spread of rumors, the probability p(t) that an individual becomes a rumor spreader from an initially unaware person at time t is built. p(t) reflects the extent of event ambiguity, and a parameter c of p(t) is used to measure the speed at which the event moves from ambiguity to confirmation. At the same time, a principle is given to decide on the correct value for parameter c A rumor spreading model is then developed with this function added as a parameter to the traditional model. Then, several rumor spreading model simulations are conducted with different values for c on both regular networks and ER random networks. The simulation results indicate that a rumor spreads faster and more broadly when c is smaller. This shows that if events are ambiguous over a longer time, rumor spreading appears to be more effective, and is influenced more significantly by parameter c in a random network than in a regular network. We then determine parameters of this model through data fitting of the missing Malaysian plane, and apply this model to an analysis of the missing Malaysian plane. The simulation results demonstrate that the most critical time for authorities to control rumor spreading is in the early stages of a critical event.

  8. Give Me... Your Huddled Masses...

    ERIC Educational Resources Information Center

    Wilkinson, Ray

    2000-01-01

    Explores the ambiguity in the attitudes of the U. S. and Canadian governments toward what are perceived as "real" refugees and more dubious asylum seekers. Outlines policies toward asylum seekers, points out inconsistencies, and notes some recently proposed changes in immigration law. (SLD)

  9. Learning the Language of Evolution: Lexical Ambiguity and Word Meaning in Student Explanations

    NASA Astrophysics Data System (ADS)

    Rector, Meghan A.; Nehm, Ross H.; Pearl, Dennis

    2013-06-01

    Our study investigates the challenges introduced by students' use of lexically ambiguous language in evolutionary explanations. Specifically, we examined students' meaning of five key terms incorporated into their written evolutionary explanations: pressure, select, adapt, need, and must. We utilized a new technological tool known as the Assessment Cascade System (ACS) to investigate the frequency with which biology majors spontaneously used lexically ambiguous language in evolutionary explanations, as well as their definitions and explanations of what they meant when they used such terms. Three categories of language were identified and examined in this study: terms with Dual Ambiguity, Incompatible Ambiguity, and Unintended Ambiguity. In the sample of 1282 initial evolutionary explanations, 81 % of students spontaneously incorporated lexically ambiguous language at least once. Furthermore, the majority of these initial responses were judged to be inaccurate from a scientific point of view. While not significantly related to gender, age, or reading/writing ability, students' use of contextually appropriate evolutionary language ( pressure and adapt) was significantly associated with academic performance in biology. Comparisons of initial responses to follow-up responses demonstrated that the majority of student explanations were not reinterpreted after consideration of the follow-up response; nevertheless, a sizeable minority was interpreted differently. Most cases of interpretation change were a consequence of resolving initially ambiguous responses, rather than a change of accuracy, resulting in an increased understanding of students' evolutionary explanations. We discuss a series of implications of lexical ambiguity for evolution education.

  10. Another model for giving.

    PubMed

    Bergman, Stanley M

    2008-12-01

    Most of the global healthcare issues facing us--from expanding access to care, to providing medical and dental care in the aftermath of disasters--are far too complex for any single sector to successfully solve. Industry, the healthcare profession, government, academia and non-governmental organizations (NGOs) are all limited in their scope and their ability to effectively address the necessary challenges of these multifaceted issues. It is only though public-private partnerships, in which the participants contribute resources and skills for which they individually are best suited, that true progress can be made in affecting change. In addition, every effort should be made to expand the pool of participants for these partnerships, including small and mid-sized organizations that may be inclined to help, but lack the experience or the infrastructure to initiate programs on their own. As the largest distributor of healthcare products and services to office-based practitioners in the combined North American and European markets, Henry Schein, Inc., is uniquely positioned to use its association with thousands of healthcare product manufacturers and its day-to-day relationships with more than 550,000 healthcare practices around the world to catalyze awareness of and support for important healthcare issues. Through Henry Schein's model for giving, the Company has been successful in forging new partnerships among industry, the healthcare profession, government, academia and NGOs, and in expanding existing ones to help meet the healthcare challenges facing us all. PMID:18781610

  11. European starlings unriddle the ambiguous-cue problem.

    PubMed

    Vasconcelos, Marco; Monteiro, Tiago

    2014-01-01

    The ambiguous-cue problem is deceptively simple. It involves two concurrently trained simultaneous discriminations (known as PA and NA trials), but only three stimuli. Stimulus A is common to both discriminations, but serves as non-reinforced stimulus (S-) on PA trials and as reinforced stimulus (S+) on NA trials. Typically, animals' accuracy is lower on PA trials-the ambiguous-cue effect. We conducted two experiments with European starlings (Sturnus vulgaris) using Urcuioli and Michalek's (2007, Psychon B Rev 14, 658-662) experimental manipulations as a springboard to test the predictions of two of the most important theoretical accounts of the effect: the interfering cue hypothesis and value transfer theory. Both experiments included two groups of birds, one trained with a regular ambiguous-cue problem (Group Continuous) and another trained with partial reinforcement on PA trials (Group PA-Partial). The experiments differed only in the number of sessions (18 vs. 36) and daily trials (360 vs. 60). As previously observed, we found faster acquisition on NA trials than on PA trials in both experiments, but by the end of training PA performance was surprisingly high, such that no ambiguous-cue effect was present in Group Continuous of either experiment. The effect was still present in both PA-Partial groups, but to a smaller degree than expected. These findings are inconsistent with the literature, in particular with the results of Urcuioli and Michalek (2007) with pigeons, and question the aforementioned theoretical accounts as complete explanations of the ambiguous-cue effect. In our view, to achieve such high levels of accuracy on PA trials, starlings must have attended to configural (i.e., contextual) cues, thus differentiating stimulus A when presented on PA trials from stimulus A when presented on NA trials. A post hoc simulation of a reinforcement-based configural model supported our assertion. PMID:25206346

  12. European starlings unriddle the ambiguous-cue problem

    PubMed Central

    Vasconcelos, Marco; Monteiro, Tiago

    2014-01-01

    The ambiguous-cue problem is deceptively simple. It involves two concurrently trained simultaneous discriminations (known as PA and NA trials), but only three stimuli. Stimulus A is common to both discriminations, but serves as non-reinforced stimulus (S-) on PA trials and as reinforced stimulus (S+) on NA trials. Typically, animals accuracy is lower on PA trialsthe ambiguous-cue effect. We conducted two experiments with European starlings (Sturnus vulgaris) using Urcuioli and Michaleks (2007, Psychon B Rev 14, 658662) experimental manipulations as a springboard to test the predictions of two of the most important theoretical accounts of the effect: the interfering cue hypothesis and value transfer theory. Both experiments included two groups of birds, one trained with a regular ambiguous-cue problem (Group Continuous) and another trained with partial reinforcement on PA trials (Group PA-Partial). The experiments differed only in the number of sessions (18 vs. 36) and daily trials (360 vs. 60). As previously observed, we found faster acquisition on NA trials than on PA trials in both experiments, but by the end of training PA performance was surprisingly high, such that no ambiguous-cue effect was present in Group Continuous of either experiment. The effect was still present in both PA-Partial groups, but to a smaller degree than expected. These findings are inconsistent with the literature, in particular with the results of Urcuioli and Michalek (2007) with pigeons, and question the aforementioned theoretical accounts as complete explanations of the ambiguous-cue effect. In our view, to achieve such high levels of accuracy on PA trials, starlings must have attended to configural (i.e., contextual) cues, thus differentiating stimulus A when presented on PA trials from stimulus A when presented on NA trials. A post hoc simulation of a reinforcement-based configural model supported our assertion. PMID:25206346

  13. Improved PPP ambiguity resolution by COES FCB estimation

    NASA Astrophysics Data System (ADS)

    Li, Yihe; Gao, Yang; Shi, Junbo

    2016-01-01

    Precise point positioning (PPP) integer ambiguity resolution is able to significantly improve the positioning accuracy with the correction of fractional cycle biases (FCBs) by shortening the time to first fix (TTFF) of ambiguities. When satellite orbit products are adopted to estimate the satellite FCB corrections, the narrow-lane (NL) FCB corrections will be contaminated by the orbit's line-of-sight (LOS) errors which subsequently affect ambiguity resolution (AR) performance, as well as positioning accuracy. To effectively separate orbit errors from satellite FCBs, we propose a cascaded orbit error separation (COES) method for the PPP implementation. Instead of using only one direction-independent component in previous studies, the satellite NL improved FCB corrections are modeled by one direction-independent component and three directional-dependent components per satellite in this study. More specifically, the direction-independent component assimilates actual FCBs, whereas the directional-dependent components are used to assimilate the orbit errors. To evaluate the performance of the proposed method, GPS measurements from a regional and a global network are processed with the IGSReal-time service (RTS), IGS rapid (IGR) products and predicted orbits with > 10 cm 3D root mean square (RMS) error. The improvements by the proposed FCB estimation method are validated in terms of ambiguity fractions after applying FCB corrections and positioning accuracy. The numerical results confirm that the obtained FCBs using the proposed method outperform those by conventional method. The RMS of ambiguity fractions after applying FCB corrections is reduced by 13.2 %. The position RMSs in north, east and up directions are reduced by 30.0, 32.0 and 22.0 % on average.

  14. Ambiguity Can Be Pragmatic, and a Good Thing, Too.

    ERIC Educational Resources Information Center

    Chen, Rong

    Both the speaker and hearer of a conversation can make use of ambiguity to achieve their special purpose in a given situation. The strategies stemming from pragmatic ambiguity offer distinct advantages to speakers and hearers. When dealing with ambiguity, linguists have concentrated on the source of ambiguity and how to analyze it. References to…

  15. Clarity and ambiguity in psychoanalytic practice.

    PubMed

    Szajnberg, Nathan

    2011-03-01

    The author explores the presence and the essential tension between clarity and ambiguity as processes within our minds that become prominent in psychoanalysis. We learn from aesthetics and literary criticism that ambiguity can shade from taut disorganization to tolerating life's richness; clarity can range from a concrete fixity to a lucid grasp of one's state of mind. This article responds to Wallerstein's (1991) challenge to find common ground in psychoanalytic practice: We attempt this by avoiding metapsychological jargon and relying on more experience-near terms, such as clarity and ambiguity. The article also refers to Sandler's (1983) concept of implicit theory-that psychoanalysts use "preconscious, overlapping but not fully integrated models" (Sandler, 1988, p. 388)-in this case explicating how clarity and ambiguity are frequent but implicit phenomena in clinical work. Identifying these and the essential tension between them permits us to both improve training and identify our clinical efforts. The analyst's and analysand's tolerance of the tension between clarity and ambiguity facilitates increased structuralization and emotional robustness. PMID:21500957

  16. How to Safely Give Ibuprofen

    MedlinePLUS

    ... Kids Deal With Bullies Pregnant? What to Expect How to Safely Give Ibuprofen KidsHealth > Parents > Doctors & Hospitals > ... of ibuprofen are available in similar forms. Continue How to Give When giving ibuprofen, refer to the ...

  17. Phalloplasty in Complete Aphallia and Ambiguous Genitalia

    PubMed Central

    Bluebond-Langner, Rachel; Redett, Richard J.

    2011-01-01

    The most common indications for phalloplasty in children include aphallia, micropenis/severe penile inadequacy, ambiguous genitalia, phallic inadequacy associated with epispadias/bladder exstrophy and female to male gender reassignment in adolescents. There are many surgical options for phalloplasty; both local pedicled tissue as well as free tissue transfer. The advantages of local tissue include a more concealed donor site, less complex operation and potentially faster recovery. However, pedicled options are generally less sensate, making placement of a penile prosthesis more risky and many children with bladder exstrophy have been previously operated upon making the blood supply for local pedicled flaps less reliable. This Here the authors discuss free tissue transfer, including the radial forearm, the anterolateral thigh, the scapula and latissimus, and the fibula free flaps, as well as local rotational flaps from the abdomen, groin, and thigh. The goal of reconstruction should be an aesthetic and functional (ability to penetrate) phallus, which provides tactile and erogenous sensation, and the ability to urinate standing. Ideally, the operation should be completed in one to two operations with minimal donor site morbidity. There are advantages and disadvantages of each of flap and thus the choice of donor site should be a combination of the patient's preference and surgeon's ability to produce a consistent result. PMID:22851911

  18. Raising Expectations, Giving Hope

    ERIC Educational Resources Information Center

    Principal Leadership, 2005

    2005-01-01

    "Hold school!" was the directive that Principal Patricia Ashmore received from the deputy superintendent of Madison County Schools when she was appointed to Velma Jackson Magnet High School five years ago. The explicit instruction came as a direct result of looking at student achievement, attendance, and graduation data that confirmed the need to

  19. Mentoring relationships and the levels of role conflict and role ambiguity experienced by novice nursing faculty.

    PubMed

    Specht, Jennifer A

    2013-01-01

    This study explored the effect of mentoring on the levels of role conflict and role ambiguity experienced by novice nursing faculty related to their transitions into academe using a descriptive, comparative design. It also measured the relationship between the quality of mentoring experiences of novice nursing faculty and their levels of role conflict and role ambiguity using a correlational design. P. Benner's (1984) novice to expert model was utilized as a framework for successful role transition. J. R. Rizzo, R. J. House, and S. I. Lirtzman's (1970) role conflict and role ambiguity scale was used to measure the levels of role conflict and role ambiguity experienced by novice nursing faculty. Results indicate that participants (n = 224) who were mentored have significantly lower levels of role conflict (M = 3.57) and role ambiguity (M = 3.02) than those who were not mentored (M = 4.62 and M = 3.90, respectively). Also significant, the higher the participants' reported levels of quality of mentoring experiences were, the lower their levels of role conflict and role ambiguity were. The results of this study indicate that mentoring eases the transition of novice nursing faculty from practice into academe by decreasing the degree of role ambiguity and role conflict that they experience. PMID:24075268

  20. The impact of fluctuations on the recognition of ambiguous patterns.

    PubMed

    Ditzinger, T; Haken, H

    1990-01-01

    The recognition of ambiguous patterns by humans is modelled by coupled differential equations which describe the formation of percepts by means of order parameters which in turn are determined by the saturation of attention parameters. We study the impact of fluctuations on the attention parameters and thus indirectly on the recognition of ambiguous patterns. Excellent agreement with psychophysical experimental results by Price on the transient behaviour of switching times and by Borsellino et al. on the distribution function of switching times as function of the size of the visual field is obtained. Our model allows us to deal also with the shift of width and position of the distribution function with respect to slow and fast observers in the sense of Borsellino. PMID:2257283

  1. Children's understanding of ambiguous idioms and conversational perspective-taking.

    PubMed

    Le Sourn-Bissaoui, Sandrine; Caillies, Stphanie; Bernard, Stphane; Deleau, Michel; Brul, Lauriane

    2012-08-01

    The aim of this study was to test the hypothesis that conversational perspective-taking is a determinant of unfamiliar ambiguous idiom comprehension. We investigated two types of ambiguous idiom, decomposable and nondecomposable expressions, which differ in the degree to which the literal meanings of the individual words contribute to the overall idiomatic meaning. We designed an experiment to assess the relationship between the acquisition of figurative comprehension and conversational perspective-taking. Our sample of children aged 5-7 years performed three conversational perspective-taking tasks (language acts, shared/unshared information, and conversational maxims). They then listened to decomposable and nondecomposable idiomatic expressions presented in context before performing a multiple-choice task (figurative, literal, and contextual responses). Results indicated that decomposable idiom comprehension was predicted by conversational perspective-taking scores and language skills, whereas nondecomposable idiom comprehension was predicted solely by language skills. We discuss our findings with respect to verbal and pragmatic skills. PMID:22542058

  2. Doppler shift and ambiguity velocity caused by relative motion in quantum-enhanced measurement.

    PubMed

    Shen, Yanghe; Xu, Luping; Zhang, Hua; Yang, Peng

    2015-07-13

    We study the effect of relative motion on a frequency-entangled-based ranging scheme. Two major puzzles arise, i.e., Doppler shift and ambiguity velocity. During condition of rapid relative motion, Doppler shift invalidates the measurement result of this scheme; while during condition of slow relative motion, the ambiguity velocity turns into a major limitation. If relative speed between targets and measurement platform exceeds the ambiguity velocity, an accumulated profile obtained by the coincidence measurement will be distorted, which causes a lower ranging accuracy. Theoretical analysis shows a time-varying delay can be introduced to solve the two major puzzles. PMID:26191903

  3. A new approach to modernized GPS phase-only ambiguity resolution over long baselines

    NASA Astrophysics Data System (ADS)

    Chu, Feng-Yu; Yang, Ming; Wu, Joz

    2015-10-01

    With the advent of modernized GPS, triple-frequency phase measurements (L1, L2, and L5) are available for civil use. The successful ambiguity resolution of the integer ambiguities of the phase measurements will be the key to centimeter-level positioning. In order to achieve ambiguity resolution over long baselines, code measurements (pseudorange) are regularly incorporated with the phase measurements in the observation model. However, code multipath affects ambiguity resolution and thus completely eliminating the influence is an important issue. Therefore, the present study proposes an approach that uses only the phase measurements in the observation model. The proposed approach has three steps and focuses on resolving the integer ambiguities of the triple-frequency phase measurements. Simulation baseline data were processed by the proposed approach and the results show that the integer ambiguities of the phase measurements can be successfully resolved and that satellite geometry is an important factor for the phase-only ambiguity resolution performance. Real triple-frequency GPS data from currently available Block IIF satellites were also processed to demonstrate the feasibility of the proposed approach.

  4. A new approach to modernized GPS phase-only ambiguity resolution over long baselines

    NASA Astrophysics Data System (ADS)

    Chu, Feng-Yu; Yang, Ming; Wu, Joz

    2016-03-01

    With the advent of modernized GPS, triple-frequency phase measurements (L1, L2, and L5) are available for civil use. The successful ambiguity resolution of the integer ambiguities of the phase measurements will be the key to centimeter-level positioning. In order to achieve ambiguity resolution over long baselines, code measurements (pseudorange) are regularly incorporated with the phase measurements in the observation model. However, code multipath affects ambiguity resolution and thus completely eliminating the influence is an important issue. Therefore, the present study proposes an approach that uses only the phase measurements in the observation model. The proposed approach has three steps and focuses on resolving the integer ambiguities of the triple-frequency phase measurements. Simulation baseline data were processed by the proposed approach and the results show that the integer ambiguities of the phase measurements can be successfully resolved and that satellite geometry is an important factor for the phase-only ambiguity resolution performance. Real triple-frequency GPS data from currently available Block IIF satellites were also processed to demonstrate the feasibility of the proposed approach.

  5. The effect of stereotypical primes on the neural processing of racially ambiguous faces.

    PubMed

    Dickter, Cheryl L; Kittel, Julie A

    2012-01-01

    Previous research has demonstrated that an early attentional component of the event-related potential (ERP), the P2, is sensitive to the distinction between the processing of racial outgroup and ingroup faces but may not be sensitive to the distinction between racially ambiguous and ingroup faces. Recent behavioral work, however, has suggested that contextual information may affect the processing of racially ambiguous faces. Thus, the first goal of this study was to examine whether the early neural processing of racially ambiguous faces would be affected by primed stereotypes. White college student participants (n = 29) completed a task in which they racially categorized monoracial Black and White faces and racially ambiguous Black-White morphs. These faces were preceded by positive and negative Black and White stereotypical primes. Results indicated that P2 amplitude to the racially ambiguous faces was moderated by the valence of the primes such that negative primes led to greater neural processing of the racially ambiguous faces than positive primes. Furthermore, the extent to which P2 amplitude was affected by prime valence was moderated by individual differences in preference for structure and categorical thinking, as well as comfort with ambiguity. PMID:22642396

  6. Do you like Arcimboldo's? Esthetic appreciation modulates brain activity in solving perceptual ambiguity.

    PubMed

    Boccia, M; Nemmi, F; Tizzani, E; Guariglia, C; Ferlazzo, F; Galati, G; Giannini, A M

    2015-02-01

    Esthetic experience is a unique, affectively colored, self-transcending subject-object relationship in which cognitive processing is felt to flow differently than during everyday experiences. Notwithstanding previous multidisciplinary investigations, how esthetic experience modulates perception is still obscure. We used Arcimboldo's ambiguous portraits to assess how the esthetic context organizes ambiguous percepts. The study was carried out using functional magnetic resonance imaging (fMRI) in healthy young volunteers (mean age 25.45; S.D. 4.51; 9 females), during both an explicit esthetic judgment task and an artwork/non-artwork classification task. We show that a distinct neural mechanism in the fusiform gyrus contributes to the esthetic experience of ambiguous portraits, according to the valence of the esthetic experience. Ambiguous artworks eliciting a negative esthetic experience lead to more pronounced activation of the fusiform face areas than ambiguous artworks eliciting a positive esthetic experience. We also found an interaction between task and ambiguity in the right superior parietal lobule. Taken together, our results demonstrate that a neural mechanism in the content-dependent brain regions of face processing underlies the esthetic experience of ambiguous portraits. Furthermore, they suggest that esthetic experience interacts with perceptual qualities of stimuli in the right superior parietal lobe, supporting the idea that esthetic experience arises from the interaction between top-down orienting of attention and bottom-up perceptual facilitation. PMID:25289490

  7. Dispositional sources of sanction perceptions: Emotionality, cognitive style, intolerance of ambiguity, and self-efficacy.

    PubMed

    Pickett, Justin T; Bushway, Shawn D

    2015-12-01

    This study contributes to efforts to identify the sources of arrest risk perceptions and ambiguity (or lack of confidence) in such perceptions. Drawing on dual-process theories of reasoning, we argue that arrest risk perceptions often represent intuitive judgments that are influenced by cognitive heuristics and dispositional attributes. Multivariate regression models are estimated with data from 3 national surveys to test 6 hypotheses about the relationships between specific dispositional attributes and perceived arrest risk and ambiguity. We find evidence that dispositional positive affect and intolerance of ambiguity are both positively related to perceived arrest risk, and are also both negatively related to ambiguity. We also find evidence that cognitive reflection and general self-efficacy are, respectively, positively and negatively associated with ambiguity. Mixed evidence emerges about whether cognitive reflection is related to risk perceptions, and about whether either dispositional negative affect or thoughtfully reflective decision making correlate with ambiguity. Taken together, the results provide partial support for each of our hypotheses, and suggest that dispositional attributes are important sources of perceptions of arrest risk as well as of ambiguity in such perceptions. (PsycINFO Database Record PMID:26375260

  8. Sensitivity to Referential Ambiguity in Discourse: The Role of Attention, Working Memory, and Verbal Ability

    PubMed Central

    Boudewyn, Megan A.; Long, Debra L.; Traxler, Matthew J.; Lesh, Tyler A.; Dave, Shruti; Mangun, George R.; Carter, Cameron S.; Swaab, Tamara Y.

    2016-01-01

    The establishment of reference is essential to language comprehension. The goal of this study was to examine listeners’ sensitivity to referential ambiguity as a function of individual variation in attention, working memory capacity, and verbal ability. Participants listened to stories in which two entities were introduced that were either very similar (e.g., two oaks) or less similar (e.g., one oak and one elm). The manipulation rendered an anaphor in a subsequent sentence (e.g., oak) ambiguous or unambiguous. EEG was recorded as listeners comprehended the story, after which participants completed tasks to assess working memory, verbal ability, and the ability to use context in task performance. Power in the alpha and theta frequency bands when listeners received critical information about the discourse entities (e.g., oaks) was used to index attention and the involvement of the working memory system in processing the entities. These measures were then used to predict an ERP component that is sensitive to referential ambiguity, the Nref, which was recorded when listeners received the anaphor. Nref amplitude at the anaphor was predicted by alpha power during the earlier critical sentence: Individuals with increased alpha power in ambiguous compared with unambiguous stories were less sensitive to the anaphor's ambiguity. Verbal ability was also predictive of greater sensitivity to referential ambiguity. Finally, increased theta power in the ambiguous compared with unambiguous condition was associated with higher working-memory span. These results highlight the role of attention and working memory in referential processing during listening comprehension. PMID:26401815

  9. Acute stress affects risk taking but not ambiguity aversion

    PubMed Central

    Buckert, Magdalena; Schwieren, Christiane; Kudielka, Brigitte M.; Fiebach, Christian J.

    2014-01-01

    Economic decisions are often made in stressful situations (e.g., at the trading floor), but the effects of stress on economic decision making have not been systematically investigated so far. The present study examines how acute stress influences economic decision making under uncertainty (risk and ambiguity) using financially incentivized lotteries. We varied the domain of decision making as well as the expected value of the risky prospect. Importantly, no feedback was provided to investigate risk taking and ambiguity aversion independent from learning processes. In a sample of 75 healthy young participants, 55 of whom underwent a stress induction protocol (Trier Social Stress Test for Groups), we observed more risk seeking for gains. This effect was restricted to a subgroup of participants that showed a robust cortisol response to acute stress (n = 26). Gambling under ambiguity, in contrast to gambling under risk, was not influenced by the cortisol response to stress. These results show that acute psychosocial stress affects economic decision making under risk, independent of learning processes. Our results further point to the importance of cortisol as a mediator of this effect. PMID:24834024

  10. Teachers' Burnout, Depression, Role Ambiguity and Conflict

    ERIC Educational Resources Information Center

    Papastylianou, Antonia; Kaila, Maria; Polychronopoulos, Michael

    2009-01-01

    The present study investigates issues associated with teachers' burnout in primary education as related to depression and role conflict-ambiguity. At the time of the study the participants (562 teachers) were working in seventy nine (79) Primary Education State Schools in Greece (Athens and two prefectures in the southern part of the country). The…

  11. Teachers' Burnout, Depression, Role Ambiguity and Conflict

    ERIC Educational Resources Information Center

    Papastylianou, Antonia; Kaila, Maria; Polychronopoulos, Michael

    2009-01-01

    The present study investigates issues associated with teachers' burnout in primary education as related to depression and role conflict-ambiguity. At the time of the study the participants (562 teachers) were working in seventy nine (79) Primary Education State Schools in Greece (Athens and two prefectures in the southern part of the country). The

  12. The Development of Ambiguous Figure Perception

    ERIC Educational Resources Information Center

    Wimmer, Marina C.; Doherty, Martin J.

    2011-01-01

    Ambiguous figures have fascinated researchers for almost 200 years. The physical properties of these figures remain constant, yet two distinct interpretations are possible; these reverse (switch) from one percept to the other. The consensus is that reversal requires complex interaction of perceptual bottom-up and cognitive top-down elements. The

  13. Actions and Affordances in Syntactic Ambiguity Resolution

    ERIC Educational Resources Information Center

    Chambers, Craig G.; Tanenhaus, Michael K.; Magnuson, James S.

    2004-01-01

    In 2 experiments, eye movements were monitored as participants followed instructions containing temporary syntactic ambiguities (e.g., "Pour the egg in the bowl over the flour"). The authors varied the affordances of task-relevant objects with respect to the action required by the instruction (e.g., whether 1 or both eggs in the visual workspace

  14. Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences

    PubMed Central

    Vitello, Sylvia; Warren, Jane E.; Devlin, Joseph T.; Rodd, Jennifer M.

    2014-01-01

    Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., “bark,” “bank”). Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG) and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretation of an ambiguous word. Here we used fMRI to investigate this hypothesis. 20 native British English monolinguals were scanned whilst listening to sentences that contained an ambiguous word. To induce semantic reinterpretation, the disambiguating information was presented after the ambiguous word and delayed until the end of the sentence (e.g., “the teacher explained that the BARK was going to be very damp”). These sentences were compared to well-matched unambiguous sentences. Supporting the reinterpretation hypothesis, these ambiguous sentences produced more activation in both the LIFG and the left posterior inferior temporal cortex. Importantly, all but one subject showed ambiguity-related peaks within both regions, demonstrating that the group-level results were driven by high inter-subject consistency. Further support came from the finding that activation in both regions was modulated by meaning dominance. Specifically, sentences containing biased ambiguous words, which have one more dominant meaning, produced greater activation than those with balanced ambiguous words, which have two equally frequent meanings. Because the context always supported the less frequent meaning, the biased words require reinterpretation more often than balanced words. This is the first evidence of dominance effects in the spoken modality and provides strong support that frontal and temporal regions support the updating of semantic representations during speech comprehension. PMID:25120445

  15. Charitable giving expenditures and the faith factor.

    PubMed

    Showers, Vince E; Showers, Linda S; Beggs, Jeri M; Cox, James E

    2011-01-01

    Using a permanent income hypothesis approach and an income-giving status interaction effect, a double hurdle model provides evidence of significant differences from the impact of household income and various household characteristics on both a household's likelihood of giving and its level of giving to religion, charity, education, others outside the household, and politics. An analysis of resulting income elasticity estimates revealed that households consider religious giving a necessity good at all levels of income, while other categories of giving are generally found to be luxury goods. Further, those who gave to religion were found to give more to education and charity then those not giving to religion, and higher education households were more likely to give to religion than households with less education. This analysis suggests that there may be more to religious giving behavior than has been assumed in prior studies and underscores the need for further research into the motivation for religious giving. Specifically, these findings point to an enduring, internal motivation for giving rather than an external, “What do I get for what I give,” motive. PMID:21322897

  16. Visual Working Memory Contents Bias Ambiguous Structure from Motion Perception

    PubMed Central

    Scocchia, Lisa; Valsecchi, Matteo; Gegenfurtner, Karl R.; Triesch, Jochen

    2013-01-01

    The way we perceive the visual world depends crucially on the state of the observer. In the present study we show that what we are holding in working memory (WM) can bias the way we perceive ambiguous structure from motion stimuli. Holding in memory the percept of an unambiguously rotating sphere influenced the perceived direction of motion of an ambiguously rotating sphere presented shortly thereafter. In particular, we found a systematic difference between congruent dominance periods where the perceived direction of the ambiguous stimulus corresponded to the direction of the unambiguous one and incongruent dominance periods. Congruent dominance periods were more frequent when participants memorized the speed of the unambiguous sphere for delayed discrimination than when they performed an immediate judgment on a change in its speed. The analysis of dominance time-course showed that a sustained tendency to perceive the same direction of motion as the prior stimulus emerged only in the WM condition, whereas in the attention condition perceptual dominance dropped to chance levels at the end of the trial. The results are explained in terms of a direct involvement of early visual areas in the active representation of visual motion in WM. PMID:23527141

  17. Textbook presentations of weight: Conceptual difficulties and language ambiguities

    NASA Astrophysics Data System (ADS)

    Taibu, Rex; Rudge, David; Schuster, David

    2015-06-01

    The term "weight" has multiple related meanings in both scientific and everyday usage. Even among experts and in textbooks, weight is ambiguously defined as either the gravitational force on an object or operationally as the magnitude of the force an object exerts on a measuring scale. This poses both conceptual and language difficulties for learners, especially for accelerating objects where the scale reading is different from the gravitational force. But while the underlying physical constructs behind the two referents for the term weight (and their relation to each other) are well understood scientifically, it is unclear how the concept of weight should be introduced to students and how the language ambiguities should be dealt with. We investigated treatments of weight in a sample of twenty introductory college physics textbooks, analyzing and coding their content based on the definition adopted, how the distinct constructs were dealt with in various situations, terminologies used, and whether and how language issues were handled. Results indicate that language-related issues, such as different, inconsistent, or ambiguous uses of the terms weight, "apparent weight," and "weightlessness," were prevalent both across and within textbooks. The physics of the related constructs was not always clearly presented, particularly for accelerating bodies such as astronauts in spaceships, and the language issue was rarely addressed. Our analysis of both literature and textbooks leads us to an instructional position which focuses on the physics constructs before introducing the term weight, and which explicitly discusses the associated language issues.

  18. Shale oil, water, and the politics of ambiguity

    SciTech Connect

    Prindle, D.F.

    1982-10-01

    This report examines the public policy problems surrounding the development of shale oil, focusing on the many difficulties associated with shale and water, and the attempts of private and public decisionmakers to deal with those problems. Deposits of shale oil in northwestern Colorado are so enormous that this fuel has the potential to liberate the United State from dependence on foreign sources of energy for many decades. Yet the technical, environmental, economic, and political problems facing the exploitation of this resource are themselves so great that they call into question the very possibility of development. Two themes dominate the discussion. The first and most important is ambiguity. Uncertainty pervades every discussion of shale oil and water, so much so that industry, academic, and political observers are unable to evaluate realistically the possible costs, benefits, and dangers of developing the shale resource. The second theme is complexity. The process of judging the opportunities and dangers of shale and water, and the political maneuvering surrounding this process, are almost endlessly complex. Ambiguity adds to complexity, and vice-versa. The result is that both private and public policymakers treat the subject of shale with extreme caution. Policy advances incrementally when it moves at all. There is also a discussion of some of the political fights surrounding shale policy, to help illustrate the ambiguity and complexity of the process.

  19. How to Safely Give Acetaminophen

    MedlinePLUS

    ... All About Food Allergies How to Safely Give Acetaminophen KidsHealth > For Parents > How to Safely Give Acetaminophen ... without getting a doctor's OK first. What Is Acetaminophen Also Called? Acetaminophen is the generic name of ...

  20. Zero-difference GPS ambiguity resolution at CNES-CLS IGS Analysis Center

    NASA Astrophysics Data System (ADS)

    Loyer, Sylvain; Perosanz, Flix; Mercier, Flavien; Capdeville, Hugues; Marty, Jean-Charles

    2012-11-01

    CNES (Centre National d'Etudes Spatiales) and CLS (Collecte Localisation Satellites) became an International GNSS Service (IGS) Analysis Center (AC) the 20th of May 2010. Since 2009, we are using the integer ambiguity fixing at the zero-difference level strategy in our software package (GINS/Dynamo) as an alternative to classical differential approaches. This method played a key role among all the improvements in the GPS processing we made during this period. This paper provides to the users the theoretical background, the strategies and the models used to compute the products (GPS orbits and clocks, weekly station coordinate estimates and Earth orientation parameters) that are submitted weekly to the IGS. The practical realization of the two-step, ambiguity-fixing scheme (wide-lane and narrow-lane) is described in detail. The ambiguity fixing improved our orbit overlaps from 6 to 3 cm WRMS in the tangential and normal directions. Since 2008, our products have been also regularly compared to the IGS final solutions by the IGS Analysis Center Coordinator. The joint effects of ambiguity fixing and dynamical model changes (satellite solar radiation pressure and albedo force) improved the consistency with IGS orbits from 35 to 18 mm 3D-WRMS. Our innovative strategy also gives additional powerful properties to the GPS satellite phase clock solutions. Single receiver (zero-difference) ambiguity resolution becomes possible. An overview of the applications is given.

  1. A table of geometrical ambiguities in powder indexing obtained by exhaustive search.

    PubMed

    Oishi-Tomiyasu, R

    2016-01-01

    Geometrical ambiguity means the cases in which more than one powder indexing solution exists. Using a new function implemented in the powder indexing software CONOGRAPH, unit cells that involve geometrical ambiguity are exhaustively searched. As a result, many unknown cases are obtained, although the number of such unit cells is still rather limited. It is also proven that the number of solutions in powder auto-indexing is not always unique, but generally finite. PMID:26697869

  2. Relation of tolerance of ambiguity to global and specific paranormal experience.

    PubMed

    Houran, J; Williams, C

    1998-12-01

    We examined the relationship of tolerance of ambiguity to severe global factors and specific types of anomalous or paranormal experience. 107 undergraduate students completed MacDonald's 1970 AT-20 and the Anomalous Experiences Inventory of Kumar, Pekala, and Gallagher. Scores on the five subscales of the Anomalous Experiences Inventory correlated differently with tolerance of ambiguity. Global paranormal beliefs, abilities, experiences, and drug use were positively associated with tolerance of ambiguity, whereas a fear of paranormal experience showed a negative relation. The specific types of anomalous experiences that correlated with tolerance of ambiguity often involved internal or physiological experience, e.g., precognitive dreams, memories of reincarnation, visual apparitions, and vestibular alterations. We generally found no effects of age of sex. These results are consistent with the idea that some paranormal experiences are misattributions of internal experience to external ('paranormal') sources, a process analogous to mechanisms underpinning delusions and hallucinations. PMID:9923156

  3. The processing of lexical ambiguity: homonymy and polysemy in the mental lexicon.

    PubMed

    Klepousniotou, Ekaterini

    2002-01-01

    Under the theoretical assumption that lexical ambiguity is not a homogeneous phenomenon, but rather that it is subdivided into two distinct types, namely homonymy and polysemy, the present study investigated whether these different types of lexical ambiguity are psychologically real. Four types of ambiguous words, homonymous words (e.g., "pen"), polysemous words with metaphorical extensions (e.g., "eye"), polysemous words with a count/mass metonymic extension (e.g., "turkey"), and polysemous words with a producer/product metonymic extension (e.g., "Dali"), were used in a cross-modal sentence-priming lexical decision task. Overall, the theoretical distinction between homonymy and polysemy was reflected in the results of the present study, which revealed differential processing depending on the type of ambiguity. PMID:12081393

  4. Perceptions of boundary ambiguity in the process of leaving an abusive partner.

    PubMed

    Khaw, Lyndal; Hardesty, Jennifer L

    2015-06-01

    The process of leaving an abusive partner has been theorized using the Stages of Change Model. Although useful, this model does not account for changes in relational boundaries unique to the process of leaving. Using family stress and feminist perspectives, this study sought to integrate boundary ambiguity into the Stages of Change Model. Boundary ambiguity is defined as a perception of uncertainty as to who is in or out of a family system (Boss & Greenberg, 1984). Twenty-five mothers who had temporarily or permanently left their abusers were interviewed. Data were analyzed using constructivist grounded theory methods. Results identify types, indicators of, and mothers' responses to boundary ambiguity throughout the five stages of change. Most mothers and abusers fluctuated between physical and psychological presence and absence over multiple separations. The integration of boundary ambiguity into the Stages of Change Model highlights the process of leaving an abusive partner as systemic, fluid, and nonlinear. PMID:25286330

  5. Queer sentences, ambiguity, and levels of processing.

    PubMed

    Mistler-Lachman, J L

    1975-07-01

    Subjects judged linguistic strings "meaningful" or "meaningless." Meaningful sentences were identical for all subjects; however, for each of five groups, meaningless foils containing different kinds of linguistic violation were interspersed among the meaningful sentences. Type of foil influenced processing time for meaningful items, suggesting that laboratory language processing may be determined by the entire set of linguistic materials used. Effect of foil type on comprehension depth for meaningful items was assessed from the extent to which three kinds of ambiguity slowed judgments on those items as compared to unambiguous sentences. Foil type appears to affect depth of meaningful sentence processing in such a way as to support a "levels of analysis" view of sentence comprehension. Foil type and kind of ambiguity interacted to suggest that sentence comprehension requires computation of underlying logical relationships prior to computation of surface structural relationships and the unequivocal determination of word meanings. PMID:21287093

  6. Steps in the Child's Grasp of Ambiguities through Word Play.

    ERIC Educational Resources Information Center

    Geller, Linda Gibson

    A study examined the differences in the appreciation of language ambiguity as represented in the word play of children aged 6 through 11 years. In six weekly play sessions, students were read stories containing many lexical ambiguities and pictures and were invited to verbalize and to draw similar ambiguities. Criteria necessary to the

  7. The Effect of Role Ambiguity on Competitive State Anxiety.

    ERIC Educational Resources Information Center

    Beauchamp, Mark R.; Bray, Steven R.; Eys, Mark A.; Carron, Albert V.

    2003-01-01

    Investigated the relationship between role ambiguity and precompetition state anxiety among high school athletes playing field hockey. Surveys of male and female field hockey players in the United Kingdom indicated that ambiguity concerning the scope of one's offensive responsibilities was predictive cognitive state anxiety, while ambiguity

  8. A Mixture Approach to Vagueness and Ambiguity

    PubMed Central

    Verheyen, Steven; Storms, Gert

    2013-01-01

    When asked to indicate which items from a set of candidates belong to a particular natural language category inter-individual differences occur: Individuals disagree which items should be considered category members. The premise of this paper is that these inter-individual differences in semantic categorization reflect both ambiguity and vagueness. Categorization differences are said to be due to ambiguity when individuals employ different criteria for categorization. For instance, individuals may disagree whether hiking or darts is the better example of sports because they emphasize respectively whether an activity is strenuous and whether rules apply. Categorization differences are said to be due to vagueness when individuals employ different cut-offs for separating members from non-members. For instance, the decision to include hiking in the sports category or not, may hinge on how strenuous different individuals require sports to be. This claim is supported by the application of a mixture model to categorization data for eight natural language categories. The mixture model can identify latent groups of categorizers who regard different items likely category members (i.e., ambiguity) with categorizers within each of the groups differing in their propensity to provide membership responses (i.e., vagueness). The identified subgroups are shown to emphasize different sets of category attributes when making their categorization decisions. PMID:23667627

  9. Disambiguation of ambiguous figures in the brain

    PubMed Central

    Ishizu, Tomohiro

    2013-01-01

    Disambiguation refers to the ability to interpret ambiguous information in a sensible way, which is important in an ever-changing external environment. Disambiguation occurs when prior knowledge is given before an ambiguous stimulus is presented. For example, labeling a series of meaningless blobs as a human body can change the observer's perception. The aim of this experiment was to study the neural circuitry underlying disambiguation caused by prior knowledge. We presented to participants a series of meaningless blobs with different contextual information. As participants performed this task, we used magnetoencephalography to map the brain areas that were activated when participants perceived blobs as a human body. The participants were presented identical sets of blob stimuli, and were instructed that a human body would appear more frequently in the high body condition than in the low body condition. We found the blob stimuli were more frequently perceived as the human body when they were presented in the high body condition. Such contextual modulation correlated with activity in the extrastriate body area (EBA) and the inferior frontal gyrus (IFG). Furthermore, we observed that IFG activation preceded EBA activation. These findings suggest that top-down processing in the IFG plays a role in disambiguating ambiguous information and modifying an individual's perceptions. PMID:24009570

  10. No reduction in instrumental vaginal births and no increased risk for adverse perineal outcome in nulliparous women giving birth on a birth seat: results of a Swedish randomized controlled trial

    PubMed Central

    2011-01-01

    Background The WHO advises against recumbent or supine position for longer periods during labour and birth and states that caregivers should encourage and support the woman to take the position in which she feels most comfortable. It has been suggested that upright positions may improve childbirth outcomes and reduce the risk for instrumental delivery; however RCTs of interventions to encourage upright positions are scarce. The aim of this study was to test, by means of a randomized controlled trial, the hypothesis that the use of a birthing seat during the second stage of labor, for healthy nulliparous women, decreases the number of instrumentally assisted births and may thus counterbalance any increase in perineal trauma and blood loss. Methods A randomized controlled trial in Sweden where 1002 women were randomized to birth on a birth seat (experimental group) or birth in any other position (control group). Data were collected between November 2006 and July 2009. The primary outcome measurement was the number of instrumental deliveries. Secondary outcome measurements included perineal lacerations, perineal edema, maternal blood loss and hemoglobin. Analysis was by intention to treat. Results The main findings of this study were that birth on the birth seat did not reduce the number of instrumental vaginal births, there was an increase in blood loss between 500 ml and 1000 ml in women who gave birth on the seat but no increase in bleeding over 1000 ml and no increase in perineal lacerations or perineal edema. Conclusions The birth seat did not reduce the number of instrumental vaginal births. The study confirmed an increased blood loss 500 ml - 1000 ml but not over 1000 ml for women giving birth on the seat. Giving birth on a birth seat caused no adverse consequences for perineal outcomes and may even be protective against episiotomies. Trial registration number ClinicalTrials.gov.ID: NCT01182038 PMID:21435238

  11. Human Perception of Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Zhang, Guan-Lu

    2010-01-01

    Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that the GIF resolution hypothesis is completely valid for non-rotational periodic motions. Additionally, human perception of translation is impaired without visual or spatial reference. The performance of ground-base subjects in estimating tilt after brief training is comparable with that of crewmembers without training.

  12. Ionosphere influence on success rate of GPS ambiguity resolution in a satellite formation flying

    NASA Astrophysics Data System (ADS)

    Baroni, Leandro

    2015-10-01

    Satellite formation flying is one of the most promising technologies for future space missions. The distribution of sensors and payloads among different satellites provides more redundancy, flexibility, improved communication coverage, among other advantages. One of the fundamental issues in spacecraft formation flying is precise position and velocity determination between satellites. For missions in low Earth orbits, GPS system can meet the precision requirement in relative positioning, since the satellite dynamics is modeled properly. The key for high accuracy GPS relative positioning is to resolve the ambiguities to their integer values. Ambiguities resolved successfully can improve the positioning accuracy to decimetre or even millimetre-level. So, integer carrier phase ambiguity resolution is often a prerequisite for high precision GPS positioning. The determination of relative position was made using an extended Kalman filter. The filter must take into account imperfections in dynamic modeling of perturbations affecting the orbital flight, and changes in solar activity that affects the GPS signal propagation, for mitigating these effects on relative positioning accuracy. Thus, this work aims to evaluate the impact of ionosphere variation, caused by changes in solar activity, in success rate of ambiguity resolution. Using the Ambiguity Dilution of Precision (ADOP) concept, the ambiguity success rate is analyzed and the expected precision of the ambiguity-fixed solution is calculated. Evaluations were performed using actual data from GRACE mission and analyzed for their performance in real scenarios. Analyses were conducted in different configurations of relative position and during different levels of solar activity. Results bring the impact of various disturbances and modeling of solar activity level on the success rate of ambiguity resolution.

  13. The Inertial Attitude Augmentation for Ambiguity Resolution in SF/SE-GNSS Attitude Determination

    PubMed Central

    Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

    2014-01-01

    The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation. PMID:24971472

  14. A study of potential sources of linguistic ambiguity in written work instructions.

    SciTech Connect

    Matzen, Laura E.

    2009-11-01

    This report describes the results of a small experimental study that investigated potential sources of ambiguity in written work instructions (WIs). The English language can be highly ambiguous because words with different meanings can share the same spelling. Previous studies in the nuclear weapons complex have shown that ambiguous WIs can lead to human error, which is a major cause for concern. To study possible sources of ambiguity in WIs, we determined which of the recommended action verbs in the DOE and BWXT writer's manuals have numerous meanings to their intended audience, making them potentially ambiguous. We used cognitive psychology techniques to conduct a survey in which technicians who use WIs in their jobs indicated the first meaning that came to mind for each of the words. Although the findings of this study are limited by the small number of respondents, we identified words that had many different meanings even within this limited sample. WI writers should pay particular attention to these words and to their most frequent meanings so that they can avoid ambiguity in their writing.

  15. Planned Giving for Catholic Schools.

    ERIC Educational Resources Information Center

    Bourbeau, Mary Ann

    Good development officers in elementary and high schools need to be aware of planned giving and knowledgeable about a variety of gift categories. Most school-development directors are not experts in this complex field. Yet, when a school decides to initiate a planned-giving program, the director of development must make a serious commitment to

  16. Utilitarian relevance and face management in the interpretation of ambiguous question/request statements.

    PubMed

    Demeure, Virginie; Bonnefon, Jean-François; Raufaste, Eric

    2008-06-01

    Often, requests are made in an indirect manner and phrased in such a way that they can also be construed as questions. For example, the sentence "Is there any coffee left?" can be construed either as a question about coffee or as a request for coffee. This article offers a combined test of some key predictions of two approaches to the disambiguation of question/request statements: (1) the face management approach, which gives a prominent role to variables such as status and potential loss of face; and (2) the utilitarian relevance approach, which gives a prominent role to the goals pursued by the speaker at the time he or she issues the statement. Ambiguous question/request statements provide a natural test bed for the latter approach in particular. A board game paradigm is developed to allow for a clean, orthogonal manipulation of all variables. The results wholly support the utilitarian relevance approach and offer new perspectives on the face management approach. PMID:18604968

  17. A United Methodist approach to end-of-life decisions: intentional ambiguity or ambiguous intentions.

    PubMed

    Thobaben, James R

    1997-12-01

    The position of the United Methodist Church on end-of-life decisions is best described as intentional ambiguity or ambiguous intentions or both. The paper analyzes the official position of the denomination and then considers the actions of a U.M.C. bishop who served as a foreman for a trial of Dr. Jack Kevorkian. In an effort to find some common ground within an increasingly divided denomination, the work concludes with a consideration of the work of John Wesley and his approach to human death. PMID:11655315

  18. Simply Imagining Sunshine, Lollipops and Rainbows Will Not Budge the Bias: The Role of Ambiguity in Interpretive Bias Modification.

    PubMed

    Clarke, Patrick J F; Nanthakumar, Shenooka; Notebaert, Lies; Holmes, Emily A; Blackwell, Simon E; Macleod, Colin

    2014-01-01

    Imagery-based interpretive bias modification (CBM-I) involves repeatedly imagining scenarios that are initially ambiguous before being resolved as either positive or negative in the last word/s. While the presence of such ambiguity is assumed to be important to achieve change in selective interpretation, it is also possible that the act of repeatedly imagining positive or negative events could produce such change in the absence of ambiguity. The present study sought to examine whether the ambiguity in imagery-based CBM-I is necessary to elicit change in interpretive bias, or, if the emotional content of the imagined scenarios is sufficient to produce such change. An imagery-based CBM-I task was delivered to participants in one of four conditions, where the valence of imagined scenarios were either positive or negative, and the ambiguity of the scenario was either present (until the last word/s) or the ambiguity was absent (emotional valence was evident from the start). Results indicate that only those who received scenarios in which the ambiguity was present acquired an interpretive bias consistent with the emotional valence of the scenarios, suggesting that the act of imagining positive or negative events will only influence patterns of interpretation when the emotional ambiguity is a consistent feature. PMID:24634553

  19. GNSS triple-frequency geometry-free and ionosphere-free track-to-track ambiguities

    NASA Astrophysics Data System (ADS)

    Wang, Kan; Rothacher, Markus

    2015-06-01

    During the last few years, more and more GNSS satellites have become available sending signals on three or even more frequencies. Examples are the GPS Block IIF and the Galileo In-Orbit-Validation (IOV) satellites. Various investigations have been performed to make use of the increasing number of frequencies to find a compromise between eliminating different error sources and minimizing the noise level, including the investigations in the triple-frequency geometry-free (GF) and ionosphere-free (IF) linear combinations, which eliminate all the geometry-related errors and the first-order term of the ionospheric delays. In contrast to the double-difference GF and IF ambiguity resolution, the resolution of the so-called track-to-track GF and IF ambiguities between two tracks of a satellite observed by the same station only requires one receiver and one satellite. Most of the remaining errors like receiver and satellite delays (electronics, cables, etc.) are eliminated, if they are not changing rapidly in time, and the noise level is reduced theoretically by a factor of square root of two compared to double-differences. This paper presents first results concerning track-to-track ambiguity resolution using triple-frequency GF and IF linear combinations based on data from the Multi-GNSS Experiment (MGEX) from April 29 to May 9, 2012 and from December 23 to December 29, 2012. This includes triple-frequency phase and code observations with different combinations of receiver tracking modes. The results show that it is possible to resolve the combined track-to-track ambiguities of the best two triple-frequency GF and IF linear combinations for the Galileo frequency triplet E1, E5b and E5a with more than 99.6% of the fractional ambiguities for the best linear combination being located within ± 0.03 cycles and more than 98.8% of the fractional ambiguities for the second best linear combination within ± 0.2 cycles, while the fractional parts of the ambiguities for the GPS frequency triplet L1, L2 and L5 are more disturbed by errors as e.g. the uncalibrated Phase Center Offsets (PCOs) and Phase Center Variations (PCVs), that have not been considered. The best two GF and IF linear combinations between tracks are helpful to detect problems in data and receivers. Furthermore, resolving the track-to-track ambiguities is helpful to connect the single-receiver ambiguities on the normal equation level and to improve ambiguity resolution.

  20. Effects of pitch accents in attachment ambiguity resolution

    PubMed Central

    Lee, Eun-Kyung; Watson, Duane G.

    2011-01-01

    Previous work has found that listeners prefer to attach ambiguous syntactic constituents to nouns produced with a pitch accent (Schafer et al., 1996). This study examines what factors underlie previously established accent attachment effects by testing whether these effects are driven by a preference to attach syntactic constituents to new or important information (the Syntax Hypothesis) or whether there is a bias to respond to post-sentence probe questions with an accented word (the Salience Hypothesis). One of the predictions of the Salience Hypothesis is that selection of accented words should be greater when a sentence is complex and processing resources are limited. The results from the experiments presented here show that the probability of listeners’ selecting accented words when asked about the interpretation of a relative clause varies with sentence type: listeners selected accented words more frequently in long sentences than in short sentences, consistent with the predictions of the Salience Hypothesis. Furthermore, Experiment 4 demonstrates that listeners are more likely to respond to post-sentence questions with accented words than with non-accented words, even when no ambiguity is present, and even when the response results in an incorrect answer. These findings suggest that accent-driven attachment effects found in earlier studies reflect a post-sentence selection process rather than a syntactic processing mechanism. PMID:22287815

  1. Utilization of Prosodic Information in Syntactic Ambiguity Resolution

    PubMed Central

    2010-01-01

    Two self paced listening experiments examined the role of prosodic phrasing in syntactic ambiguity resolution. In Experiment 1, the stimuli consisted of early closure sentences (e.g., “While the parents watched, the child sang a song.”) containing transitive-biased subordinate verbs paired with plausible direct objects or intransitive-biased subordinate verbs paired with implausible direct objects. Experiment 2 also contained early closure sentences with transitively and intransitive-biased subordinate verbs, but the subordinate verbs were always followed by plausible direct objects. In both experiments, there were two prosodic conditions. In the subject-biased prosodic condition, an intonational phrase boundary marked the clausal boundary following the subordinate verb. In the object-biased prosodic condition, the clause boundary was unmarked. The results indicate that lexical and prosodic cues interact at the subordinate verb and plausibility further affects processing at the ambiguous noun. Results are discussed with respect to models of the role of prosody in sentence comprehension. PMID:20033849

  2. Immirzi ambiguity in the kinematics of quantum general relativity

    NASA Astrophysics Data System (ADS)

    Garay, Luis J.; Mena Marugn, Guillermo A.

    2002-07-01

    The Immirzi ambiguity arises in loop quantum gravity when geometric operators are represented in terms of different connections that are related by means of an extended Wick transform. We analyze the action of this transform in gravity coupled with matter fields and discuss its analogy with the Wick rotation on which the Thiemann transform between Euclidean and Lorentzian gravity is based. In addition, we prove that the effect of this extended Wick transform is equivalent to a constant scale transformation as far as the symplectic structure and kinematical constraints are concerned. This equivalence is broken in the dynamical evolution. Our results are applied to the discussion of the black hole entropy in the limit of large horizon areas. We first argue that, since the entropy calculation is performed for horizons of fixed constant area, one might in principle choose an Immirzi parameter that depends on this quantity. This would spoil the linearity with the area in the entropy formula. We then show that the Immirzi parameter appears as a constant scaling in all the steps where dynamical information plays a relevant role in the entropy calculation. This fact, together with the kinematical equivalence of the Immirzi ambiguity with a change of scale, is used to preclude the potential nonlinearity of the entropy on physical grounds.

  3. Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Clement, G. R.; Harm, D L.; Rupert, A. H.; Guedry, F. E.; Reschke, M. F.

    2005-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. For example, the semicircular canals, vision and neck proprioception provide information about head tilt on orbit without the normal otolith head-tilt position that is omnipresent on Earth. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

  4. Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Clement, G. R.; Harm, D. L.; Rupert, A. H.; Guedry, F. E.; Reschke, M. F.

    2005-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Our general hypothesis is that the central nervous system utilizes both multi-sensory integration and frequency segregation as neural strategies to resolve the ambiguity of tilt and translation stimuli. Movement in an altered gravity environment, such as weightlessness without a stable gravity reference, results in new patterns of sensory cues. For example, the semicircular canals, vision and neck proprioception provide information about head tilt on orbit without the normal otolith head-tilt position that is omnipresent on Earth. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth's gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of disorientation and tilt-translation disturbances reported by crewmembers during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

  5. Is ambiguity tolerance malleable? Experimental evidence with potential implications for future research

    PubMed Central

    Endres, Megan L.; Camp, Richaurd; Milner, Morgan

    2015-01-01

    We conducted two research studies to address the malleability of tolerance of ambiguity (TA) by manipulating situational ambiguity. Students participated in a semester-end assessment of their management skills (n = 306). In Study 1, students in low and moderate ambiguity conditions had significantly higher post-experiment TA, more positive change in self-efficacy, and marginally higher faculty ratings. In Study 2, a control group (n = 103) did not participate in the assessment and was established for comparison to the first study results. The Study 2 students reported TA significantly lower than Study 1 students in the low and moderate ambiguity conditions. The control group TA was not significantly different from that of the Study 1 high ambiguity condition. This further suggested TAs situational malleability, as those who had controlled access to structured information appeared to have increased their TA over that observed in the other two groups. These results suggest that TA may be malleable. We review the relevant literature, offer hypotheses, report our analyses and findings, and then propose future research, and potential prescriptive applications in such areas as management development, assessment, and decision-making. PMID:26042059

  6. The New Planned Giving Officer.

    ERIC Educational Resources Information Center

    Jordan, Ronald R.; Quynn, Katelyn L.

    1994-01-01

    A planned giving officer is seen as an asset to college/university development for technical expertise, credibility, and connections. Attorneys, certified public accountants, bank trust officers, financial planners, investment advisers, life insurance agents, and real estate brokers may be qualified but probably also need training. (MSE)

  7. Giving Psychology Away Is Expensive

    ERIC Educational Resources Information Center

    Gorsuch, Richard L.; Wallace, William L.

    2005-01-01

    This article presents comments on "Does Psychology make a significant difference in our lives?" by P. Zimbardo. We deeply appreciate the documentation and inspiration provided by Zimbardo on how psychology is reaching out to the public by "giving psychology away" (p. 340). We totally agree that psychology has much, much more to offer that could be

  8. Corporate Change and Corporate Giving.

    ERIC Educational Resources Information Center

    Pollack, Rachel H.; Toward, Christopher

    1999-01-01

    With each merger or corporate restructuring comes the possibility that corporate giving to higher education will suffer. A combination of patience, understanding of the processes at work in corporate change, and regular contact with affected companies can help position the college or university to make the most of any outcome. (MSE)

  9. Dealing with the Ambiguities of Science Inquiry

    NASA Astrophysics Data System (ADS)

    Tan, Yuen Sze Michelle; Caleon, Imelda Santos

    2016-03-01

    The current vision of science education in myriad educational contexts encourages students to learn through the process of science inquiry. Science inquiry has been used to promote conceptual learning and engage learners in an active process of meaning-making and investigation to understand the world around them. The science inquiry process typically involves asking questions and defining problems; constructing explanations and designing solutions; planning and carrying out investigations; analyzing and interpreting data; and engaging in argument from evidence. Despite the importance and provision of new directions and standards about science inquiry, ambiguities in conceptualizations of inquiry still exist. These conceptualizations may serve as barriers to students learning science. In this article, we detail three main concerns related to teachers' conceptualization of science inquiry in the context of a Singapore classroom—concerns that may be similarly faced by teachers elsewhere.

  10. Ambiguity resolution for satellite Doppler positioning systems

    NASA Technical Reports Server (NTRS)

    Argentiero, P. D.; Marini, J. W.

    1977-01-01

    A test for ambiguity resolution was derived which was the most powerful in the sense that it maximized the probability of a correct decision. When systematic error sources were properly included in the least squares reduction process to yield an optimal solution, the test reduced to choosing the solution which provided the smaller valuation of the least squares loss function. When systematic error sources were ignored in the least squares reduction, the most powerful test was a quadratic form comparison with the weighting matrix of the quadratic form obtained by computing the pseudo-inverse of a reduced rank square matrix. A formula is presented for computing the power of the most powerful test. A numerical example is included in which the power of the test is computed for a situation which may occur during an actual satellite aided search and rescue mission.

  11. How ambiguous is the local kinetic energy?

    PubMed

    Anderson, James S M; Ayers, Paul W; Hernandez, Juan I Rodriguez

    2010-08-26

    The local kinetic energy and the closely related local electronic stress tensor are commonly used to elucidate chemical bonding patterns, especially for covalent bonds. We use three different approaches-transformation properties of the stress tensor, quasiprobability distributions, and the virial theorem from density-functional theory-to clarify the inherent ambiguity in these quantities, discussing the implications for analyses based on the local kinetic energy and stress tensor. An expansive-but not universal-family of local kinetic energy forms that includes the most common choices and is suitable for both chemical-bonding and atoms-in-molecule analysis is derived. A family of local electronic stress tensors is also derived. Several local kinetic energy functions that are mathematically justified, but unlikely to be conceptually useful, are derived. The implications of these forms for atoms-in-molecule analysis are discussed. PMID:20586467

  12. Decreasing Ambiguity of the Safety Culture Concept

    SciTech Connect

    Inoue, Shiichiro; Hosoda, Satoshi; Suganuma, Takashi; Monta, Kazuo; Kameda, Akiyuki

    2001-06-17

    The status of the concept of ''safety culture'' is reviewed. It has not sufficiently taken root. One cause for this is the abstract nature of the concept. Organizations must become aware of the necessity of improving safety and have sufficient power to promote this. The culture of safety must be instilled in each employee, so that each of them will feel responsible for identifying weak points in plant safety. The authors devised a tool for a self-assessment of the safety culture. The tool will bring to light information divides, communication gaps, etc. Recognizing the vulnerabilities of the organization by themselves and discussing these weak points among them is the first step to decrease the ambiguity of the safety culture. The next step is to make these gaps known along with agreed-upon countermeasures. The concept of safety culture will be greatly clarified in this way and lead to safer nuclear power plants.

  13. Random unitaries give quantum expanders

    SciTech Connect

    Hastings, M. B.

    2007-09-15

    We show that randomly choosing the matrices in a completely positive map from the unitary group gives a quantum expander. We consider Hermitian and non-Hermitian cases, and we provide asymptotically tight bounds in the Hermitian case on the typical value of the second largest eigenvalue. The key idea is the use of Schwinger-Dyson equations from lattice gauge theory to efficiently compute averages over the unitary group.

  14. Impressions of people with gender-ambiguous male or female first names.

    PubMed

    McKelvie, Stuart J; Waterhouse, Kelly

    2005-10-01

    Undergraduates (12 men, 12 women) read a scenario in which they formed an impression of nine people who had left their first name on an answering machine. Participants rated the extent to which seven characteristics (Ethical, Caring, Popular, Cheerful, Successful, Masculine, Feminine) applied to people whose first names were gender-ambiguous (e.g., Chris), male (e.g., Ken) or female (e.g., Pam). People with gender-ambiguous names were rated less Ethical than those with female names, and people with gender-ambiguous names and male names were rated less Caring, less Cheerful, and less Feminine than those with female names. These results are consistent with the idea that there is a bias towards assuming that a person of unspecified sex is a male. PMID:16383061

  15. Effect of ambiguity and lexical availability on syntactic and lexical production.

    PubMed

    Ferreira, V S; Dell, G S

    2000-06-01

    Speakers only sometimes include the that in sentence complement structures like The coach knew (that) you missed practice. Six experiments tested the predictions concerning optional word mention of two general approaches to language production. One approach claims that language production processes choose syntactic structures that ease the task of creating sentences, so that words are spoken opportunistically, as they are selected for production. The second approach claims that a syntactic structure is chosen that is easiest to comprehend, so that optional words like that are used to avoid temporarily ambiguous, difficult-to-comprehend sentences. In all experiments, speakers did not consistently include optional words to circumvent a temporary ambiguity, but they did omit optional words (the complementizer that) when subsequent material was either repeated (within a sentence) or prompted with a recall cue. The results suggest that speakers choose syntactic structures to permit early mention of available material and not to circumvent disruptive temporary ambiguities. PMID:10888342

  16. Propagation and wavefront ambiguity of linear nondiffracting beams

    NASA Astrophysics Data System (ADS)

    Grunwald, R.; Bock, M.

    2014-02-01

    Ultrashort-pulsed Bessel and Airy beams in free space are often interpreted as "linear light bullets". Usually, interconnected intensity profiles are considered a "propagation" along arbitrary pathways which can even follow curved trajectories. A more detailed analysis, however, shows that this picture gives an adequate description only in situations which do not require to consider the transport of optical signals or causality. To also cover these special cases, a generalization of the terms "beam" and "propagation" is necessary. The problem becomes clearer by representing the angular spectra of the propagating wave fields by rays or Poynting vectors. It is known that quasi-nondiffracting beams can be described as caustics of ray bundles. Their decomposition into Poynting vectors by Shack-Hartmann sensors indicates that, in the frame of their classical definition, the corresponding local wavefronts are ambiguous and concepts based on energy density are not appropriate to describe the propagation completely. For this reason, quantitative parameters like the beam propagation factor have to be treated with caution as well. For applications like communication or optical computing, alternative descriptions are required. A heuristic approach based on vector field based information transport and Fourier analysis is proposed here. Continuity and discontinuity of far field distributions in space and time are discussed. Quantum aspects of propagation are briefly addressed.

  17. The Learning Teacher: Role of Ambiguity in Education

    ERIC Educational Resources Information Center

    Suzawa, Gilbert S.

    2013-01-01

    Life is full of ambiguities, but as teachers we generally try to teach our students in a manner that sanitizes knowledge of all of its ambiguities. In doing so, we create an educational environment which forces students to learn in a rather meaningless fashion and this in turn leads to a lack of vitality and relevance within the academy. This need

  18. Examining English-German Translation Ambiguity Using Primed Translation Recognition

    ERIC Educational Resources Information Center

    Eddington, Chelsea M.; Tokowicz, Natasha

    2013-01-01

    Many words have more than one translation across languages. Such "translation-ambiguous" words are translated more slowly and less accurately than their unambiguous counterparts. We examine the extent to which word context and translation dominance influence the processing of translation-ambiguous words. We further examine how these factors

  19. Kindergarten Children Can Be Taught to Detect Lexical Ambiguities

    ERIC Educational Resources Information Center

    Kamowski-Shakibai, Margaret T.; Cairns, Helen Smith

    2016-01-01

    This study investigates the development of metalinguistic skills, particularly ambiguity detection, and whether training accelerates this development for prereaders in kindergarten (5;5-6;6). It is the first to compare homophone detection with lexically ambiguous sentence detection in which the same homophones appear. The experimental group…

  20. U.S./Arab Reflections on Our Tolerance for Ambiguity

    ERIC Educational Resources Information Center

    Bright, Larry K.; Mahdi, Ghada S.

    2012-01-01

    As the authors, a Midwestern American educational administration professor and a Middle Eastern Iraqi doctoral candidate, have continued to interact over the past 3 years, both have come to appreciate the importance of increasing their tolerance for ambiguity--ambiguities in examining cultural, linguistic, and religious customs and complexities in

  1. Detecting the Ambiguity of Sentences: Relationship to Early Reading Skill

    ERIC Educational Resources Information Center

    Cairns, Helen Smith; Waltzman, Dava; Schlisselberg, Gloria

    2004-01-01

    The authors of this article report on a preliminary study of 18, 4- and 5-year-old children, followed by a longitudinal study of 44 children, who were tested in the first, second, and third grades. The children's ability to detect the ambiguity of lexically ambiguous sentences (e. g., "The children saw the bat lying by the fence") and structurally

  2. GLONASS ionosphere-free ambiguity resolution for precise point positioning

    NASA Astrophysics Data System (ADS)

    Banville, Simon

    2016-02-01

    Current GLONASS satellites transmit signals based on the frequency division multiple access (FDMA) technology. Due to equipment delays occurring within GNSS receivers, GLONASS carrier phase and code observations are contaminated by inter-frequency biases. As a consequence, GLONASS ambiguity parameters in long-baseline processing are typically estimated as float values. In this paper, a strategy is investigated which benefits from the frequency spacing of GLONASS frequencies on the L1 and L2 bands, allowing for an ionosphere-free ambiguity with a wavelength of approximately 5 cm to be defined; therefore, avoiding the problematic wide-lane ambiguity resolution. Based on 12 independent baselines with a mean inter-station distance of about 850 km over a 1-week period, it is demonstrated that close to 95 % of the estimated double-differenced ionosphere-free ambiguities are within 0.15 cycles of an integer, thereby suggesting that long-baseline ambiguity resolution can be achieved for GLONASS. Applying between-station ambiguity constraints in precise point positioning (PPP) solutions was found to improve longitudinal repeatability in static mode by more than 20 % for sessions between 2 and 6 h in duration. In kinematic mode, only limited improvements were made to the initial convergence period since the short wavelength of GLONASS ionosphere-free ambiguities requires the solution to be nearly converged before successful ambiguity resolution can be achieved.

  3. Cognitive Flexibility Supports Preschoolers' Detection of Communicative Ambiguity

    ERIC Educational Resources Information Center

    Gillis, Randall; Nilsen, Elizabeth S.

    2014-01-01

    To become successful communicators, children must be sensitive to the clarity/ambiguity of language. Significant gains in children's ability to detect communicative ambiguity occur during the early school-age years. However, little is known about the cognitive abilities that support this development. Relations between cognitive flexibility and

  4. U.S./Arab Reflections on Our Tolerance for Ambiguity

    ERIC Educational Resources Information Center

    Bright, Larry K.; Mahdi, Ghada S.

    2012-01-01

    As the authors, a Midwestern American educational administration professor and a Middle Eastern Iraqi doctoral candidate, have continued to interact over the past 3 years, both have come to appreciate the importance of increasing their tolerance for ambiguity--ambiguities in examining cultural, linguistic, and religious customs and complexities in…

  5. The Role of Verb Information in Syntactic Ambiguity Resolution.

    ERIC Educational Resources Information Center

    Kennison, Shelia M.

    This study, consisting of two experiments, investigated the role of verb information in resolving ambiguous noun phrases (NPs) in reading comprehension. Both experiments extended earlier studies. The first measured and compared reading time for sentences containing temporarily ambiguous subject complements and unambiguous complements, which were

  6. Children's Understanding of Ambiguous Idioms and Conversational Perspective-Taking

    ERIC Educational Resources Information Center

    Le Sourn-Bissaoui, Sandrine; Caillies, Stephanie; Bernard, Stephane; Deleau, Michel; Brule, Lauriane

    2012-01-01

    The aim of this study was to test the hypothesis that conversational perspective-taking is a determinant of unfamiliar ambiguous idiom comprehension. We investigated two types of ambiguous idiom, decomposable and nondecomposable expressions, which differ in the degree to which the literal meanings of the individual words contribute to the overall

  7. Quantification Scope Ambiguity Resolution: Evidence from Persian and English

    ERIC Educational Resources Information Center

    Asadollahfam, Hassan; Lotfi, Ahmad Reza

    2010-01-01

    This study investigates the interpretation of scopally ambiguous sentences containing noun phrases with double quantified constituents from a processing perspective. The questions this study tried to answer were: whether or not the preferred interpretation for doubly quantified ambiguous sentences in English was influenced by English learners' L1…

  8. Tolerance of ambiguity and fear of the paranormal.

    PubMed

    Houran, J; Lange, R

    1996-10-01

    Houran, et al's model for haunting phenomena predicts that fear of "paranormal phenomena" is associated with intolerance of ambiguity. Consistent with this prediction, ratings by 86 undergraduates (14 men and 72 women) showed a correlation of 33 between the scores on the Anomalous Experiences Inventory and the Rydell Rosen Ambiguity Tolerance Scale. PMID:8902004

  9. How Do Adults and Children Process Referentially Ambiguous Pronouns?

    ERIC Educational Resources Information Center

    Sekerina, Irina A.; Stromswold, Karin; Hestvik, Arild

    2004-01-01

    In two eye-tracking experiments, we investigate adults' and children's on-line processing of referentially ambiguous English pronouns. Sixteen adults and 16 four-to-seven-year-olds listened to sentences with either an unambiguous reflexive ("himself") or an ambiguous pronoun ("him") and chose a picture with two characters that corresponded to…

  10. Not So Black and White: Memory for Ambiguous Group Members

    PubMed Central

    Pauker, Kristin; Weisbuch, Max; Ambady, Nalini; Sommers, Samuel R; Ivcevic, Zorana; Adams, Reginald B

    2013-01-01

    Exponential increases in multi-racial identities expected over the next century, creates a conundrum for perceivers accustomed to classifying people as “own” or “other” race. The current research examines how perceivers resolve this dilemma with regard to the “own-race bias.” We hypothesized that perceivers would not be motivated to include ambiguous-race individuals in the in-group and would therefore have some difficulty remembering them. Both racially-ambiguous and other-race faces were misremembered more often than own-race faces (Study 1), though memory for ambiguous faces was improved among perceivers motivated to include biracial individuals in the in-group (Study 2). Racial labels assigned to racially ambiguous faces determined memory for these faces, suggesting that uncertainty provides the motivational context for discounting ambiguous faces in memory (Study 3). Finally, an inclusion motivation fostered cognitive associations between racially-ambiguous faces and the in-group. Moreover, the extent to which perceivers associated racially-ambiguous faces with the in-group predicted memory for ambiguous faces and accounted for the impact of motivation on memory (Study 4). Thus, memory for biracial individuals seems to involve a flexible person construal process shaped by motivational factors. PMID:19309203

  11. Top-Down Influence in Young Children's Linguistic Ambiguity Resolution

    ERIC Educational Resources Information Center

    Rabagliati, Hugh; Pylkkanen, Liina; Marcus, Gary F.

    2013-01-01

    Language is rife with ambiguity. Do children and adults meet this challenge in similar ways? Recent work suggests that while adults resolve syntactic ambiguities by integrating a variety of cues, children are less sensitive to top-down evidence. We test whether this top-down insensitivity is specific to syntax or a general feature of children's…

  12. Top-Down Influence in Young Children's Linguistic Ambiguity Resolution

    ERIC Educational Resources Information Center

    Rabagliati, Hugh; Pylkkanen, Liina; Marcus, Gary F.

    2013-01-01

    Language is rife with ambiguity. Do children and adults meet this challenge in similar ways? Recent work suggests that while adults resolve syntactic ambiguities by integrating a variety of cues, children are less sensitive to top-down evidence. We test whether this top-down insensitivity is specific to syntax or a general feature of children's

  13. Modelling the Effects of Semantic Ambiguity in Word Recognition

    ERIC Educational Resources Information Center

    Rodd, Jennifer M.; Gaskell, M. Gareth; Marslen-Wilson, William D.

    2004-01-01

    Most words in English are ambiguous between different interpretations; words can mean different things in different contexts. We investigate the implications of different types of semantic ambiguity for connectionist models of word recognition. We present a model in which there is competition to activate distributed semantic representations. The

  14. The Effect of Role Ambiguity on Competitive State Anxiety.

    ERIC Educational Resources Information Center

    Beauchamp, Mark R.; Bray, Steven R.; Eys, Mark A.; Carron, Albert V.

    2003-01-01

    Investigated the relationship between role ambiguity and precompetition state anxiety among high school athletes playing field hockey. Surveys of male and female field hockey players in the United Kingdom indicated that ambiguity concerning the scope of one's offensive responsibilities was predictive cognitive state anxiety, while ambiguity…

  15. Children's Uncertainty about the Interpretation of Ambiguous Messages.

    ERIC Educational Resources Information Center

    Robinson, E. J.; Robinson, W. P.

    1983-01-01

    Investigates the ability of 63 children between five and six years of age to interpret ambiguous messages. Three studies were made into the relationship between children's uncertainty about the correctness of their interpretation of an ambiguous message and their judgment of the quality of that message. (Author/CI)

  16. Who is respectful? Effects of social context and individual empathic ability on ambiguity resolution during utterance comprehension

    PubMed Central

    Jiang, Xiaoming; Zhou, Xiaolin

    2015-01-01

    Verbal communication is often ambiguous. By employing the event-related potential (ERP) technique, this study investigated how a comprehender resolves referential ambiguity by using information concerning the social status of communicators. Participants read a conversational scenario which included a minimal conversational context describing a speaker and two other persons of the same or different social status and a directly quoted utterance. A singular, second-person pronoun in the respectful form (nin/nin-de in Chinese) in the utterance could be ambiguous with respect to which of the two persons was the addressee (the “Ambiguous condition”). Alternatively, the pronoun was not ambiguous either because one of the two persons was of higher social status and hence should be the addressee according to social convention (the “Status condition”) or because a word referring to the status of a person was additionally inserted before the pronoun to help indicate the referent of the pronoun (the “Referent condition”). Results showed that the perceived ambiguity decreased over the Ambiguous, Status, and Referent conditions. Electrophysiologically, the pronoun elicited an increased N400 in the Referent than in the Status and the Ambiguous conditions, reflecting an increased integration demand due to the necessity of linking the pronoun to both its antecedent and the status word. Relative to the Referent condition, a late, sustained positivity was elicited for the Status condition starting from 600 ms, while a more delayed, anterior negativity was elicited for the Ambiguous condition. Moreover, the N400 effect was modulated by individuals' sensitivity to the social status information, while the late positivity effect was modulated by individuals' empathic ability. These findings highlight the neurocognitive flexibility of contextual bias in referential processing during utterance comprehension. PMID:26557102

  17. Who is respectful? Effects of social context and individual empathic ability on ambiguity resolution during utterance comprehension.

    PubMed

    Jiang, Xiaoming; Zhou, Xiaolin

    2015-01-01

    Verbal communication is often ambiguous. By employing the event-related potential (ERP) technique, this study investigated how a comprehender resolves referential ambiguity by using information concerning the social status of communicators. Participants read a conversational scenario which included a minimal conversational context describing a speaker and two other persons of the same or different social status and a directly quoted utterance. A singular, second-person pronoun in the respectful form (nin/nin-de in Chinese) in the utterance could be ambiguous with respect to which of the two persons was the addressee (the "Ambiguous condition"). Alternatively, the pronoun was not ambiguous either because one of the two persons was of higher social status and hence should be the addressee according to social convention (the "Status condition") or because a word referring to the status of a person was additionally inserted before the pronoun to help indicate the referent of the pronoun (the "Referent condition"). Results showed that the perceived ambiguity decreased over the Ambiguous, Status, and Referent conditions. Electrophysiologically, the pronoun elicited an increased N400 in the Referent than in the Status and the Ambiguous conditions, reflecting an increased integration demand due to the necessity of linking the pronoun to both its antecedent and the status word. Relative to the Referent condition, a late, sustained positivity was elicited for the Status condition starting from 600 ms, while a more delayed, anterior negativity was elicited for the Ambiguous condition. Moreover, the N400 effect was modulated by individuals' sensitivity to the social status information, while the late positivity effect was modulated by individuals' empathic ability. These findings highlight the neurocognitive flexibility of contextual bias in referential processing during utterance comprehension. PMID:26557102

  18. Competitive helping in online giving.

    PubMed

    Raihani, Nichola J; Smith, Sarah

    2015-05-01

    Unconditional generosity in humans is a puzzle. One possibility is that individuals benefit from being seen as generous if there is competition for access to partners and if generosity is a costly-and therefore reliable-signal of partner quality [1-3]. The "competitive helping" hypothesis predicts that people will compete to be the most generous, particularly in the presence of attractive potential partners [1]. However, this key prediction has not been directly tested. Using data from online fundraising pages, we demonstrate competitive helping in the real world. Donations to fundraising pages are public and made sequentially. Donors can therefore respond to the behavior of previous donors, creating a potential generosity tournament. Our test of the competitive helping hypothesis focuses on the response to large, visible donations. We show that male donors show significantly stronger responses (by donating more) when they are donating to an attractive female fundraiser and responding to a large donation made by another male donor. The responses for this condition are around four times greater than when males give to less-attractive female (or male) fundraisers or when they respond to a large donation made by a female donor. Unlike males, females do not compete in donations when giving to attractive male fundraisers. These data suggest that males use competitive helping displays in the presence of attractive females and suggest a role for sexual selection in explaining unconditional generosity. PMID:25891407

  19. Ambiguous Loss in a Non-Western Context: Families of the Disappeared in Postconflict Nepal

    ERIC Educational Resources Information Center

    Robins, Simon

    2010-01-01

    Ambiguous loss has become a standard theory for understanding the impact of situations where the presence of a family member is subject to ambiguity. A number of studies of ambiguous loss have been made in a range of situations of ambiguity, but almost all have been firmly located within a Western cultural context. Here, ambiguous loss is explored

  20. Local hardness equalization: Exploiting the ambiguity

    NASA Astrophysics Data System (ADS)

    Ayers, Paul W.; Parr, Robert G.

    2008-05-01

    In the density-functional theory of chemical reactivity, the local hardness is known to be an ambiguous concept. The mathematical structure associated with this problematic situation is elaborated and three common definitions for the local hardness are critically examined: the frontier local hardness [S. K. Ghosh, Chem. Phys. Lett. 172, 77 (1990)], the total local hardness [S. K. Ghosh and M. Berkowitz, J. Chem. Phys. 83, 2976 (1985)], and the unconstrained local hardness [P. W. Ayers and R. G. Parr, J. Am. Chem. Soc. 122, 2010 (2000)]. The frontier local hardness has particularly nice properties: (a) it has smaller norm than most, if not all, other choices of the local hardness and (b) it is "unbiased" in an information-theoretic sense. For the ground electronic state of a molecular system, the frontier local hardness is equal to the global hardness. For an electronic system in its ground state, both the chemical potential and the frontier local hardness are equalized. The frontier local hardness equalization principle provides a computational approach for designing reagents with desirable chemical reactivity profiles.

  1. Ambiguity resolution for satellite Doppler positioning systems

    NASA Technical Reports Server (NTRS)

    Argentiero, P.; Marini, J.

    1979-01-01

    The implementation of satellite-based Doppler positioning systems frequently requires the recovery of transmitter position from a single pass of Doppler data. The least-squares approach to the problem yields conjugate solutions on either side of the satellite subtrack. It is important to develop a procedure for choosing the proper solution which is correct in a high percentage of cases. A test for ambiguity resolution which is the most powerful in the sense that it maximizes the probability of a correct decision is derived. When systematic error sources are properly included in the least-squares reduction process to yield an optimal solution the test reduces to choosing the solution which provides the smaller valuation of the least-squares loss function. When systematic error sources are ignored in the least-squares reduction, the most powerful test is a quadratic form comparison with the weighting matrix of the quadratic form obtained by computing the pseudoinverse of a reduced-rank square matrix. A formula for computing the power of the most powerful test is provided. Numerical examples are included in which the power of the test is computed for situations that are relevant to the design of a satellite-aided search and rescue system.

  2. The ambiguity in ray perturbation theory

    SciTech Connect

    Snieder, R.; Sambridge, M. |

    1993-12-01

    Ray perturbation theory is concerned with the change in ray paths and travel times due to changes in the slowness model or the end-point conditions of rays. Several different formulations of ray perturbation theory have been developed. Even for the same physical problem different perturbation equations have been derived. The reason for this is that ray perturbation theory contains a fundamental ambiguity. One can move a point along a curve without changing the shape of the curve. This means that the mapping from a reference curve to a perturbed curve is not uniquely defined, because on may associated a point on the reference curve with different points on the perturbed curve. The mapping that is used is usually defined implicitly by the choice of the coordinate system or the independent parameter. In this paper, a fomalism is developed where one can specify explicitly the mapping from the reference curve to the perturbed curve by choosing a stretch factor that relates increments in arc length along the reference curve and the perturbed curve. This is incorporated in a theory that is accurate to first order in the ray position and to second order in the travel time. The second order travel time perturbation describes the effect of changes in the position of the ray on the travel time. In the formulation of this paper, paraxial ray perturbations, slowness perturbations, and pure ray bending are treated in a uniform fashion. This may be very useful in nonlinear tomographic inversions which include earthquake relocation.

  3. Responses of A and B Subjects to Normal, Neurotic, Schizophrenic, and Ambiguous Communications

    ERIC Educational Resources Information Center

    Hoffnung, Robert J.; Stein, Leonard S.

    1970-01-01

    This study investigated the initial reactions of 20 A and 20 B Ss to encounter situations in which they were asked for help by four hypothetical patients communicating in normal, neurotic, schizophrenic, or ambiguous styles. The results were related to previous A and B findings. (Author)

  4. Essentialist Thinking Predicts Decrements in Children's Memory for Racially Ambiguous Faces

    ERIC Educational Resources Information Center

    Gaither, Sarah E.; Schultz, Jennifer R.; Pauker, Kristin; Sommers, Samuel R.; Maddox, Keith B.; Ambady, Nalini

    2014-01-01

    Past research shows that adults often display poor memory for racially ambiguous and racial outgroup faces, with both face types remembered worse than own-race faces. In the present study, the authors examined whether children also show this pattern of results. They also examined whether emerging essentialist thinking about race predicts

  5. Resolving the 180-degree ambiguity in vector magnetic field measurements: The 'minimum' energy solution

    NASA Technical Reports Server (NTRS)

    Metcalf, Thomas R.

    1994-01-01

    I present a robust algorithm that resolves the 180-deg ambiguity in measurements of the solar vector magnetic field. The technique simultaneously minimizes both the divergence of the magnetic field and the electric current density using a simulated annealing algorithm. This results in the field orientation with approximately minimum free energy. The technique is well-founded physically and is simple to implement.

  6. Effect of Prefrontal Cortex Damage on Resolving Lexical Ambiguity in Text

    ERIC Educational Resources Information Center

    Frattali, Carol; Hanna, Rebecca; McGinty, Anita Shukla; Gerber, Lynn; Wesley, Robert; Grafman, Jordan; Coelho, Carl

    2007-01-01

    The function of suppression of context-inappropriate meanings during lexical ambiguity resolution was examined in 25 adults with prefrontal cortex damage (PFCD) localized to the left (N = 8), right (N = 6), or bilaterally (N = 11); and 21 matched Controls. Results revealed unexpected inverse patterns of suppression between PFCD and Control groups,…

  7. Practice makes perfect: Training the interpretation of emotional ambiguity.

    PubMed

    Clifton, Jessica L; Hedley, Sophie; Mountier, Emily; Tiszai, Boglarka; Grimshaw, Gina M

    2016-06-01

    The interpretation of emotionally ambiguous words, sentences, or scenarios can be altered through training procedures that are collectively called cognitive bias modification for interpretation (CBM-I). In three experiments, we systematically manipulated the nature of the training in order to discriminate between emotional priming and ambiguity resolution accounts of training effects. In Experiment 1 participants completed word fragments that were consistently related to either a negative or benign interpretation of an ambiguous sentence. In a subsequent semantic priming task they demonstrated an interpretation bias, in that they were faster to identify relatedness of targets that were associated with the training-congruent meaning of an emotionally ambiguous homograph. We then manipulated the training sentences to show that interpretation bias was eliminated when participants simply completed valenced word fragments following unrelated sentences (Experiment 2), or completed fragments that were related to emotional but unambiguous sentences (Experiment 3). Only when participants were required to actively resolve emotionally ambiguous sentences during training did changes in interpretation emerge at test. Findings suggest that CBM-I achieves its effects by altering a production rule that aids the selection of meaning from emotionally ambiguous alternatives, in line with an ambiguity resolution account. PMID:25807872

  8. Quadri-stability of a spatially ambiguous auditory illusion

    PubMed Central

    Bainbridge, Constance M.; Bainbridge, Wilma A.; Oliva, Aude

    2014-01-01

    In addition to vision, audition plays an important role in sound localization in our world. One way we estimate the motion of an auditory object moving towards or away from us is from changes in volume intensity. However, the human auditory system has unequally distributed spatial resolution, including difficulty distinguishing sounds in front vs. behind the listener. Here, we introduce a novel quadri-stable illusion, the Transverse-and-Bounce Auditory Illusion, which combines front-back confusion with changes in volume levels of a nonspatial sound to create ambiguous percepts of an object approaching and withdrawing from the listener. The sound can be perceived as traveling transversely from front to back or back to front, or bouncing to remain exclusively in front of or behind the observer. Here we demonstrate how human listeners experience this illusory phenomenon by comparing ambiguous and unambiguous stimuli for each of the four possible motion percepts. When asked to rate their confidence in perceiving each sounds motion, participants reported equal confidence for the illusory and unambiguous stimuli. Participants perceived all four illusory motion percepts, and could not distinguish the illusion from the unambiguous stimuli. These results show that this illusion is effectively quadri-stable. In a second experiment, the illusory stimulus was looped continuously in headphones while participants identified its perceived path of motion to test properties of perceptual switching, locking, and biases. Participants were biased towards perceiving transverse compared to bouncing paths, and they became perceptually locked into alternating between front-to-back and back-to-front percepts, perhaps reflecting how auditory objects commonly move in the real world. This multi-stable auditory illusion opens opportunities for studying the perceptual, cognitive, and neural representation of objects in motion, as well as exploring multimodal perceptual awareness. PMID:25642180

  9. Ambiguity and the image of the king.

    PubMed

    Mack, R T

    1994-01-01

    The following essay explores problems posed by a recently-published fresco (dated to the first century AD) that depicts Alexander the Great standing opposite an unknown female figure. The fresco is unusual in its use of conventional or codified figure types, in particular a widely-found statue type known as the "Alexander with the Lance," and for its placement of Alexander in anecdotal relation with a woman. While discussions of the picture thus far have tried to identify the scene depicted (by reference to histories of Alexander's life), the following analysis takes the difficulty of doing so itself as a motivated aspect of the image. I argue that the fresco's mode of representation is to bring together figure types whose conventional fields of meaning are in conflict with one another, and then to highlight this conflict in order to comment upon the fields (or figure types) themselves. In this case, the fresco's ambiguity in signification (the undecidability of its reference) enables a highly strategic critique of the "Alexander with the Lance" because the latter, as a prototypical "image of the king," depends upon the necessary and transparent extension of its signs. By virtue of the anecdotal relation between "Alexander" and the depicted female figure (an Aphrodite type) the fresco's critique reveals the close association between the claims for representation made by the image of the king and the patriarchal structures of power they seek to instantiate. The fresco thus offers remarkably direct data for understanding the intersection of representation and gender in the early Roman empire. I suggest in conclusion that because the image seems also to posit a specifically gendered (male) gaze, its critique is extended to the spectator and thereby provides data for understanding the intersection of the practice of representation (here, viewing) and gender. PMID:7798598

  10. Reaction Order Ambiguity in Integrated Rate Plots

    ERIC Educational Resources Information Center

    Lee, Joe

    2008-01-01

    Integrated rate plots are frequently used in reaction kinetics to determine orders of reactions. It is often emphasised, when using this methodology in practice, that it is necessary to monitor the reaction to a substantial fraction of completion for these plots to yield unambiguous orders. The present article gives a theoretical and statistical…

  11. Reaction Order Ambiguity in Integrated Rate Plots

    ERIC Educational Resources Information Center

    Lee, Joe

    2008-01-01

    Integrated rate plots are frequently used in reaction kinetics to determine orders of reactions. It is often emphasised, when using this methodology in practice, that it is necessary to monitor the reaction to a substantial fraction of completion for these plots to yield unambiguous orders. The present article gives a theoretical and statistical

  12. Intolerance of Ambiguity and Student Performance in Social Work Education.

    ERIC Educational Resources Information Center

    Davis, Liane V.; Sherman, Edmund

    1987-01-01

    Social workers must assist people in coping with complex, often apparently insoluble, problems. Data are presented on the relationship between intolerance of ambiguity and a variety of performance and preference measures of 212 social work students. (Author/MH)

  13. Administration in Higher Education: Making the Most of Ambiguity.

    ERIC Educational Resources Information Center

    Ecker, George

    1979-01-01

    In an examination of administrative organization of higher education institutions, colleges and universities are viewed as organized anarchies and loosely coupled systems. Ambiguity inherent for leadership and administration in these organizations is discussed. (SF)

  14. Ambiguity Of Doppler Centroid In Synthetic-Aperture Radar

    NASA Technical Reports Server (NTRS)

    Chang, Chi-Yung; Curlander, John C.

    1991-01-01

    Paper discusses performances of two algorithms for resolution of ambiguity in estimated Doppler centroid frequency of echoes in synthetic-aperture radar. One based on range-cross-correlation technique, other based on multiple-pulse-repetition-frequency technique.

  15. Top-down influence in young children's linguistic ambiguity resolution.

    PubMed

    Rabagliati, Hugh; Pylkkänen, Liina; Marcus, Gary F

    2013-06-01

    Language is rife with ambiguity. Do children and adults meet this challenge in similar ways? Recent work suggests that while adults resolve syntactic ambiguities by integrating a variety of cues, children are less sensitive to top-down evidence. We test whether this top-down insensitivity is specific to syntax or a general feature of children's linguistic ambiguity resolution by evaluating whether children rely largely or completely on lexical associations to resolve lexical ambiguities (e.g., the word swing primes the baseball meaning of bat) or additionally integrate top-down global plausibility. Using a picture choice task, we compared 4-year-olds' ability to resolve polysemes and homophones with a Bayesian algorithm reliant purely on lexical associations and found that the algorithm's power to predict children's choices was limited. A 2nd experiment confirmed that children override associations and integrate top-down plausibility. We discuss this with regard to models of psycholinguistic development. PMID:22229852

  16. Mentalizing under Uncertainty: Dissociated Neural Responses to Ambiguous and Unambiguous Mental State Inferences

    PubMed Central

    Mitchell, Jason P.

    2010-01-01

    The ability to read the minds of others (i.e., to mentalize) requires that perceivers understand a wide range of different kinds of mental states, including not only others’ beliefs and knowledge but also their feelings, desires, and preferences. Moreover, although such inferences may occasionally rely on observable features of a situation, perceivers more typically mentalize under conditions of “uncertainty,” in which they must generate plausible hypotheses about a target's mental state from ambiguous or otherwise underspecified information. Here, we use functional neuroimaging to dissociate the neural bases of these 2 distinct social–cognitive challenges: 1) mentalizing about different types of mental states (beliefs vs. preferences) and 2) mentalizing under conditions of varying ambiguity. Although these 2 aspects of mentalizing have typically been confounded in earlier research, we observed a double dissociation between the brain regions sensitive to type of mental state and ambiguity. Whereas ventral and dorsal aspects of medial prefrontal cortex responded more during ambiguous than unambiguous inferences regardless of the type of mental state, the right temporoparietal junction was sensitive to the distinction between beliefs and preferences irrespective of certainty. These results underscore the emerging consensus that, rather than comprising a single mental operation, social cognition makes flexible use of different processes as a function of the particular demands of the social context. PMID:19478034

  17. Functional neuroimaging of grammatical class: ambiguous and unambiguous nouns and verbs.

    PubMed

    Burton, Martha W; Krebs-Noble, Donna; Gullapalli, Rao P; Berndt, Rita Sloan

    2009-03-01

    Neuropsychological and neuroimaging studies of grammatical-class differences suggest that nouns and verbs may be associated with different brain regions. The current functional magnetic resonance imaging (fMRI) study focused on auditory grammaticality judgements of two-word stimuli consisting of noun/verb ambiguous and unambiguous nouns and verbs preceded by either "the" or "to". The fMRI results showed effects of class ambiguity in the left inferior frontal gyrus, possibly due to greater selection demands, and effects of grammaticality ("yes" vs. "no" response) in left superior temporal gyrus, consistent with greater activation for trials with greater conflict. In addition, posterior left temporal lobe regions showed increased activity on unambiguous trials for verbs than for nouns, consistent with prior imaging studies. Thus, in a task specifically focused on the grammatical (rather than semantic) aspects of words and that used morphologically simple nouns and verbs controlled for imageability, verbs preferentially activated posterior temporal but not frontal lobe regions. However, for ambiguous trials in this same region, nouns showed greater activation than verbs, suggesting that these effects can be modulated by class ambiguity. PMID:19105056

  18. Mentalizing under uncertainty: dissociated neural responses to ambiguous and unambiguous mental state inferences.

    PubMed

    Jenkins, Adrianna C; Mitchell, Jason P

    2010-02-01

    The ability to read the minds of others (i.e., to mentalize) requires that perceivers understand a wide range of different kinds of mental states, including not only others' beliefs and knowledge but also their feelings, desires, and preferences. Moreover, although such inferences may occasionally rely on observable features of a situation, perceivers more typically mentalize under conditions of "uncertainty," in which they must generate plausible hypotheses about a target's mental state from ambiguous or otherwise underspecified information. Here, we use functional neuroimaging to dissociate the neural bases of these 2 distinct social-cognitive challenges: 1) mentalizing about different types of mental states (beliefs vs. preferences) and 2) mentalizing under conditions of varying ambiguity. Although these 2 aspects of mentalizing have typically been confounded in earlier research, we observed a double dissociation between the brain regions sensitive to type of mental state and ambiguity. Whereas ventral and dorsal aspects of medial prefrontal cortex responded more during ambiguous than unambiguous inferences regardless of the type of mental state, the right temporoparietal junction was sensitive to the distinction between beliefs and preferences irrespective of certainty. These results underscore the emerging consensus that, rather than comprising a single mental operation, social cognition makes flexible use of different processes as a function of the particular demands of the social context. PMID:19478034

  19. The (IR-)relevance of the Gribov ambiguity in SU(2)U(1) gauge theories with fundamental Higgs matter

    SciTech Connect

    Capri, M.A.L.; Dudal, D.; Guimaraes, M.S.; Justo, I.F.; Sorella, S.P.; and others

    2014-04-15

    It is well accepted that dealing with the Gribov ambiguity has a major impact on correlation functions in gauge-fixed YangMills theories, in particular in the low momentum regime where standard perturbation theory based on the FaddeevPopov approach fails. Recent results, derived from functional tools (DysonSchwinger equations or exact RG) or the effective GribovZwanziger action method, pointed towards e.g. gauge boson correlation functions that are not compatible with the properties of observable degrees of freedom. Although such an observation is a welcome feature for gauge theories exhibiting confinement, it would be a discomfort for gauge theories supplemented with Higgs fields, cf.the experimental success of the electroweak model based on a SU(2)U(1) gauge group. The purpose of this short note is to assure that the effective action resolution to the Gribov ambiguity reduces to the standard FaddeevPopov method in the perturbative regime of sufficiently small coupling/large Higgs condensate, thereby not compromising the physical particle spectrum of massive gauge bosons and a massless photon for the SU(2)U(1) gaugeHiggs model. The closer the theory gets to the limit of vanishing Higgs condensate, the more the Gribov problem resurfaces with all its consequences. We give some speculations w.r.t.the FradkinShenker insights about the phase diagram. -- Highlights: Gribov horizon influences gauge propagators in a strong-coupling regime. No influence of Gribov horizon in weak-coupling. Inclusion of U(1) factor leads to very rich behavior of propagators.

  20. Improving Ambiguity Resolution for Medium Baselines Using Combined GPS and BDS Dual/Triple-Frequency Observations

    PubMed Central

    Gao, Wang; Gao, Chengfa; Pan, Shuguo; Wang, Denghui; Deng, Jiadong

    2015-01-01

    The regional constellation of the BeiDou navigation satellite system (BDS) has been providing continuous positioning, navigation and timing services since 27 December 2012, covering China and the surrounding area. Real-time kinematic (RTK) positioning with combined BDS and GPS observations is feasible. Besides, all satellites of BDS can transmit triple-frequency signals. Using the advantages of multi-pseudorange and carrier observations from multi-systems and multi-frequencies is expected to be of much benefit for ambiguity resolution (AR). We propose an integrated AR strategy for medium baselines by using the combined GPS and BDS dual/triple-frequency observations. In the method, firstly the extra-wide-lane (EWL) ambiguities of triple-frequency system, i.e., BDS, are determined first. Then the dual-frequency WL ambiguities of BDS and GPS were resolved with the geometry-based model by using the BDS ambiguity-fixed EWL observations. After that, basic (i.e., L1/L2 or B1/B2) ambiguities of BDS and GPS are estimated together with the so-called ionosphere-constrained model, where the ambiguity-fixed WL observations are added to enhance the model strength. During both of the WL and basic AR, a partial ambiguity fixing (PAF) strategy is adopted to weaken the negative influence of new-rising or low-elevation satellites. Experiments were conducted and presented, in which the GPS/BDS dual/triple-frequency data were collected in Nanjing and Zhengzhou of China, with the baseline distance varying from about 28.6 to 51.9 km. The results indicate that, compared to the single triple-frequency BDS system, the combined system can significantly enhance the AR model strength, and thus improve AR performance for medium baselines with a 75.7% reduction of initialization time on average. Besides, more accurate and stable positioning results can also be derived by using the combined GPS/BDS system. PMID:26528977

  1. Improving Ambiguity Resolution for Medium Baselines Using Combined GPS and BDS Dual/Triple-Frequency Observations.

    PubMed

    Gao, Wang; Gao, Chengfa; Pan, Shuguo; Wang, Denghui; Deng, Jiadong

    2015-01-01

    The regional constellation of the BeiDou navigation satellite system (BDS) has been providing continuous positioning, navigation and timing services since 27 December 2012, covering China and the surrounding area. Real-time kinematic (RTK) positioning with combined BDS and GPS observations is feasible. Besides, all satellites of BDS can transmit triple-frequency signals. Using the advantages of multi-pseudorange and carrier observations from multi-systems and multi-frequencies is expected to be of much benefit for ambiguity resolution (AR). We propose an integrated AR strategy for medium baselines by using the combined GPS and BDS dual/triple-frequency observations. In the method, firstly the extra-wide-lane (EWL) ambiguities of triple-frequency system, i.e., BDS, are determined first. Then the dual-frequency WL ambiguities of BDS and GPS were resolved with the geometry-based model by using the BDS ambiguity-fixed EWL observations. After that, basic (i.e., L1/L2 or B1/B2) ambiguities of BDS and GPS are estimated together with the so-called ionosphere-constrained model, where the ambiguity-fixed WL observations are added to enhance the model strength. During both of the WL and basic AR, a partial ambiguity fixing (PAF) strategy is adopted to weaken the negative influence of new-rising or low-elevation satellites. Experiments were conducted and presented, in which the GPS/BDS dual/triple-frequency data were collected in Nanjing and Zhengzhou of China, with the baseline distance varying from about 28.6 to 51.9 km. The results indicate that, compared to the single triple-frequency BDS system, the combined system can significantly enhance the AR model strength, and thus improve AR performance for medium baselines with a 75.7% reduction of initialization time on average. Besides, more accurate and stable positioning results can also be derived by using the combined GPS/BDS system. PMID:26528977

  2. Expression vectors for quantitating in vivo translational ambiguity: their potential use to analyse frameshifting at the HIV gag-pol junction.

    PubMed

    Cassan, M; Berteaux, V; Angrand, P O; Rousset, J P

    1990-01-01

    Translational errors are necessary so as to allow gene expression in various organisms. In retroviruses, synthesis of pol gene products necessitates either readthrough of a stop codon or frameshifting. Here we present an experimental system that permits quantification of translational errors in vivo. It consists of a family of expression vectors carrying different mutated versions of the luc gene as reporter. Mutations include both an in-frame stop codon and 1-base-pair deletions that require readthrough or frameshift, respectively, to give rise to an active product. This system is sensitive enough to detect background errors in mammalian cells. In addition, one of the vectors contains two unique cloning sites that make it possible to insert any sequence of interest. This latter vector was used to analyse the effect of a DNA fragment, proposed to be the target of high level slippage at the gag-pol junction of HIV. The effect of paromomycin and kasugamycin, two antibiotics known to influence translational ambiguity, was also tested in cultured cells. The results indicate that paromomycin diversely affects readthrough and frameshifting, while kasugamycin had no effect. This family of vectors can be used to analyse the influence of structural and external factors on translational ambiguity in both mammalian cells and bacteria. PMID:2087598

  3. Integer ambiguity resolution in precise point positioning: method comparison

    NASA Astrophysics Data System (ADS)

    Geng, Jianghui; Meng, Xiaolin; Dodson, Alan H.; Teferle, Felix N.

    2010-09-01

    Integer ambiguity resolution at a single receiver can be implemented by applying improved satellite products where the fractional-cycle biases (FCBs) have been separated from the integer ambiguities in a network solution. One method to achieve these products is to estimate the FCBs by averaging the fractional parts of the float ambiguity estimates, and the other is to estimate the integer-recovery clocks by fixing the undifferenced ambiguities to integers in advance. In this paper, we theoretically prove the equivalence of the ambiguity-fixed position estimates derived from these two methods by assuming that the FCBs are hardware-dependent and only they are assimilated into the clocks and ambiguities. To verify this equivalence, we implement both methods in the Position and Navigation Data Analyst software to process 1 year of GPS data from a global network of about 350 stations. The mean biases between all daily position estimates derived from these two methods are only 0.2, 0.1 and 0.0 mm, whereas the standard deviations of all position differences are only 1.3, 0.8 and 2.0 mm for the East, North and Up components, respectively. Moreover, the differences of the position repeatabilities are below 0.2 mm on average for all three components. The RMS of the position estimates minus those from the International GNSS Service weekly solutions for the former method differs by below 0.1 mm on average for each component from that for the latter method. Therefore, considering the recognized millimeter-level precision of current GPS-derived daily positions, these statistics empirically demonstrate the theoretical equivalence of the ambiguity-fixed position estimates derived from these two methods. In practice, we note that the former method is compatible with current official clock-generation methods, whereas the latter method is not, but can potentially lead to slightly better positioning quality.

  4. Spontaneous giving and calculated greed.

    PubMed

    Rand, David G; Greene, Joshua D; Nowak, Martin A

    2012-09-20

    Cooperation is central to human social behaviour. However, choosing to cooperate requires individuals to incur a personal cost to benefit others. Here we explore the cognitive basis of cooperative decision-making in humans using a dual-process framework. We ask whether people are predisposed towards selfishness, behaving cooperatively only through active self-control; or whether they are intuitively cooperative, with reflection and prospective reasoning favouring 'rational' self-interest. To investigate this issue, we perform ten studies using economic games. We find that across a range of experimental designs, subjects who reach their decisions more quickly are more cooperative. Furthermore, forcing subjects to decide quickly increases contributions, whereas instructing them to reflect and forcing them to decide slowly decreases contributions. Finally, an induction that primes subjects to trust their intuitions increases contributions compared with an induction that promotes greater reflection. To explain these results, we propose that cooperation is intuitive because cooperative heuristics are developed in daily life where cooperation is typically advantageous. We then validate predictions generated by this proposed mechanism. Our results provide convergent evidence that intuition supports cooperation in social dilemmas, and that reflection can undermine these cooperative impulses. PMID:22996558

  5. Giving Corrective Feedback: A Decisional Analysis.

    ERIC Educational Resources Information Center

    Latting, Jean Kantambu

    1992-01-01

    Notes advantages of effective feedback in improving quantity and quality of employees' performance. Presents set of guidelines for giving corrective feedback in four categories: deciding whether to give corrective feedback; deciding what to say when giving feedback; deciding how and when to give feedback; and deciding how to handle receiver's

  6. Children's Understanding of Ambiguous Figures: Which Cognitive Developments Are Necessary to Experience Reversal

    ERIC Educational Resources Information Center

    Doherty, M.J.; Wimmer, M.C.

    2005-01-01

    In two experiments involving one hundred and thirty-eight 3- to 5-year-olds we examined the claim that a complex understanding of ambiguity is required to experience reversal of ambiguous stimuli [Gopnik, A., & Rosati, A. (2001). Duck or rabbit? Reversing ambiguous figures and understanding ambiguous representations. Developmental Science, 4,

  7. GP consortia: navigating ambiguity to produce greater public value?

    PubMed

    Holbeche, Linda

    2011-05-01

    The UK's NHS is about to be significantly remodelled according to a white paper published in July 2010 that outlines the devolution of commissioning responsibilities away from strategic health authorities and primary care trusts to consortia of GPs, which are to be established at local level. Details of how the new GP consortia will operate are as yet unclear, but in essence they will be strategic alliances and it is likely that they will develop more or less formal arrangements between consortia partners, such as those of a commercial joint venture. This article draws on primary research into strategic alliances between organizations in all sectors. It suggests that there can be significant challenges for those working within strategic alliances, given that these tend to be beset by ambiguity and political tensions. In a context of ever greater transparency and accountability, it will be crucial to attend to the human aspects of strategic alliances since these represent significant risk if neglected. Conversely, alliances also offer the opportunity to develop the synergy of people, organizations and communities to deliver greater public value. Successful collaborations need to get three things right: governance, operations and behaviours. Relationships between consortia partners have a significant bearing on their ability to deliver desired outcomes. They must be able to build and maintain trust. Consortia partners will need sophisticated negotiating and stakeholder management skills and must be able to engage the public in setting the strategic goals for which they will be accountable. They also need strategic and operational management skills and must be able to cope with ambiguity and manage complexity. This paper argues that specific forms of leadership are needed in collaborative arrangements to mobilize people for positive action. People must work together by willingly and effectively pooling their initiative and expertise, and create a product or energy that is greater than the sum of their parts. The nature of leadership required to produce such high performance outcomes is likely to supersede leadership that is the result of structural relationships or of individual action. In particular, distributed leadership is likely to be relevant. PMID:21692401

  8. Geometrical ambiguity of pair statistics. II. Heterogeneous media.

    PubMed

    Jiao, Yang; Stillinger, Frank H; Torquato, Salvatore

    2010-07-01

    In the first part of this series of two papers [Y. Jiao, F. H. Stillinger, and S. Torquato, Phys. Rev. E 81, 011105 (2010)], we considered the geometrical ambiguity of pair statistics associated with point configurations. Here we focus on the analogous problem for heterogeneous media (materials). Heterogeneous media are ubiquitous in a host of contexts, including composites and granular media, biological tissues, ecological patterns, and astrophysical structures. The complex structures of heterogeneous media are usually characterized via statistical descriptors, such as the n -point correlation function Sn. An intricate inverse problem of practical importance is to what extent a medium can be reconstructed from the two-point correlation function S2 of a target medium. Recently, general claims of the uniqueness of reconstructions using S2 have been made based on numerical studies, which implies that S2 suffices to uniquely determine the structure of a medium within certain numerical accuracy. In this paper, we provide a systematic approach to characterize the geometrical ambiguity of S2 for both continuous two-phase heterogeneous media and their digitized representations in a mathematically precise way. In particular, we derive the exact conditions for the case where two distinct media possess identical S2 , i.e., they form a degenerate pair. The degeneracy conditions are given in terms of integral and algebraic equations for continuous media and their digitized representations, respectively. By examining these equations and constructing their rigorous solutions for specific examples, we conclusively show that in general S2 is indeed not sufficient information to uniquely determine the structure of the medium, which is consistent with the results of our recent study on heterogeneous-media reconstruction [Y. Jiao, F. H. Stillinger, and S. Torquato, Proc. Natl. Acad. Sci. U.S.A. 106, 17634 (2009)]. The analytical examples include complex patterns composed of building blocks bearing the letter "T" and the word "WATER" as well as degenerate stacking variants of the densest sphere packing in three dimensions (Barlow films). Several numerical examples of degeneracy (e.g., reconstructions of polycrystal microstructures, laser-speckle patterns and sphere packings) are also given, which are virtually exact solutions of the degeneracy equations. The uniqueness issue of multiphase media reconstructions and additional structural information required to characterize heterogeneous media are discussed, including two-point quantities that contain topological connectedness information about the phases. PMID:20866564

  9. Giving curriculum planners an edge

    PubMed Central

    Oandasan, Ivy F.; Archibald, Douglas; Authier, Louise; Lawrence, Kathrine; McEwen, Laura April; Palacios, Maria; Parkkari, Marie; Plant, Heidi; Slade, Steve; Ross, Shelley

    2015-01-01

    Abstract Objective To pilot a survey of family medicine residents entering residency, describing their exposure to family medicine and their perspectives related to their future intentions to practise family medicine, in order to inform curriculum planners; and to test the methodology, feasibility, and utility of delivering a longitudinal survey to multiple residency programs. Design Pilot study using surveys. Setting Five Canadian residency programs. Participants A total of 454 first-year family medicine residents were surveyed. Main outcome measures Residents previous exposure to family medicine, perspectives on family medicine, and future practice intentions. Results Overall, 70% of first-year residents surveyed responded (n = 317). Although only 5 residency programs participated, respondents included graduates from each of the medical schools in Canada, as well as international medical graduates. Among respondents, 92% felt positive or strongly positive about their choice to be family physicians. Most (73%) indicated they had strong or very strong exposure to family medicine in medical school, yet more than 40% had no or minimal exposure to key clinical domains of family medicine like palliative care, home care, and care of underserved groups. Similar responses were found about residents lack of intention to practise in these domains. Conclusion Exposure to clinical domains in family medicine could influence future practice intentions. Surveys at entrance to residency can help medical school and family medicine residency planners consider important learning experiences to include in training. PMID:26052601

  10. Reduction of Phase Ambiguity in an Offset-QPSK Receiver

    NASA Technical Reports Server (NTRS)

    Berner, Jeff; Kinman, Peter

    2004-01-01

    Proposed modifications of an offset-quadri-phase-shift keying (offset-QPSK) transmitter and receiver would reduce the amount of signal processing that must be done in the receiver to resolve the QPSK fourfold phase ambiguity. Resolution of the phase ambiguity is necessary in order to synchronize, with the received carrier signal, the signal generated by a local oscillator in a carrier-tracking loop in the receiver. Without resolution of the fourfold phase ambiguity, the loop could lock to any of four possible phase points, only one of which has the proper phase relationship with the carrier. The proposal applies, more specifically, to an offset-QPSK receiver that contains a carrier-tracking loop like that shown in Figure 1. This carrier-tracking loop does not resolve or reduce the phase ambiguity. A carrier-tracking loop of a different design optimized for the reception of offset QPSK could reduce the phase ambiguity from fourfold to twofold, but would be more complex. Alternatively, one could resolve the fourfold phase ambiguity by use of differential coding in the transmitter, at a cost of reduced power efficiency. The proposed modifications would make it possible to reduce the fourfold phase ambiguity to twofold, with no loss in power efficiency and only relatively simple additional signal-processing steps in the transmitter and receiver. The twofold phase ambiguity would then be resolved by use of a unique synchronization word, as is commonly done in binary phase-shift keying (BPSK). Although the mathematical and signal-processing principles underlying the modifications are too complex to explain in detail here, the modifications themselves would be relatively simple and are best described with the help of simple block diagrams (see Figure 2). In the transmitter, one would add a unit that would periodically invert bits going into the QPSK modulator; in the receiver, one would add a unit that would effect different but corresponding inversions of bits coming out of the QPSK demodulator. The net effect of all the inversions would be that depending on which lock point the carrier-tracking loop had selected, all the output bits would be either inverted or non-inverted together; hence, the ambiguity would be reduced from fourfold to twofold, as desired.

  11. Rainbow-shift mechanism behind discrete optical-potential ambiguities

    SciTech Connect

    Brandan, M.E. ); McVoy, K.W. )

    1991-03-01

    Some years ago, Drisko {ital et} {ital al}. suggested that the discrete ambiguity often encountered for elastic scattering optical potentials could be understood as being due to the interior or small-{ital l} {ital S}-matrix elements for two equivalent'' potentials differing in phase by 2{pi}, {ital l}-by-{ital l}. We point out that the {ital absence} of this phase change for peripheral partial waves is equally essential, and suggest that a deeper understanding of the ambiguity may be achieved by viewing it as a consequence of a farside interference between interior and peripheral partial waves. It is this interference which produces the broad Airy maxima'' of a nuclear rainbow, and we show that a Drisko-type phase-shift increment {delta}{sub {ital l}}{r arrow}({delta}{sub {ital l}}+{pi}) for low-{ital l} phases relative to the high-{ital l} ones is exactly what is needed to shift a farside rainbow pattern by one Airy maximum, thus providing an equivalent rainbow-shift'' interpretation of the discrete ambiguity. The physical importance of both interpretations lies in the fact that the existence of discrete ambiguities (as well as of nuclear rainbows) is explicit evidence for low-{ital l} transparency in nucleus-nucleus collisions. The essential role played by low partial waves explains why peripheral reactions have generally not proven helpful in resolving this ambiguity.

  12. Auditory Scene Analysis: The Sweet Music of Ambiguity

    PubMed Central

    Pressnitzer, Daniel; Suied, Clara; Shamma, Shihab A.

    2011-01-01

    In this review paper aimed at the non-specialist, we explore the use that neuroscientists and musicians have made of perceptual illusions based on ambiguity. The pivotal issue is auditory scene analysis (ASA), or what enables us to make sense of complex acoustic mixtures in order to follow, for instance, a single melody in the midst of an orchestra. In general, ASA uncovers the most likely physical causes that account for the waveform collected at the ears. However, the acoustical problem is ill-posed and it must be solved from noisy sensory input. Recently, the neural mechanisms implicated in the transformation of ambiguous sensory information into coherent auditory scenes have been investigated using so-called bistability illusions (where an unchanging ambiguous stimulus evokes a succession of distinct percepts in the mind of the listener). After reviewing some of those studies, we turn to music, which arguably provides some of the most complex acoustic scenes that a human listener will ever encounter. Interestingly, musicians will not always aim at making each physical source intelligible, but rather express one or more melodic lines with a small or large number of instruments. By means of a few musical illustrations and by using a computational model inspired by neuro-physiological principles, we suggest that this relies on a detailed (if perhaps implicit) knowledge of the rules of ASA and of its inherent ambiguity. We then put forward the opinion that some degree perceptual ambiguity may participate in our appreciation of music. PMID:22174701

  13. Annual Giving Strategies: A Comprehensive Guide to Better Results.

    ERIC Educational Resources Information Center

    Gee, Ann D., Ed.

    This collection of 32 papers focuses on the annual fund as a basic and central part of development programs at schools, colleges, and universities. It describes the fundamental elements of the annual fund from planning to evaluation and sets forth methods of solicitation that reach all the institution's constituencies. Section 1, titled "Overview

  14. Housing conditions affect rat responses to two types of ambiguity in a reward-reward discrimination cognitive bias task.

    PubMed

    Parker, Richard M A; Paul, Elizabeth S; Burman, Oliver H P; Browne, William J; Mendl, Michael

    2014-11-01

    Decision-making under ambiguity in cognitive bias tasks is a promising new indicator of affective valence in animals. Rat studies support the hypothesis that animals in a negative affective state evaluate ambiguous cues negatively. Prior automated operant go/go judgement bias tasks have involved training rats that an auditory cue of one frequency predicts a Reward and a cue of a different frequency predicts a Punisher (RP task), and then measuring whether ambiguous cues of intermediate frequency are judged as predicting reward ('optimism') or punishment ('pessimism'). We investigated whether an automated Reward-Reward (RR) task yielded similar results to, and was faster to train than, RP tasks. We also introduced a new ambiguity test (simultaneous presentation of the two training cues) alongside the standard single ambiguous cue test. Half of the rats experienced an unpredictable housing treatment (UHT) designed to induce a negative state. Control rats were relatively 'pessimistic', whilst UHT rats were quicker, but no less accurate, in their responses in the RR test, and showed less anxiety-like behaviour in independent tests. A possible reason for these findings is that rats adapted to and were stimulated by UHT, whilst control rats in a predictable environment were more sensitive to novelty and change. Responses in the new ambiguity test correlated positively with those in single ambiguous cue tests, and may provide a measure of attention bias. The RR task was quicker to train than previous automated RP tasks. Together, they could be used to disentangle how reward and punishment processes underpin affect-induced cognitive biases. PMID:25106739

  15. Housing conditions affect rat responses to two types of ambiguity in a reward–reward discrimination cognitive bias task

    PubMed Central

    Parker, Richard M.A.; Paul, Elizabeth S.; Burman, Oliver H.P.; Browne, William J.; Mendl, Michael

    2014-01-01

    Decision-making under ambiguity in cognitive bias tasks is a promising new indicator of affective valence in animals. Rat studies support the hypothesis that animals in a negative affective state evaluate ambiguous cues negatively. Prior automated operant go/go judgement bias tasks have involved training rats that an auditory cue of one frequency predicts a Reward and a cue of a different frequency predicts a Punisher (RP task), and then measuring whether ambiguous cues of intermediate frequency are judged as predicting reward (‘optimism’) or punishment (‘pessimism’). We investigated whether an automated Reward–Reward (RR) task yielded similar results to, and was faster to train than, RP tasks. We also introduced a new ambiguity test (simultaneous presentation of the two training cues) alongside the standard single ambiguous cue test. Half of the rats experienced an unpredictable housing treatment (UHT) designed to induce a negative state. Control rats were relatively ‘pessimistic’, whilst UHT rats were quicker, but no less accurate, in their responses in the RR test, and showed less anxiety-like behaviour in independent tests. A possible reason for these findings is that rats adapted to and were stimulated by UHT, whilst control rats in a predictable environment were more sensitive to novelty and change. Responses in the new ambiguity test correlated positively with those in single ambiguous cue tests, and may provide a measure of attention bias. The RR task was quicker to train than previous automated RP tasks. Together, they could be used to disentangle how reward and punishment processes underpin affect-induced cognitive biases. PMID:25106739

  16. Assumptions and ambiguities in nonplanar acoustic soliton theory

    SciTech Connect

    Verheest, Frank; School of Chemistry and Physics, University of KwaZulu-Natal, Durban 4000 ; Hellberg, Manfred A.

    2014-02-15

    There have been many recent theoretical investigations of the nonlinear evolution of electrostatic modes with cylindrical or spherical symmetry. Through a reductive perturbation analysis based on a quasiplanar stretching, a modified form of the Korteweg-de Vries or related equation is derived, containing an additional term which is linear in the electrostatic potential and singular at time t = 0. Unfortunately, these analyses contain several restrictive assumptions and ambiguities which are normally neither properly explained nor discussed, and severely limit the applicability of the technique. Most glaring are the use of plane-wave stretchings, the assumption that shape-preserving cylindrical modes can exist and that, although time is homogeneous, the origin of time (which can be chosen arbitrarily) needs to be avoided. Hence, only in the domain where the nonlinear modes are quasiplanar, far from the axis of cylindrical or from the origin of spherical symmetry can acceptable but unexciting results be obtained. Nonplanar nonlinear modes are clearly an interesting topic of research, as some of these phenomena have been observed in experiments. However, it is argued that a proper study of such modes needs numerical simulations rather than ill-suited analytical approximations.

  17. Sexual picture processing interferes with decision-making under ambiguity.

    PubMed

    Laier, Christian; Pawlikowski, Mirko; Brand, Matthias

    2014-04-01

    Many people watch sexually arousing material on the Internet in order to receive sexual arousal and gratification. When browsing for sexual stimuli, individuals have to make several decisions, all possibly leading to positive or negative consequences. Decision-making research has shown that decisions under ambiguity are influenced by consequences received following earlier decisions. Sexual arousal might interfere with the decision-making process and should therefore lead to disadvantageous decision-making in the long run. In the current study, 82 heterosexual, male participants watched sexual pictures, rated them with respect to sexual arousal, and were asked to indicate their current level of sexual arousal before and following the sexual picture presentation. Afterwards, subjects performed one of two modified versions of the Iowa Gambling Task in which sexual pictures were displayed on the advantageous and neutral pictures on the disadvantageous card decks or vice versa (n = 41/n = 41). Results demonstrated an increase of sexual arousal following the sexual picture presentation. Decision-making performance was worse when sexual pictures were associated with disadvantageous card decks compared to performance when the sexual pictures were linked to the advantageous decks. Subjective sexual arousal moderated the relationship between task condition and decision-making performance. This study emphasized that sexual arousal interfered with decision-making, which may explain why some individuals experience negative consequences in the context of cybersex use. PMID:23733155

  18. A contrast function for independent component analysis without permutation ambiguity.

    PubMed

    Zarzoso, Vicente; Comon, Pierre; Phlypo, Ronald

    2010-05-01

    This brief deals with the problem of blind source separation (BSS) via independent component analysis (ICA). We prove that a linear combination of the separator output fourth-order marginal cumulants (kurtoses) is a valid contrast function for ICA under prewhitening if the weights have the same sign as the source kurtoses. If, in addition, the source kurtoses are different and so are the linear combination weights, the contrast eliminates the permutation ambiguity typical to ICA, as the estimated sources are sorted at the separator output according to their kurtosis values in the same order as the weights. If the weights equal the source kurtoses, the contrast is a cumulant matching criterion based on the maximum-likelihood principle. The contrast can be maximized by means of a cost-efficient Jacobi-type pairwise iteration. In the real-valued two-signal case, the asymptotic variance of the resulting Givens angle estimator is determined in closed form, leading to the contrast weights with optimal finite-sample performance. A fully blind solution can be implemented by computing the optimum weights from the initial source estimates obtained by a classical ICA stage. An experimental study validates the features of the proposed technique and shows its superior performance compared to related previous methods. PMID:20350848

  19. Phase ambiguity resolution for offset QPSK modulation systems

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M. (inventor)

    1991-01-01

    A demodulator for Offset Quaternary Phase Shift Keyed (OQPSK) signals modulated with two words resolves eight possible combinations of phase ambiguity which may produce data error by first processing received I(sub R) and Q(sub R) data in an integrated carrier loop/symbol synchronizer using a digital Costas loop with matched filters for correcting four of eight possible phase lock errors, and then the remaining four using a phase ambiguity resolver which detects the words to not only reverse the received I(sub R) and Q(sub R) data channels, but to also invert (complement) the I(sub R) and/or Q(sub R) data, or to at least complement the I(sub R) and Q(sub R) data for systems using nontransparent codes that do not have rotation direction ambiguity.

  20. Domain-specific genetic influence on visual-ambiguity resolution.

    PubMed

    Wang, Ying; Wang, Li; Xu, Qian; Liu, Dong; Jiang, Yi

    2014-08-01

    The visual world is flooded with ambiguity. Generally, people can resolve the ambiguity almost instantaneously, as when they distinguish at a glance whether a maiden in a portrait by Picasso is in profile or facing front. However, perception of the same reality, though relatively stable at the individual level, can vary dramatically from person to person, manifesting idiosyncratic perceptual biases. What drives the heterogeneity of human vision as reflected in the resolution of visual ambiguity? Using the twin method, we demonstrated a significant genetic contribution to individual differences in the visual disambiguation of bistable biological-motion stimuli but not inanimate motion stimuli. These findings challenge the prevailing view that the way the human brain makes sense of visual input is largely shaped by a person's perceptual history. Rather, the visual perception of biologically salient information can be guided by adaptive mental "priors" that are genetically transmitted. PMID:24914030

  1. Instantaneous and controllable integer ambiguity resolution: review and an alternative approach

    NASA Astrophysics Data System (ADS)

    Zhang, Jingyu; Wu, Meiping; Li, Tao; Zhang, Kaidong

    2015-11-01

    In the high-precision application of Global Navigation Satellite System (GNSS), integer ambiguity resolution is the key step to realize precise positioning and attitude determination. As the necessary part of quality control, integer aperture (IA) ambiguity resolution provides the theoretical and practical foundation for ambiguity validation. It is mainly realized by acceptance testing. Due to the constraint of correlation between ambiguities, it is impossible to realize the controlling of failure rate according to analytical formula. Hence, the fixed failure rate approach is implemented by Monte Carlo sampling. However, due to the characteristics of Monte Carlo sampling and look-up table, we have to face the problem of a large amount of time consumption if sufficient GNSS scenarios are included in the creation of look-up table. This restricts the fixed failure rate approach to be a post process approach if a look-up table is not available. Furthermore, if not enough GNSS scenarios are considered, the table may only be valid for a specific scenario or application. Besides this, the method of creating look-up table or look-up function still needs to be designed for each specific acceptance test. To overcome these problems in determination of critical values, this contribution will propose an instantaneous and CONtrollable (iCON) IA ambiguity resolution approach for the first time. The iCON approach has the following advantages: (a) critical value of acceptance test is independently determined based on the required failure rate and GNSS model without resorting to external information such as look-up table; (b) it can be realized instantaneously for most of IA estimators which have analytical probability formulas. The stronger GNSS model, the less time consumption; (c) it provides a new viewpoint to improve the research about IA estimation. To verify these conclusions, multi-frequency and multi-GNSS simulation experiments are implemented. Those results show that IA estimators based on iCON approach can realize controllable ambiguity resolution. Besides this, compared with ratio test IA based on look-up table, difference test IA and IA least square based on the iCON approach most of times have higher success rates and better controllability to failure rates.

  2. Income Tax Policy and Charitable Giving

    ERIC Educational Resources Information Center

    Brooks, Arthur C.

    2007-01-01

    Many studies over the past 20 years have looked at the response of charitable donations to tax incentives--the tax price elasticity of giving. Generally, authors have assumed this elasticity is constant across all types of giving. Using the 2001 Panel Study of Income Dynamics data on charitable giving, this paper estimates the tax price elasticity

  3. On reducing ambiguity in the interpretation of transient electromagnetic sounding data

    SciTech Connect

    Goldman, M.; Plooy, A. du; Eckard, M.

    1994-01-01

    An attempt to resolve non-uniqueness in the interpretation of transient electromagnetic (TEM) sounding data using measured data alone is made. It is shown in the various examples studied that sufficiently early time measurements can be the determining factor in reducing the ambiguity caused by model equivalence. The early delay times thus play a dual role in transient soundings: they are responsible for resolving shallow structures and they may eliminate the ambiguity in the interpretation of geoelectric parameters of deeper targets. This is illustrated by the results of a follow-up TEM survey at the Dead Sea coast of Israel where the use of supplementary early time measurements allowed non-uniqueness in the determination of the depth to fresh/saline groundwater interface to be resolved.

  4. Assessing Ambiguity of Context Data in Intelligent Environments: Towards a More Reliable Context Managing System

    PubMed Central

    Almeida, Aitor; Lpez-de-Ipia, Diego

    2012-01-01

    Modeling and managing correctly the user context in Smart Environments is important to achieve robust and reliable systems. When modeling reality we must take into account its ambiguous nature. Considering the uncertainty and vagueness in context data information it is possible to attain a more precise picture of the environment, thus leading to a more accurate inference process. To achieve these goals we present an ontology that models the ambiguity in intelligent environments and a data fusion and inference process that takes advantage of that extra information to provide better results. Our system can assess the certainty of the captured measurements, discarding the unreliable ones and combining the rest into a unified vision of the current user context. It also models the vagueness of the system, combining it with the uncertainty to obtain a richer inference process. PMID:22666068

  5. Substrate ambiguity among the nudix hydrolases: biologically significant, evolutionary remnant, or both?

    PubMed

    McLennan, Alexander G

    2013-02-01

    Many members of the nudix hydrolase family exhibit considerable substrate multispecificity and ambiguity, which raises significant issues when assessing their functions in vivo and gives rise to errors in database annotation. Several display low antimutator activity when expressed in bacterial tester strains as well as some degree of activity in vitro towards mutagenic, oxidized nucleotides such as 8-oxo-dGTP. However, many of these show greater activity towards other nucleotides such as ADP-ribose or diadenosine tetraphosphate (Ap(4)A). The antimutator activities have tended to gain prominence in the literature, whereas they may in fact represent the residual activity of an ancestral antimutator enzyme that has become secondary to the more recently evolved major activity after gene duplication. Whether any meaningful antimutagenic function has also been retained in vivo requires very careful assessment. Then again, other examples of substrate ambiguity may indicate as yet unexplored regulatory systems. For example, bacterial Ap(4)A hydrolases also efficiently remove pyrophosphate from the 5' termini of mRNAs, suggesting a potential role for Ap(4)A in the control of bacterial mRNA turnover, while the ability of some eukaryotic mRNA decapping enzymes to degrade IDP and dIDP or diphosphoinositol polyphosphates (DIPs) may also be indicative of new regulatory networks in RNA metabolism. DIP phosphohydrolases also degrade diadenosine polyphosphates and inorganic polyphosphates, suggesting further avenues for investigation. This article uses these and other examples to highlight the need for a greater awareness of the possible significance of substrate ambiguity among the nudix hydrolases as well as the need to exert caution when interpreting incomplete analyses. PMID:23184251

  6. Children's Use of Gesture in Ambiguous Pronoun Interpretation

    ERIC Educational Resources Information Center

    Goodrich Smith, Whitney; Hudson Kam, Carla L.

    2015-01-01

    This study explores whether children can use gesture to inform their interpretation of ambiguous pronouns. Specifically, we ask whether four- to eight-year-old English-speaking children are sensitive to information contained in co-referential localizing gestures in video narrations. The data show that the older (7-8 years of age) but not younger

  7. Ambiguous Argument as Advocacy in Organizational Crisis Communication.

    ERIC Educational Resources Information Center

    Sellnow, Timothy L.; Ulmer, Robert R.

    1995-01-01

    Posits that organizations in crisis situations must address multiple audiences with distinct needs. Analyzes the public communication offered by Jack in the Box restaurants during a food poisoning outbreak. Finds that ambiguity may provide organizations with a means for satisfying the divergent needs of their audiences--even where these distinct

  8. Expecting and Accepting: The Temporal Ambiguity of Recovery Identities

    ERIC Educational Resources Information Center

    Howard, Jenna

    2006-01-01

    This paper has two complementary agendas. One is to develop a formal analysis of temporal ambiguity in self-identification. This refers specifically to having two conflicting orientations toward the future with regard to one's identity (e.g., a temporary expecting orientation and a permanent accepting orientation). I use the recovery identity

  9. A Mindfulness Experiential Small Group to Help Students Tolerate Ambiguity

    ERIC Educational Resources Information Center

    Bohecker, Lynn; Vereen, Linwood G.; Wells, Pamela C.; Wathen, Cristen C.

    2016-01-01

    This study explored the lived experiences of 20 counselors-in-training (CITs) in a mindfulness experiential small group. Using grounded theory, the authors described a 5-dimensional model for navigating ambiguity. Findings suggest mindfulness training provides CITs self-reflection skills and a greater ability to manage cognitive complexity.

  10. Sublexical Ambiguity Effect in Reading Chinese Disyllabic Compounds

    ERIC Educational Resources Information Center

    Huang, Hsu-Wen; Lee, Chia-Ying; Tsai, Jie-Li; Tzeng, Ovid J.-L.

    2011-01-01

    For Chinese compounds, neighbors can share either both orthographic forms and meanings, or orthographic forms only. In this study, central presentation and visual half-field (VF) presentation methods were used in conjunction with ERP measures to investigate how readers solve the sublexical semantic ambiguity of the first constituent character in…

  11. Textbook Presentations of Weight: Conceptual Difficulties and Language Ambiguities

    ERIC Educational Resources Information Center

    Taibu, Rex; Rudge, David; Schuster, David

    2015-01-01

    The term "weight" has multiple related meanings in both scientific and everyday usage. Even among experts and in textbooks, weight is ambiguously defined as either the gravitational force on an object or operationally as the magnitude of the force an object exerts on a measuring scale. This poses both conceptual and language difficulties

  12. Long-term priming of the meanings of ambiguous words

    ERIC Educational Resources Information Center

    Rodd, Jennifer M.; Lopez Cutrin, Belen; Kirsch, Hannah; Millar, Allesandra; Davis, Matthew H.

    2013-01-01

    Comprehension of semantically ambiguous words (e.g., "bark") is strongly influenced by the relative frequencies of their meanings, such that listeners are biased towards retrieving the most frequent meaning. These biases are often assumed to reflect a highly stable property of an individual's long-term lexical-semantic representations. We present

  13. What Is Reflection? Looking for Clarity in an Ambiguous Notion

    ERIC Educational Resources Information Center

    Clarà, Marc

    2015-01-01

    The notion of reflection nowadays is considered crucial in the field of teaching and teacher education. However, although the great majority of approaches to reflection are grounded on the same main theoretical sources, the meaning of this notion is unanimously recognized in the field to be ambiguous. This article aims to look for clarity about…

  14. What Is Reflection? Looking for Clarity in an Ambiguous Notion

    ERIC Educational Resources Information Center

    Clar, Marc

    2015-01-01

    The notion of reflection nowadays is considered crucial in the field of teaching and teacher education. However, although the great majority of approaches to reflection are grounded on the same main theoretical sources, the meaning of this notion is unanimously recognized in the field to be ambiguous. This article aims to look for clarity about

  15. Prosody and the Interpretation of Hierarchically Ambiguous Discourse

    ERIC Educational Resources Information Center

    Tyler, Joseph

    2014-01-01

    Although significant attention has been devoted to prosody in discourse production, relatively little is known about prosody's effect on discourse interpretation. This article explores the ability of synthetic manipulations of prosody to bias interpretation of discourse ambiguities where a first sentence is linked to two following sentences

  16. Trait Ambiguity and Controllability in Evaluations of Self and Others.

    ERIC Educational Resources Information Center

    Powell, Jack L.; Jacobson, Alan S.

    Research has found that most people tend to rate themselves as above average on desirable skills or qualities and below average on undesirable qualities. Two factors have been found to influence this self-serving bias: (1) controllability or the perceived control one has over developing a trait; and (2) trait ambiguity in which a positive trait

  17. Difficulty Processing Temporary Syntactic Ambiguities in Lewy Body Spectrum Disorder

    ERIC Educational Resources Information Center

    Grossman, Murray; Gross, Rachel G.; Moore, Peachie; Dreyfuss, Michael; McMillan, Corey T.; Cook, Philip A.; Ash, Sherry; Siderowf, Andrew

    2012-01-01

    While grammatical aspects of language are preserved, executive deficits are prominent in Lewy body spectrum disorder (LBSD), including Parkinson's disease (PD), Parkinson's dementia (PDD) and dementia with Lewy bodies (DLB). We examined executive control during sentence processing in LBSD by assessing temporary structural ambiguities. Using an

  18. Utilization of Prosodic Information in Syntactic Ambiguity Resolution

    ERIC Educational Resources Information Center

    DeDe, Gayle

    2010-01-01

    Two self paced listening experiments examined the role of prosodic phrasing in syntactic ambiguity resolution. In Experiment 1, the stimuli consisted of early closure sentences (e.g., "While the parents watched, the child sang a song.") containing transitive-biased subordinate verbs paired with plausible direct objects or intransitive-biased

  19. Difficulty Processing Temporary Syntactic Ambiguities in Lewy Body Spectrum Disorder

    ERIC Educational Resources Information Center

    Grossman, Murray; Gross, Rachel G.; Moore, Peachie; Dreyfuss, Michael; McMillan, Corey T.; Cook, Philip A.; Ash, Sherry; Siderowf, Andrew

    2012-01-01

    While grammatical aspects of language are preserved, executive deficits are prominent in Lewy body spectrum disorder (LBSD), including Parkinson's disease (PD), Parkinson's dementia (PDD) and dementia with Lewy bodies (DLB). We examined executive control during sentence processing in LBSD by assessing temporary structural ambiguities. Using an…

  20. Creativity and Tolerance of Ambiguity: An Empirical Study

    ERIC Educational Resources Information Center

    Zenasni, Franck; Besancon, Maud; Lubart, Todd

    2008-01-01

    This study examines the relationship between creativity and tolerance of ambiguity. Participants were parents and their adolescent children. Three measures of creativity were used: a divergent thinking task, a story-writing task and self-evaluation of creative attitudes and behavior. Participants completed two self-report measures of tolerance of

  1. Children's Use of Gesture to Resolve Lexical Ambiguity

    ERIC Educational Resources Information Center

    Kidd, Evan; Holler, Judith

    2009-01-01

    We report on a study investigating 3-5-year-old children's use of gesture to resolve lexical ambiguity. Children were told three short stories that contained two homonym senses; for example, "bat" (flying mammal) and "bat" (sports equipment). They were then asked to re-tell these stories to a second experimenter. The data were coded for the means…

  2. Prosody and the Interpretation of Hierarchically Ambiguous Discourse

    ERIC Educational Resources Information Center

    Tyler, Joseph

    2014-01-01

    Although significant attention has been devoted to prosody in discourse production, relatively little is known about prosody's effect on discourse interpretation. This article explores the ability of synthetic manipulations of prosody to bias interpretation of discourse ambiguities where a first sentence is linked to two following sentences…

  3. "What Happened?" Teaching Attribution Theory through Ambiguous Prompts

    ERIC Educational Resources Information Center

    McArthur, John

    2011-01-01

    The concept of attribution, "the act of explaining why something happens or why a person acts a particular way," is typically an abstract concept. This 35-50-minute activity invites students to make a series of attributions by asking them "What happened?" in ambiguous scenes presented in class. Then, students retrospectively identify what

  4. Children's Use of Gesture to Resolve Lexical Ambiguity

    ERIC Educational Resources Information Center

    Kidd, Evan; Holler, Judith

    2009-01-01

    We report on a study investigating 3-5-year-old children's use of gesture to resolve lexical ambiguity. Children were told three short stories that contained two homonym senses; for example, "bat" (flying mammal) and "bat" (sports equipment). They were then asked to re-tell these stories to a second experimenter. The data were coded for the means

  5. Is Multilingualism Linked to a Higher Tolerance of Ambiguity?

    ERIC Educational Resources Information Center

    DeWaele, Jean-Marc; Wei, Li

    2013-01-01

    The present study investigates the link between multilingualism and the personality trait Tolerance of Ambiguity (TA) among 2158 mono-, bi- and multilinguals. Monolinguals and bilinguals scored significantly lower on TA compared to multilinguals. A high level of global proficiency of various languages was linked to higher TA scores. A stay abroad

  6. Psychometric Analysis of Role Conflict and Ambiguity Scales in Academia

    ERIC Educational Resources Information Center

    Khan, Anwar; Yusoff, Rosman Bin Md.; Khan, Muhammad Muddassar; Yasir, Muhammad; Khan, Faisal

    2014-01-01

    A comprehensive Psychometric Analysis of Rizzo et al.'s (1970) Role Conflict & Ambiguity (RCA) scales were performed after its distribution among 600 academic staff working in six universities of Pakistan. The reliability analysis includes calculation of Cronbach Alpha Coefficients and Inter-Items statistics, whereas validity was determined by

  7. Sublexical Ambiguity Effect in Reading Chinese Disyllabic Compounds

    ERIC Educational Resources Information Center

    Huang, Hsu-Wen; Lee, Chia-Ying; Tsai, Jie-Li; Tzeng, Ovid J.-L.

    2011-01-01

    For Chinese compounds, neighbors can share either both orthographic forms and meanings, or orthographic forms only. In this study, central presentation and visual half-field (VF) presentation methods were used in conjunction with ERP measures to investigate how readers solve the sublexical semantic ambiguity of the first constituent character in

  8. The Control over Marginality. Structural Integration of Ambiguity.

    ERIC Educational Resources Information Center

    Kruithof, C. L.

    1990-01-01

    Examines structural marginality on two levels, substantial and functional. Argues that fundamental organizational framework of economic and political institutions determines the relationship between substantial and functional marginality. Explores the ambiguity involved when dominant society defines and controls marginal groups and individuals.

  9. Range ambiguity suppression technique for the spaceborne synthetic aperture radar

    NASA Astrophysics Data System (ADS)

    Jha, A. M.; Majmudar, Archana; Pillai, N. S.

    1988-10-01

    The aim of any spaceborne Synthetic Aperture Radar (SAR) system design is to keep the range ambiguous responses as low as possible. A higher value of range ambiguity deteriorates the SAR image quality. The wider swath requirement at higher incidence angle (greater than 45 deg) deteriorates the range ambiguity ratio (RAR) and hence the image quality of SAR quite significantly. The requirement of minimum acceptable RAR even for very nominal swath at these incidence angles may necessitate larger antenna width, very complex weighting, and highly asymmetrical antenna elevation pattern. An alternate scheme is suggested in this paper to alleviate the criticality and complexity of the design aspects for such a requirement. Here, the chirp slope of the transmitted linear frequency modulated pulses is reversed alternately. Hence, during the range compression, a significant portion of the ambiguous return is suppressed due to the mismatching with the signal reference function. The proposed method provides significant improvement in RAR and can be utilized in attaining wider swath, specifically at higher incidence angles.

  10. Bidirectional Transfer: Consequences of Translation Ambiguity for Bilingual Word Meaning

    ERIC Educational Resources Information Center

    Degani, Tamar

    2011-01-01

    Could a second language (L2) influence how bilinguals process their native language (L1)? The work described in this dissertation examined this issue focusing on the way bilinguals interpret the meanings of words. Capitalizing on the prevalence of words that can be translated in more than one way across languages (i.e., "translation ambiguity,"

  11. Children's Use of Gesture in Ambiguous Pronoun Interpretation

    ERIC Educational Resources Information Center

    Goodrich Smith, Whitney; Hudson Kam, Carla L.

    2015-01-01

    This study explores whether children can use gesture to inform their interpretation of ambiguous pronouns. Specifically, we ask whether four- to eight-year-old English-speaking children are sensitive to information contained in co-referential localizing gestures in video narrations. The data show that the older (7-8 years of age) but not younger…

  12. Creativity and Tolerance of Ambiguity: An Empirical Study

    ERIC Educational Resources Information Center

    Zenasni, Franck; Besancon, Maud; Lubart, Todd

    2008-01-01

    This study examines the relationship between creativity and tolerance of ambiguity. Participants were parents and their adolescent children. Three measures of creativity were used: a divergent thinking task, a story-writing task and self-evaluation of creative attitudes and behavior. Participants completed two self-report measures of tolerance of…

  13. Translation Ambiguity but Not Word Class Predicts Translation Performance

    ERIC Educational Resources Information Center

    Prior, Anat; Kroll, Judith F.; Macwhinney, Brian

    2013-01-01

    We investigated the influence of word class and translation ambiguity on cross-linguistic representation and processing. Bilingual speakers of English and Spanish performed translation production and translation recognition tasks on nouns and verbs in both languages. Words either had a single translation or more than one translation. Translation

  14. Knowing what a novel word is not: Two-year-olds 'listen through' ambiguous adjectives in fluent speech.

    PubMed

    Thorpe, Kirsten; Fernald, Anne

    2006-07-01

    Three studies investigated how 24-month-olds and adults resolve temporary ambiguity in fluent speech when encountering prenominal adjectives potentially interpretable as nouns. Children were tested in a looking-while-listening procedure to monitor the time course of speech processing. In Experiment 1, the familiar and unfamiliar adjectives preceding familiar target nouns were accented or deaccented. Target word recognition was disrupted only when lexically ambiguous adjectives were accented like nouns. Experiment 2 measured the extent of interference experienced by children when interpreting prenominal words as nouns. In Experiment 3, adults used prosodic cues to identify the form class of adjective/noun homophones in string-identical sentences before the ambiguous words were fully spoken. Results show that children and adults use prosody in conjunction with lexical and distributional cues to 'listen through' prenominal adjectives, avoiding costly misinterpretation. PMID:16125688

  15. The effects of cocaine and mazindol on the cognitive judgement bias of rats in the ambiguous-cue interpretation paradigm.

    PubMed

    Rygula, Rafal; Szczech, Ewa; Papciak, Justyna; Nikiforuk, Agnieszka; Popik, Piotr

    2014-08-15

    Recent research has shown that pharmacological enhancement of dopaminergic function increases an optimism bias in humans. The present study investigated whether acute dopaminergic system stimulation through the administration of two dopamine-mimetic drugs, cocaine and mazindol, have similar effects in rats. To accomplish this goal, after initial behavioural training, two groups of rats received single injections of either cocaine or mazindol and were subsequently tested with the ambiguous-cue interpretation (ACI) paradigm. Both drugs were administered in three doses using the fully randomised Latin square designs. Cocaine (1, 2 and 5mg/kg) had no significant effect on the interpretation of the ambiguous cue. Mazindol at all three doses (0.5, 1 and 2mg/kg) significantly biased animals towards negative interpretation of the ambiguous cue. The results are discussed in relation to pharmacological and behaviourally evoked actions of tested compounds. PMID:24859175

  16. Knowing what a novel word is not: Two-year-olds listen through ambiguous adjectives in fluent speech

    PubMed Central

    Thorpe, Kirsten; Fernald, Anne

    2011-01-01

    Three studies investigated how 24-month-olds and adults resolve temporary ambiguity in fluent speech when encountering prenominal adjectives potentially interpretable as nouns. Children were tested in a looking-while-listening procedure to monitor the time course of speech processing. In Experiment 1, the familiar and unfamiliar adjectives preceding familiar target nouns were accented or deaccented. Target word recognition was disrupted only when lexically ambiguous adjectives were accented like nouns. Experiment 2 measured the extent of interference experienced by children when interpreting prenominal words as nouns. In Experiment 3, adults used prosodic cues to identify the form class of adjective/noun homophones in string-identical sentences before the ambiguous words were fully spoken. Results show that children and adults use prosody in conjunction with lexical and distributional cues to listen through prenominal adjectives, avoiding costly misinterpretation. PMID:16125688

  17. Processing ambiguity in a linguistic context: decision-making difficulties in non-aphasic patients with behavioral variant frontotemporal degeneration.

    PubMed

    Spotorno, Nicola; Healey, Meghan; McMillan, Corey T; Rascovsky, Katya; Irwin, David J; Clark, Robin; Grossman, Murray

    2015-01-01

    Some extent of ambiguity is ubiquitous in everyday conversations. For example, words have multiple meaning and very common pronouns, like "he" and "she" (anaphoric pronouns), have little meaning on their own and refer to a noun that has been previously introduced in the discourse. Ambiguity triggers a decision process that is not a subroutine of language processing but rather a more general domain resource. Therefore non-aphasic patients with limited decision-making capability can encounter severe limitation in language processing due to extra linguistic limitations. In the present study, we test patients with behavioral variant frontotemporal degeneration (bvFTD), focusing on anaphora as a paradigmatic example of ambiguity resolution in the linguistic domain. bvFTD is characterized by gray matter (GM) atrophy in prefrontal cortex, but relative sparing of peri-Sylvian cortex. A group of patients with parietal disease due to corticobasal syndrome (CBS) was also tested here in order to investigate the specific role of prefrontal cortex in the task employed in the current study. Participants were presented with a pair of sentences in which the first sentence contained two nouns while the second contained a pronoun. In the experimental (ambiguous) condition, both nouns are plausible referents of the pronoun, thus requiring decision-making resources. The results revealed that bvFTD patients are significantly less accurate than healthy seniors in identifying the correct referent of a pronoun in the ambiguous condition, although CBS patients were as accurate as healthy seniors. Imaging analyses related bvFTD patients' performance to GM atrophy in ventromedial prefrontal cortex (vmPFC). These results suggest that bvFTD patients have difficulties in decision processes that involve the resolution of an ambiguity. PMID:26578928

  18. Processing ambiguity in a linguistic context: decision-making difficulties in non-aphasic patients with behavioral variant frontotemporal degeneration

    PubMed Central

    Spotorno, Nicola; Healey, Meghan; McMillan, Corey T.; Rascovsky, Katya; Irwin, David J.; Clark, Robin; Grossman, Murray

    2015-01-01

    Some extent of ambiguity is ubiquitous in everyday conversations. For example, words have multiple meaning and very common pronouns, like “he” and “she” (anaphoric pronouns), have little meaning on their own and refer to a noun that has been previously introduced in the discourse. Ambiguity triggers a decision process that is not a subroutine of language processing but rather a more general domain resource. Therefore non-aphasic patients with limited decision-making capability can encounter severe limitation in language processing due to extra linguistic limitations. In the present study, we test patients with behavioral variant frontotemporal degeneration (bvFTD), focusing on anaphora as a paradigmatic example of ambiguity resolution in the linguistic domain. bvFTD is characterized by gray matter (GM) atrophy in prefrontal cortex, but relative sparing of peri-Sylvian cortex. A group of patients with parietal disease due to corticobasal syndrome (CBS) was also tested here in order to investigate the specific role of prefrontal cortex in the task employed in the current study. Participants were presented with a pair of sentences in which the first sentence contained two nouns while the second contained a pronoun. In the experimental (ambiguous) condition, both nouns are plausible referents of the pronoun, thus requiring decision-making resources. The results revealed that bvFTD patients are significantly less accurate than healthy seniors in identifying the correct referent of a pronoun in the ambiguous condition, although CBS patients were as accurate as healthy seniors. Imaging analyses related bvFTD patients’ performance to GM atrophy in ventromedial prefrontal cortex (vmPFC). These results suggest that bvFTD patients have difficulties in decision processes that involve the resolution of an ambiguity. PMID:26578928

  19. Secondary traumatization of partners of war veterans: The role of boundary ambiguity.

    PubMed

    Dekel, Rachel; Levinstein, Yoav; Siegel, Alana; Fridkin, Shimon; Svetlitzky, Vlad

    2016-02-01

    The existing literature has shown that war veterans' posttraumatic stress disorder (PTSD) symptoms are associated with a higher level of distress in their female partners. However, less agreement exists regarding the sources of this distress and the mechanism by which this process occurs. The current study examined the consequences of Israeli war veterans' PTSD on their female partners, as manifested by the females' PTSD symptoms, mental health status, and functioning, while taking into account females' earlier traumatic events. Using the theory of ambiguous loss, it also suggested boundary ambiguity as a mediating variable by which the PTSD of the male veteran is transmitted to his female partner. Participants were 300 men who had served in the 2006 Israel-Lebanon War and their female partners. Results revealed direct associations between males' PTSD and their female partners' PTSD, functioning, and mental health. In addition, boundary ambiguity mediated the association between males' PTSD and females' adjustment. Finally, females' own earlier traumatic events were directly associated with their own PTSD symptoms. Implications of this model for intervention and research are further discussed. (PsycINFO Database Record PMID:26618520

  20. Benefits of using culturally unfamiliar stimuli in ambiguous emotion identification: A cross-cultural study.

    PubMed

    Koelkebeck, Katja; Kohl, Waldemar; Luettgenau, Julia; Triantafillou, Susanna; Ohrmann, Patricia; Satoh, Shinji; Minoshita, Seiko

    2015-07-30

    A novel emotion recognition task that employs photos of a Japanese mask representing a highly ambiguous stimulus was evaluated. As non-Asians perceive and/or label emotions differently from Asians, we aimed to identify patterns of task-performance in non-Asian healthy volunteers with a view to future patient studies. The Noh mask test was presented to 42 adult German participants. Reaction times and emotion attribution patterns were recorded. To control for emotion identification abilities, a standard emotion recognition task was used among others. Questionnaires assessed personality traits. Finally, results were compared to age- and gender-matched Japanese volunteers. Compared to other tasks, German participants displayed slowest reaction times on the Noh mask test, indicating higher demands of ambiguous emotion recognition. They assigned more positive emotions to the mask than Japanese volunteers, demonstrating culture-dependent emotion identification patterns. As alexithymic and anxious traits were associated with slower reaction times, personality dimensions impacted on performance, as well. We showed an advantage of ambiguous over conventional emotion recognition tasks. Moreover, we determined emotion identification patterns in Western individuals impacted by personality dimensions, suggesting performance differences in clinical samples. Due to its properties, the Noh mask test represents a promising tool in the differential diagnosis of psychiatric disorders, e.g. schizophrenia. PMID:25933477

  1. Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults.

    PubMed

    Groch, Sabine; McMakin, Dana; Guggenbühl, Patrick; Rasch, Björn; Huber, Reto; Wilhelm, Ines

    2016-02-01

    The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between ambiguous pictures and words that disambiguate the valence of the pictures in a positive or negative direction. Half of the words were acoustically presented (i.e. cued) during post-learning sleep which is known to benefit memory consolidation by inducing reactivation of learned information. Cued compared to un-cued stimuli were remembered better the next morning. Importantly, cueing positively disambiguated pictures resulted in more positive interpretations whereas cueing negatively disambiguated pictures led to less positive interpretations of new ambiguous pictures with similar contents the next morning. These effects were not modulated by participants' age indicating that memory cueing was as efficient in adolescents as in adults. Our findings suggest that memory cueing during sleep can modify interpretation biases by benefitting memory stabilization and generalization. Implications for clinical settings are discussed. PMID:26588358

  2. Ambiguity Function of the Transmit Beamspace-Based MIMO Radar

    NASA Astrophysics Data System (ADS)

    Li, Yongzhe; Vorobyov, Sergiy A.; Koivunen, Visa

    2015-09-01

    In this paper, we derive an ambiguity function (AF) for the transmit beamspace (TB)-based multipleinput multiple-output (MIMO) radar for the case of far-field targets and narrow-band waveforms. The effects of transmit coherent processing gain and waveform diversity are incorporated into the AF definition. To cover all the phase information conveyed by different factors, we introduce the equivalent transmit phase centers. The newly defined AF serves as a generalized AF form for which the phased-array (PA) and traditional MIMO radar AFs are important special cases. We establish relationships among the defined TB-based MIMO radar AF and the existing AF results including the Woodward's AF, the AFs defined for the traditional colocated MIMO radar, and also the PA radar AF, respectively. Moreover, we compare the TB-based MIMO radar AF with the square-summation-form AF definition and identify two limiting cases to bound its 'clear region' in Doppler-delay domain that is free of sidelobes. Corresponding bounds for these two cases are derived, and it is shown that the bound for the worst case is inversely proportional to the number of transmitted waveforms K, whereas the bound for the best case is independent of K. The actual 'clear region' of the TB-based MIMO radar AF depends on the array configuration and is in between of the worst- and best-case bounds. We propose a TB design strategy to reduce the levels of the AF sidelobes, and show in simulations that proper design of the TB matrix leads to reduction of the relative sidelobe levels of the TB-based MIMO radar AF.

  3. Morphology: An Ambiguous Indicator of Biogenicity

    NASA Astrophysics Data System (ADS)

    Garca Ruiz, Juan Manuel; Carnerup, Anna; Christy, Andrew G.; Welham, Nicholas J.; Hyde, Stephen T.

    2002-08-01

    This paper deals with the difficulty of decoding the origins of natural structures through the study of their morphological features. We focus on the case of primitive life detection, where it is clear that the principles of comparative anatomy cannot be applied. A range of inorganic processes are described that result in morphologies emulating biological shapes, with particular emphasis on geochemically plausible processes. In particular, the formation of inorganic biomorphs in alkaline silica-rich environments are described in detail.

  4. Anisotropy in an ambiguous kinetic depth effect

    NASA Technical Reports Server (NTRS)

    Mulligan, Jeffrey B.

    1992-01-01

    A set of animated stimuli (Lissajous figures), each element of which is physically consistent with two different 3D shapes undergoing rigid rotations about orthogonal axes is presented. Predictions of which shape will be seen are made by utilizing an adaptation of Hildreth's smoothest-velocity-field computation. Results indicate that the ambiquity in 2D visual motion, i.e., the aperture problem, is not resolved before the interpretation of the 3D structure.

  5. Ambiguity produces attention shifts in category learning.

    PubMed

    Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Nelson, James Byron

    2016-04-01

    It has been suggested that people and nonhuman animals protect their knowledge from interference by shifting attention toward the context when presented with information that contradicts their previous beliefs. Despite that suggestion, no studies have directly measured changes in attention while participants are exposed to an interference treatment. In the present experiments, we adapted a dot-probe task to track participants' attention to cues and contexts while they were completing a simple category learning task. The results support the hypothesis that interference produces a change in the allocation of attention to cues and contexts. PMID:26980780

  6. Perceived ambiguity about cancer prevention recommendations: associations with cancer-related perceptions and behaviours in a US population survey

    PubMed Central

    Han, Paul K. J.; Moser, Richard P.; Klein, William M. P.

    2014-01-01

    Background Health information reaching the public today is often characterized by what decision theorists have termed ‘ambiguity’ – i.e. uncertainty regarding the information’s reliability, credibility or adequacy. This is a critical problem, as growing research suggests that ambiguity has important effects–promoting pessimistic judgments about risks and potential outcomes of risk-reducing behaviours, and lowering adoption of these behaviours. However, little is known about the public’s perceptions of ambiguity in the health information domain, the effects of these perceptions, and the factors that influence these effects. Objective To examine associations between perceived ambiguity regarding cancer prevention recommendations and prevention-related perceptions and behaviours, and to explore how these associations differ by cancer type. Study design and participants Cross-sectional analysis of data on 4070 adults participating in the 2005 US Health Information National Trends Survey. Main variables and outcome measures We examined associations between perceived ambiguity about colon, skin and lung cancer prevention recommendations and two main outcome variables: (i) risk-related cognitions (perceived cancer risk and preventability, cancer-related worry) and (ii) risk-modifying behaviours (colon cancer screening, sunscreen use and smoking abstinence). Results Perceived ambiguity was inversely associated with perceptions of the preventability of all three cancers, and with cancer-specific risk-modifying behaviours including sigmoidoscopy–colonoscopy testing, sunscreen use and smoking abstinence. Relationships with cancer risk perceptions and worry varied across different cancer types. Conclusions Perceived ambiguity about cancer prevention recommendations has significant and predictable associations with cancer prevention-related cognitions and behaviours, and some associations differ by cancer type. These findings have implications for future research and communication efforts. PMID:17986069

  7. The processing of lexical ambiguity in healthy ageing and Parkinson?s disease: role of cortico-subcortical networks.

    PubMed

    Ketteler, Simon; Ketteler, Daniel; Vohn, Ren; Kastrau, Frank; Schulz, Jrg B; Reetz, Kathrin; Huber, Walter

    2014-09-18

    Previous neuroimaging studies showed that correct resolution of lexical ambiguity relies on the integrity of prefrontal and inferior parietal cortices. Whereas prefrontal brain areas were associated with executive control over semantic selection, inferior parietal areas were linked with access to modality-independent representations of semantic memory. Yet insufficiently understood is the contribution of subcortical structures in ambiguity processing. Patients with disturbed basal ganglia function such as Parkinson?s disease (PD) showed development of discourse comprehension deficits evoked by lexical ambiguity. To further investigate the engagement of cortico-subcortical networks functional Magnetic Resonance Imaging (fMRI) was monitored during ambiguity resolution in eight early PD patients without dementia and 14 age- and education-matched controls. Participants were required to relate meanings to a lexically ambiguous target (homonym). Each stimulus consisted of two words arranged on top of a screen, which had to be attributed to a homonym at the bottom. Brain activity was found in bilateral inferior parietal (BA 39), right middle temporal (BA 21/22), left middle frontal (BA 10) and bilateral inferior frontal areas (BA 45/46). Extent and amplitude of activity in the angular gyrus changed depending on semantic association strength that varied between conditions. Less activity in the left caudate was associated with semantic integration deficits in PD. The results of the present study suggest a relationship between subtle language deficits and early stages of basal ganglia dysfunction. Uncovering impairments in ambiguity resolution may be of future use in the neuropsychological assessment of non-motor deficits in PD. PMID:24992291

  8. Top-down influences on ambiguous perception: the role of stable and transient states of the observer

    PubMed Central

    Scocchia, Lisa; Valsecchi, Matteo; Triesch, Jochen

    2014-01-01

    The world as it appears to the viewer is the result of a complex process of inference performed by the brain. The validity of this apparently counter-intuitive assertion becomes evident whenever we face noisy, feeble or ambiguous visual stimulation: in these conditions, the state of the observer may play a decisive role in determining what is currently perceived. On this background, ambiguous perception and its amenability to top-down influences can be employed as an empirical paradigm to explore the principles of perception. Here we offer an overview of both classical and recent contributions on how stable and transient states of the observer can impact ambiguous perception. As to the influence of the stable states of the observer, we show that what is currently perceived can be influenced (1) by cognitive and affective aspects, such as meaning, prior knowledge, motivation, and emotional content and (2) by individual differences, such as gender, handedness, genetic inheritance, clinical conditions, and personality traits and by (3) learning and conditioning. As to the impact of transient states of the observer, we outline the effects of (4) attention and (5) voluntary control, which have attracted much empirical work along the history of ambiguous perception. In the huge literature on the topic we trace a difference between the observer's ability to control dominance (i.e., the maintenance of a specific percept in visual awareness) and reversal rate (i.e., the switching between two alternative percepts). Other transient states of the observer that have more recently drawn researchers' attention regard (6) the effects of imagery and visual working memory. (7) Furthermore, we describe the transient effects of prior history of perceptual dominance. (8) Finally, we address the currently available computational models of ambiguous perception and how they can take into account the crucial share played by the state of the observer in perceiving ambiguous displays. PMID:25538601

  9. Cesare Lombroso: Methodological ambiguities and brilliant intuitions.

    PubMed

    Gatti, Uberto; Verde, Alfredo

    2012-01-01

    This paper on Cesare Lombroso aims to assess his contribution to the criminological sciences. Although much praised worldwide, Lombroso was also the target of scathing criticism and unmitigated condemnation. Examination of Lombroso's method of data collection and analysis reveals his weakness. Indeed, his approach was extremely naive, simplistic and uncritical, aimed at irrefutably demonstrating the hypotheses that he championed, without exercising the methodological caution that was already beginning to characterize scientific research in his day. However, we must acknowledge that his biological theories of crime are undergoing new developments as a result of the recent success of biological psychiatry. On the other hand we should recognize that his work was not limited to his biological central theory; rather, it covered a range of cues and concepts, for the most part ignored, that demonstrate his interest in the economic, cultural and social factors that impact on crime. For these reasons, Lombroso appears to have anticipated many modern conceptions regarding delinquent behavior and criminal justice, such as those of restorative justice, the so-called "situational" theories of criminal behavior and white collar crime. PMID:22154472

  10. Thrombinaptamer recognition: a revealed ambiguity

    PubMed Central

    Russo Krauss, Irene; Merlino, Antonello; Giancola, Concetta; Randazzo, Antonio; Mazzarella, Lelio; Sica, Filomena

    2011-01-01

    Aptamers are structured oligonucleotides that recognize molecular targets and can function as direct protein inhibitors. The best-known example is the thrombin-binding aptamer, TBA, a single-stranded 15-mer DNA that inhibits the activity of thrombin, the key enzyme of coagulation cascade. TBA folds as a G-quadruplex structure, as proved by its NMR structure. The X-ray structure of the complex between TBA and human ?-thrombin was solved at 2.9- resolution, but did not provide details of the aptamer conformation and the interactions with the protein molecule. TBA is rapidly processed by nucleases. To improve the properties of TBA, a number of modified analogs have been produced. In particular, a modified TBA containing a 5?-5? polarity inversion site, mTBA, has higher stability and higher affinity toward thrombin with respect to TBA, although it has a lower inhibitory activity. We present the crystal structure of the thrombinmTBA complex at 2.15- resolution; the resulting model eventually provides a clear picture of thrombinaptamers interaction, and also highlights the structural bases of the different properties of TBA and mTBA. Our findings open the way for a rational design of modified aptamers with improved potency as anticoagulant drugs. PMID:21715374

  11. Processing of the Reduced Relative Clause versus Main Verb Ambiguity in L2 Learners at Different Proficiency Levels

    ERIC Educational Resources Information Center

    Rah, Anne; Adone, Dany

    2010-01-01

    This article presents new evidence from offline and online processing of garden-path sentences that are ambiguous between reduced relative clause resolution and main verb resolution. The participants of this study are intermediate and advanced German learners of English who have learned the language in a nonimmersed context. The results show that

  12. Context sensitivity and ambiguity in component-based systems design

    SciTech Connect

    Bespalko, S.J.; Sindt, A.

    1997-10-01

    Designers of components-based, real-time systems need to guarantee to correctness of soft-ware and its output. Complexity of a system, and thus the propensity for error, is best characterized by the number of states a component can encounter. In many cases, large numbers of states arise where the processing is highly dependent on context. In these cases, states are often missed, leading to errors. The following are proposals for compactly specifying system states which allow the factoring of complex components into a control module and a semantic processing module. Further, the need for methods that allow for the explicit representation of ambiguity and uncertainty in the design of components is discussed. Presented herein are examples of real-world problems which are highly context-sensitive or are inherently ambiguous.

  13. Resolving the range ambiguity in OFDR using digital signal processing

    NASA Astrophysics Data System (ADS)

    Riesen, Nicolas; T-Y Lam, Timothy; Chow, Jong H.

    2014-12-01

    A digitally range-gated variant of optical frequency domain reflectometry is demonstrated which overcomes the beat note ambiguity when sensing beyond a single frequency sweep. The range-gating is achieved using a spread spectrum technique involving time-stamping of the optical signal using high-frequency pseudorandom phase modulation. The reflections from different sections of fiber can then be isolated in the time domain by digitally inverting the phase modulation using appropriately-delayed copies of the pseudorandom noise code. Since the technique overcomes the range ambiguity in OFDR, it permits high sweep repetition rates without sacrificing range, thus allowing for high-bandwidth sensing over long lengths of fiber. This is demonstrated for the case of quasi-distributed sensing.

  14. Integer-ambiguity resolution in astronomy and geodesy

    NASA Astrophysics Data System (ADS)

    Lannes, A.; Prieur, J.-L.

    2014-02-01

    Recent theoretical developments in astronomical aperture synthesis have revealed the existence of integer-ambiguity problems. Those problems, which appear in the self-calibration procedures of radio imaging, have been shown to be similar to the nearest-lattice point (NLP) problems encountered in high-precision geodetic positioning and in global navigation satellite systems. In this paper we analyse the theoretical aspects of the matter and propose new methods for solving those NLP~problems. The related optimization aspects concern both the preconditioning stage, and the discrete-search stage in which the integer ambiguities are finally fixed. Our algorithms, which are described in an explicit manner, can easily be implemented. They lead to substantial gains in the processing time of both stages. Their efficiency was shown via intensive numerical tests.

  15. Relational coherence in ambiguous and unambiguous relational networks.

    PubMed

    Quinones, Jennifer L; Hayes, Steven C

    2014-01-01

    Clinical theories often appeal to general cognitive styles in explaining psychopathology, but without describing in detail how the patterns are formed. In the present investigation, two experiments were conducted to examine how individuals respond to ambiguous relational networks. In both experiments, the participants learned two 3-stimulus networks (A1 LESS THAN B1, A1 GREATER THAN C1 and A2 GREATER THAN B2, C2 LESS THAN A2). Participants were presented with test trials to examine if they classified the combinatorial relations (B1 ? C1 and B2 ? C2) as SAME or DIFFERENT and as GREATER THAN or LESS THAN. Although the B-C combinatorial relation in Network 1 is derivable in a readily coherent way (B1 GREATER THAN C1 and thus also B1 DIFFERENT C1), in Network 2 the combinatorial relation is ambiguous. When participants were required to specify the Network 2 B-C relation as either SAME or DIFFERENT, those who chose DIFFERENT, also consistently chose B2 as either GREATER THAN or LESS THAN C2. Conversely, those who classified the B-C relation as SAME were inconsistent within themselves in choosing B2 as GREATER THAN or LESS THAN C2. In Experiment 2, nonarbitrary multiple exemplar pretraining was used to bias SAME versus DIFFERENT as a response for ambiguous combinatorial relations. In accord with the pattern seen in Experiment 1, those biased toward DIFFERENT consistently chose a comparative relation between B2 and C2 while those biased toward SAME were inconsistent in their comparative choices. The findings provide support for the importance of history and coherence in establishing patterns of responding to ambiguous relational networks, providing a beginning behavioral model of cognitive styles and errors. PMID:24347511

  16. Decision making and ambiguity in auditory stream segregation

    PubMed Central

    Deike, Susann; Heil, Peter; Bckmann-Barthel, Martin; Brechmann, Andr

    2015-01-01

    Researchers of auditory stream segregation have largely taken a bottom-up view on the link between physical stimulus parameters and the perceptual organization of sequences of ABAB sounds. However, in the majority of studies, researchers have relied on the reported decisions of the subjects regarding which of the predefined percepts (e.g., one stream or two streams) predominated when subjects listened to more or less ambiguous streaming sequences. When searching for neural mechanisms of stream segregation, it should be kept in mind that such decision processes may contribute to brain activation, as also suggested by recent human imaging data. The present study proposes that the uncertainty of a subject in making a decision about the perceptual organization of ambiguous streaming sequences may be reflected in the time required to make an initial decision. To this end, subjects had to decide on their current percept while listening to ABAB auditory streaming sequences. Each sequence had a duration of 30 s and was composed of A and B harmonic tone complexes differing in fundamental frequency (?F). Sequences with seven different ?F were tested. We found that the initial decision time varied non-monotonically with ?F and that it was significantly correlated with the degree of perceptual ambiguity defined from the proportions of time the subjects reported a one-stream or a two-stream percept subsequent to the first decision. This strong relation of the proposed measures of decision uncertainty and perceptual ambiguity should be taken into account when searching for neural correlates of auditory stream segregation. PMID:26321899

  17. The classification of ambiguity in polarimetric reconstruction of coronal mass ejection

    SciTech Connect

    Dai, Xinghua; Wang, Huaning; Huang, Xin; Du, Zhanle; He, Han

    2014-01-10

    The Thomson scattering theory indicates that there exist explicit and implicit ambiguities in polarimetric analyses of coronal mass ejection (CME) observations. We suggest a classification for these ambiguities in CME reconstruction. Three samples, including double explicit, mixed, and double implicit ambiguity, are shown with the polarimetric analyses of STEREO CME observations. These samples demonstrate that this classification is helpful for improving polarimetric reconstruction.

  18. Another Kind of Ambiguous Loss: Seventh-Day Adventist Women in Mixed-Orientation Marriages

    ERIC Educational Resources Information Center

    Hernandez, Barbara C.; Wilson, Colwick M.

    2007-01-01

    Narratives of five Seventh-day Adventist heterosexual women whose mixed-orientation marriages ended were analyzed through the lens of ambiguous loss. Thematic coding identified a wave-like process of changing emotional foci that emerged from their experience during marital dissolution. Elements of ambiguous loss included boundary ambiguity,…

  19. Boundary Ambiguity in Parents with Chronically Ill Children: Integrating Theory and Research

    ERIC Educational Resources Information Center

    Berge, Jerica M.; Holm, Kristen E.

    2007-01-01

    This article integrates theory and research related to boundary ambiguity in parents of children with a chronic health condition. We propose that boundary ambiguity is a risk factor for psychological distress in these parents. Clinical applications and a case example highlight how boundary ambiguity can be assessed and managed in clinical settings

  20. Ambiguous Loss after Lesbian Couples with Children Break up: A Case for Same-Gender Divorce

    ERIC Educational Resources Information Center

    Allen, Katherine R.

    2007-01-01

    The theory of ambiguous loss is applied to structural ambiguity and personal transcendence in the parent-child relationship following a same-gender relational ending. Working recursively through the six guidelines of ambiguous loss (finding meaning, tempering mastery, reconstructing identity, normalizing ambivalence, revising attachment, and

  1. Elimination of the direction ambiguity and the dead zone in spectrally resolved interferometry

    NASA Astrophysics Data System (ADS)

    Yun, Young Ho; Seo, Yong Bum; Joo, Ki-Nam

    2016-03-01

    We propose a very simple and effective technique to eliminate the direction ambiguity and the dead zone, which limit the measurable range in spectrally resolved interferometry (SRI). By using a dispersive material, the nonlinear spectral phase caused by the dispersion can provide useful information and determine the direction of measuring distances. In addition, the dead zone is removed by two complementary measurement results in dichroic SRI. As the results of feasibility experiments, it was confirmed that the nonlinearity of the spectral phase successfully determined the direction of the measuring distances. Moreover, the final linear distances in the whole measurement range without the dead zone was obtained in dichroic SRI with two LEDs.

  2. Results.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Describes the Collegiate Results Instrument (CRI), which measures a range of collegiate outcomes for alumni 6 years after graduation. The CRI was designed to target alumni from institutions across market segments and assess their values, abilities, work skills, occupations, and pursuit of lifelong learning. (EV)

  3. Know Concentration Before Giving Acetaminophen to Infants

    MedlinePLUS

    ... For Consumers Consumer Updates Know Concentration Before Giving Acetaminophen to Infants Share Tweet Linkedin Pin it More ... Consumer Updates RSS Feed Download PDF (221 K) Acetaminophen Safety (Podcast) On this page Overdosing Has Been ...

  4. A new ionosphere-free ambiguity resolution method for long-range baseline with GNSS triple-frequency signals

    NASA Astrophysics Data System (ADS)

    Xu, Ying; Ji, Shengyue; Chen, Wu; Weng, Duojie

    2015-10-01

    New GNSS systems (i.e. GPS modernization, BeiDou, and Galileo) will provide multiple navigation signals for reliable navigation services. The triple or even multiple frequency signals are expected to bring great benefits to the ambiguity resolution (AR) over long-range baselines, which is always regarded as a huge challenge. Another issue in the long baseline AR is the unmodeled ionospheric delay, which is one of the major errors in ranging signals. A new triple-frequency, ionosphere-free technique for ambiguity resolution of long-range baseline is developed in this study. In this technique, the optimal observation combinations are chosen considering the effect of ionospheric delay. At the same time, using this technique, the double difference (DD) ionospheric delay is nullified in the ambiguity search process. The performance of the new technique is examined using the simulated GPS triple frequency data as well as the real BDS observation. Results show that the ambiguity can be fixed within 10 min for GPS and BDS long-range baselines with this new technique.

  5. The Role of Informative and Ambiguous Feedback in Avoidance Behavior: Empirical and Computational Findings

    PubMed Central

    Moustafa, Ahmed A.; Sheynin, Jony; Myers, Catherine E.

    2015-01-01

    Avoidance behavior is a critical component of many psychiatric disorders, and as such, it is important to understand how avoidance behavior arises, and whether it can be modified. In this study, we used empirical and computational methods to assess the role of informational feedback and ambiguous outcome in avoidance behavior. We adapted a computer-based probabilistic classification learning task, which includes positive, negative and no-feedback outcomes; the latter outcome is ambiguous as it might signal either a successful outcome (missed punishment) or a failure (missed reward). Prior work with this task suggested that most healthy subjects viewed the no-feedback outcome as strongly positive. Interestingly, in a later version of the classification task, when healthy subjects were allowed to opt out of (i.e. avoid) responding, some subjects (“avoiders”) reliably avoided trials where there was a risk of punishment, but other subjects (“non-avoiders”) never made any avoidance responses at all. One possible interpretation is that the “non-avoiders” valued the no-feedback outcome so positively on punishment-based trials that they had little incentive to avoid. Another possible interpretation is that the outcome of an avoided trial is unspecified and that lack of information is aversive, decreasing subjects’ tendency to avoid. To examine these ideas, we here tested healthy young adults on versions of the task where avoidance responses either did or did not generate informational feedback about the optimal response. Results showed that provision of informational feedback decreased avoidance responses and also decreased categorization performance, without significantly affecting the percentage of subjects classified as “avoiders.” To better understand these results, we used a modified Q-learning model to fit individual subject data. Simulation results suggest that subjects in the feedback condition adjusted their behavior faster following better-than-expected outcomes, compared to subjects in the no-feedback condition. Additionally, in both task conditions, “avoiders” adjusted their behavior faster following worse-than-expected outcomes, and treated the ambiguous no-feedback outcome as less rewarding, compared to non-avoiders. Together, results shed light on the important role of ambiguous and informative feedback in avoidance behavior. PMID:26630279

  6. Ambiguity resolution in precise point positioning with hourly data for global single receiver

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaohong; Li, Pan; Guo, Fei

    2013-01-01

    Integer ambiguity resolution (IAR) can improve precise point positioning (PPP) performance significantly. IAR for PPP became a highlight topic in global positioning system (GPS) community in recent years. More and more researchers focus on this issue. Progress has been made in the latest years. In this paper, we aim at investigating and demonstrating the performance of a global zero-differenced (ZD) PPP IAR service for GPS users by providing routine ZD uncalibrated fractional offsets (UFOs) for wide-lane and narrow-lane. Data sets from all IGS stations collected on DOY 1, 100, 200 and 300 of 2010 are used to validate and demonstrate this global service. Static experiment results show that an accuracy better than 1 cm in horizontal and 1-2 cm in vertical could be achieved in ambiguity-fixed PPP solution with only hourly data. Compared with PPP float solution, an average improvement reaches 58.2% in east, 28.3% in north and 23.8% in vertical for all tested stations. Results of kinematic experiments show that the RMS of kinematic PPP solutions can be improved from 21.6, 16.6 and 37.7 mm to 12.2, 13.3 and 34.3 mm for the fixed solutions in the east, north and vertical components, respectively. Both static and kinematic experiments show that wide-lane and narrow-lane UFO products of all satellites can be generated and provided in a routine way accompanying satellite orbit and clock products for the PPP user anywhere around the world, to obtain accurate and reliable ambiguity-fixed PPP solutions.

  7. Embedded promotions in online services: how goal-relevance ambiguity shapes response and affect.

    PubMed

    Brasel, S Adam

    2010-09-01

    Adding promotions to online services is increasingly commonplace, yet consumers may have difficulty determining whether service-embedded promotions are goal-relevant, due to the linear and transactional nature of online services. This contextual effect of goal-relevance ambiguity on promotions is explored across three studies. An exploratory study utilizing actual service websites and a broad range of consumers as participants showed promotional elements in online services generated considerable confusion, and instructions labeling promotions as optional did little to relieve goal-relevance ambiguity. A second study using student participants inserted promotions into an online airline ticket service, a shopping site, a local news blog, and a news headline aggregator, to explore how linear and transactional sites such as online services compared to more exploratory or informational online environments. Results showed that service-embedded promotions enjoyed initial compliance far beyond promotions in traditional websites but also generated increased confusion, frustration, and anger. A third study utilizing student participants explored how varying levels of online service experience created differing responses to promotions in services; novices were less able to judge promotional goal-relevance and experienced more confusion, whereas experienced searchers were more likely to respond with frustration and anger. Many participants complied with promotional offers at the time of the service transaction, but stated intentions to use the promotion postservice were very low. The overall results spotlight goal-relevance ambiguity as an important driver of consumer response to online promotions, and highlight the role website context can play in the processing of online promotional elements. PMID:20853986

  8. The Effect of Media on Charitable Giving and Volunteering: Evidence from the "Give Five" Campaign

    ERIC Educational Resources Information Center

    Yoruk, Baris K.

    2012-01-01

    Fundraising campaigns advertised via mass media are common. To what extent such campaigns affect charitable behavior is mostly unknown, however. Using giving and volunteering surveys conducted biennially from 1988 to 1996, I investigate the effect of a national fundraising campaign, "Give Five," on charitable giving and volunteering patterns. The

  9. Dressed skeleton expansion and the coupling scale ambiguity problem

    SciTech Connect

    Lu, Hung Jung

    1992-09-01

    Perturbative expansions in quantum field theories are usually expressed in powers of a coupling constant. In principle, the infinite sum of the expansion series is independent of the renormalization scale of the coupling constant. In practice, there is a remnant dependence of the truncated series on the renormalization scale. This scale ambiguity can severely restrict the predictive power of theoretical calculations. The dressed skeleton expansion is developed as a calculational method which avoids the coupling scale ambiguity problem. In this method, physical quantities are expressed as functional expansions in terms of a coupling vertex function. The arguments of the vertex function are given by the physical momenta of each process. These physical momenta effectively replace the unspecified renormalization scale and eliminate the ambiguity problem. This method is applied to various field theoretical models and its main features and limitations are explored. For quantum chromodynamics, an expression for the running coupling constant of the three-gluon vertex is obtained. The effective coupling scale of this vertex is shown to be essentially given by {mu}{sup 2} {approximately} Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} where Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} are respectively the smallest, the next-to-smallest and the largest scale among the three gluon virtualities. This functional form suggests that the three-gluon vertex becomes non-perturbative at asymmetric momentum configurations. Implications for four-jet physics is discussed.

  10. Sounding of the Ion Energization Region: Resolving Ambiguities

    NASA Technical Reports Server (NTRS)

    LaBelle, James

    2003-01-01

    Dartmouth College provided a single-channel high-frequency wave receiver to the Sounding of the Ion Energization Region: Resolving Ambiguities (SIERRA) rocket experiment launched from Poker Flat, Alaska, in January 2002. The receiver used signals from booms, probes, preamplifiers, and differential amplifiers provided by Cornell University coinvestigators. Output was to a dedicated 5 MHz telemetry link provided by WFF, with a small amount of additional Pulse Code Modulation (PCM) telemetry required for the receiver gain information. We also performed preliminary analysis of the data. The work completed is outlined below, in chronological order.

  11. Sibling jealousy and aesthetic ambiguity in Austen's Pride and Prejudice.

    PubMed

    Hanly, Margaret Ann Fitzpatrick

    2009-04-01

    Jane Austen's most popular novel, Pride and Prejudice (1813), illuminates and is illuminated by psychoanalytic aesthetics. When Austen dramatizes unconscious oedipal/sibling rivalries, irony acts as a type of aesthetic ambiguity (E. Kris 1952). A psychoanalytic perspective shows that Austen uses a grammar of negatives (negation, denial, minimization) to achieve the dual meanings of irony, engaging the reader's unconscious instinctual satisfactions, while at the same time protecting the reader from unpleasant affects. Austen's plot, which portrays regressions driven by sibling jealousy, reveals that a new tolerance of remorse and depression in her heroine and hero leads to psychic growth. PMID:19507448

  12. Ambiguity and the evolution of the genetic code.

    PubMed

    Kocherlakota, R R; Acland, N D

    1982-03-01

    The evolution of the genetic code is an extremely complex problem. The addition of a new method by which the code could evolve, however, allows much to be explained about the way in which the present codes (gamma 3 and gamma 3) originated. The idea that ambiguity would allow the length of the codon to change is very useful, since it predicts the distribution of the 4-blocs and 2-blocs in the code, determines where variations in the code are probable, and presents a scenario for the evolution of the code. PMID:7133671

  13. Sensorimotor Adaptation Following Exposure to Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Clement, G. R.; Rupert, A. H.; Reschke, M. F.; Harm, D. L.; Guedry, F. E.

    2007-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. Adaptive changes in how inertial cues from the otolith system are integrated with other sensory information lead to perceptual and postural disturbances upon return to Earth s gravity. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation during tilt and translation motion.

  14. Particle filter-based estimation of inter-frequency phase bias for real-time GLONASS integer ambiguity resolution

    NASA Astrophysics Data System (ADS)

    Tian, Yumiao; Ge, Maorong; Neitzel, Frank

    2015-11-01

    GLONASS could hardly reach the positioning performance of GPS, especially for fast and real-time precise positioning. One of the reasons is the phase inter-frequency bias (IFB) at the receiver end prevents its integer ambiguity resolution. A number of studies were carried out to achieve the integer ambiguity resolution for GLONASS. Based on some of the revealed IFB characteristics, for instance IFB is a linear function of the received carrier frequency and L1 and L2 have the same IFB in unit of length, most of recent methods recommend estimating the IFB rate together with ambiguities. However, since the two sets of parameters are highly correlated, as demonstrated in previous studies, observations over several hours up to 1 day are needed even with simultaneous GPS observations to obtain a reasonable solution. Obviously, these approaches cannot be applied for real-time positioning. Actually, it can be demonstrated that GLONASS ambiguity resolution should also be available even for a single epoch if the IFB rate is precisely known. In addition, the closer the IFB rate value is to its true value, the larger the fixing RATIO will be. Based on this fact, in this paper, a new approach is developed to estimate the IFB rate by means of particle filtering with the likelihood function derived from RATIO. This approach is evaluated with several sets of experimental data. For both static and kinematic cases, the results show that IFB rates could be estimated precisely just with GLONASS data of a few epochs depending on the baseline length. The time cost with a normal PC can be controlled around 1 s and can be further reduced. With the estimated IFB rate, integer ambiguity resolution is available immediately and as a consequence, the positioning accuracy is improved significantly to the level of GPS fixed solution. Thus the new approach enables real-time precise applications of GLONASS.

  15. Partial Ambiguity Resolution for Ground and Space-Based Applications in a GPS+Galileo scenario: A simulation study

    NASA Astrophysics Data System (ADS)

    Nardo, A.; Li, B.; Teunissen, P. J. G.

    2016-01-01

    Integer Ambiguity Resolution (IAR) is the key to fast and precise GNSS positioning. The proper diagnostic metric for successful IAR is provided by the ambiguity success rate being the probability of correct integer estimation. In this contribution we analyse the performance of different GPS+Galileo models in terms of number of epochs needed to reach a pre-determined success rate, for various ground and space-based applications. The simulation-based controlled model environment enables us to gain insight into the factors contributing to the ambiguity resolution strength of the different GPS+Galileo models. Different scenarios of modernized GPS+Galileo are studied, encompassing the long baseline ground case as well as the medium dynamics case (airplane) and the space-based Low Earth Orbiter (LEO) case. In our analyses of these models the capabilities of partial ambiguity resolution (PAR) are demonstrated and compared to the limitations of full ambiguity resolution (FAR). The results show that PAR is generally a more efficient way than FAR to reduce the time needed to achieve centimetre-level positioning precision. For long single baselines, PAR can achieve time reductions of fifty percent to achieve such precision levels, while for multiple baselines it even becomes more effective, reaching reductions up to eighty percent for four station networks. For a LEO, the rapidly changing observation geometry does not even allow FAR, while PAR is then still possible for both dual- and triple-frequency scenarios. With the triple-frequency GPS+Galileo model the availability of precise positioning improves by fifteen percent with respect to the dual-frequency scenario.

  16. Tactile input and empathy modulate the perception of ambiguous biological motion

    PubMed Central

    Yiltiz, Hrmetjan; Chen, Lihan

    2015-01-01

    Evidence has shown that task-irrelevant auditory cues can bias perceptual decisions regarding directional information associated with biological motion, as indicated in perceptual tasks using point-light walkers (PLWs) (Brooks et al., 2007). In the current study, we extended the investigation of cross-modal influences to the tactile domain by asking how tactile input resolves perceptual ambiguity in visual apparent motion, and how empathy plays a role in this cross-modal interaction. In Experiment 1, we simulated the tactile feedback on the observers' fingertips when the (upright or inverted) PLWs (comprised of either all red or all green dots) were walking (leftwards or rightwards). The temporal periods between tactile events and critical visual events (the PLW's feet hitting the ground) were manipulated so that the tap could lead, synchronize, or lag the visual foot-hitting-ground event. We found that the temporal structures between tactile (feedback) and visual (hitting) events systematically biases the directional perception for upright PLWs, making either leftwards or rightwards more dominant. However, this effect was absent for inverted PLWs. In Experiment 2, we examined how empathy modulates cross-modal capture. Instead of giving tactile feedback on participants' fingertips, we gave taps on their ankles and presented the PLWs with motion directions of approaching (facing toward observer)/receding (facing away from observer) to resemble normal walking postures. With the same temporal structure, we found that individuals with higher empathy were more subject to perceptual bias in the presence of tactile feedback. Taken together, our findings showed that task-irrelevant tactile input can resolve the otherwise ambiguous perception of the direction of biological motion, and this cross-modal bias was mediated by higher level social-cognitive factors, including empathy. PMID:25750631

  17. GNSS Carrier Phase Integer Ambiguity Resolution with Camera and Satellite images

    NASA Astrophysics Data System (ADS)

    Henkel, Patrick

    2015-04-01

    Ambiguity Resolution is the key to high precision position and attitude determination with GNSS. However, ambiguity resolution of kinematic receivers becomes challenging in environments with substantial multipath, limited satellite availability and erroneous cycle slip corrections. There is a need for other sensors, e.g. inertial sensors that allow an independent prediction of the position. The change of the predicted position over time can then be used for cycle slip detection and correction. In this paper, we provide a method to improve the initial ambiguity resolution for RTK and PPP with vision-based position information. Camera images are correlated with geo-referenced aerial/ satellite images to obtain an independent absolute position information. This absolute position information is then coupled with the GNSS and INS measurements in an extended Kalman filter to estimate the position, velocity, acceleration, attitude, angular rates, code multipath and biases of the accelerometers and gyroscopes. The camera and satellite images are matched based on some characteristic image points (e.g. corners of street markers). We extract these characteristic image points from the camera images by performing the following steps: An inverse mapping (homogenous projection) is applied to transform the camera images from the driver's perspective to bird view. Subsequently, we detect the street markers by performing (a) a color transformation and reduction with adaptive brightness correction to focus on relevant features, (b) a subsequent morphological operation to enhance the structure recognition, (c) an edge and corner detection to extract feature points, and (d) a point matching of the corner points with a template to recognize the street markers. We verified the proposed method with two low-cost u-blox LEA 6T GPS receivers, the MPU9150 from Invensense, the ASCOS RTK corrections and a PointGrey camera. The results show very precise and seamless position and attitude estimates in an urban environment with substantial multipath.

  18. Effects of task-switching on neural representations of ambiguous sound input.

    PubMed

    Sussman, Elyse S; Bregman, Albert S; Lee, Wei-Wei

    2014-09-30

    The ability to perceive discrete sound streams in the presence of competing sound sources relies on multiple mechanisms that organize the mixture of the auditory input entering the ears. Many studies have focused on mechanisms that contribute to integrating sounds that belong together into one perceptual stream (integration) and segregating those that come from different sound sources (segregation). However, little is known about mechanisms that allow us to perceive individual sound sources within a dynamically changing auditory scene, when the input may be ambiguous, and heard as either integrated or segregated. This study tested the question of whether focusing on one of two possible sound organizations suppressed representation of the alternative organization. We presented listeners with ambiguous input and cued them to switch between tasks that used either the integrated or the segregated percept. Electrophysiological measures indicated which organization was currently maintained in memory. If mutual exclusivity at the neural level was the rule, attention to one of two possible organizations would preclude neural representation of the other. However, significant MMNs were elicited to both the target organization and the unattended, alternative organization, along with the target-related P3b component elicited only to the designated target organization. Results thus indicate that both organizations (integrated and segregated) were simultaneously maintained in memory regardless of which task was performed. Focusing attention to one aspect of the sounds did not abolish the alternative, unattended organization when the stimulus input was ambiguous. In noisy environments, such as walking on a city street, rapid and flexible adaptive processes are needed to help facilitate rapid switching to different sound sources in the environment. Having multiple representations available to the attentive system would allow for such flexibility, needed in everyday situations to maintain stable auditory percepts, and to allow rapid scanning of interesting events in a busy environment. PMID:25281308

  19. Community College Alumni: Predicting Who Gives

    ERIC Educational Resources Information Center

    Skari, Lisa Ann

    2014-01-01

    Due to the decrease in public funding, community colleges are in a position where they need to generate private gifts. Alumni represent the largest untapped pool of prospective donors, and the success of alumni giving at 4-year institutions illustrates the potential that exists for community colleges. To develop effective fundraising strategies,

  20. How School Boards Give Recognition to Staff.

    ERIC Educational Resources Information Center

    Canadian Education Association, Toronto (Ontario).

    This report focuses on measures that can be taken by school boards to give recognition to their staff and improve the quality of their employees' working life. The report is based on the findings of a survey done by the Canadian Education Association, to which 103 out of 224 school boards responded. The first section describes ways of recognizing

  1. Asian American Giving to US Higher Education

    ERIC Educational Resources Information Center

    Tsunoda, Kozue

    2010-01-01

    Asian Americans have had significant impacts on and within mainstream US society, and their great efforts and gifts in the name of charitable causes are no exception. This study aims to examine perceptions within American university development offices about Asian American giving to US higher education. The article begins with a literature review…

  2. Todd Baumann Gives a Thumbs Up

    USGS Multimedia Gallery

    USGS hydrologist Todd Baumann gives a thumbs up after setting the Acoustic Doppler Current Profiler (ADCP) aboard the Butta Bean during the 2011 Flood. USGS uses the ADCP to make streamflow measurements. The ADCP emits soundwaves through the water column, which rebound off particles in the water ...

  3. Satiation or availability? Effects of attention, memory, and imagery on the perception of ambiguous figures

    NASA Technical Reports Server (NTRS)

    Horlitz, Krista L.; O'Leary, Ann

    1993-01-01

    The prolonged-inspection technique has been used to demonstrate effects of satiation on the perception of ambiguous figures. We propose that the inspection phase, in which subjects view an unambiguous version of the stimulus prior to observing the ambiguous figure, does not create neural fatigue but rather provides a context in which the alternative percept is apprehended and gains perceptual strength through processes such as imagination or memory. The consequent availability of the alternative organization drives the perceptual phenomena that have been thought to reflect satiation. In Experiment 1, we demonstrated that (1) preexperimental exposure to the target figures and (2) allocation of attention to the inspection figures were both necessary in order to obtain results similar to those predicted by the satiation model. In Experiment 2, we obtained similar results, finding that effects of prior inspection were greater the greater the amount and availability of information regarding the alternative percept during the inspection phase. Subjects who generated visual images of the noninspected alternative during inspection yielded results comparable to those from subjects to whom both versions were presented visually.

  4. Perceived Ambiguity About Cancer Prevention Recommendations: Relationship to Perceptions of Cancer Preventability, Risk, and Worry

    PubMed Central

    Han, Paul K. J.; Moser, Richard P.; Klein, William M. P.

    2014-01-01

    In this study, we apply the concept of “ambiguity,” as developed in the decision theory literature, to an analysis of potential psychological consequences of uncertainty about cancer prevention recommendations. We used Health Information National Trends Survey (HINTS) 2003 data to examine how perceived ambiguity about cancer prevention recommendations relates to three other cognitive variables known to influence cancer-protective behavior: perceived cancer preventability, perceived cancer risk, and cancer-related worry. Using logistic regression analyses, we tested several predictions derived from a review of literature on the effects of ambiguity perceptions on decision making, cognitions, and emotions. We found perceived ambiguity to have a strong negative relationship with perceived cancer preventability, consistent with “ambiguity aversion”—a pessimistic bias in the interpretation of ambiguity. Cancer worry moderated this relationship; ambiguity aversion increased with higher levels of worry. At the same time, perceived ambiguity was positively related to both perceived cancer risk and cancer worry. Furthermore, perceived risk partially mediated the relationship between perceived ambiguity and worry. These findings suggest that perceived ambiguity about cancer prevention recommendations may have broad and important effects on other health cognitions. We discuss ethical implications of these findings for health communication efforts, and propose a tentative causal model to guide future research. PMID:16641074

  5. Statistical analysis of the ambiguities in the asteroid period determinations

    NASA Astrophysics Data System (ADS)

    Butkiewicz, M.; Kwiatkowski, T.; Bartczak, P.; Dudziński, G.

    2014-07-01

    A synodic period of an asteroid can be derived from its lightcurve by standard methods like Fourier-series fitting. A problem appears when results of observations are based on less than a full coverage of a lightcurve and/or high level of noise. Also, long gaps between individual lightcurves create an ambiguity in the cycle count which leads to aliases. Excluding binary systems and objects with non-principal-axis rotation, the rotation period is usually identical to the period of the second Fourier harmonic of the lightcurve. There are cases, however, where it may be connected with the 1st, 3rd, or 4th harmonic and it is difficult to choose among them when searching for the period. To help remove such uncertainties we analysed asteroid lightcurves for a range of shapes and observing/illuminating geometries. We simulated them using a modified internal code from the ISAM service (Marciniak et al. 2012, A&A 545, A131). In our computations, shapes of asteroids were modeled as Gaussian random spheres (Muinonen 1998, A&A, 332, 1087). A combination of Lommel-Seeliger and Lambert scattering laws was assumed. For each of the 100 shapes, we randomly selected 1000 positions of the spin axis, systematically changing the solar phase angle with a step of 5°. For each lightcurve, we determined its peak-to-peak amplitude, fitted the 6th-order Fourier series and derived the amplitudes of its harmonics. Instead of the number of the lightcurve extrema, which in many cases is subjective, we characterized each lightcurve by the order of the highest-amplitude Fourier harmonic. The goal of our simulations was to derive statistically significant conclusions (based on the underlying assumptions) about the dominance of different harmonics in the lightcurves of the specified amplitude and phase angle. The results, presented in the Figure, can be used in individual cases to estimate the probability that the obtained lightcurve is dominated by a specified Fourier harmonic. Some of the conclusions are: (1) the 4th harmonic dominates about 1 percent of lightcurves only at low amplitudes (A<0.1 mag, α < 40°). (2) The dominance of the 3rd harmonic can be observed more often only in the case of near-Earth asteroids, observed at α > 30°; for the main-belt asteroids (MBAs), it can be present only in small amplitude lightcurves (A < 0.1 mag). (3) The 1st harmonic is present quite often in the low-amplitude (A < 0.2 mag) lightcurves of MBAs; for NEAs it can be seen even in high-amplitude lightcurves (A<0.7~mag for α≃ 40°, A<0.9~mag for α ≃ 50°). (4) In 100 percent of the cases, the 2nd harmonic dominates the lightcurves of MBAs whose amplitudes A > 0.2 mag.

  6. Vaccine Hesitancy: Clarifying a Theoretical Framework for an Ambiguous Notion

    PubMed Central

    Peretti-Watel, Patrick; Larson, Heidi J; Ward, Jeremy K.; Schulz, William S; Verger, Pierre

    2015-01-01

    Today, according to many public health experts, public confidence in vaccines is waning. The term “vaccine hesitancy” (VH) is increasingly used to describe the spread of such vaccine reluctance. But VH is an ambiguous notion and its theoretical background appears uncertain. To clarify this concept, we first review the current definitions of VH in the public health literature and examine its most prominent characteristics. VH has been defined as a set of beliefs, attitudes, or behaviours, or some combination of them, shared by a large and heterogeneous portion of the population and including people who exhibit reluctant conformism (they may either decline a vaccine, delay it or accept it despite their doubts) and vaccine-specific behaviours. Secondly, we underline some of the ambiguities of this notion and argue that it is more a catchall category than a real concept. We also call into question the usefulness of understanding VH as an intermediate position along a continuum ranging from anti-vaccine to pro-vaccine attitudes, and we discuss its qualification as a belief, attitude or behaviour. Thirdly, we propose a theoretical framework, based on previous literature and taking into account some major structural features of contemporary societies, that considers VH as a kind of decision-making process that depends on people’s level of commitment to healthism/risk culture and on their level of confidence in the health authorities and mainstream medicine. PMID:25789201

  7. Stochastic exploration of ambiguities for nonrigid shape recovery.

    PubMed

    Moreno-Noguer, Francesc; Fua, Pascal

    2013-02-01

    Recovering the 3D shape of deformable surfaces from single images is known to be a highly ambiguous problem because many different shapes may have very similar projections. This is commonly addressed by restricting the set of possible shapes to linear combinations of deformation modes and by imposing additional geometric constraints. Unfortunately, because image measurements are noisy, such constraints do not always guarantee that the correct shape will be recovered. To overcome this limitation, we introduce a stochastic sampling approach to efficiently explore the set of solutions of an objective function based on point correspondences. This allows us to propose a small set of ambiguous candidate 3D shapes and then use additional image information to choose the best one. As a proof of concept, we use either motion or shading cues to this end and show that we can handle a complex objective function without having to solve a difficult nonlinear minimization problem. The advantages of our method are demonstrated on a variety of problems including both real and synthetic data. PMID:22547426

  8. Speech rhythm facilitates syntactic ambiguity resolution: ERP evidence.

    PubMed

    Roncaglia-Denissen, Maria Paula; Schmidt-Kassow, Maren; Kotz, Sonja A

    2013-01-01

    In the current event-related potential (ERP) study, we investigated how speech rhythm impacts speech segmentation and facilitates the resolution of syntactic ambiguities in auditory sentence processing. Participants listened to syntactically ambiguous German subject- and object-first sentences that were spoken with either regular or irregular speech rhythm. Rhythmicity was established by a constant metric pattern of three unstressed syllables between two stressed ones that created rhythmic groups of constant size. Accuracy rates in a comprehension task revealed that participants understood rhythmically regular sentences better than rhythmically irregular ones. Furthermore, the mean amplitude of the P600 component was reduced in response to object-first sentences only when embedded in rhythmically regular but not rhythmically irregular context. This P600 reduction indicates facilitated processing of sentence structure possibly due to a decrease in processing costs for the less-preferred structure (object-first). Our data suggest an early and continuous use of rhythm by the syntactic parser and support language processing models assuming an interactive and incremental use of linguistic information during language processing. PMID:23409109

  9. Radiological Evaluation of Ambiguous Genitalia with Various Imaging Modalities

    NASA Astrophysics Data System (ADS)

    Ravi, N.; Bindushree, Kadakola

    2012-07-01

    Disorders of sex development (DSDs) are congenital conditions in which the development of chromosomal, gonadal, or anatomic sex is atypical. These can be classified broadly into four categories on the basis of gonadal histologic features: female pseudohermaphroditism (46,XX with two ovaries); male pseudohermaphroditism (46,XY with two testes); true hermaphroditism (ovotesticular DSD) (both ovarian and testicular tissues); and gonadal dysgenesis, either mixed (a testis and a streak gonad) or pure (bilateral streak gonads). Imaging plays an important role in demonstrating the anatomy and associated anomalies. Ultrasonography is the primary modality for demonstrating internal organs and magnetic resonance imaging is used as an adjunct modality to assess for internal gonads and genitalia. Early and appropriate gender assignment is necessary for healthy physical and psychologic development of children with ambiguous genitalia. Gender assignment can be facilitated with a team approach that involves a pediatric endocrinologist, geneticist, urologist, psychiatrist, social worker, neonatologist, nurse, and radiologist, allowing timely diagnosis and proper management. We describe case series on ambiguous genitalia presented to our department who were evaluated with multiple imaging modalities.

  10. Psychoanalytic and musical ambiguity: the tritone in gee, officer krupke.

    PubMed

    Jaffee Nagel, Julie

    2010-02-01

    The poignant and timeless Broadway musical West Side Story is viewed from the standpoint of taking musical forms as psychoanalytic data. The musical configuration of notes called the tritone (or diabolus in musica) is taken as a sonic metaphor expressing ambiguity both in musical vocabulary and in mental life. The tritone, which historically and harmonically represents instability, is heard throughout the score and emphasizes the intrapsychic, interpersonal, and social dramas that unfold within and between the two gangs in West Side Story. Particular emphasis is given to the comic but exceedingly sober song Gee, Officer Krupke. Bernstein's sensitivity to the ambiguity and tension inherent in the tritone in West Side Story is conceptualized as an intersection of music theory and theories of mind; this perspective holds implications for clinical practice and transports psychoanalytic concepts from the couch to the Broadway stage and into the community to address the complexities of love, hate, aggression, prejudice, and violence. Ultimately, West Side Story cross-pollinates music and theater, as well as music and psychoanalytic concepts. PMID:20234007

  11. Phase-wrapping ambiguity in along-track interferometry

    NASA Astrophysics Data System (ADS)

    Deming, Ross; Ilin, Roman; Best, Matthew

    2013-05-01

    In a previous SPIE paper we described several variations of along-track interferometry (ATI), which can be used for moving target detection and geo-location in clutter. ATI produces a phase map in range/Doppler coordinates by combining radar data from several receive channels separated fore-and-aft (along-track) on the sensor platform. In principle, the radial velocity of a moving target can be estimated from the ATI phase of the pixels in the target signature footprint. Once the radial velocity is known, the target azimuth follows directly. Unfortunately, the ATI phase is wrapped, i.e., it repeats in the interval [-?, ?], and therefore the mapping from ATI phase to target azimuth is non-unique. In fact, depending on the radar system parameters, each detected target can map to several equally-likely azimuth values. In the present paper we discuss a signal processing method for resolving the phase wrapping ambiguity, in which the radar bandwidth is split into a high and low sub-band in software, and an ATI phase map is generated for each. By subtracting these two phase maps we can generate a coarse, but unambiguous, radial velocity estimate. This coarse estimate is then combined with the fine, but ambiguous estimate to pinpoint the target radial velocity, and therefore its azimuth. Since the coarse estimate is quite sensitive to noise, a rudimentary tracker is used to help smooth out the phase errors. The method is demonstrated on Gotcha 2006 Challenge data.

  12. Narrowing historical uncertainty: probabilistic classification of ambiguously identified tree species in historical forest survey data

    USGS Publications Warehouse

    Mladenoff, D.J.; Dahir, S.E.; Nordheim, E.V.; Schulte, L.A.; Guntenspergen, G.R.

    2002-01-01

    Historical data have increasingly become appreciated for insight into the past conditions of ecosystems. Uses of such data include assessing the extent of ecosystem change; deriving ecological baselines for management, restoration, and modeling; and assessing the importance of past conditions on the composition and function of current systems. One historical data set of this type is the Public Land Survey (PLS) of the United States General Land Office, which contains data on multiple tree species, sizes, and distances recorded at each survey point, located at half-mile (0.8 km) intervals on a 1-mi (1.6 km) grid. This survey method was begun in the 1790s on US federal lands extending westward from Ohio. Thus, the data have the potential of providing a view of much of the US landscape from the mid-1800s, and they have been used extensively for this purpose. However, historical data sources, such as those describing the species composition of forests, can often be limited in the detail recorded and the reliability of the data, since the information was often not originally recorded for ecological purposes. Forest trees are sometimes recorded ambiguously, using generic or obscure common names. For the PLS data of northern Wisconsin, USA, we developed a method to classify ambiguously identified tree species using logistic regression analysis, using data on trees that were clearly identified to species and a set of independent predictor variables to build the models. The models were first created on partial data sets for each species and then tested for fit against the remaining data. Validations were conducted using repeated, random subsets of the data. Model prediction accuracy ranged from 81% to 96% in differentiating congeneric species among oak, pine, ash, maple, birch, and elm. Major predictor variables were tree size, associated species, landscape classes indicative of soil type, and spatial location within the study region. Results help to clarify ambiguities formerly present in maps of historic ecosystems for the region and can be applied to PLS datasets elsewhere, as well as other sources of ambiguous historical data. Mapping the newly classified data with ecological land units provides additional information on the distribution, abundance, and associations of tree species, as well as their relationships to environmental gradients before the industrial period, and clarifies the identities of species formerly mapped only to genus. We offer some caveats on the appropriate use of data derived in this way, as well as describing their potential.

  13. Living With Ambiguity: A Metasynthesis of Qualitative Research on Mild Cognitive Impairment

    PubMed Central

    Gomersall, Tim; Astell, Arlene; Nygård, Louise; Sixsmith, Andrew; Mihailidis, Alex; Hwang, Amy

    2015-01-01

    Purpose of the study: Mild Cognitive Impairment (MCI) is a diagnosis proposed to describe an intermediate state between normal cognitive aging and dementia. MCI has been criticised for its conceptual fuzziness, its ambiguous relationship to dementia, and the tension it creates between medical and sociological understandings of “normal aging”. Design and Methods: We examined the published qualitative literature on experiences of being diagnosed and living with MCI using metasynthesis as the methodological framework. Results: Two overarching conceptual themes were developed. The first, MCI and myself-in-time, showed that a diagnosis of MCI could profoundly affect a person’s understanding of their place in the world. This impact appears to be mediated by multiple factors including a person’s social support networks, which daily activities are affected, and subjective interpretations of the meaning of MCI. The second theme, Living with Ambiguity, describes the difficulties people experienced in making sense of their diagnosis. Uncertainty arose, in part, from lack of clarity and consistency in the information received by people with MCI, including whether they are even told MCI is the diagnosis. Implications: We conclude by suggesting an ethical tension is always at play when a MCI diagnosis is made. Specifically, earlier support and services afforded by a diagnosis may come at the expense of a person’s anxiety about the future, with continued uncertainty about how his or her concerns and needs can be addressed. PMID:26315317

  14. Interpretation of ambiguity: Differences between children and adolescents with and without an anxiety disorder

    PubMed Central

    Waite, Polly; Codd, Jon; Creswell, Cathy

    2015-01-01

    Background Theory and treatment of anxiety disorders in young people are commonly based on the premise that interpretation biases found in anxious adults are also found in children and adolescents. Although there is some evidence that this may be the case, studies have not typically taken age into account, which is surprising given the normative changes in cognition that occur throughout childhood. The aim of the current study was to identify whether associations between anxiety disorder status and interpretation biases differed in children and adolescents. Methods The responses of children (7–10 years) and adolescents (13–16 years) with and without anxiety disorders (n=120) were compared on an ambiguous scenarios task. Results Children and adolescents with an anxiety disorder showed significantly higher levels of threat interpretation and avoidant strategies than non-anxious children and adolescents. However, age significantly moderated the effect of anxiety disorder status on interpretation of ambiguity, in that adolescents with anxiety disorders showed significantly higher levels of threat interpretation and associated negative emotion than non-anxious adolescents, but a similar relationship was not observed among children. Conclusions The findings suggest that theoretical accounts of interpretation biases in anxiety disorders in children and adolescents should distinguish between different developmental periods. For both ages, treatment that targets behavioral avoidance appears warranted. However, while adolescents are likely to benefit from treatment that addresses interpretation biases, there may be limited benefit for children under the age of ten. PMID:26363617

  15. A new ambiguity acceptance test threshold determination method with controllable failure rate

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Verhagen, Sandra

    2015-04-01

    The ambiguity acceptance test is an important quality control procedure in high precision GNSS data processing. Although the ambiguity acceptance test methods have been extensively investigated, its threshold determine method is still not well understood. Currently, the threshold is determined with the empirical approach or the fixed failure rate (FF-) approach. The empirical approach is simple but lacking in theoretical basis, while the FF-approach is theoretical rigorous but computationally demanding. Hence, the key of the threshold determination problem is how to efficiently determine the threshold in a reasonable way. In this study, a new threshold determination method named threshold function method is proposed to reduce the complexity of the FF-approach. The threshold function method simplifies the FF-approach by a modeling procedure and an approximation procedure. The modeling procedure uses a rational function model to describe the relationship between the FF-difference test threshold and the integer least-squares (ILS) success rate. The approximation procedure replaces the ILS success rate with the easy-to-calculate integer bootstrapping (IB) success rate. Corresponding modeling error and approximation error are analysed with simulation data to avoid nuisance biases and unrealistic stochastic model impact. The results indicate the proposed method can greatly simplify the FF-approach without introducing significant modeling error. The threshold function method makes the fixed failure rate threshold determination method feasible for real-time applications.

  16. Virtual baseline method for Beidou attitude determination - An improved long-short baseline ambiguity resolution method

    NASA Astrophysics Data System (ADS)

    Lu, Liangqing; Li, Yong; Rizos, Chris

    2013-03-01

    Ambiguity resolution (AR) is a critical step for successful attitude determination using carrier phase measurements of a satellite navigation system such as Beidou. This paper proposes an improved method for AR in support of Beidou attitude determination based on the concept of a "virtual baseline". In the traditional long-short baseline method, the short baseline is limited to a length less than half of the carrier wave length of the Beidou signals. In the proposed method, a virtual short baseline is formed by differencing two collinear baselines. The AR equations for virtual short and long baselines are derived and the factors impacting the AR accuracy are analysed. Numerical simulation studies were carried out to evaluate the performance of the proposed AR method. The simulation results confirmed that the proposed method is an improvement over the traditional approach -- not only is it easier to deploy collinear antennas but also it keeps the capability of epoch-by-epoch AR, which makes it immune to cycle slips and there is no need for initialisation of ambiguity searching.

  17. Resolution of sensory ambiguities for gaze stabilization requires a second neural integrator

    NASA Technical Reports Server (NTRS)

    Green, Andrea M.; Angelaki, Dora E.

    2003-01-01

    The ability to simultaneously move in the world and maintain stable visual perception depends critically on the contribution of vestibulo-ocular reflexes (VORs) to gaze stabilization. It is traditionally believed that semicircular canal signals drive compensatory responses to rotational head disturbances (rotational VOR), whereas otolith signals compensate for translational movements [translational VOR (TVOR)]. However, a sensory ambiguity exists because otolith afferents are activated similarly during head translations and reorientations relative to gravity (i.e., tilts). Extra-otolith cues are, therefore, necessary to ensure that dynamic head tilts do not elicit a TVOR. To investigate how extra-otolith signals contribute, we characterized the temporal and viewing distance-dependent properties of a TVOR elicited in the absence of a lateral acceleration stimulus to the otoliths during combined translational/rotational motion. We show that, in addition to otolith signals, angular head position signals derived by integrating sensory canal information drive the TVOR. A physiological basis for these results is proposed in a model with two distinct integration steps. Upstream of the well known oculomotor velocity-to-position neural integrator, the model incorporates a separate integration element that could represent the "velocity storage integrator," whose functional role in the oculomotor system has so far remained controversial. We propose that a key functional purpose of the velocity storage network is to temporally integrate semicircular canal signals, so that they may be used to extract translation information from ambiguous otolith afferent signals in the natural and functionally relevant bandwidth of head movements.

  18. Polymorphisms and ambiguous sites present in DNA sequences of Leishmania clones: looking closer.

    PubMed

    Boit, Mariana Crtes; de Oliveira, Tase Salgado; Ferreira, Gabriel Eduardo Melim; Trannin, Marcos; dos Santos, Barbara Neves; Porrozzi, Renato; Cupolillo, Elisa

    2014-07-01

    In genetic studies of Leishmania parasites, co-dominant markers are chosen for their ability to detect heterozygous polymorphisms, to infer the occurrence of inbreeding and to resolve genetic variability. The majority of DNA sequence based reports perform conventional dye terminator cycle sequencing where perfectly ambiguous sites or double peaks in the chromatogram are interpreted as heterozygous strains. However, molecular peculiarities of the parasite such as aneuploidy, mixed populations and homologous recombination advise that data from regular DNA sequence analysis should be carefully evaluated. We report here a closer look at ambiguous sites observed in 6pgd DNA sequences obtained for a multilocus sequence analysis project on Leishmania (Viannia) strains. After comparing 286 DNA sequences from biological and molecular clones of six L. (Viannia) strains we could distinguish events that contribute to genetic variation in Leishmania (recombination, mutation, chromosomal mosaics). Also, the results suggest how diversity might not be completely revealed through regular DNA sequence analysis and demonstrate the importance for molecular epidemiology research to be aware of such possibilities while choosing samples for studies. PMID:24768683

  19. Trait Anxiety Has Effect on Decision Making under Ambiguity but Not Decision Making under Risk

    PubMed Central

    Zhang, Long; Wang, Kai; Zhu, Chunyan; Yu, Fengqiong; Chen, Xingui

    2015-01-01

    Previous studies have reported that trait anxiety (TA) affects decision making. However, results remain largely inconsistent across studies. The aim of the current study was to further address the interaction between TA and decision making. 304 subjects without depression from a sample consisting of 642 participants were grouped into high TA (HTA), medium TA (MTA) and low TA (LTA) groups based on their TA scores from State Trait Anxiety Inventory. All subjects were assessed with the Iowa Gambling Task (IGT) that measures decision making under ambiguity and the Game of Dice Task (GDT) that measures decision making under risk. While the HTA and LTA groups performed worse on the IGT compared to the MTA group, performances on the GDT between the three groups did not differ. Furthermore, the LTA and HTA groups showed different individual deck level preferences in the IGT: the former showed a preference for deck B indicating that these subjects focused more on the magnitude of rewards, and the latter showed a preference for deck A indicating significant decision making impairment. Our findings suggest that trait anxiety has effect on decision making under ambiguity but not decision making under risk and different levels of trait anxiety related differently to individual deck level preferences in the IGT. PMID:26000629

  20. Resolving ambiguities in nanowire field-effect transistor characterization

    NASA Astrophysics Data System (ADS)

    Heedt, Sebastian; Otto, Isabel; Sladek, Kamil; Hardtdegen, Hilde; Schubert, Jürgen; Demarina, Natalia; Lüth, Hans; Grützmacher, Detlev; Schäpers, Thomas

    2015-10-01

    We have modeled InAs nanowires using finite element methods considering the actual device geometry, the semiconducting nature of the channel and surface states, providing a comprehensive picture of charge distribution and gate action. The effective electrostatic gate width and screening effects are taken into account. A pivotal aspect is that the gate coupling to the nanowire is compromised by the concurrent coupling of the gate electrode to the surface/interface states, which provide the vast majority of carriers for undoped nanowires. In conjunction with field-effect transistor (FET) measurements using two gates with distinctly dissimilar couplings, the study reveals the density of surface states that gives rise to a shallow quantum well at the surface. Both gates yield identical results for the electron concentration and mobility only at the actual surface state density. Our method remedies the flaws of conventional FET analysis and provides a straightforward alternative to intricate Hall effect measurements on nanowires.

  1. Ambiguities and symmetry relations associated with fermionic tensor densities

    SciTech Connect

    Dallabona, G.; Battistel, O. A.

    2004-09-15

    We consider the consistent evaluation of perturbative (divergent) Green functions associated with fermionic tensor densities and the derivation of symmetry relations for them. We show that, in spite of current algebra methods being not applicable, it is possible to derive symmetry properties analogous to the Ward identities of vector and axial-vector densities. The proposed method, which is applicable to any previously chosen order of perturbative calculation, gives the same results as those of current algebra when such a tool is applicable. By using a very general calculational strategy, concerning the manipulations and calculations involving divergent Feynman integrals, we evaluate the purely fermionic two-point functions containing tensor vertices and derive their symmetry properties. The present investigation is the first step in the study and characterization of possible anomalies involving fermionic tensor densities, particularly in purely fermionic three-point functions.

  2. Freud in Trieste: journey to an ambiguous city.

    PubMed

    Gandolfi, Laura

    2010-01-01

    This article provides an insightful exploration of the relationship between Sigmund Freud and the city of Trieste. Through an analysis of the correspondence between Freud and his friend Eduard Silberstein, Gandolfi follows those places visited by the future father of psychoanalysis and analyses their link to Freud's life. The journey to Trieste is considered as an experience that played a fundamental role in his future decisions as well as in the development of some of his psychoanalytic theories. The article eventually relates the ambiguous nature of the city - a peculiar space in with North and South, East and West converge - to Freud's own Triestine experience, that not only remits to his initial scientific researches, but also symbolizes a first significant contact with the world of sexuality. PMID:20842812

  3. Fast Integer Ambiguity Resolution for GPS Attitude Determination

    NASA Technical Reports Server (NTRS)

    Lightsey, E. Glenn; Crassidis, John L.; Markley, F. Landis

    1999-01-01

    In this paper, a new algorithm for GPS (Global Positioning System) integer ambiguity resolution is shown. The algorithm first incorporates an instantaneous (static) integer search to significantly reduce the search space using a geometric inequality. Then a batch-type loss function is used to check the remaining integers in order to determine the optimal integer. This batch function represents the GPS sightline vectors in the body frame as the sum of two vectors, one depending on the phase measurements and the other on the unknown integers. The new algorithm has several advantages: it does not require an a-priori estimate of the vehicle's attitude; it provides an inherent integrity check using a covariance-type expression; and it can resolve the integers even when coplanar baselines exist. The performance of the new algorithm is tested on a dynamic hardware simulator.

  4. Differential age effects on lexical ambiguity resolution mechanisms

    PubMed Central

    Lee, Chia-lin; Federmeier, Kara D.

    2010-01-01

    Multiple neurocognitive subsystems are involved in resolving lexical ambiguity under different circumstances. We examined how processing in these subsystems changes with normal aging by comparing ERP responses to homographs and unambiguous words completing congruent sentences (with both semantic and syntactic contextual information) or syntactic prose (syntactic information only). Like young adults in prior work, older adults elicited more negative N400s to homographs in congruent sentences, suggesting mismatch between the context and residual activation of the contextually-irrelevant sense. However, the frontal negativity seen in young adults to homographs in syntactically well-defined but semantically neutral contexts was absent in older adults as a group, suggesting decline in recruiting additional neural resources to aid difficult semantic selection. A subset of older adults with high verbal fluency maintained a young-like effect pattern. PMID:21175671

  5. Success, failure and ambiguity of the dilution effect among competitors.

    PubMed

    Strauss, Alexander T; Civitello, David J; Cceres, Carla E; Hall, Spencer R

    2015-09-01

    It remains challenging to predict variation in the magnitude of disease outbreaks. The dilution effect seeks to explain this variation by linking multiple host species to disease transmission. It predicts that disease risk increases for a focal host when host species diversity declines. However, when an increase in species diversity does not reduce disease, we are often unable to diagnose why. Here, we increase mechanistic and predictive clarity of the dilution effect with a general trait-based model of disease transmission in multi-host communities. Then, we parameterise and empirically test our model with a multi-generational case study of planktonic disease. The model-experiment combination shows that hosts that vary in competitive ability (R*) and potential to spread disease (R0 ) can produce three qualitatively disparate outcomes of dilution on disease: the dilution effect can succeed, fail, or be ambiguous/irrelevant. PMID:26119173

  6. Dynamical ambiguities in models with spontaneous Lorentz violation

    NASA Astrophysics Data System (ADS)

    Bonder, Yuri; Escobar, Carlos A.

    2016-01-01

    Spontaneous Lorentz violation is a viable mechanism to look for Planck scale physics. In this work, we study spontaneous Lorentz violation models, in flat spacetime, where a vector field produces such a violation and matter is modeled by a complex scalar field. We show that it is possible to construct a Hamilton density for which the evolution respects the dynamical constraints. However, we also find that the initial data, as required by standard field theory, does not determine the fields evolution in a unique way. In addition, we present some examples where the physical effects of such ambiguities can be recognized. As a consequence, the proposals in which the electromagnetic and gravitational interactions emerge from spontaneous Lorentz violation are challenged.

  7. Cytogenetic abnormalities in acute leukaemia of ambiguous lineage: an overview.

    PubMed

    Manola, Kalliopi N

    2013-10-01

    Acute leukaemia of ambiguous lineage (ALAL) is a rare complex entity with heterogeneous clinical, immunophenotypic, cytogenetic and molecular genetic features and adverse outcome. According to World Health Organization 2008 classification, ALAL encompasses those leukaemias that show no clear evidence of differentiation along a single lineage. The rarity of ALAL and the lack of uniform diagnostic criteria have made it difficult to establish its cytogenetic features, although cytogenetic analysis reveals clonal chromosomal abnormalities in 59-91% of patients. This article focuses on the significance of cytogenetic analysis in ALAL supporting the importance of cytogenetic analysis in the pathogenesis, diagnosis, prognosis, follow up and treatment selection of ALAL. It reviews in detail the types of chromosomal aberrations, their molecular background, their correlation with immunophenotype and age distribution and their prognostic relevance. It also summarizes some novel chromosome aberrations that have been observed only once. Furthermore, it highlights the ongoing and future research on ALAL in the field of cytogenetics. PMID:23888868

  8. Sensorimotor Adaptations Following Exposure to Ambiguous Inertial Motion Cues

    NASA Technical Reports Server (NTRS)

    Wood, S. J.; Harm, D. L.; Reschke, M. F.; Rupert, A. H.; Clement, G. R.

    2009-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive accurate spatial orientation awareness. We hypothesize that multi-sensory integration will be adaptively optimized in altered gravity environments based on the dynamics of other sensory information available, with greater changes in otolith-mediated responses in the mid-frequency range where there is a crossover of tilt and translation responses. The primary goals of this ground-based research investigation are to explore physiological mechanisms and operational implications of tilt-translation disturbances during and following re-entry, and to evaluate a tactile prosthesis as a countermeasure for improving control of whole-body orientation.

  9. Space-time ambiguity functions for electronically scanned ISR applications

    NASA Astrophysics Data System (ADS)

    Swoboda, John; Semeter, Joshua; Erickson, Philip

    2015-05-01

    Electronically steerable array (ESA) technology has recently been applied to incoherent scatter radar (ISR) systems. These arrays allow for pulse-to-pulse steering of the antenna beam to collect data in a three-dimensional region. This is in direct contrast to dish-based antennas, where ISR acquisition is limited at any one time to observations in a two-dimensional slice. This new paradigm allows for more flexibility in the measurement of ionospheric plasma parameters. Multiple ESA-based ISR systems operate currently in the high-latitude region where the ionosphere is highly variable in both space and time. Because of the highly dynamic nature of the ionosphere in this region, it is important to differentiate between measurement-induced artifacts and the true behavior of the plasma. Often, three-dimensional ISR data produced by ESA systems are fitted in a spherical coordinate space and then the parameters are interpolated to a Cartesian grid, potentially introducing error and impacting the reconstructions of the plasma parameters. To take advantage of the new flexibility inherent in ESA systems, we present a new way of analyzing ISR observations through use of the space-time ambiguity function. The use of this new measurement ambiguity function allows us to pose the ISR observational problem in terms of a linear inverse problem whose goal is the estimate of the time domain lags of the intrinsic plasma autocorrelation function used for parameter fitting. The framework allows us to explore the impact of nonuniformity in plasma parameters in both time and space. We discuss examples of possible artifacts in high-latitude situations and discuss possible ways of reducing them and improving the quality of data products from electronically steerable ISRs.

  10. Ionospheric effects in uncalibrated phase delay estimation and ambiguity-fixed PPP based on raw observable model

    NASA Astrophysics Data System (ADS)

    Gu, Shengfeng; Shi, Chuang; Lou, Yidong; Liu, Jingnan

    2015-05-01

    Zero-difference (ZD) ambiguity resolution (AR) reveals the potential to further improve the performance of precise point positioning (PPP). Traditionally, PPP AR is achieved by Melbourne-Wübbena and ionosphere-free combinations in which the ionosphere effect are removed. To exploit the ionosphere characteristics, PPP AR with L1 and L2 raw observable has also been developed recently. In this study, we apply this new approach in uncalibrated phase delay (UPD) generation and ZD AR and compare it with the traditional model. The raw observable processing strategy treats each ionosphere delay as an unknown parameter. In this manner, both a priori ionosphere correction model and its spatio-temporal correlation can be employed as constraints to improve the ambiguity resolution. However, theoretical analysis indicates that for the wide-lane (WL) UPD retrieved from L1/L2 ambiguities to benefit from this raw observable approach, high precision ionosphere correction of better than 0.7 total electron content unit (TECU) is essential. This conclusion is then confirmed with over 1 year data collected at about 360 stations. Firstly, both global and regional ionosphere model were generated and evaluated, the results of which demonstrated that, for large-scale ionosphere modeling, only an accuracy of 3.9 TECU can be achieved on average for the vertical delays, and this accuracy can be improved to about 0.64 TECU when dense network is involved. Based on these ionosphere products, WL/narrow-lane (NL) UPDs are then extracted with the raw observable model. The NL ambiguity reveals a better stability and consistency compared to traditional approach. Nonetheless, the WL ambiguity can be hardly improved even constrained with the high spatio-temporal resolution ionospheric corrections. By applying both these approaches in PPP-RTK, it is interesting to find that the traditional model is more efficient in AR as evidenced by the shorter time to first fix, while the three-dimensional positioning accuracy of the RAW model outperforms the combination model by about . This reveals that, with the current ionosphere models, there is actually no optimal strategy for the dual-frequency ZD ambiguity resolution, and the combination approach and raw approach each has merits and demerits.

  11. Happy hamsters? Enrichment induces positive judgement bias for mildly (but not truly) ambiguous cues to reward and punishment in Mesocricetus auratus.

    PubMed

    Bethell, Emily J; Koyama, Nicola F

    2015-07-01

    Recent developments in the study of animal cognition and emotion have resulted in the 'judgement bias' model of animal welfare. Judgement biases describe the way in which changes in affective state are characterized by changes in information processing. In humans, anxiety and depression are characterized by increased expectation of negative events and negative interpretation of ambiguous information. Positive wellbeing is associated with enhanced expectation of positive outcomes and more positive interpretation of ambiguous information. Mood-congruent judgement biases for ambiguous information have been demonstrated in a range of animal species, with large variation in the way tests are administered and in the robustness of analyses. We highlight and address some issues using a laboratory species not previously tested: the Syrian hamster (Mesocricetus auratus). Hamsters were tested using a spatial judgement go/no-go task in enriched and unenriched housing. We included a number of controls and additional behavioural tests and applied a robust analytical approach using linear mixed effects models. Hamsters approached the ambiguous cues significantly more often when enriched than unenriched. There was no effect of enrichment on responses to the middle cue. We discuss these findings in light of mechanisms underlying processing cues to reward, punishment and true ambiguity, and the implications for the welfare of laboratory hamsters. PMID:26587255

  12. Rapid Linguistic Ambiguity Resolution in Young Children with Autism Spectrum Disorder: Eye Tracking Evidence for the Limits of Weak Central Coherence.

    PubMed

    Hahn, Noemi; Snedeker, Jesse; Rabagliati, Hugh

    2015-12-01

    Individuals with autism spectrum disorders (ASD) have often been reported to have difficulty integrating information into its broader context, which has motivated the Weak Central Coherence theory of ASD. In the linguistic domain, evidence for this difficulty comes from reports of impaired use of linguistic context to resolve ambiguous words. However, recent work has suggested that impaired use of linguistic context may not be characteristic of ASD, and is instead better explained by co-occurring language impairments. Here, we provide a strong test of these claims, using the visual world eye tracking paradigm to examine the online mechanisms by which children with autism resolve linguistic ambiguity. To address concerns about both language impairments and compensatory strategies, we used a sample whose verbal skills were strong and whose average age (7; 6) was lower than previous work on lexical ambiguity resolution in ASD. Participants (40 with autism and 40 controls) heard sentences with ambiguous words in contexts that either strongly supported one reading or were consistent with both (John fed/saw the bat). We measured activation of the unintended meaning through implicit semantic priming of an associate (looks to a depicted baseball glove). Contrary to the predictions of weak central coherence, children with ASD, like controls, quickly used context to resolve ambiguity, selecting appropriate meanings within a second. We discuss how these results constrain the generality of weak central coherence. Autism Res 2015, 8: 717-726. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. PMID:25820816

  13. Happy hamsters? Enrichment induces positive judgement bias for mildly (but not truly) ambiguous cues to reward and punishment in Mesocricetus auratus

    PubMed Central

    Bethell, Emily J.; Koyama, Nicola F.

    2015-01-01

    Recent developments in the study of animal cognition and emotion have resulted in the ‘judgement bias’ model of animal welfare. Judgement biases describe the way in which changes in affective state are characterized by changes in information processing. In humans, anxiety and depression are characterized by increased expectation of negative events and negative interpretation of ambiguous information. Positive wellbeing is associated with enhanced expectation of positive outcomes and more positive interpretation of ambiguous information. Mood-congruent judgement biases for ambiguous information have been demonstrated in a range of animal species, with large variation in the way tests are administered and in the robustness of analyses. We highlight and address some issues using a laboratory species not previously tested: the Syrian hamster (Mesocricetus auratus). Hamsters were tested using a spatial judgement go/no-go task in enriched and unenriched housing. We included a number of controls and additional behavioural tests and applied a robust analytical approach using linear mixed effects models. Hamsters approached the ambiguous cues significantly more often when enriched than unenriched. There was no effect of enrichment on responses to the middle cue. We discuss these findings in light of mechanisms underlying processing cues to reward, punishment and true ambiguity, and the implications for the welfare of laboratory hamsters. PMID:26587255

  14. Intolerance of Uncertainty Is Associated With Increased Threat Appraisal and Negative Affect Under Ambiguity but Not Uncertainty.

    PubMed

    Chen, Jessamine Tsan-Hsiang; Lovibond, Peter F

    2016-01-01

    Intolerance of Uncertainty (IU) has gained increasing interest as a vulnerability factor for worry in Generalized Anxiety Disorder and other emotional disorders. We extended the procedure of Grupe and Nitschke (2011) to compare threat processing in High IU (n=29) and Low IU (n=26) participants. Participants viewed four cues: two reference cues that preceded aversive pictures on 100% or 0% of trials, and a target cue that preceded aversive pictures on 50% of trials (Uncertain condition). Participants were instructed about these probabilities in advance. In addition, we surprised participants with a second target cue that also preceded aversive pictures on 50% of trials but that had not been mentioned in the instructions (Ambiguous condition). Results provided preliminary evidence that High IU participants showed greater online threat expectancy, postexperimental covariation estimates and negative mood for the target cues compared to the reference cues. The results also suggest that among high IU individuals, ambiguity, rather than uncertainty per se, may be a particularly powerful trigger for biased threat appraisal and negative affect. Clinically, the results suggest that patients with high IU may benefit from interventions to help them calibrate the degree of risk in situations involving ambiguous threat. PMID:26763496

  15. Predicting atmospheric delays for rapid ambiguity resolution in precise point positioning

    NASA Astrophysics Data System (ADS)

    Li, Xingxing; Zhang, Xiaohong; Guo, Fei

    2014-09-01

    Integer ambiguity resolution in precise point positioning (PPP) can shorten the initialization and re-initialization time, and ambiguity-fixed PPP solutions are also more reliable and accurate than ambiguity-float PPP solutions. However, signal interruptions are unavoidable in practical applications, particularly while operating in urban areas. Such signal interruptions can cause discontinuity of carrier phase arc, which introduces new integer ambiguities. Usually it will take approximately 15 min of continuous tracking to a reasonable number of satellites to fix new integer ambiguities. In many applications, it is impractical for a PPP user to wait for such a long time for the re-initialization. In this paper, a method for rapid ambiguity fixing in PPP is developed to avoid such a long re-initialization time. Firstly, the atmospheric delays were estimated epoch by epoch from ambiguity-fixed PPP solutions before the data gap or cycle slip occurs. A random walk procedure is then applied to predict the atmospheric delays accurately over a short time span. The predicted atmospheric delays then can be used to correct the observations which suffer from signal interruptions. Finally, the new ambiguities can be fixed with a distinct WL-LX-L3 (here LX denotes either of L1, L2) cascade ambiguity resolution strategy. Comprehensive experiments have demonstrated that the proposed method and strategy can fix zero-difference integer ambiguities successfully with only a single-epoch observation immediately after a short data gap. This technique works even when all satellites are interrupted at the same time. The duration of data gap bridged by this technique could be possibly extended if a more precise atmospheric delay prediction is found or on-the-fly (OTF) technology is applied. Based on the proposed method, real-time PPP with integer ambiguity fixing becomes more feasible in practice.

  16. A physical-model-based, field-wise and self-contained algorithm for removing directional ambiguities of ocean surface winds retrieved from scatterometer measurements

    NASA Astrophysics Data System (ADS)

    Kim, Young-Joon

    2000-09-01

    An algorithm is introduced to remove the directional ambiguities in ocean surface winds measured by scatterometers, which requires scatterometer data only. It is based on two versions of PBL (planetary boundary layer) models and a low-pass filter. A pressure field is first derived from the median-filtered scatterometer winds, is then noise-filtered, and is finally converted back to the winds, respectively, by an inverted PBL model, a smoothing algorithm, and a PBL model. The derived wind field is used to remove the directional ambiguities in the scatterometer data. This new algorithm is applied to Hurricane Eugene and produces results comparable to those from the current standard ambiguity removal algorithm for NASA/JPL SeaWinds project, which requires external numerical weather forecast/analyses data.

  17. An ambiguity of information content and error in an ill-posed satellite inversion

    NASA Astrophysics Data System (ADS)

    Koner, Prabhat

    According to Rodgers (2000, stochastic approach), the averaging kernel (AK) is the representational matrix to understand the information content in a scholastic inversion. On the other hand, in deterministic approach this is referred to as model resolution matrix (MRM, Menke 1989). The analysis of AK/MRM can only give some understanding of how much regularization is imposed on the inverse problem. The trace of the AK/MRM matrix, which is the so-called degree of freedom from signal (DFS; stochastic) or degree of freedom in retrieval (DFR; deterministic). There are no physical/mathematical explanations in the literature: why the trace of the matrix is a valid form to calculate this quantity? We will present an ambiguity between information and error using a real life problem of SST retrieval from GOES13. The stochastic information content calculation is based on the linear assumption. The validity of such mathematics in satellite inversion will be questioned because it is based on the nonlinear radiative transfer and ill-conditioned inverse problems. References: Menke, W., 1989: Geophysical data analysis: discrete inverse theory. San Diego academic press. Rodgers, C.D., 2000: Inverse methods for atmospheric soundings: theory and practice. Singapore :World Scientific.

  18. Ambiguity in running spectral index with an extra light field during inflation

    SciTech Connect

    Kohri, Kazunori; Matsuda, Tomohiro E-mail: matsuda@sit.ac.jp

    2015-02-01

    At the beginning of inflation there could be extra dynamical scalar fields that will soon disappear (become static) before the end of inflation. In the light of multi-field inflation, those extra degrees of freedom may alter the time-dependence of the original spectrum of the curvature perturbation. It is possible to remove such fields introducing extra number of e-foldings prior to 0N{sub e}∼ 6, however such extra e-foldings may make the trans-Planckian problem worse due to the Lyth bound. We show that such extra scalar fields can change the running of the spectral index to give correction of ± 0.01 without adding significant contribution to the spectral index. The corrections to the spectral index (and the amplitude) could be important in considering global behavior of the corrected spectrum, although they can be neglected in the estimation of the spectrum and its spectral index at the pivot scale. The ambiguity in the running of the spectral index, which could be due to such fields, can be used to nullify tension between BICEP2 and Planck experiments.

  19. An Analysis of the Associations between Ambiguity Tolerance and EFL Reading Strategy Awareness

    ERIC Educational Resources Information Center

    Kamran, Saeedeh Karbalaee; Maftoon, Parviz

    2012-01-01

    The current study is an attempt to investigate whether any statistically significant relationship existed between Iranian EFL learners' ambiguity tolerance (AT) and their reading strategy use. To this end, three instruments of Survey of Reading Strategy (Mokhtari & Sheorey, 2002), Second Language Ambiguity Tolerance Scale (Ely, 1995), and a

  20. Implicit and Explicit Understanding of Ambiguous Figures by Adolescents with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Allen, Melissa L.; Chambers, Alison

    2011-01-01

    Children with autism spectrum disorder (ASD) can process both interpretations of an ambiguous figure (e.g. rabbit/duck) when told about the ambiguity, however they tend not to do so spontaneously. Here we show that although adolescents with ASD can explicitly experience such "reversals", implicit measures suggest they are conceptually processing

  1. Ambiguity Detection in Adolescents with Asperger Syndrome: Is Central Coherence or Theory of Mind Impaired?

    ERIC Educational Resources Information Center

    Le Sourn-Bissaoui, Sandrine; Caillies, Stephanie; Gierski, Fabien; Motte, Jacques

    2011-01-01

    The aim of this study was to investigate the role of central coherence skills and theory of mind competences in ambiguity detection in adolescents with Asperger syndrome (AS). We sought to pinpoint the level at which AS individuals experience difficulty detecting semantic ambiguity and identify the factors that account for their problems. We…

  2. Ambiguity Advantage Revisited: Two Meanings Are Better than One when Accessing Chinese Nouns

    ERIC Educational Resources Information Center

    Lin, Chien-Jer Charles; Ahrens, Kathleen

    2010-01-01

    This paper revisits the effect of lexical ambiguity in word recognition, which has been controversial as previous research reported advantage, disadvantage, and null effects. We discuss factors that were not consistently treated in previous research (e.g., the level of lexical ambiguity investigated, parts of speech of the experimental stimuli,

  3. On the Impact of L2 Speech Rhythm on Syntactic Ambiguity Resolution

    ERIC Educational Resources Information Center

    Roncaglia-Denissen, M. Paula; Schmidt-Kassow, Maren; Heine, Angela; Kotz, Sonja A.

    2015-01-01

    In an event-related potential (ERP) study we investigated the role of age of acquisition (AoA) on the use of second language rhythmic properties during syntactic ambiguity resolution. Syntactically ambiguous sentences embedded in rhythmically regular and irregular contexts were presented to Turkish early and late second language (L2) learners of

  4. Transfer in L3 Sentence Processing: Evidence from Relative Clause Attachment Ambiguities

    ERIC Educational Resources Information Center

    Rah, Anne

    2010-01-01

    The present study investigates transfer effects in two groups of German learners of French for ambiguous relative clause (RC) constructions. The first learner group had started to learn French before English, whereas the second group had started to learn English before French. The RC attachment ambiguity is interesting to study possible transfer

  5. Exploiting Lexical Ambiguity to Help Students Understand the Meaning of "Random"

    ERIC Educational Resources Information Center

    Kaplan, Jennifer J.; Rogness, Neal T.; Fisher, Diane G.

    2014-01-01

    Words that are part of colloquial English but used differently in a technical domain may possess lexical ambiguity. The use of such words by instructors may inhibit student learning if incorrect connections are made by students between the technical and colloquial meanings. One fundamental word in statistics that has lexical ambiguity for students

  6. On the Impact of L2 Speech Rhythm on Syntactic Ambiguity Resolution

    ERIC Educational Resources Information Center

    Roncaglia-Denissen, M. Paula; Schmidt-Kassow, Maren; Heine, Angela; Kotz, Sonja A.

    2015-01-01

    In an event-related potential (ERP) study we investigated the role of age of acquisition (AoA) on the use of second language rhythmic properties during syntactic ambiguity resolution. Syntactically ambiguous sentences embedded in rhythmically regular and irregular contexts were presented to Turkish early and late second language (L2) learners of…

  7. Exploiting Degrees of Inflectional Ambiguity: Stem Form and the Time Course of Morphological Processing

    ERIC Educational Resources Information Center

    Jarvikivi, Juhani; Pyykkonen, Pirita; Niemi, Jussi

    2009-01-01

    The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish. Experiment 1 showed equal facilitation for all prime types with a short 60-ms stimulus onset asynchrony (SOA) but significant

  8. The Influence of Readers' Prior Knowledge and Level of Involvement on Interpreting Ambiguous Text.

    ERIC Educational Resources Information Center

    Henk, William A.; And Others

    A study investigated the role of prior knowledge in ambiguous text interpretation by directly measuring readers' knowledge of, and level of involvement with, three distinct topical domains that could be assigned during reading of an ambiguous passage. Subjects, 52 athletes of average or above average reading ability competing in one of three

  9. The Relationship between Tolerance of Ambiguity and Stereotyping: Implications for BSW Education

    ERIC Educational Resources Information Center

    Valutis, Stephanie A.

    2015-01-01

    Ambiguity tolerance and intolerance can influence one's professional practice. The study of such influences remains sparse within the social work literature. Behaviors that reduce uncertainty, including categorizing or stereotyping, are used by those who feel discomfort in ambiguous situations. This study explores explore the relationship between

  10. Ambiguity Tolerance: Adolescents' Responses to Uncertainty in Life. Research Report, September 1996-December 1997.

    ERIC Educational Resources Information Center

    Stoycheva, Katya

    Adolescents today have to live with incoherence for longer periods than before, and that makes ambiguity tolerance a socially significant personality dimension. Studies of the development of ambiguity tolerance in adolescents are reported. The pilot study, "Adaptation of MAT-50 for Use with Bulgarian Population," involves translation and

  11. Ambiguous Belonging and the Challenge of Inclusion: Parent Perspectives on School Membership

    ERIC Educational Resources Information Center

    Scorgie, Kate

    2015-01-01

    Boundary ambiguity occurs when members of a family are confused or uncertain regarding roles, responsibilities and subsystem configurations within the family. Research suggests that perception of boundary ambiguity is associated with family stress despite internal and external resource availability. It has been suggested that research on family

  12. Medical Student and Junior Doctors' Tolerance of Ambiguity: Development of a New Scale

    ERIC Educational Resources Information Center

    Hancock, Jason; Roberts, Martin; Monrouxe, Lynn; Mattick, Karen

    2015-01-01

    The practice of medicine involves inherent ambiguity, arising from limitations of knowledge, diagnostic problems, complexities of treatment and outcome and unpredictability of patient response. Research into doctors' tolerance of ambiguity is hampered by poor conceptual clarity and inadequate measurement scales. We aimed to create and pilot a…

  13. The Kindergarten Path Effect Revisited: Children's Use of Context in Processing Structural Ambiguities

    ERIC Educational Resources Information Center

    Weighall, Anna R.

    2008-01-01

    Research with adults has shown that ambiguous spoken sentences are resolved efficiently, exploiting multiple cues--including referential context--to select the intended meaning. Paradoxically, children appear to be insensitive to referential cues when resolving ambiguous sentences, relying instead on statistical properties intrinsic to the

  14. The Kindergarten Path Effect Revisited: Children's Use of Context in Processing Structural Ambiguities

    ERIC Educational Resources Information Center

    Weighall, Anna R.

    2008-01-01

    Research with adults has shown that ambiguous spoken sentences are resolved efficiently, exploiting multiple cues--including referential context--to select the intended meaning. Paradoxically, children appear to be insensitive to referential cues when resolving ambiguous sentences, relying instead on statistical properties intrinsic to the…

  15. Medical Student and Junior Doctors' Tolerance of Ambiguity: Development of a New Scale

    ERIC Educational Resources Information Center

    Hancock, Jason; Roberts, Martin; Monrouxe, Lynn; Mattick, Karen

    2015-01-01

    The practice of medicine involves inherent ambiguity, arising from limitations of knowledge, diagnostic problems, complexities of treatment and outcome and unpredictability of patient response. Research into doctors' tolerance of ambiguity is hampered by poor conceptual clarity and inadequate measurement scales. We aimed to create and pilot a

  16. Aging and the Use of Context in Ambiguity Resolution: Complex Changes from Simple Slowing

    ERIC Educational Resources Information Center

    Dagerman, Karen Stevens; MacDonald, Maryellen C.; Harm, Michael W.

    2006-01-01

    Older and younger adults' abilities to use context information rapidly during ambiguity resolution were investigated. In Experiments 1 and 2, younger and older adults heard ambiguous words (e.g., fires) in sentences where the preceding context supported either the less frequent or more frequent meaning of the word. Both age groups showed good…

  17. Children's Gender Orientation and Perceptions of Female, Male, and Gender-Ambiguous Animal Characters.

    ERIC Educational Resources Information Center

    Karniol, Rachel; Reichman, Shiri; Fund, Liat

    2000-01-01

    Examined the effects of preadolescents' gender orientation on social perception of animal characters whose gender was clearly female, male, or gender-ambiguous. Children's gender orientation did not influence perceptions of the gender of characters that were clearly female and male, but did influence perceptions of ambiguous characters. Children's

  18. As Far As Words Go: Activities for Understanding Ambiguous Language and Humor, Revised Edition

    ERIC Educational Resources Information Center

    Spector, Cecile Cyrul

    2009-01-01

    Understanding ambiguous words, phrases, and sentences is an important part of reading well, communicating skillfully, and enjoying humor based on word play. With this seven-unit activity book--filled with creative, ready-to-use activities based on jokes and puns--students will learn how to decipher the language ambiguities they encounter inside

  19. Ambiguous Loss Research, Theory, and Practice: Reflections after 9-11

    ERIC Educational Resources Information Center

    Boss, Pauline

    2004-01-01

    This article contains an overview of three decades of research, theory development, and clinical application about ambiguous loss. Although the work includes both physical and psychological types of ambiguous loss, the focus is the aftermath of 9-11 (September 11, 2001) when the World Trade Center collapsed following terrorist attacks. On the

  20. Midwestern Millennial University Students' Tolerance for Ambiguity in a Period of Complex World Conflicts

    ERIC Educational Resources Information Center

    Mahdi, Ghada S.

    2012-01-01

    Though age and gender do not affect students' knowledge of global issues and associated ambiguity, the academic major of undergraduates did. Students' combined perceptions on knowledge of these issues and their associated ambiguities varied among the four academic groups of majors. Unlike teacher education majors and in combined other majors…

  1. Implicit and Explicit Understanding of Ambiguous Figures by Adolescents with Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Allen, Melissa L.; Chambers, Alison

    2011-01-01

    Children with autism spectrum disorder (ASD) can process both interpretations of an ambiguous figure (e.g. rabbit/duck) when told about the ambiguity, however they tend not to do so spontaneously. Here we show that although adolescents with ASD can explicitly experience such "reversals", implicit measures suggest they are conceptually processing…

  2. Exploiting Degrees of Inflectional Ambiguity: Stem Form and the Time Course of Morphological Processing

    ERIC Educational Resources Information Center

    Jarvikivi, Juhani; Pyykkonen, Pirita; Niemi, Jussi

    2009-01-01

    The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish. Experiment 1 showed equal facilitation for all prime types with a short 60-ms stimulus onset asynchrony (SOA) but significant…

  3. Confronting the "F" Word: The Effects of Gender, Ambiguity, and Individual Difference Variables on Non-Targets' Confrontation of Heterosexist Comments.

    PubMed

    Weber, Danielle M; Dickter, Cheryl L

    2015-01-01

    The present study used an experimental setting to examine individual and situational variables that influence the confronting of heterosexist remarks by non-target heterosexuals. College student participants (n=120) responded to a heterosexist comment made in an online setting in which the ambiguity of the heterosexist remark was manipulated. Results indicated that the effect of the ambiguity of the comment on confronting behavior was moderated by individual differences in optimism. Confronting was also affected by sexual prejudice and experience with gay and lesbian individuals. In addition, females confronted more often and more strongly than males, especially following negative affective responses to the comment. PMID:26073029

  4. Ambiguity tolerance in organizations: definitional clarification and perspectives on future research

    PubMed Central

    McLain, David L.; Kefallonitis, Efstathios; Armani, Kimberly

    2015-01-01

    Ambiguity tolerance is an increasingly popular subject for study in a wide variety of fields. The definition of ambiguity tolerance has changed since its inception, and accompanying that change are changes in measurement and the research questions that interest researchers. There is a wealth of opportunity for research related to ambiguity tolerance and recent advances in neuroscience, measurement, trait research, perception, problem solving, and other fields highlight areas of interest and point to issues that need further attention. The future of ambiguity tolerance research is promising and it is expected that future studies will yield new insights into individual differences in reactions to the complex, unfamiliar, confusing, indeterminate, and incomplete stimuli that fall within the conceptual domain of ambiguity. PMID:25972818

  5. Spaceborne Hybrid Quad-Pol SAR Range Ambiguity Analysis and Simulations

    NASA Astrophysics Data System (ADS)

    Yang, Shilin; Li, Yang; Zhang, Jingjing; Hong, Wen

    2014-11-01

    The higher levels of range ambiguities in the cross-polarized measurement channels are the primary limitations for the matched quad-pol (e.g., HH, VV, VH, and HV) spaceborne synthetic aperture radar (SAR) systems. These ambiguities severely constrain the useful range of incident angles and the swath widths particularly at larger incidence. Adopting hybridpolarimetric architecture can remarkably reduce these ambiguities. In this paper, we analyse and develop the expression of range ambiguity to signal ratio (RASR) in the hybrid-polarimetric architecture. Simulations are made to testify this novel architectures advantage in the improvement of range ambiguities. The system operating parameters are derived from NASAs DESDynl mission. In addition, we used the second order moments of polarimetric covariance matrices to depict target or the environment which are more precisely.

  6. Ambiguity tolerance in organizations: definitional clarification and perspectives on future research.

    PubMed

    McLain, David L; Kefallonitis, Efstathios; Armani, Kimberly

    2015-01-01

    Ambiguity tolerance is an increasingly popular subject for study in a wide variety of fields. The definition of ambiguity tolerance has changed since its inception, and accompanying that change are changes in measurement and the research questions that interest researchers. There is a wealth of opportunity for research related to ambiguity tolerance and recent advances in neuroscience, measurement, trait research, perception, problem solving, and other fields highlight areas of interest and point to issues that need further attention. The future of ambiguity tolerance research is promising and it is expected that future studies will yield new insights into individual differences in reactions to the complex, unfamiliar, confusing, indeterminate, and incomplete stimuli that fall within the conceptual domain of ambiguity. PMID:25972818

  7. A sequential and partial ambiguity resolution strategy for improving the initialization performance of medium-baseline relative positioning

    NASA Astrophysics Data System (ADS)

    Zhang, Shoujian; Zhao, Lei; Li, Xintan; Cheng, Bing

    2016-02-01

    Ionosphere products that are relatively precise are available thanks to the efforts of the International GNSS Service (IGS), and it might be possible to obtain a high success rate for the fixed integer ambiguities for medium- or longer-baseline ambiguity resolution (AR) using the ionosphere products as a priori information constraints. In this study, we used the IGS precise ionosphere products as a priori information before forming double-difference (DD) measurement equations using only original observables in a mid-range relative positioning and estimated the ionosphere residuals explicitly after DD. Furthermore, we proposed a sequential and partial ambiguity resolution (SPAR) strategy under the integer least square condition to realize fast and reliable AR. To demonstrate our proposed strategy, we randomly selected seven baselines ranging from 30 to 111 km and undertook positioning in a post-processing mode using real GPS dual-frequency data. According to the results, the SPAR strategy has a faster convergence process compared with batch AR. For instance, the convergence time with >90 % cumulative frequency percentage (probability) for 30, 40, 56, 66, 80, 95, and 111 km baselines was advanced by 55, 50, >75, 85, >110, 65, and >35 epochs, respectively, with a 30-s sample interval. By considering ionospheric correction before DD, we found further improvement in the initialization performance with the use of the SPAR strategy.

  8. Remediation of context-processing deficits in schizophrenia: preliminary data with ambiguous sentences

    PubMed Central

    Besche-Richard, Chrystel; Terrien, Sarah; Lesgourgues, Marion; Bchiri-Payet, Clia; Gierski, Fabien; Limosin, Frdric

    2014-01-01

    Background Processing of contextual information is essential for the establishment of good interpersonal relations and communicational interactions. Nevertheless, it is known that schizophrenic patients present impairments in the processing of contextual information. The aim of this study is to explore the influence of the remediation of context processing in schizophrenic patients. Methods Thirty-one schizophrenic patients and 28 matched healthy participants were included in this study. All participants were assessed on verbal knowledge (Mill-Hill test) and depression intensity (Beck Depression Scale 21 items). Schizophrenic patients were also assessed on thought, language, and communication disorders (Thought, Language and Communication scale). All participants completed a disambiguation task with two different levels of contextualization (high or low context) and a context-processing remediation task containing social scenarios that included ambiguous words and were presented with two different types of instruction: with or without context explanation. Results For the disambiguation task, results showed no effect of group, but a main effect of context, with better performances in the high-context than the low-context condition. For the context-processing remediation task, results showed a main effect of group: The performance of schizophrenic patients who had received explanations differed from that both of healthy participants and of schizophrenic patients who had not received explanations. Conclusion This study revealed that for all participants, the structuring of context had a positive effect on the contextual integration of ambiguous words. Concerning the remediation task, explanations about the strategies that could be used to take context into account improved the schizophrenic patients performances. This allows us to consider new methods of remediation that could improve social interaction in schizophrenia. PMID:25516712

  9. Source estimation with surface-related multiples—fast ambiguity-resolved seismic imaging

    NASA Astrophysics Data System (ADS)

    Tu, Ning; Aravkin, Aleksandr; van Leeuwen, Tristan; Lin, Tim; Herrmann, Felix J.

    2016-03-01

    We address the problem of obtaining a reliable seismic image without prior knowledge of the source wavelet, especially from data that contain strong surface-related multiples. Conventional reverse-time migration requires prior knowledge of the source wavelet, which is either technically or computationally challenging to accurately determine; inaccurate estimates of the source wavelet can result in seriously degraded reverse-time migrated images, and therefore wrong geological interpretations. To solve this problem, we present a "wavelet-free" imaging procedure that simultaneously inverts for the source wavelet and the seismic image, by tightly integrating source estimation into a fast least-squares imaging framework, namely compressive imaging, given a reasonably accurate background velocity model. However, this joint inversion problem is difficult to solve as it is plagued with local minima and the ambiguity with respect to amplitude scalings, because of the multiplicative, and therefore nonlinear, appearance of the source wavelet in the otherwise linear formalism. We have found a way to solve this nonlinear joint-inversion problem using a technique called variable projection, and a way to overcome the scaling ambiguity by including surface-related multiples in our imaging procedure following recent developments in surface-related multiple prediction by sparse inversion. As a result, we obtain without prior knowledge of the source wavelet high-resolution seismic images, comparable in quality to images obtained assuming the true source wavelet is known. By leveraging the computationally efficient compressive-imaging methodology, these results are obtained at affordable computational costs compared with conventional processing work flows that include surface-related multiple removal and reverse-time migration.

  10. A Columbine study: giving voice, hearing meaning.

    PubMed

    Mears, Carolyn Lunsford

    2008-01-01

    On a quiet spring morning, the 20th of April 1999, Columbine High School emerged from relative anonymity as a typical suburban high school and became internationally recognized as a symbol of school violence and tragic loss. As a parent whose child was in the school at the time of the attack, I struggled to make sense of the tragedy. I decided to conduct research into the experience as a way to learn lessons that might help others exposed to community-wide trauma in the future. Through modified oral history interviews of other Columbine parents in combination with other qualitative research strategies, I collected and studied stories of the events of that day and the years following. An unexpected by-product emerged from the study, for it seemed that I was not only learning about crisis response and trauma care but also offering a means for parents to gain comfort in reflecting on their own experience. This paper describes the distinct approach that I employed to create a gateway to understanding this experience. It does not explicate the findings of the Columbine study but instead explores the potential for positive outcomes for those who, by giving voice to their stories, can connect to a deeper appreciation for their own experience. PMID:19256102

  11. Dissecting the Ambiguity of FMA Concept Names Using Taxonomy and Partonomy Structural Information.

    PubMed

    Luo, Lingyun; Xu, Rong; Zhang, Guo-Qiang

    2013-01-01

    The complex inner structures of concept names in the Foundational Model of Anatomy (FMA) remain an obstacle for further analyzing the ontology using lexical methods. A very common problem is the ambiguity lying in names with the sometimes multiple occurrences of the preposition "of." In this paper, we propose an automatic method to help disambiguating FMA terms by leveraging the taxonomy and partonomy information. If a sub-phrase of a concept name also appears in its parents, it is likely to occur as a sub-tree in its parse tree, hence should be parsed as such. We classified all the concept names with a single occurrence of the preposition "of" by the appearances of their sub-phrases in the parent names using three test suites. Results show that more than 90% of them can be provided with useful information to assist their correct parsing. PMID:24303256

  12. Prosodic facilitation in the resolution of syntactic ambiguities in subjects with left and right hemisphere damage.

    PubMed

    Walker, J P; Fongemie, K; Daigle, T

    2001-08-01

    The purpose of this study was to determine if prosody facilitates the comprehension of sentences containing temporary syntactic ambiguities in control, and left (LHD) and right hemisphere damaged (RHD) subjects. To test for effects of prosodic facilitation, sentences were created where prosodic boundaries coincided with (cooperating), were absent (baseline), or conflicted (conflicting) with syntactic boundaries in three response times (RTs) experiments. Despite differences in overall RTs and response accuracy for each group, all three groups responded faster and more accurately to sentences in the cooperating than in the baseline and conflicting conditions across experiments, indicating that prosody facilitates syntactic parsing in brain-damaged subjects just as it does with normal control subjects. Results are discussed in relation to psycholinguistic theories of syntactic parsing and neurolinguistic theories of hemispheric specialization in processing the acoustic properties of prosodic structures. PMID:11500068

  13. Parents' experiences of having a baby with ambiguous genitalia.

    PubMed

    Oliveira, Mailme de Souza; de Paiva-e-Silva, Roberto Benedito; Guerra-Junior, Gil; Maciel-Guerra, Andra Trevas

    2015-07-01

    Health professionals must be aware of the impact on parents of the birth of children with ambiguous genitalia. This study aimed to analyze the experiences and perceptions of such parents. Parents of 30 children who were evaluated in a reference center for disorders of sex development (DSD) were interviewed. The questionnaire covered the prenatal period, the moment they were told about the disorder, initial management by health professionals, and problems they experienced. Only two cases were detected during pregnancy. The news was usually given to the mother alone by pediatricians. Most parents kept it secret and avoided exposing the baby to the prejudice of others. Parents of children who were referred without sex assignment usually held a personal belief of their child's sex. Previous assignment was based on clinical examination and/or karyotype. Spreading knowledge about DSD could increase awareness of this issue, thus reducing parents' shock and societal stigma. Training of neonatal care teams is required to avoid assignment before evaluation. PMID:26068900

  14. Method for ambiguity resolution in range-Doppler measurements

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald M. (inventor); Miller, Lee S. (inventor)

    1994-01-01

    A method for resolving range and Doppler target ambiguities when the target has substantial range or has a high relative velocity in which a first signal is generated and a second signal is also generated which is coherent with the first signal but at a slightly different frequency such that there exists a difference in frequency between these two signals of Delta f(sub t). The first and second signals are converted into a dual-frequency pulsed signal, amplified, and the dual-frequency pulsed signal is transmitted towards a target. A reflected dual-frequency signal is received from the target, amplified, and changed to an intermediate dual-frequency signal. The intermediate dual-frequency signal is amplified, with extracting of a shifted difference frequency Delta f(sub r) from the amplified intermediate dual-frequency signal done by a nonlinear detector. The final step is generating two quadrature signals from the difference frequency Delta f(sub t) and the shifted difference frequency Delta f(sub r) and processing the two quadrature signals to determine range and Doppler information of the target.

  15. Uncertainty As Knowledge: Harnessing Ambiguity and Uncertainty into Policy Constraints

    NASA Astrophysics Data System (ADS)

    Lewandowsky, S.; Risbey, J.

    2014-12-01

    There are numerous sources of uncertainty that impact policy decisions relating to climate change: There is scientific uncertainty, as for example encapsulated in estimates of climate sensitivity. There is policy uncertainty, which arises when mitigation efforts are erratic or are reversed (as recently happened in Australia). There is also technological uncertainty which affects the mitigation pathway. How can policy decisions be informed in light of these multiple sources of uncertainty? We propose an "ordinal" approach that relies on comparisons such as "greater than" or "lesser than" (known as ordinal), which can help sidestep disagreement about specific parameter estimates (e.g., climate sensitivity). To illustrate, recent analyses (Lewandowsky et al., 2014, Climatic Change) have shown that the magnitude of uncertainty about future temperature increases is directly linked with the magnitude of future risk: the greater the uncertainty, the greater the risk of mitigation failure (defined as exceeding a carbon budget for a predetermined threshold). Here we extend this approach to other sources of uncertainty, with a particular focus on "ambiguity" or "second-order" uncertainty, which arises when there is dissent among experts.

  16. Rocking or Rolling – Perception of Ambiguous Motion after Returning from Space

    PubMed Central

    Clément, Gilles; Wood, Scott J.

    2014-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz) where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1–2 days. During dynamic linear acceleration (0.15–0.6 Hz, ±1.7 m/s2) perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore–aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions. PMID:25354042

  17. Rocking or rolling--perception of ambiguous motion after returning from space.

    PubMed

    Clment, Gilles; Wood, Scott J

    2014-01-01

    The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz) where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, 1.7 m/s2) perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions. PMID:25354042

  18. Semiconductor Bolometers Give Background-Limited Performance

    NASA Technical Reports Server (NTRS)

    Goebel, John; McMurray, Robert

    2006-01-01

    Semiconductor bolometers that are capable of detecting electromagnetic radiation over most or all of the infrared spectrum and that give background-limited performance at operating temperatures from 20 to 300 K have been invented. The term background-limited performance as applied to a bolometer, thermopile, or other infrared detector signifies that the ability to detect infrared signals that originate outside the detector is limited primarily by thermal noise attributable to the background radiation generated external to the bolometer. The signal-to-noise ratios and detectivities of the bolometers and thermopiles available prior to this invention have been lower than those needed for background-limited performance by factors of about 100 and 10, respectively. Like other electrically resistive bolometers, a device according to the invention exhibits an increase in electrical resistance when heated by infrared radiation. Depending on whether the device is operated under the customary constant- current or constant-voltage bias, the increase in electrical resistance can be measured in terms of an increase in voltage across the device or a decrease in current through the device, respectively. In the case of a semiconductor bolometer, it is necessary to filter out visible and shorter-wavelength light that could induce photoconductivity and thereby counteract all or part of the desired infrared- induced increase in resistance. The basic semiconductor material of a bolometer according to the invention is preferably silicon doped with one or more of a number of elements, each of which confers a different variable temperature coefficient of resistance. Suitable dopants include In, Ga, S, Se, Te, B, Al, As, P, and Sb. The concentration of dopant preferably lies in the range between 0.1 and 1,000 parts per billion.

  19. Analysis of Genetic Code Ambiguity Arising from Nematode-Specific Misacylated tRNAs

    PubMed Central

    Hamashima, Kiyofumi; Mori, Masaru; Andachi, Yoshiki; Tomita, Masaru; Kohara, Yuji; Kanai, Akio

    2015-01-01

    The faithful translation of the genetic code requires the highly accurate aminoacylation of transfer RNAs (tRNAs). However, it has been shown that nematode-specific V-arm-containing tRNAs (nev-tRNAs) are misacylated with leucine in vitro in a manner that transgresses the genetic code. nev-tRNAGly (CCC) and nev-tRNAIle (UAU), which are the major nev-tRNA isotypes, could theoretically decode the glycine (GGG) codon and isoleucine (AUA) codon as leucine, causing GGG and AUA codon ambiguity in nematode cells. To test this hypothesis, we investigated the functionality of nev-tRNAs and their impact on the proteome of Caenorhabditis elegans. Analysis of the nucleotide sequences in the 3 end regions of the nev-tRNAs showed that they had matured correctly, with the addition of CCA, which is a crucial posttranscriptional modification required for tRNA aminoacylation. The nuclear export of nev-tRNAs was confirmed with an analysis of their subcellular localization. These results show that nev-tRNAs are processed to their mature forms like common tRNAs and are available for translation. However, a whole-cell proteome analysis found no detectable level of nev-tRNA-induced mistranslation in C. elegans cells, suggesting that the genetic code is not ambiguous, at least under normal growth conditions. Our findings indicate that the translational fidelity of the nematode genetic code is strictly maintained, contrary to our expectations, although deviant tRNAs with misacylation properties are highly conserved in the nematode genome. PMID:25602944

  20. Analysis of genetic code ambiguity arising from nematode-specific misacylated tRNAs.

    PubMed

    Hamashima, Kiyofumi; Mori, Masaru; Andachi, Yoshiki; Tomita, Masaru; Kohara, Yuji; Kanai, Akio

    2015-01-01

    The faithful translation of the genetic code requires the highly accurate aminoacylation of transfer RNAs (tRNAs). However, it has been shown that nematode-specific V-arm-containing tRNAs (nev-tRNAs) are misacylated with leucine in vitro in a manner that transgresses the genetic code. nev-tRNA(Gly) (CCC) and nev-tRNA(Ile) (UAU), which are the major nev-tRNA isotypes, could theoretically decode the glycine (GGG) codon and isoleucine (AUA) codon as leucine, causing GGG and AUA codon ambiguity in nematode cells. To test this hypothesis, we investigated the functionality of nev-tRNAs and their impact on the proteome of Caenorhabditis elegans. Analysis of the nucleotide sequences in the 3' end regions of the nev-tRNAs showed that they had matured correctly, with the addition of CCA, which is a crucial posttranscriptional modification required for tRNA aminoacylation. The nuclear export of nev-tRNAs was confirmed with an analysis of their subcellular localization. These results show that nev-tRNAs are processed to their mature forms like common tRNAs and are available for translation. However, a whole-cell proteome analysis found no detectable level of nev-tRNA-induced mistranslation in C. elegans cells, suggesting that the genetic code is not ambiguous, at least under normal growth conditions. Our findings indicate that the translational fidelity of the nematode genetic code is strictly maintained, contrary to our expectations, although deviant tRNAs with misacylation properties are highly conserved in the nematode genome. PMID:25602944

  1. VNTR fingerprinting of Kluyveromyces marxianus strains WT, 7-1, and 8-1 by using different primer types to give best results in PCR and on electrophorese gel in order to find differentiation of the DNA of the yeast strains.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using mutagenized Kluyveromyces marxianus strains (WT, 7-1, 8-1) we wish to find out the variable numbered tandem repeats (VNTR) of each of the DNA strains from the different mutagenized K. marxianus strains. To do this we used Phusion HF Buffer Pack to try and give a clear picture of the VNTR by u...

  2. [The ambiguous concept of predialysis: proposal for a model].

    PubMed

    Alberghini, Elena; Gambirasio, Maria Cristina; Sarcina, Cristina; Biazzi, Cecilia; Ferrario, Francesca; Corghi, Enzo; Baragetti, Ivano; Buzzi, Laura; Visciano, Bianca; Terraneo, Veronica; Santagostino, Gaia; Pozzi, Claudio

    2011-01-01

    In 2009, 90% of nephrology centers in Lombardy declared to have a ''predialysis'' outpatient department, without, however, specifying its meaning. Research carried out in 2008 among nephrology centers in Piemonte showed how ambiguous this term was. According to the 2007 EDTA-ERA Registry, about 68% of European nephrology centers stated that they had an outpatient department for stage 4-5 CKD patients, but no information was available about the role of patients in the choice of dialysis. It is known that when the predialysis phase is poorly managed, the patient's rehabilitation will be more difficult. Dissatisfaction with dialysis often leads to withdrawal from dialysis, as several registries have shown. For this reason, we created a predialysis course at our center, involving a nephrologist, a nurse, and a dietician. The nephrologist helps the patient choose the most suitable therapeutic strategy, which means that doctor and patient share the responsibility for the treatment choice. The offered options are hemodialysis, peritoneal dialysis, preemptive kidney transplant, and a conservative dietary-pharmacological program. The nurse plans at least 4 meetings: 1) to talk with the patient in order to get to know him or her and his/her family; 2) to provide information about the dialysis procedure and establish the patient's preferences; 3) to clear any doubts about the treatment and deliver a booklet with information about the chosen dialysis procedure; 4) to explain the chosen dialysis procedure; 5) to meet the patient after their preparation for dialysis (vascular access or peritoneal catheter). The dietician manages the dietary programs both for patients who are close to starting dialysis and those on a longlasting conservative program. The predialysis course includes a meeting among all those involved with the patient (nephrologists, nurses, dieticians) to exchange information with the purpose of shared evaluation and decision-making. PMID:22028269

  3. Processing ambiguous Spanish se in a minimal chain.

    PubMed

    Meseguer, Enrique; Acuña-Fariña, Carlos; Carreiras, Manuel

    2009-04-01

    The recovery of pieces of information that are not linguistically expressed is a constant feature of the process of language comprehension. In the processing literature, such missing information is generally referred to as "gaps". Usually, one resolves gaps by finding "fillers" in either the sentence or the context. For instance, in Peter seemed to be upset, Peter is really the subject of being upset but appears as surface subject of seems. Sometimes constituents move, leaving gaps behind. Various Romance languages such as Spanish or Italian have a grammatical particle se/si, which, as it is extremely ambiguous, licenses different sorts of gaps. In Spanish, se can encode at least reflexive, impersonal, and passive meanings. In an eye-tracking experiment we contrast reflexive structures containing postverbal subjects with impersonal structures with no subjects (GAP se vendó apresuradamente el corredor/"the runner bandaged himself hurriedly" vs. GAP se vendó apresuradamente al corridor/"(someone) bandaged the runner hurriedly"). In a second manipulation we contrast the presence of an extra argument with se-passives (GAP se vendó el tobillo el corredor/"the runner bandaged his ankle" vs. GAP se vendó el tobillo al corridor/"the runner's ankle was bandaged"). Our comparisons involve contrasting standard transitive structures with nonstandard word order (postverbal subject and a preverbal subject gap) against inherently complex and less habitual structures such as impersonals (with no subject) or se-passives (with subjects in canonical object position). We evaluate the minimal chain principle (de Vincenzi, 1991), according to which displacement is costly because it entails complex (derivational) "chains" that must be undone before phrasal packaging can commence. We show the minimal chain principle to be essentially correct when contrasting more complex but more frequent structures with less complex but less frequent structures. A noteworthy feature of this research is that the gaps appear before the fillers in the structures that we analyse. PMID:18720277

  4. Resolution of a phase ambiguity in a calibration procedure for polarimetric radar systems

    SciTech Connect

    Sletten, M.A. . Radar Div.)

    1994-01-01

    In response to the remote sensing communities' interest in radar polarimetry, considerable effort has recently been devoted to the development of calibration techniques for polarimetric radar systems. A cross-pol/co-pol phase ambiguity in a previously published calibration procedure for polarimetric radar systems is discussed. The original procedure is modified to resolve the ambiguity while still retaining insensitivity to calibration target orientation. The modified form is then generalized and applied to an ultrawideband radar system for which the ambiguity in the original procedure is particularly evident.

  5. Using uniformat and gene[rate] to Analyze Data with Ambiguities in Population Genetics

    PubMed Central

    Nunes, José Manuel

    2015-01-01

    Some genetic systems frequently present ambiguous data that cannot be straightforwardly analyzed with common methods of population genetics. Two possibilities arise to analyze such data: one is the arbitrary simplification of the data and the other is the development of methods adapted to such ambiguous data. In this article, we present an attempt at such a development, the uniformat grammar and The gene[rate] tools, highlighting the specific aspects and the adaptations required to analyze ambiguous nominal data in population genetics. PMID:26917942

  6. Give Better Feedback on Engineering Drawings

    ERIC Educational Resources Information Center

    Cobb, Robert, Jr.; Graham, Tony; Kapur, Arjun; Rhodes, Craig; Blackwell, Ellinor

    2005-01-01

    Most, if not all, systems have a mechanism that collects information to facilitate monitoring performance. This information is primarily used to modify the system to make it more efficient in performing desired tasks and, thus, attaining desired results. Similar to electrical, mechanical, or hydraulic systems, the feedback mechanism in an

  7. Giving Pediatric Immunizations the Priority They Deserve.

    ERIC Educational Resources Information Center

    Shalala, Donna E.

    1993-01-01

    Stresses the need for increased federal, state, and local support for child immunizations resulting from the alarming increases in the incidence of rubella and other infectious diseases, and endorses the Standards for Pediatric Immunization Practices recently published in the "Journal of the American Medical Association." (MDM)

  8. Give Better Feedback on Engineering Drawings

    ERIC Educational Resources Information Center

    Cobb, Robert, Jr.; Graham, Tony; Kapur, Arjun; Rhodes, Craig; Blackwell, Ellinor

    2005-01-01

    Most, if not all, systems have a mechanism that collects information to facilitate monitoring performance. This information is primarily used to modify the system to make it more efficient in performing desired tasks and, thus, attaining desired results. Similar to electrical, mechanical, or hydraulic systems, the feedback mechanism in an…

  9. Doctoral Alumni Giving: Motivations for Donating to the University of Pennsylvania

    ERIC Educational Resources Information Center

    Mastroieni, Anita

    2010-01-01

    This study sought to ascertain the specific motivations behind doctoral alumni giving. Most U.S. colleges and universities depend on alumni giving to supplement revenues from tuition and governmental support; however, relatively little alumni giving is generated from PhD graduates. The result is untapped revenue for doctoral-granting institutions.

  10. An overview of information giving in fertility clinics.

    PubMed

    Mounce, Ginny

    2013-03-01

    Information giving is a key aspect of the provision of high-quality patient-centred health care, resulting in patients who are well-informed, better adjusted to their circumstances and are compliant with their treatment. Fertility patients generally appear to be satisfied with the information they are given but a significant minority are not. Giving information to infertile patients is complicated by the nature of their condition, desire for a child and complexity of treatment options. Patients need detailed, well-timed information to support difficult decision-making, such as when to end treatment. The experiences of some individual patients and particular sub-groups in receiving and understanding information suggest that the quality of information or the way it is communicated could be improved. It is suggested that this may be achieved by reviewing the format and timing of the information provided, ensuring adequate staff training and facilitating flexibility in clinic organisation. PMID:23360453

  11. Resolving the Azimuthal Ambiguity in Vector Magnetogram Data with the Divergence-Free Condition: Theoretical Examination

    NASA Technical Reports Server (NTRS)

    Crouch, A.; Barnes, G.

    2008-01-01

    We demonstrate that the azimuthal ambiguity that is present in solar vector magnetogram data can be resolved with line-of-sight and horizontal heliographic derivative information by using the divergence-free property of magnetic fields without additional assumptions. We discuss the specific derivative information that is sufficient to resolve the ambiguity away from disk center, with particular emphasis on the line-of-sight derivative of the various components of the magnetic field. Conversely, we also show cases where ambiguity resolution fails because sufficient line-of-sight derivative information is not available. For example, knowledge of only the line-of-sight derivative of the line-of-sight component of the field is not sufficient to resolve the ambiguity away from disk center.

  12. Role conflict and ambiguity of CEOs in international joint ventures: a transaction cost perspective.

    PubMed

    Gong, Y; Shenkar, O; Luo, Y; Nyaw, M K

    2001-08-01

    Insights from transaction cost economics were used to study the boundary conditions underlying the role conflict and ambiguity of 265 CEOs in Chinese-based international joint ventures. Role conflict and ambiguity were lower when the contract between parents was more complete. Contract completeness fully mediated the effects of parent objective gap and parent formalization on role ambiguity but only partially so in the case of role conflict. Role conflict was lower when the foreign parent was dominant in the venture but higher when the local parent was dominant. Role conflict and ambiguity were inversely related to cultural distance. Neither construct had a detrimental effect on international joint venture performance. Implications for role theory are discussed. PMID:11519659

  13. Ambiguity involving two illusory melodies induced by a simple configuration of tones.

    PubMed

    Nemoto, Iku; Yuhara, Ryosuke

    2015-08-01

    Auditory scene analysis is essential in daily life to extract necessary information from complex acoustic environment and also from intricate development of music compositions. Auditory illusions and ambiguity are important factors in auditory scene analysis and have been studied extensively. We here report a novel form of ambiguity involving two illusory melodies implied by a very simple stimulus consisting of two sustained tones of different frequencies and an intermittently repeated tone of a frequency between the sustained tones. The measured time elapsed before a first perception change showed that illusion, ambiguity and disambiguation actually took place. We anticipate that the proposed illusion and ambiguity will provide a well-controlled approach for behavioral and neurophysiological studies of music recognition because of the simplicity of stimulus. PMID:26737828

  14. The contribution of BDS triple-frequency signals to ambiguity resolution

    NASA Astrophysics Data System (ADS)

    Dai, Zhiqiang

    2014-05-01

    At present, it is a trend to introduce multi-frequency technique to global navigation satellite system (GNSS). The new generations of GNSS all transmit three or more carriers, for example, the modernizing GPS introduce the L5 signal, besides the existing L1 and L2 signals, the upcoming European Galileo system is designed to transmit L1, E6, E5B, E5A signals, and the developing Chinese BeiDou navigation satellite system (BDS) is transmitting B1, B2, and B3 signals. The extra frequencies are expected to benefit the precise GNSS data processing, especially for carrier phase ambiguity resolution (AR). By the end of 2012, the Chinese BDS has achieved the second phase, realizing regional service for Asian-Pacific area. More than 16 BDS satellites are transmitting triple-frequency signals, which is much more than GPS and Galileo. How much do the triple-frequency signals contribute to AR? To answer this question, we collected the simultaneous BDS triple-frequency observations for baselines with different lengths. These simultaneous observations were double differenced for each baseline to resolve the baseline components and the double-differenced (DD) ambiguities. We resolved the DD ambiguities in two steps. Firstly, the extra-wide-lane (EWL) and wide-lane (WL) ambiguities were resolved in the geometry-free observation model. Secondly, ambiguities of the original carrier-phase observations were estimated in the geometry-based model along with the baseline components, in which, the fixed EWL and WL ambiguities are used to constraint the original carrier-phase ambiguities. Since the AR performance is strongly dependent on the baseline length, we investigated the AR success rate and time to first fix for each baseline, and evaluated the AR improvement brought by the triple-frequency signals. Keywords: GNSS, BDS, Triple-frequency ambiguity resolution, AR

  15. The effects of acute pharmacological stimulation of the 5-HT, NA and DA systems on the cognitive judgement bias of rats in the ambiguous-cue interpretation paradigm.

    PubMed

    Rygula, Rafal; Papciak, Justyna; Popik, Piotr

    2014-07-01

    In the present study, we investigated the effects of acute pharmacological stimulation of the serotonergic (5-HT), noradrenergic (NA) and dopaminergic (DA) systems on the valence of cognitive judgement bias of rats in the ambiguous-cue interpretation (ACI) paradigm. To accomplish this goal, after initial behavioural training, different groups of rats received single injections of citalopram, desipramine or d-amphetamine and were subsequently tested with the ACI paradigm. Each drug was administered in 3 doses using a fully randomised Latin square design. Citalopram at the dose of 1mg/kg significantly biased animals towards positive interpretation of the ambiguous cue, while at higher doses (5 and 10mg/kg), the animals interpreted the ambiguous cue more negatively. Desipramine at all 3 tested doses (1, 2 and 5mg/kg) significantly biased animals towards negative interpretation of the ambiguous cue, while d-amphetamine at the dose of 1mg/kg induced positive bias, having no effects at lower doses (0.1 and 0.5mg/kg). Our results indicate that cognitive bias in rats can be influenced by acute pharmacological intervention. PMID:24503278

  16. Giving students the run of sprinting models

    NASA Astrophysics Data System (ADS)

    Heck, André; Ellermeijer, Ton

    2009-11-01

    A biomechanical study of sprinting is an interesting task for students who have a background in mechanics and calculus. These students can work with real data and do practical investigations similar to the way sports scientists do research. Student research activities are viable when the students are familiar with tools to collect and work with data from sensors and video recordings and with modeling tools for comparing simulation and experimental results. This article describes a multipurpose system, named COACH, that offers a versatile integrated set of tools for learning, doing, and teaching mathematics and science in a computer-based inquiry approach. Automated tracking of reference points and correction of perspective distortion in videos, state-of-the-art algorithms for data smoothing and numerical differentiation, and graphical system dynamics based modeling are some of the built-in techniques that are suitable for motion analysis. Their implementation and their application in student activities involving models of running are discussed.

  17. Medical student and junior doctors' tolerance of ambiguity: development of a new scale.

    PubMed

    Hancock, Jason; Roberts, Martin; Monrouxe, Lynn; Mattick, Karen

    2015-03-01

    The practice of medicine involves inherent ambiguity, arising from limitations of knowledge, diagnostic problems, complexities of treatment and outcome and unpredictability of patient response. Research into doctors' tolerance of ambiguity is hampered by poor conceptual clarity and inadequate measurement scales. We aimed to create and pilot a measurement scale for tolerance of ambiguity in medical students and junior doctors that addresses the limitations of existing scales. After defining tolerance of ambiguity, scale items were generated by literature review and expert consultation. Feedback on the draft scale was sought and incorporated. 411 medical students and 75 foundation doctors in Exeter, UK were asked to complete the scale. Psychometric analysis enabled further scale refinement and comparison of scale scores across subgroups. The pilot study achieved a 64% response rate. The final 29 item version of the Tolerance of Ambiguity in Medical Students and Doctors (TAMSAD) scale had good internal reliability (Cronbach's ? 0.80). Tolerance of ambiguity was higher in foundation year 2 doctors than first, third and fourth year medical students (-5.23, P = 0.012; -5.98, P = 0.013; -4.62, P = 0.035, for each year group respectively). The TAMSAD scale offers a valid and reliable alternative to existing scales. Further work is required in different settings and in longitudinal studies but this study offers intriguing provisional insights. PMID:24841480

  18. Old Star's "Rebirth" Gives Astronomers Surprises

    NASA Astrophysics Data System (ADS)

    2005-04-01

    Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope are taking advantage of a once-in-a-lifetime opportunity to watch an old star suddenly stir back into new activity after coming to the end of its normal life. Their surprising results have forced them to change their ideas of how such an old, white dwarf star can re-ignite its nuclear furnace for one final blast of energy. Sakurai's Object Radio/Optical Images of Sakurai's Object: Color image shows nebula ejected thousands of years ago. Contours indicate radio emission. Inset is Hubble Space Telescope image, with contours indicating radio emission; this inset shows just the central part of the region. CREDIT: Hajduk et al., NRAO/AUI/NSF, ESO, StSci, NASA Computer simulations had predicted a series of events that would follow such a re-ignition of fusion reactions, but the star didn't follow the script -- events moved 100 times more quickly than the simulations predicted. "We've now produced a new theoretical model of how this process works, and the VLA observations have provided the first evidence supporting our new model," said Albert Zijlstra, of the University of Manchester in the United Kingdom. Zijlstra and his colleagues presented their findings in the April 8 issue of the journal Science. The astronomers studied a star known as V4334 Sgr, in the constellation Sagittarius. It is better known as "Sakurai's Object," after Japanese amateur astronomer Yukio Sakurai, who discovered it on February 20, 1996, when it suddenly burst into new brightness. At first, astronomers thought the outburst was a common nova explosion, but further study showed that Sakurai's Object was anything but common. The star is an old white dwarf that had run out of hydrogen fuel for nuclear fusion reactions in its core. Astronomers believe that some such stars can undergo a final burst of fusion in a shell of helium that surrounds a core of heavier nuclei such as carbon and oxygen. However, the outburst of Sakurai's Object is the first such blast seen in modern times. Stellar outbursts observed in 1670 and 1918 may have been caused by the same phenomenon. Astronomers expect the Sun to become a white dwarf in about five billion years. A white dwarf is a dense core left after a star's normal, fusion-powered life has ended. A teaspoon of white dwarf material would weigh about 10 tons. White dwarfs can have masses up to 1.4 times that of the Sun; larger stars collapse at the end of their lives into even-denser neutron stars or black holes. Computer simulations indicated that heat-spurred convection (or "boiling") would bring hydrogen from the star's outer envelope down into the helium shell, driving a brief flash of new nuclear fusion. This would cause a sudden increase in brightness. The original computer models suggested a sequence of observable events that would occur over a few hundred years. "Sakurai's object went through the first phases of this sequence in just a few years -- 100 times faster than we expected -- so we had to revise our models," Zijlstra said. The revised models predicted that the star should rapidly reheat and begin to ionize gases in its surrounding region. "This is what we now see in our latest VLA observations," Zijlstra said. "It's important to understand this process. Sakurai's Object has ejected a large amount of the carbon from its inner core into space, both in the form of gas and dust grains. These will find their way into regions of space where new stars form, and the dust grains may become incorporated in new planets. Some carbon grains found in a meteorite show isotope ratios identical to those found in Sakurai's Object, and we think they may have come from such an event. Our results suggest this source for cosmic carbon may be far more important than we suspected before," Zijlstra added. The scientists continue to observe Sakurai's Object to take advantage of the rare opportunity to learn about the process of re-ignition. They are making new VLA observations just

  19. The Advantage of Ambiguity? Enhanced Neural Responses to Multi-Stable Percepts Correlate with the Degree of Perceived Instability

    PubMed Central

    Dyson, Benjamin J.

    2011-01-01

    Artwork can often pique the interest of the viewer or listener as a result of the ambiguity or instability contained within it. Our engagement with uncertain sensory experiences might have its origins in early cortical responses, in that perceptually unstable stimuli might preclude neural habituation and maintain activity in early sensory areas. To assess this idea, participants engaged with an ambiguous visual stimulus wherein two squares alternated with one another, in terms of simultaneously opposing vertical and horizontal locations relative to fixation (i.e., stroboscopic alternating motion; von Schiller, 1933). At each trial, participants were invited to interpret the movement of the squares in one of five ways: traditional vertical or horizontal motion, novel clockwise or counter-clockwise motion, and, a free-view condition in which participants were encouraged to switch the direction of motion as often as possible. Behavioral reports of perceptual stability showed clockwise and counter-clockwise motion to possess an intermediate level of stability compared to relatively stable vertical and horizontal motion, and, relatively unstable motion perceived during free-view conditions. Early visual evoked components recorded at parietaloccipital sites such as C1, P1, and N1 modulated as a function of visual intention. Both at a group and individual level, increased perceptual instability was related to increased negativity in all three of these early visual neural responses. Engagement with increasingly ambiguous input may partly result from the underlying exaggerated neural response to it. The study underscores the utility of combining neuroelectric recording with the presentation of perceptually multi-stable yet physically identical stimuli, in revealing brain activity associated with the purely internal process of interpreting and appreciating the sensory world that surrounds us. PMID:21897812

  20. Sex-related functional asymmetry of the ventromedial prefrontal cortex in regard to decision-making under risk and ambiguity.

    PubMed

    Sutterer, Matthew J; Koscik, Timothy R; Tranel, Daniel

    2015-08-01

    Previous work has provided preliminary indication of sex-related functional asymmetry of the ventromedial prefrontal cortex (vmPFC) in social and emotional functions and complex decision-making. Findings have been inconsistent, and based on small numbers of patients. Given the rarity of these neurological cases, replicable results across studies are important to build evidence for sex-related functional asymmetry of the vmPFC. Here we used a sample of sixteen neurological patients with unilateral damage to the left or right vmPFC and examined differences between men and women on a task that probed decision-making under risk or decision-making under ambiguity. We found that men with right-hemisphere vmPFC damage and women with left-hemisphere vmPFC damage demonstrated significantly reduced aversion to risk and ambiguity. Men with damage to the left vmPFC and women with damage to the right vmPFC showed aversion to risk and ambiguity comparable to participants with left or right-sided brain damage outside the vmPFC, and to comparison participants without brain damage. Our results add to previous findings of sex-related functional asymmetry of the vmPFC in decision-making. Our study also replicates findings of no observable behavioral differences between men and women without neurological damage on tests of decision-making. This pattern of neurobiological divergence but behavioral convergence between men and women may reflect a complex interplay of neuroendocrine, developmental, and psychosocial factors. PMID:26111489

  1. Various Ambiguities in Re-constructing Laser Pulse Parameters

    NASA Technical Reports Server (NTRS)

    Roychoudhuri, Chandrasekhar; Prasa, Narasimha

    2006-01-01

    We think that mode lock laser pulses are generated by the summation process that take place between the monochromatic EM filed frequencies as if they interact with each other as shown in equation 1. In reality, the pulse generation is a collaborative interaction process between EM fields and various material medium. When we carry out the actual mode lock analysis, we do take into account of interpaly between all the temporal dynamics of the cavity gain medium, cavity round trip time and the response time of the intra cavity element (saturable absorber, Kerr medium, etc.). that really enforces the locking of the phase of the cavity spontaneous emissions. On a conceptual level, this simplistic representation of the mode locking by Eq.1 ignores all these critical physical processes. When we try to analyze a pulsed field, again we start by representing it very much like this equation, even though we can only detect the square modulus of this complex field and loose a lot of phase related information to the detectors quantum whims and their time constants. The key parameters for a light pulse are as follows. Foremost is the (i) carrier frequency, which cannot be described or imagined without its state of undulation expressed as its (ii) phase. Next is our imagined time finite (iii) carrier envelope that provides the temporal boundary of the field amplitude strength of the undulating E-field. The final parameter is the (iv) state of polarization or the unique plane along which the strength of the E-field gradient undulates. None of these filed characteristics are made self-evident to us by the fields themselves. We do not see light. Light does not see light. Light beams pass through each other without altering each others energy distribution unless there are interacting material molecules (dipoles) within the physical volume of superposition of the beams. In contrast, we can sense the material particles. Material particles sense each other and they cannot pass through each other without interacting with (scattering from) each other. Thus the interpretation of the superposition phenomenon of multiple fields on detectors should not be lumped under the mysterious "wave-particle duality" philosophy. The phenomenon of superposition can be understood better when we focus on the actual process experienced by the detecting dipoles when allowed by QM rules, they respond to and sum all the induced stimulations due to all the superposed fields followed by the proportionate energy absorption giving rise to the fringes we observe. We will present various experimental results to illustrate our arguments. Our position is that such detector behavior driven interpretations rather than the generally implied field-field interaction driven explanations, will help us better understand the ultimate nature of light and hence invent better and newer devices and instruments.

  2. Resummation ambiguities in the Higgs transverse-momentum spectrum in the Standard Model and beyond

    NASA Astrophysics Data System (ADS)

    Bagnaschi, E.; Harlander, R. V.; Mantler, H.; Vicini, A.; Wiesemann, M.

    2016-01-01

    We study the prediction for the Higgs transverse momentum distribution in gluon fusion and focus on the problem of matching fixed- and all-order perturbative results. The main sources of matching ambiguities on this distribution are investigated by means of a twofold comparison. On the one hand, we present a detailed qualitative and quantitative comparison of two recently introduced algorithms for determining the matching scale [1, 2]. On the other hand, we apply the results of both methods to three widely used approaches for the resummation of logarithmically enhanced contributions at small transverse momenta: the MC@NLO and POWHEG Monte Carlo approaches, and analytic resummation. While the three sets of results are largely compatible in the low- p ⊥ region, they exhibit sizable differences at large p ⊥. We show that these differences can be significantly reduced by suitable modifications of formally subleading terms in the Monte Carlo implementations. We apply our study to the Standard Model Higgs boson and to the neutral Higgs bosons of the Two-Higgs-Doublet Model for representative scenarios of the parameter space, where the top- and bottom-quark diagrams enter the cross section at different strengths.

  3. Johnny Depp, Reconsidered: How Category-Relative Processing Fluency Determines the Appeal of Gender Ambiguity

    PubMed Central

    Owen, Helen E.; Halberstadt, Jamin; Carr, Evan W.; Winkielman, Piotr

    2016-01-01

    Individuals that combine features of both genders–gender blends–are sometimes appealing and sometimes not. Heretofore, this difference was explained entirely in terms of sexual selection. In contrast, we propose that part of individuals’ preference for gender blends is due to the cognitive effort required to classify them, and that such effort depends on the context in which a blend is judged. In two studies, participants judged the attractiveness of male-female morphs. Participants did so after classifying each face in terms of its gender, which was selectively more effortful for gender blends, or classifying faces on a gender-irrelevant dimension, which was equally effortful for gender blends. In both studies, gender blends were disliked when, and only when, the faces were first classified by gender, despite an overall preference for feminine features in all conditions. Critically, the preferences were mediated by the effort of stimulus classification. The results suggest that the variation in attractiveness of gender-ambiguous faces may derive from context-dependent requirements to determine gender membership. More generally, the results show that the difficulty of resolving social category membership–not just attitudes toward a social category–feed into perceivers’ overall evaluations toward category members. PMID:26845341

  4. Foul or dive? Motor contributions to judging ambiguous foul situations in football.

    PubMed

    Renden, Peter G; Kerstens, Sander; Oudejans, Raul R D; Caal-Bruland, Rouwen

    2014-01-01

    Football (soccer) referees frequently face situations in which they have to distinguish dives and fouls. Yet, little is known about the contributing factors that characterise the ability to judge these ambiguous situations correctly. To this end, in the current article we tested the hypothesis that motor experience of observers contributes to the visual identification of deceptive actions. Thereto, we asked skilled football referees, skilled football players, wheelchair bounded football fans (thus with limited motor experience) and novices to judge whether potential tackle situations in football were either fouls or dives. Results revealed that the referees (accuracy 72.2%, s=6.2) and players (accuracy 72.0%, s=6.4) were better at discriminating fouls and dives than the fans (accuracy 61.1%, s=7.2) and the novices (accuracy 57.4%, s=7.0) (P < 0.001). The results seem to point to an added value of motor experience in detecting deceptive movements. PMID:24444210

  5. Ambiguity in measuring matrix diffusion with single-well injection/recovery tracer tests

    USGS Publications Warehouse

    Lessoff, S.C.; Konikow, L.F.

    1997-01-01

    Single-well injection/recovery tracer tests are considered for use in characterizing and quantifying matrix diffusion in dual-porosity aquifers. Numerical modeling indicates that neither regional drift in homogeneous aquifers, nor heterogeneity in aquifers having no regional drift, nor hydrodynamic dispersion significantly affects these tests. However, when drift is coupled simultaneously with heterogeneity, they can have significant confounding effects on tracer return. This synergistic effect of drift and heterogeneity may help explain irreversible flow and inconsistent results sometimes encountered in previous single-well injection/recovery tracer tests. Numerical results indicate that in a hypothetical single-well injection/recovery tracer test designed to demonstrate and measure dual-porosity characteristics in a fractured dolomite, the simultaneous effects of drift and heterogeneity sometimes yields responses similar to those anticipated in a homogeneous dual-porosity formation. In these cases, tracer recovery could provide a false indication of the occurrence of matrix diffusion. Shortening the shut-in period between injection and recovery periods may make the test less sensitive to drift. Using multiple tracers having different diffusion characteristics, multiple tests having different pumping schedules, and testing the formation at more than one location would decrease the ambiguity in the interpretation of test data.

  6. GLONASS fractional-cycle bias estimation across inhomogeneous receivers for PPP ambiguity resolution

    NASA Astrophysics Data System (ADS)

    Geng, Jianghui; Bock, Yehuda

    2015-12-01

    The key issue to enable precise point positioning with ambiguity resolution (PPP-AR) is to estimate fractional-cycle biases (FCBs), which mainly relate to receiver and satellite hardware biases, over a network of reference stations. While this has been well achieved for GPS, FCB estimation for GLONASS is difficult because (1) satellites do not share the same frequencies as a result of Frequency Division Multiple Access (FDMA) signals; (2) and even worse, pseudorange hardware biases of receivers vary in an irregular manner with manufacturers, antennas, domes, firmware, etc., which especially complicates GLONASS PPP-AR over inhomogeneous receivers. We propose a general approach where external ionosphere products are introduced into GLONASS PPP to estimate precise FCBs that are less impaired by pseudorange hardware biases of diverse receivers to enable PPP-AR. One month of GLONASS data at about 550 European stations were processed. From an exemplary network of 51 inhomogeneous receivers, including four receiver types with various antennas and spanning about 800 km in both longitudinal and latitudinal directions, we found that 92.4 % of all fractional parts of GLONASS wide-lane ambiguities agree well within ± 0.15 cycles with a standard deviation of 0.09 cycles if global ionosphere maps (GIMs) are introduced, compared to only 51.7 % within ± 0.15 cycles and a larger standard deviation of 0.22 cycles otherwise. Hourly static GLONASS PPP-AR at 40 test stations can reach position estimates of about 1 and 2 cm in RMS from ground truth for the horizontal and vertical components, respectively, which is comparable to hourly GPS PPP-AR. Integrated GLONASS and GPS PPP-AR can further achieve an RMS of about 0.5 cm in horizontal and 1-2 cm in vertical components. We stress that the performance of GLONASS PPP-AR across inhomogeneous receivers depends on the accuracy of ionosphere products. GIMs have a modest accuracy of only 2-8 TECU (Total Electron Content Unit) in vertical which confines PPP-AR to an approximately 800× 800 km area in Europe. We expect that a regional ionosphere map with a better than 1 TECU accuracy is likely to improve the GLONASS PPP-AR efficiency.

  7. Four motivations for charitable giving: implications for marketing strategy to attract monetary donations for medical research.

    PubMed

    Dawson, S

    1988-06-01

    Medical research foundations can compete more effectively for charitable dollars by being aware of motivations for giving when designing marketing strategy. The study tests the extent to which the motives of reciprocity, income, career, and self-esteem predict monetary giving to medical research. The results indicate that reciprocity and income motives are significant predictors of giving, as are household assets and age. Interpretation of these results leads to several suggestions for marketing strategy. PMID:10287903

  8. The impact of formalization, role conflict, role ambiguity, and communication quality on perceived organizational innovativeness in the Cancer Information Service.

    PubMed

    Johnson, J D; La France, B H; Meyer, M; Speyer, J B; Cox, D

    1998-03-01

    Organizational members' levels of perceived innovativeness represent an insider's viewpoint of the organization's overall approach to innovation. This study tested a model of the impact of formalization, role ambiguity, role conflict, and communication quality on perceived organizational innovativeness in the Cancer Information Service. Data were gathered from self-report questionnaires completed by organizational members (n = 86) within the Cancer Information Service, a geographically dispersed federal government health information program that was implementing innovative intervention strategies related to disseminating health information to the public. Results indicated that although the predicted model provided a good overall fit to the data, there were some problematic paths. A revised model is offered to reconceptualize the relationships among role conflict, role ambiguity, and communication quality. These results are discussed in terms of their implications for managers and scholars who hope to understand the factors that contribute to perceptions of innovativeness in the new organizational forms emerging in the health service arena. These data suggest that formalization makes an important contribution to innovation in the highly uncertain world of new organizational forms. PMID:10183337

  9. Understanding Alumni Giving: Theory and Predictors of Donor Status

    ERIC Educational Resources Information Center

    Hoyt, Jeff E.

    2004-01-01

    The current study tests a theoretical model of alumni giving developed inductively from prior research. Donor status is directly predicted by willingness to give, alumni involvement, perceptions of the economic environment, perceived need, charitable preferences, receipt of a scholarship and capacity to give along with several indirect predictors.

  10. 27 CFR 29.51 - Failure to give notice; penalty.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Failure to give notice... BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL STILLS AND MISCELLANEOUS REGULATIONS Stills 29.51 Failure to give notice; penalty. Failure to give notice of manufacture of still or notice of setup of still...

  11. 27 CFR 29.51 - Failure to give notice; penalty.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Failure to give notice... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS STILLS AND MISCELLANEOUS REGULATIONS Stills 29.51 Failure to give notice; penalty. Failure to give notice of manufacture of still or notice of setup of still...

  12. 27 CFR 29.51 - Failure to give notice; penalty.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Failure to give notice... BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL STILLS AND MISCELLANEOUS REGULATIONS Stills 29.51 Failure to give notice; penalty. Failure to give notice of manufacture of still or notice of setup of still...

  13. 27 CFR 29.51 - Failure to give notice; penalty.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Failure to give notice... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS STILLS AND MISCELLANEOUS REGULATIONS Stills 29.51 Failure to give notice; penalty. Failure to give notice of manufacture of still or notice of setup of still...

  14. 27 CFR 29.51 - Failure to give notice; penalty.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Failure to give notice... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS STILLS AND MISCELLANEOUS REGULATIONS Stills 29.51 Failure to give notice; penalty. Failure to give notice of manufacture of still or notice of setup of still...

  15. Direction-Giving Skills in the Classroom (A Teaching Tip).

    ERIC Educational Resources Information Center

    Ross, Charlynn

    1992-01-01

    Offers a unit on direction giving to help students identify effective and ineffective direction giving; become familiar with the preparation and presentation components of sound direction giving; and determine whether the message intended was the massage received. Discusses barriers to listening, misunderstandings, and provides exercises and steps

  16. Characteristics of Planned Giving Officers: Practicing Professionals' Perceptions.

    ERIC Educational Resources Information Center

    Miller, Michael T.; Seagren, Alan T.

    As state and federal governments and private industry begin to slow the pace of giving to institutions of higher education, the planned giving officer becomes increasingly interested in competing for the gifts given through philanthropy. A study was conducted using 3,006 questionnaires obtained from members of the Association of Planned Giving

  17. Rate-Gyro-Integral Constraint for Ambiguity Resolution in GNSS Attitude Determination Applications

    PubMed Central

    Zhu, Jiancheng; Li, Tao; Wang, Jinling; Hu, Xiaoping; Wu, Meiping

    2013-01-01

    In the field of Global Navigation Satellite System (GNSS) attitude determination, the constraints usually play a critical role in resolving the unknown ambiguities quickly and correctly. Many constraints such as the baseline length, the geometry of multi-baselines and the horizontal attitude angles have been used extensively to improve the performance of ambiguity resolution. In the GNSS/Inertial Navigation System (INS) integrated attitude determination systems using low grade Inertial Measurement Unit (IMU), the initial heading parameters of the vehicle are usually worked out by the GNSS subsystem instead of by the IMU sensors independently. However, when a rotation occurs, the angle at which vehicle has turned within a short time span can be measured accurately by the IMU. This measurement will be treated as a constraint, namely the rate-gyro-integral constraint, which can aid the GNSS ambiguity resolution. We will use this constraint to filter the candidates in the ambiguity search stage. The ambiguity search space shrinks significantly with this constraint imposed during the rotation, thus it is helpful to speeding up the initialization of attitude parameters under dynamic circumstances. This paper will only study the applications of this new constraint to land vehicles. The impacts of measurement errors on the effect of this new constraint will be assessed for different grades of IMU and current average precision level of GNSS receivers. Simulations and experiments in urban areas have demonstrated the validity and efficacy of the new constraint in aiding GNSS attitude determinations. PMID:23793044

  18. Application of the multiple PRF technique to resolve Doppler centroid estimation ambiguity for spaceborne SAR

    NASA Technical Reports Server (NTRS)

    Chang, C. Y.; Curlander, J. C.

    1992-01-01

    Estimation of the Doppler centroid ambiguity is a necessary element of the signal processing for SAR systems with large antenna pointing errors. Without proper resolution of the Doppler centroid estimation (DCE) ambiguity, the image quality will be degraded in the system impulse response function and the geometric fidelity. Two techniques for resolution of DCE ambiguity for the spaceborne SAR are presented; they include a brief review of the range cross-correlation technique and presentation of a new technique using multiple pulse repetition frequencies (PRFs). For SAR systems, where other performance factors control selection of the PRF's, an algorithm is devised to resolve the ambiguity that uses PRF's of arbitrary numerical values. The performance of this multiple PRF technique is analyzed based on a statistical error model. An example is presented that demonstrates for the Shuttle Imaging Radar-C (SIR-C) C-band SAR, the probability of correct ambiguity resolution is higher than 95 percent for antenna attitude errors as large as 3 deg.

  19. Who gives? Multilevel effects of gender and ethnicity on workplace charitable giving.

    PubMed

    Leslie, Lisa M; Snyder, Mark; Glomb, Theresa M

    2013-01-01

    Research on diversity in organizations has largely focused on the implications of gender and ethnic differences for performance, to the exclusion of other outcomes. We propose that gender and ethnic differences also have implications for workplace charitable giving, an important aspect of corporate social responsibility. Drawing from social role theory, we hypothesize and find that gender has consistent effects across levels of analysis; women donate more money to workplace charity than do men, and the percentage of women in a work unit is positively related to workplace charity, at least among men. Alternatively and consistent with social exchange theory, we hypothesize and find that ethnicity has opposing effects across levels of analysis; ethnic minorities donate less money to workplace charity than do Whites, but the percentage of minorities in a work unit is positively related to workplace charity, particularly among minorities. The findings provide a novel perspective on the consequences of gender and ethnic diversity in organizations and highlight synergies between organizational efforts to increase diversity and to build a reputation for corporate social responsibility. PMID:22985116

  20. Accessing characters in spoken Chinese disyllables: An ERP study on the resolution of auditory ambiguity.

    PubMed

    Chen, Xuqian; Huang, Guoliang; Huang, Jian

    2016-01-01

    Chinese differs from most Indo-European languages in its phonological, lexical, and syntactic structures. One of its unique properties is the abundance of homophones at the monosyllabic/morphemic level, with the consequence that monosyllabic homophones are all ambiguous in speech perception. Two-morpheme Chinese words can be composed of two high homophone-density morphemes (HH words), two low homophone-density morphemes (LL words), or one high and one low homophone-density morphemes (LH or HL words). The assumption of a simple inhibitory homophone effect is called into question in the case of disyllabic spoken word recognition, in which the recognition of one morpheme is affected by semantic information given by the other. Event-related brain potentials (ERPs) were used to trace on-line competitions among morphemic homophones in accessing Chinese disyllables. Results showing significant differences in ERP amplitude when comparing LL and LH words, but not when comparing LL and HL words, suggested that the first morpheme cannot be accessed without feedback from the second morpheme. Most importantly, analyses of N400 amplitude among different densities showed a converse homophone effect in which LL words, rather than LH or HL words, triggered larger N400. These findings provide strong evidence of a dynamic integration system at work during spoken Chinese disyllable recognition. PMID:26589544

  1. Improved PPP Ambiguity Resolution Considering the Stochastic Characteristics of Atmospheric Corrections from Regional Networks

    PubMed Central

    Li, Yihe; Li, Bofeng; Gao, Yang

    2015-01-01

    With the increased availability of regional reference networks, Precise Point Positioning (PPP) can achieve fast ambiguity resolution (AR) and precise positioning by assimilating the satellite fractional cycle biases (FCBs) and atmospheric corrections derived from these networks. In such processing, the atmospheric corrections are usually treated as deterministic quantities. This is however unrealistic since the estimated atmospheric corrections obtained from the network data are random and furthermore the interpolated corrections diverge from the realistic corrections. This paper is dedicated to the stochastic modelling of atmospheric corrections and analyzing their effects on the PPP AR efficiency. The random errors of the interpolated corrections are processed as two components: one is from the random errors of estimated corrections at reference stations, while the other arises from the atmospheric delay discrepancies between reference stations and users. The interpolated atmospheric corrections are then applied by users as pseudo-observations with the estimated stochastic model. Two data sets are processed to assess the performance of interpolated corrections with the estimated stochastic models. The results show that when the stochastic characteristics of interpolated corrections are properly taken into account, the successful fix rate reaches 93.3% within 5 min for a medium inter-station distance network and 80.6% within 10 min for a long inter-station distance network. PMID:26633400

  2. Influence of Gribov ambiguities in a class of nonlinear covariant gauges

    NASA Astrophysics Data System (ADS)

    Serreau, J.; Tissier, M.; Tresmontant, A.

    2015-11-01

    We consider Yang-Mills theories in a recently proposed family of nonlinear covariant gauges that consistently deals with the issue of Gribov ambiguities. Such gauges provide a generalization of the Curci-Ferrari-Delbourgo-Jarvis gauges which can be formulated as an extremization procedure and might be implemented in numerical calculations. This would allow for nonperturbative studies of Yang-Mills correlators in a broad class of covariant gauges continuously connected to the well-studied Landau gauge. We compute the ghost and gluon propagators in the continuum formulation at one-loop order in perturbation theory and we study their momentum dependence down to the deep infrared regime, with and without renormalization-group improvement. In particular, we show that the theory admits infrared-safe renormalization-group trajectories with no Landau pole. Both the gluon and the ghost behave as massive fields at low energy, and the gluon propagator is transverse even away from the Landau gauge limit. We compare our results to those obtained in the usual Curci-Ferrari model, which allows us to pinpoint the specific effects arising from our treatment of Gribov copies.

  3. Improved PPP Ambiguity Resolution Considering the Stochastic Characteristics of Atmospheric Corrections from Regional Networks.

    PubMed

    Li, Yihe; Li, Bofeng; Gao, Yang

    2015-01-01

    With the increased availability of regional reference networks, Precise Point Positioning (PPP) can achieve fast ambiguity resolution (AR) and precise positioning by assimilating the satellite fractional cycle biases (FCBs) and atmospheric corrections derived from these networks. In such processing, the atmospheric corrections are usually treated as deterministic quantities. This is however unrealistic since the estimated atmospheric corrections obtained from the network data are random and furthermore the interpolated corrections diverge from the realistic corrections. This paper is dedicated to the stochastic modelling of atmospheric corrections and analyzing their effects on the PPP AR efficiency. The random errors of the interpolated corrections are processed as two components: one is from the random errors of estimated corrections at reference stations, while the other arises from the atmospheric delay discrepancies between reference stations and users. The interpolated atmospheric corrections are then applied by users as pseudo-observations with the estimated stochastic model. Two data sets are processed to assess the performance of interpolated corrections with the estimated stochastic models. The results show that when the stochastic characteristics of interpolated corrections are properly taken into account, the successful fix rate reaches 93.3% within 5 min for a medium inter-station distance network and 80.6% within 10 min for a long inter-station distance network. PMID:26633400

  4. The influence of body movements on children's perception of music with an ambiguous expressive character.

    PubMed

    Maes, Pieter-Jan; Leman, Marc

    2013-01-01

    The theory of embodied music cognition states that the perception and cognition of music is firmly, although not exclusively, linked to action patterns associated with that music. In this regard, the focus lies mostly on how music promotes certain action tendencies (i.e., dance, entrainment, etc.). Only recently, studies have started to devote attention to the reciprocal effects that people's body movements may exert on how people perceive certain aspects of music and sound (e.g., pitch, meter, musical preference, etc.). The present study positions itself in this line of research. The central research question is whether expressive body movements, which are systematically paired with music, can modulate children's perception of musical expressiveness. We present a behavioral experiment in which different groups of children (7-8 years, N = 46) either repetitively performed a happy or a sad choreography in response to expressively ambiguous music or merely listened to that music. The results of our study show indeed that children's perception of musical expressiveness is modulated in accordance with the expressive character of the dance choreography performed to the music. This finding supports theories that claim a strong connection between action and perception, although further research is needed to uncover the details of this connection. PMID:23358805

  5. How Do Family Caregivers of Older People Give Up Caregiving?

    PubMed Central

    Mortazavi, Hamed; Peyrovi, Hamid; Joolaee, Soodabeh

    2015-01-01

    Background Population aging has social, economic and political consequences. Most family caregivers prefer to care for their family member older person with chronic disease at home. Despite traditional culture within Iranian families, in some cases, hospitalization of the elderly in nursing home is inevitable, and this affects the old person and his/her family. The aim of this study was to explain how Iranian family cargivers give up caring their older person with chronic condition at home. Methods A grounded theory approach was used to conduct the study. The study setting included four nursing homes under the auspices of Iran Welfare Organization. Fourteen participants were recruited through purposive sampling. Data were collected from December 2010 to March 2011 by Semi-structured interviews lasting about 17 to 95 minutes (average 52 minutes). Constant comparative analysis was used to analyze the data. Results Three main categories appeared at the end of the analysis: “going out of the road of usual life”, “challenge of meeting older person, family and caregivers care needs”, and “the appearance of inconstancy in the family”. They explained exclusively how family caregivers of old people give up caregiving. Conclusion Health care providers are recommended to become familiar with challenges of family caregivers in taking care of older person with chronic disease at home, and then organize their supportive and consulting actions according to family situations in order to improve the life quality of older person and family caregivers. PMID:26171407

  6. Automated detection of ambiguity in BI-RADS assessment categories in mammography reports.

    PubMed

    Bozkurt, Selen; Rubin, Daniel

    2014-01-01

    An unsolved challenge in biomedical natural language processing (NLP) is detecting ambiguities in the reports that can help physicians to improve report clarity. Our goal was to develop NLP methods to tackle the challenges of identifying ambiguous descriptions of the laterality of BI-RADS Final Assessment Categories in mammography radiology reports. We developed a text processing system that uses a BI-RADS ontology we built as a knowledge source for automatic annotation of the entities in mammography reports relevant to this problem. We used the GATE NLP toolkit and developed customized processing resources for report segmentation, named entity recognition, and detection of mismatches between BI-RADS Final Assessment Categories and mammogram laterality. Our system detected 55 mismatched cases in 190 reports and the accuracy rate was 81%. We conclude that such NLP techniques can detect ambiguities in mammography reports and may reduce discrepancy and variability in reporting. PMID:24743074

  7. Predictors of Perceived Ambiguity About Cancer Prevention Recommendations: Sociodemographic Factors and Mass Media Exposures

    PubMed Central

    Han, Paul K. J.; Moser, Richard P.; Klein, William M. P.; Beckjord, Ellen Burke; Dunlavy, Andrea C.; Hesse, Bradford W.

    2014-01-01

    Cancer prevention recommendations reaching the public today are often ambiguous—that is, of uncertain reliability, credibility, or adequacy—yet little is known about the factors that influence public perceptions of this ambiguity. We used data from the 2005 Health Information National Trends Survey, conducted by the U.S. National Cancer Institute, to explore how sociodemographic characteristics and self-reported mass media exposures relate to perceptions of ambiguity regarding recommendations for the prevention of colon, skin, and lung cancer. Various sociodemographic characteristics (age, education, race) and mass media exposures (television, radio, Internet, health news) were found to be associated with perceived ambiguity about cancer prevention recommendations, and many of these associations varied by cancer type. These findings have important implications for future health communication research and practice. PMID:20183385

  8. Resolving Ambiguity in Emotional Disorders: The Nature and Role of Interpretation Biases.

    PubMed

    Hirsch, Colette R; Meeten, Frances; Krahé, Charlotte; Reeder, Clare

    2016-03-28

    People with emotional disorders, such as social anxiety disorder (SAD), generalized anxiety disorder (GAD), and depression, demonstrate a consistent tendency, or bias, to generate negative interpretations of ambiguous material. This is different from people without emotional disorders who tend, in general, to make positive interpretations of ambiguity. If central components of an emotional disorder have high levels of inherent ambiguity (e.g., concern about the negative perceptions of others in SAD, or worry in GAD), then interpretive bias may have a causal maintaining role, and this has been demonstrated in studies using cognitive bias modification techniques. This research has also shown that interpretation biases combine with other cognitive processes, such as imagery and memory, which could exacerbate distress. Psychological interventions will benefit from effectively targeting negative interpretations, and future experimental research can inform ways to improve facilitation of more benign inferential processing to maximize amelioration of key components of emotional disorders. PMID:27019398

  9. Why do you like Arcimboldo's portraits? Effect of perceptual style on aesthetic appreciation of ambiguous artworks.

    PubMed

    Boccia, M; Barbetti, S; Margiotta, R; Guariglia, C; Ferlazzo, F; Giannini, A M

    2014-08-01

    Visual aesthetic experience reflects the states of the mind and the brain when visual artworks are being viewed. In the present study, we investigated whether perceptual style affects the aesthetic appreciation of ambiguous artworks, such as those of Arcimboldo, which are characterized by part-whole ambiguity. Participants were classified as having a global or local perceptual style and were asked to aesthetically judge two different types of artworks: portraits by Arcimboldo and by Renaissance painters. We found that perceptual style affected both the aesthetic appreciation and the degree of perceived ambiguity in Arcimboldo's artworks. Our findings suggest that aesthetic judgment is a consequence of the interaction between individual personal perceptual style and the perceptual features of artworks. PMID:25085737

  10. Impaired decision making under ambiguity but not under risk in individuals with pathological buying-behavioral and psychophysiological evidence.

    PubMed

    Trotzke, Patrick; Starcke, Katrin; Pedersen, Anya; Mller, Astrid; Brand, Matthias

    2015-09-30

    Pathological buying (PB) is described as dysfunctional buying behavior, associated with harmful consequences. It is discussed whether decision-making deficits are related to PB, because affected individuals often choose the short-term rewarding option of buying despite persistent negative long-term consequences. We investigated 30 patients suffering from PB and 30 matched control participants with two different decision-making tasks: the Iowa Gambling Task (IGT) measures decisions under ambiguity and involves emotional feedback processing, whereas the Game of Dice Task (GDT) measures decisions under risk and can be solved strategically. Potential emotional and cognitive correlates of decision making were investigated by assessing skin conductance response (SCR) and executive functioning. In comparison to the control participants, the patients showed more disadvantageous decisions under ambiguity in the IGT. These data were supported by the SCR results: patients failed to generate SCRs that usually occur before disadvantageous decisions. The physiological and behavioral performance on decisions under risk and executive functioning did not differ between groups. Thus, deficits in emotional feedback processing might be one potential factor in etiology and pathogenesis of PB and should be considered in theory and treatment. PMID:26165961

  11. On-the-fly Ambiguity Resolution Using an Estimator of the Modified Ambiguity Covariance Matrix for the GNSS Positioning Model Based on Phase Data

    NASA Astrophysics Data System (ADS)

    Cellmer, S.

    2012-01-01

    On-the-fly ambiguity resolution (OTF AR) is based on a small data set, obtained from a very short observation session or even from a single epoch observation. In these cases, a classical approach to ambiguity resolution (e.g. the Lambda method) can meet some numerical problems. The basis of the Lambda method is an integer decorrelation of the positive definite ambiguity covariance matrix (ACM). The necessary condition for the proper performing of this procedure is a positive definiteness of ACM. However, this condition is not satisfied in cases of very short observation sessions or single epoch positioning if phase-only observations are used. The subject of this contribution is such a case where phase-only observations are used in the final part of the computational process. The modification of ACM is proposed in order to ensure its positive definiteness. An estimator of modified ACM is a good ACM approximation for the purpose of performing the LAMBDA method. Another problem of short sessions (or a single epoch) positioning is the poor quality of the float solution. In this paper, a cascade adjustment with wide-lane combinations of signals L1 and L2 as a method of solving this problem is presented.

  12. Holding on to hope: A review of the literature exploring missing persons, hope and ambiguous loss.

    PubMed

    Wayland, Sarah; Maple, Myfanwy; McKay, Kathy; Glassock, Geoffrey

    2016-01-01

    When a person goes missing, those left behind mourn an ambiguous loss where grief can be disenfranchised. Different to bereavement following death, hope figures into this experience as a missing person has the potential to return. This review explores hope for families of missing people. Lived experience of ambiguous loss was deconstructed to reveal responses punctuated by hope, which had practical and psychological implications for those learning to live with an unresolved absence. Future lines of enquiry must address the dearth of research exploring the role of hope, unresolved grief, and its clinical implications when a person is missing. PMID:26207394

  13. Ambiguous Keyboards and Scanning: The Relevance of the Cell Selection Phase

    NASA Astrophysics Data System (ADS)

    Mir-Borrs, Julio; Bernabeu-Soler, Pablo; Llinares, Raul; Igual, Jorge

    This paper focuses on the relevance of the cell selection phase in the overall performance of a text entry system based on scanning and with an ambiguous keyboard. Most of the layouts are designed trying only to minimize the ambiguity of the keyboard, and taking into consideration only the disambiguation process when entering text. Nevertheless, the number of scan cycles necessary for selecting the cells has great importance in the overall performance. As we show, the performance depends on the number of cells and the linguistic model used in the cell selection phase.

  14. Efficient decomposition of cosmic microwave background polarization maps into pure E, pure B, and ambiguous components

    SciTech Connect

    Bunn, Emory F.

    2011-04-15

    Separation of the B component of a cosmic microwave background (CMB) polarization map from the much larger E component is an essential step in CMB polarimetry. For a map with incomplete sky coverage, this separation is necessarily hampered by the presence of ambiguous modes which could be either E or B modes. I present an efficient pixel-space algorithm for removing the ambiguous modes and separating the map into pure E and B components. The method, which works for arbitrary geometries, does not involve generating a complete basis of such modes and scales the cube of the number of pixels on the boundary of the map.

  15. 1 10-16 frequency transfer by GPS PPP with integer ambiguity resolution

    NASA Astrophysics Data System (ADS)

    Petit, Grard; Kanj, Amale; Loyer, Sylvain; Delporte, Jrme; Mercier, Flavien; Perosanz, Flix

    2015-04-01

    For many years, the time community has been using the precise point positioning (PPP) technique which uses GPS phase and code observations to compute time and frequency links. However, progress in atomic clocks implies that the performance of PPP frequency comparisons is a limiting factor in comparing the best frequency standards. We show that a PPP technique where the integer nature of phase ambiguities is preserved consitutes significant improvement of the classical use of floating ambiguities. We demonstrate that this integer-PPP technique allows frequency comparisons with 1? ?10-16 accuracy in a few days and can be readily operated with existing products.

  16. Microcomputer programs for back translation of protein to DNA sequences and analysis of ambiguous DNA sequences.

    PubMed Central

    Mount, D W; Conrad, B

    1984-01-01

    Three computer programs are described which may be used to translate a DNA sequence into a protein sequence, back translate the protein sequence into an ambiguous DNA sequence, and then do pattern searching in the ambiguous sequence. The programs are written in the C programming language, have been compiled to run on a microcomputer under the CP/M 80 operating system, and may be copied in binary format through a modem. They are also to become available for the IBM/PC. PMID:6546440

  17. Neural predictors of giving in to temptation in daily life.

    PubMed

    Lopez, Richard B; Hofmann, Wilhelm; Wagner, Dylan D; Kelley, William M; Heatherton, Todd F

    2014-07-01

    The ability to control desires, whether for food, sex, or drugs, enables people to function successfully within society. Yet, in tempting situations, strong impulses often result in self-control failure. Although many triggers of self-control failure have been identified, the question remains as to why some individuals are more likely than others to give in to temptation. In this study, we combined functional neuroimaging and experience sampling to determine if there are brain markers that predict whether people act on their food desires in daily life. We examined food-cue-related activity in the nucleus accumbens (NAcc), as well as activity associated with response inhibition in the inferior frontal gyrus (IFG). Greater NAcc activity was associated with greater likelihood of self-control failures, whereas IFG activity supported successful resistance to temptations. These findings demonstrate an important role for the neural mechanisms underlying desire and self-control in people's real-world experiences of temptations. PMID:24789842

  18. Human otolith-ocular reflexes during off-vertical axis rotation: effect of frequency on tilt-translation ambiguity and motion sickness

    NASA Technical Reports Server (NTRS)

    Wood, Scott J.; Paloski, W. H. (Principal Investigator)

    2002-01-01

    The purpose of this study was to examine how the modulation of tilt and translation otolith-ocular responses during constant velocity off-vertical axis rotation varies as a function of stimulus frequency. Eighteen human subjects were rotated in darkness about their longitudinal axis 30 degrees off-vertical at stimulus frequencies between 0.05 and 0.8 Hz. The modulation of torsion decreased while the modulation of horizontal slow phase velocity (SPV) increased with increasing frequency. It is inferred that the ambiguity of otolith afferent information is greatest in the frequency region where tilt (torsion) and translational (horizontal SPV) otolith-ocular responses crossover. It is postulated that the previously demonstrated peak in motion sickness susceptibility during linear accelerations around 0.3 Hz is the result of frequency segregation of ambiguous otolith information being inadequate to distinguish between tilt and translation.

  19. Giving and taking: Representational building blocks of active resource-transfer events in human infants

    PubMed Central

    Tatone, Denis; Geraci, Alessandra; Csibra, Gergely

    2015-01-01

    Active resource transfer is a pervasive and distinctive feature of human sociality. We hypothesized that humans possess an action schema of giving specific for representing social interactions based on material exchange, and specified the set of necessary assumptions about giving events that this action schema should be equipped with. We tested this proposal by investigating how 12-month-old infants interpret abstract resource-transfer events. Across eight looking-time studies using a violation-of-expectation paradigm we found that infants were able to distinguish between kinematically identical giving and taking actions. Despite the surface similarity between these two actions, only giving was represented as an object-mediated social interaction. While we found no evidence that infants expected the target of a giving or taking action to reciprocate, the present results suggest that infants interpret giving as an inherently social action, which they can possibly use to map social relations via observing resource-transfer episodes. PMID:25614012

  20. Giving and taking: representational building blocks of active resource-transfer events in human infants.

    PubMed

    Tatone, Denis; Geraci, Alessandra; Csibra, Gergely

    2015-04-01

    Active resource transfer is a pervasive and distinctive feature of human sociality. We hypothesized that humans possess an action schema of giving specific for representing social interactions based on material exchange, and specified the set of necessary assumptions about giving events that this action schema should be equipped with. We tested this proposal by investigating how 12-month-old infants interpret abstract resource-transfer events. Across eight looking-time studies using a violation-of-expectation paradigm we found that infants were able to distinguish between kinematically identical giving and taking actions. Despite the surface similarity between these two actions, only giving was represented as an object-mediated social interaction. While we found no evidence that infants expected the target of a giving or taking action to reciprocate, the present results suggest that infants interpret giving as an inherently social action, which they can possibly use to map social relations via observing resource-transfer episodes. PMID:25614012

  1. Children's Trait and Emotion Attributions in Socially Ambiguous and Unambiguous Situations

    ERIC Educational Resources Information Center

    Boseovski, Janet J.; Lapan, Candace; Bosacki, Sandra

    2013-01-01

    Children's attributions about story characters in ambiguous and unambiguous social situations were assessed. One hundred and forty-four 6-7-year-olds and 10-11-year-olds heard about actors who slighted a recipient intentionally or for an undetermined reason and then made causal attributions about the events, an emotion attribution about the…

  2. Young Word Learners' Interpretations of Words and Symbolic Gestures within the Context of Ambiguous Reference

    ERIC Educational Resources Information Center

    Suanda, Sumarga H.; Namy, Laura L.

    2013-01-01

    Early in development, many word-learning phenomena generalize to symbolic gestures. The current study explored whether children avoid lexical overlap in the gestural modality, as they do in the verbal modality, within the context of ambiguous reference. Eighteen-month-olds' interpretations of words and symbolic gestures in a symbol-disambiguation

  3. A Fine Risk To Be Run? The Ambiguity of Eros and Teacher Responsibility.

    ERIC Educational Resources Information Center

    Todd, Sharon

    2003-01-01

    Describes teachers as often being in a place of tension between responding to students as persons and responding to students in their institutional-defined roles. Studies the significance of communicative ambiguity for responsibility, and explores what is ethically at stake for teachers in erotic form of communication. Contains 14 references. (JS)

  4. Using Semantic Ambiguity Instruction to Improve Third Graders' Metalinguistic Awareness and Reading Comprehension: An Experimental Study

    ERIC Educational Resources Information Center

    Zipke, Marcy; Ehri, Linnea C.; Cairns, Helen Smith

    2009-01-01

    An experiment examined whether metalinguistic awareness involving the detection of semantic ambiguity can be taught, and whether this instruction improves students' reading comprehension. Lower SES third graders from a variety of cultural backgrounds (M = 8 yr. 7 mo., N = 46) were randomly assigned to treatment and control groups. Those receiving

  5. The Processing of Subject-Object Ambiguities in Native and Near-Native Mexican Spanish

    ERIC Educational Resources Information Center

    Jegerski, Jill

    2012-01-01

    This self-paced reading study first tested the prediction that the garden path effect previously observed during the processing of subject-object ambiguities in native English would not obtain in a null subject language like Spanish. The investigation then further explored whether the effect would be evident among near-native readers of Spanish

  6. Rule mining and classification in the presence of feature level and class label ambiguities

    NASA Astrophysics Data System (ADS)

    Hewawasam, K. K. Rohitha G.; Premaratne, Kamal; Shyu, Mei-Ling; Subasingha, Shaminda P.

    2005-03-01

    Numerous applications of topical interest call for knowledge discovery and classification from information that may be inaccurate and/or incomplete. For example, in an airport threat classification scenario, data from heterogeneous sensors are used to extract features for classifying potential threats. This requires a training set that utilizes non-traditional information sources (e.g., domain experts) to assign a threat level to each training set instance. Sensor reliability, accuracy, noise, etc., all contribute to feature level ambiguities; conflicting opinions of experts generate class label ambiguities that may however indicate important clues. To accommodate these, a belief theoretic approach is proposed. It utilizes a data structure that facilitates belief/plausibility queries regarding "ambiguous" itemsets. An efficient apriori-like algorithm is then developed to extract frequent such itemsets and to generate corresponding association rules. These are then used to classify an incoming "ambiguous" data instance into a class label (which may be "hard" or "soft"). To test its performance, the proposed algorithm is compared with C4.5 for several databases from the UCI repository and a threat assessment application scenario.

  7. Why is "that"? Structural Prediction and Ambiguity Resolution in a Very Large Corpus of English Sentences

    ERIC Educational Resources Information Center

    Roland, Douglas; Elman, Jeffrey L.; Ferreira, Victor S.

    2006-01-01

    Previous psycholinguistic research has shown that a variety of contextual factors can influence the interpretation of syntactically ambiguous structures, but psycholinguistic experimentation inherently does not allow for the investigation of the role that these factors play in natural (uncontrolled) language use. We use regression modeling in

  8. Engineering Objects for Collaboration: Strategies of Ambiguity and Clarity at Knowledge Boundaries

    ERIC Educational Resources Information Center

    Barley, William C.; Leonardi, Paul M.; Bailey, Diane E.

    2012-01-01

    Prior research suggests that boundary objects gain meaning through group interaction. Drawing from the literature on strategic ambiguity, we explore the possibility that individuals strategically create potential boundary objects in an attempt to shape the meanings that groups develop. From ethnographic observations of automotive engineers, we

  9. Learning the Language of Evolution: Lexical Ambiguity and Word Meaning in Student Explanations

    ERIC Educational Resources Information Center

    Rector, Meghan A.; Nehm, Ross H.; Pearl, Dennis

    2013-01-01

    Our study investigates the challenges introduced by students' use of lexically ambiguous language in evolutionary explanations. Specifically, we examined students' meaning of five key terms incorporated into their written evolutionary explanations: "pressure", "select", "adapt", "need", and "must". We utilized a new technological tool known as the…

  10. Capstone and Building Block: Helping Students Manage Ambiguity about their Futures through Writing

    ERIC Educational Resources Information Center

    Love, Brad; Mackert, Michael

    2013-01-01

    Encouraging students to engage with principles and ideas is one way to address ambiguity with consistent, effective approaches in situations made up of "gray area." This includes the looming post-college world where students may be unsure about choosing between job offers, geographic locations, or even communication fields. Such

  11. Young Children's Classification, Stereotyping and Play Behaviour for Gender Neutral and Ambiguous Toys

    ERIC Educational Resources Information Center

    Cherney, Isabelle D.; Dempsey, Jessica

    2010-01-01

    Developmental intergroup theory would predict that children develop fewer or weaker stereotypes about toys that have less distinguishable gender attributes than those that are clearly associated with a gender. The purpose of this study was to investigate the role of neutral and ambiguous toys in 31 three- to five-year-old children's play behaviour

  12. Children's Use of Phonological Information in Ambiguity Resolution: A View from Mandarin Chinese

    ERIC Educational Resources Information Center

    Zhou, Peng; Su, Yi; Crain, Stephen; Gao, Liqun; Zhan, Likan

    2012-01-01

    How do children develop the mapping between prosody and other levels of linguistic knowledge? This question has received considerable attention in child language research. In the present study two experiments were conducted to investigate four- to five-year-old Mandarin-speaking children's sensitivity to prosody in ambiguity resolution. Experiment

  13. Cognate and Word Class Ambiguity Effects in Noun and Verb Processing

    ERIC Educational Resources Information Center

    Bultena, Sybrine; Dijkstra, Ton; van Hell, Janet G.

    2013-01-01

    This study examined how noun and verb processing in bilingual visual word recognition are affected by within and between-language overlap. We investigated how word class ambiguous noun and verb cognates are processed by bilinguals, to see if co-activation of overlapping word forms between languages benefits from additional overlap within a

  14. Embedded Promotions in Online Services: How Goal-Relevance Ambiguity Shapes Response and Affect

    ERIC Educational Resources Information Center

    Brasel, S. Adam

    2010-01-01

    Adding promotions to online services is increasingly commonplace, yet consumers may have difficulty determining whether service-embedded promotions are goal-relevant, due to the linear and transactional nature of online services. This contextual effect of goal-relevance ambiguity on promotions is explored across three studies. An exploratory study…

  15. Aversion to Ambiguity Regarding Medical Tests and Treatments: Measurement, Prevalence, and Relationship to Sociodemographic Factors

    PubMed Central

    HAN, PAUL K. J.; REEVE, BRYCE B.; MOSER, RICHARD P.; KLEIN, WILLIAM M. P.

    2014-01-01

    Aversion to “ambiguity”—uncertainty about the reliability, credibility, or adequacy of risk-related information—is an important problem that may influence judgments and decisions about medical interventions. Ambiguity aversion (AA) varies among individuals, however, and has been understudied in the health domain. To explore this phenomenon further, we developed a new theory-based measure of aversion to ambiguity regarding medical tests and treatments, and examined the prevalence and association of AA with sociodemographic factors. The “AA-Med” scale was developed using a large survey sample of the U.S. public (n = 4,398), and scale psychometric properties and the population distribution of AA were evaluated. The scale demonstrated acceptable reliability (α = .73) and validity as ascertained by association with respondents’ interest in a hypothetical ambiguous cancer screening test. Ambiguity aversion (AA) was associated with older age, non-White race, lower education and income, and female sex. The AA-Med scale is a promising new measure, and AA is associated with several sociodemographic factors. We discuss implications of these findings and potential applications of the scale for future research. PMID:19731127

  16. How I handled ambiguity in a system to read music scores

    NASA Astrophysics Data System (ADS)

    Ruttenberg, Alan

    1992-11-01

    In a program for reading printed music, a variety of low level feature detectors were used to extract sufficient information to reconstruct the score. All feature detectors were unreliable to some extent, and were biased towards yielding false positives rather than missing features. In order to reconstruct the score, conflicting information from the feature detectors needed to be recognized and eliminated. All objects as well as their geometric and semantic relations were represented in an object oriented framework. Ambiguity (implemented as a generic predicate) was defined -- and explicitly represented -- in terms of these relationships. Examples of ambiguous relationships include: An accidental and a note head having an on-top-of geometric relationship, or the total duration of notes in a measure not being equal to the notated time signature. A method inspired by Waltz filtering was used to produce a consistent, unambiguous interpretation. Waltz filtering is a symbolic constraint propagation technique which has been applied to line drawings. During interpretation attention was focused on objects which had ambiguous relations. Ambiguity was iteratively reduced or removed by using a variety of methods employing information gathered from local unambiguous relations.

  17. Method and apparatus for reducing range ambiguity in synthetic aperture radar

    SciTech Connect

    Kare, J.T.

    1999-10-26

    A modified Synthetic Aperture Radar (SAR) system is disclosed with reduced sensitivity to range ambiguities, and which uses secondary receiver channels to detect the range ambiguous signals and subtract them from the signal received by the main channel. Both desired and range ambiguous signals are detected by a main receiver and by one or more identical secondary receivers. All receivers are connected to a common antenna with two or more feed systems offset in elevation e.g., a reflector antenna with multiple feed horns or a phased array with multiple phase shift networks. The secondary receiver output(s) is (are) then subtracted from the main receiver output in such a way as to cancel the ambiguous signals while only slightly attenuating the desired signal and slightly increasing the noise in the main channel, and thus does not significantly affect the desired signal. This subtraction may be done in real time, or the outputs of the receivers may be recorded separately and combined during signal processing.

  18. Resolving Ambiguity: A Psycholinguistic Approach to Understanding Prosody Processing in High-Functioning Autism

    ERIC Educational Resources Information Center

    Diehl, Joshua J.; Bennetto, Loisa; Watson, Duane; Gunlogson, Christine; McDonough, Joyce

    2008-01-01

    Individuals with autism exhibit significant impairments in prosody production, yet there is a paucity of research on prosody comprehension in this population. The current study adapted a psycholinguistic paradigm to examine whether individuals with autism are able to use prosody to resolve syntactically ambiguous sentences. Participants were 21

  19. Pokes, Prods, and Pushes: Information Availability and Decision Making in Ambiguous Environments

    ERIC Educational Resources Information Center

    Greenwood, Brad N.

    2013-01-01

    In this dissertation I investigate how changes in the availability of information influences decision making in inherently ambiguous environments. As the Internet has not only fostered connectivity, but also catalyzed information generation on an unprecedented scale, my objective is to revisit the concept of information availability and salience

  20. An Ambiguous, Contested Terrain: Governance Models for a New South African Education System

    ERIC Educational Resources Information Center

    Weber, Everard

    2002-01-01

    This paper reviews the development of education governance in South Africa during the 1990s. It outlines ambiguities within and between competing policies, tracing the historical trajectory and explaining its outcome. Apartheid governance, the attempts to reform it, policy options originating within the anti-apartheid movement, and the law passed

  1. Newcomer Immigrant Adolescents and Ambiguous Discrimination: The Role of Cognitive Appraisal

    ERIC Educational Resources Information Center

    Patel, Sita G.; Tabb, Kevin M.; Strambler, Michael J.; Eltareb, Fazia

    2015-01-01

    Cognitive appraisal has been shown to mediate the relationship between stressors and internalizing symptoms, but not among newcomer immigrant youth facing ambiguous discrimination. Using a mixed-methods design with a sample of newcomer adolescents from African, Arab, Asian, Caribbean, European, and Latin American countries, this study measured the…

  2. The indexing ambiguity in serial femtosecond crystallography (SFX) resolved using an expectation maximization algorithm.

    PubMed

    Liu, Haiguang; Spence, John C H

    2014-11-01

    Crystallographic auto-indexing algorithms provide crystal orientations and unit-cell parameters and assign Miller indices based on the geometric relations between the Bragg peaks observed in diffraction patterns. However, if the Bravais symmetry is higher than the space-group symmetry, there will be multiple indexing options that are geometrically equivalent, and hence many ways to merge diffraction intensities from protein nanocrystals. Structure factor magnitudes from full reflections are required to resolve this ambiguity but only partial reflections are available from each XFEL shot, which must be merged to obtain full reflections from these 'stills'. To resolve this chicken-and-egg problem, an expectation maximization algorithm is described that iteratively constructs a model from the intensities recorded in the diffraction patterns as the indexing ambiguity is being resolved. The reconstructed model is then used to guide the resolution of the indexing ambiguity as feedback for the next iteration. Using both simulated and experimental data collected at an X-ray laser for photosystem I in the P63 space group (which supports a merohedral twinning indexing ambiguity), the method is validated. PMID:25485120

  3. When Does the Brain Distinguish between Genuine and Ambiguous Smiles? An ERP Study

    ERIC Educational Resources Information Center

    Calvo, Manuel G.; Marrero, Hipolito; Beltran, David

    2013-01-01

    Event-related brain potentials (ERPs) were recorded to assess the processing time course of ambiguous facial expressions with a smiling mouth but neutral, fearful, or angry eyes, in comparison with genuinely happy faces (a smile and happy eyes) and non-happy faces (neutral, fearful, or angry mouth and eyes). Participants judged whether the faces

  4. Interpretation of Ambiguous Situations: Evidence for a Dissociation between Social and Physical Threat in Williams Syndrome

    ERIC Educational Resources Information Center

    Dodd, Helen F.; Porter, Melanie A.

    2011-01-01

    Williams syndrome (WS) is associated with an unusual profile of anxiety, characterised by increased rates of non-social anxiety but not social anxiety (Dodd and Porter, J Ment Health Res Intellect Disabil 2(2):89-109, "2009"). The present research examines whether this profile of anxiety is associated with an interpretation bias for ambiguous

  5. Learning the Language of Evolution: Lexical Ambiguity and Word Meaning in Student Explanations

    ERIC Educational Resources Information Center

    Rector, Meghan A.; Nehm, Ross H.; Pearl, Dennis

    2013-01-01

    Our study investigates the challenges introduced by students' use of lexically ambiguous language in evolutionary explanations. Specifically, we examined students' meaning of five key terms incorporated into their written evolutionary explanations: "pressure", "select", "adapt", "need", and "must". We utilized a new technological tool known as the

  6. Perirhinal Cortex Resolves Feature Ambiguity in Configural Object Recognition and Perceptual Oddity Tasks

    ERIC Educational Resources Information Center

    Bartko, Susan J.; Winters, Boyer D.; Cowell, Rosemary A.; Saksida, Lisa M.; Bussey, Timothy J.

    2007-01-01

    The perirhinal cortex (PRh) has a well-established role in object recognition memory. More recent studies suggest that PRh is also important for two-choice visual discrimination tasks. Specifically, it has been suggested that PRh contains conjunctive representations that help resolve feature ambiguity, which occurs when a task cannot easily be…

  7. Ambiguous-Cue Interpretation is Biased Under Stress- and Depression-Like States in Rats

    PubMed Central

    Enkel, Thomas; Gholizadeh, Donya; von Bohlen und Halbach, Oliver; Sanchis-Segura, Carles; Hurlemann, Rene; Spanagel, Rainer; Gass, Peter; Vollmayr, Barbara

    2010-01-01

    Negative cognitive biasthe tendency to interpret ambiguous situations pessimisticallyis a central feature of stress-related disorders such as depression. The underlying neurobiology of this bias, however, remains unclear, not least because of a lack of translational tools. We established a new ambiguous-cue interpretation paradigm and, with respect to the etiology of depression, evaluated if environmental and genetic factors contribute to a negative bias. Rats were trained to press a lever to receive a food reward contingent to one tone and to press another lever in response to a different tone to avoid punishment by electric foot-shock. In the ambiguous-cue test, the lever-press responses to tones with frequencies intermediate to the trained tones were taken as indicators for the rats' expectation of a positive or negative event. A negative response bias because of decreased positive and increased negative responding was found in congenitally helpless rats, a genetic animal model of depression. Moreover, treatment with a combined noradrenergic-glucocorticoid challenge, mimicking stress-related changes in endogenous neuromodulation, biased rats away from positive responding. This response shift was accompanied by neuronal activation in dentate gyrus and amygdala. Thus, environmental and genetic risk factors for depression induce a response bias, which resembles the pessimistic bias of patients suffering from depression. The behavioral paradigm described constitutes a useful tool to study the neuronal basis of decision making under ambiguous conditions and may promote innovative pharmaco- and psychotherapy for depression. PMID:20043002

  8. The Processing of Subject-Object Ambiguities in Native and Near-Native Mexican Spanish

    ERIC Educational Resources Information Center

    Jegerski, Jill

    2012-01-01

    This self-paced reading study first tested the prediction that the garden path effect previously observed during the processing of subject-object ambiguities in native English would not obtain in a null subject language like Spanish. The investigation then further explored whether the effect would be evident among near-native readers of Spanish…

  9. Ambiguity in Units and the Referents: Two Cases in Rational Number Operations

    ERIC Educational Resources Information Center

    Rathouz, Margaret

    2010-01-01

    I explore the impact of ambiguous referral to the unit on understanding of decimal and fraction operations during episodes in two different mathematics courses for pre-service teachers (PSTs). In one classroom, the instructor introduces a rectangular area diagram to help the PSTs visualize decimal multiplication. A transcript from this classroom…

  10. Ambiguities in the Tsallis description of non-thermal plasma species

    NASA Astrophysics Data System (ADS)

    Verheest, Frank; Verheest

    2013-12-01

    Tsallis q-non-extensive distributions have recently found favor in describing the presence of energetic particles and their influences on several plasma modes, notably electrostatic solitons. Here attention is drawn to ambiguities and subtleties in the superextensive and subextensive ranges in q, which are not always recognized in the literature, particularly in numerical studies.

  11. How Often Is Often? Reference Ambiguities of the Likert-Scale in Language Learning Strategy Research.

    ERIC Educational Resources Information Center

    Gu, Yongqi; And Others

    Based on personal experience, this paper examines the ambiguities of the Likert-type 5-point scale in learning strategy elicitation. Four parallel questionnaires consisting of the same batch of 20 items taken from the Oxford scale (1990) were administered among a group of 120 tertiary level, non-English majors in China. Questionnaire 1 used the

  12. Ambiguous-cue interpretation is biased under stress- and depression-like states in rats.

    PubMed

    Enkel, Thomas; Gholizadeh, Donya; von Bohlen Und Halbach, Oliver; Sanchis-Segura, Carles; Hurlemann, Rene; Spanagel, Rainer; Gass, Peter; Vollmayr, Barbara

    2010-03-01

    Negative cognitive bias-the tendency to interpret ambiguous situations pessimistically-is a central feature of stress-related disorders such as depression. The underlying neurobiology of this bias, however, remains unclear, not least because of a lack of translational tools. We established a new ambiguous-cue interpretation paradigm and, with respect to the etiology of depression, evaluated if environmental and genetic factors contribute to a negative bias. Rats were trained to press a lever to receive a food reward contingent to one tone and to press another lever in response to a different tone to avoid punishment by electric foot-shock. In the ambiguous-cue test, the lever-press responses to tones with frequencies intermediate to the trained tones were taken as indicators for the rats' expectation of a positive or negative event. A negative response bias because of decreased positive and increased negative responding was found in congenitally helpless rats, a genetic animal model of depression. Moreover, treatment with a combined noradrenergic-glucocorticoid challenge, mimicking stress-related changes in endogenous neuromodulation, biased rats away from positive responding. This response shift was accompanied by neuronal activation in dentate gyrus and amygdala. Thus, environmental and genetic risk factors for depression induce a response bias, which resembles the pessimistic bias of patients suffering from depression. The behavioral paradigm described constitutes a useful tool to study the neuronal basis of decision making under ambiguous conditions and may promote innovative pharmaco- and psychotherapy for depression. PMID:20043002

  13. Parsing with Focus Particles in Context: Eye Movements during the Processing of Relative Clause Ambiguities

    ERIC Educational Resources Information Center

    Filik, Ruth; Paterson, Kevin B.; Liversedge, Simon P.

    2005-01-01

    Sedivy (2002) proposed that using "only" and prior referential context to specify contrastive focus can guide the parsing of relative clause ambiguities. We report two studies investigating this hypothesis, using sentences that either temporarily allowed or disallowed a transitive main clause interpretation. Sentence completions demonstrated that…

  14. The Role of Working Memory in Syntactic Ambiguity Resolution: A Psychometric Approach

    ERIC Educational Resources Information Center

    Swets, Benjamin; Desmet, Timothy; Hambrick, David Z.; Ferreira, Fernanda

    2007-01-01

    In 2 studies, the authors used a combination of psychometric and experimental techniques to investigate the effects of domain-general and domain-specific working memory factors on offline decisions concerning attachment of an ambiguous relative clause. Both studies used English and Dutch stimuli presented to English- and Dutch-speaking

  15. When Does the Brain Distinguish between Genuine and Ambiguous Smiles? An ERP Study

    ERIC Educational Resources Information Center

    Calvo, Manuel G.; Marrero, Hipolito; Beltran, David

    2013-01-01

    Event-related brain potentials (ERPs) were recorded to assess the processing time course of ambiguous facial expressions with a smiling mouth but neutral, fearful, or angry eyes, in comparison with genuinely happy faces (a smile and happy eyes) and non-happy faces (neutral, fearful, or angry mouth and eyes). Participants judged whether the faces…

  16. The Functional Organisation of the Fronto-Temporal Language System: Evidence from Syntactic and Semantic Ambiguity

    ERIC Educational Resources Information Center

    Rodd, Jennifer M.; Longe, Olivia A.; Randall, Billi; Tyler, Lorraine K.

    2010-01-01

    Spoken language comprehension is known to involve a large left-dominant network of fronto-temporal brain regions, but there is still little consensus about how the syntactic and semantic aspects of language are processed within this network. In an fMRI study, volunteers heard spoken sentences that contained either syntactic or semantic ambiguities

  17. The Role of Prosody in the Interpretation of Structural Ambiguities: A Study of Anticipatory Eye Movements

    ERIC Educational Resources Information Center

    Weber, Andrea; Grice, Maetine; Crocker, Matthew W.

    2006-01-01

    An eye-tracking experiment examined whether prosodic cues can affect the interpretation of grammatical functions in the absence of clear morphological information. German listeners were presented with scenes depicting three potential referents while hearing temporarily ambiguous SVO and OVS sentences. While case marking on the first noun phrase

  18. Imaginary Companions and Young Children's Responses to Ambiguous Auditory Stimuli: Implications for Typical and Atypical Development

    ERIC Educational Resources Information Center

    Fernyhough, Charles; Bland, Kirsten; Meins, Elizabeth; Coltheart, Max

    2007-01-01

    Background: Previous research has reported a link between imaginary companions (ICs) in middle childhood and the perception of verbal material in ambiguous auditory stimuli. These findings have been interpreted in terms of commonalities in the cognitive processes underlying children's engagement with ICs and adults' reporting of imaginary verbal

  19. Inheritance, Heritage, and the Disinherited: Ambiguities of Religious Pedagogy in the Moroccan Public School

    ERIC Educational Resources Information Center

    Boutieri, Charis

    2013-01-01

    This article investigates how Moroccan public high-school students experience religious pedagogy. Probing the linguistic ideology that underpins their religious training, the article exposes the ambiguities inherent in educational Arabization, a project set on safeguarding the state's sacredness while mediating an agenda of indigenous…

  20. (E)pistemological Awareness, Instantiation of Methods, and Uninformed Methodological Ambiguity in Qualitative Research Projects

    ERIC Educational Resources Information Center

    Koro-Ljungberg, Mirka; Yendol-Hoppey, Diane; Smith, Jason Jude; Hayes, Sharon B.

    2009-01-01

    This article explores epistemological awareness and instantiation of methods, as well as uninformed ambiguity, in qualitative methodological decision making and research reporting. The authors argue that efforts should be made to make the research process, epistemologies, values, methodological decision points, and argumentative logic open,