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Sample records for ambiguity discounting ambiguity

  1. NICE's selective application of differential discounting: ambiguous, inconsistent, and unjustified.

    PubMed

    O'Mahony, James F; Paulden, Mike

    2014-07-01

    The National Institute for Health and Clinical Excellence (NICE) recently recommended differential discounting of costs and health effects in the economic appraisal of health care interventions in certain circumstances. The recommendation was published in an amendment to NICE's Guide to the Methods of Technology Appraisal. The amendment states that differential discounting should be applied where "treatment effects are both substantial in restoring health and sustained over a very long period (normally at least 30 years)." Renewed interest in differential discounting from NICE is welcome; however, the recommendation's selective application of differential discounting raises a number of concerns. The stated criteria for applying differential discounting are ambiguous. The rationale for the selective application of differential discounting has not been articulated by NICE and is questionable. The selective application of differential discounting leads to several inconsistencies, the most concerning of which is the lower valuation of health gains for those with less than 30 years remaining life expectancy, which can be interpreted as age discrimination. Furthermore, the discount rates chosen by NICE do not appear to be informed by recent advances in the theoretical understanding of differential discounting. NICE's apparent motivation for recommending differential discounting was to ensure a favorable cost-effectiveness ratio for a pediatric oncology drug. While flexibility may be appropriate to allow some interventions that exceed conventional cost-effectiveness thresholds to be adopted, the selective adjustment of appraisal methods is problematic and without justification. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  2. Treatment decisions under ambiguity.

    PubMed

    Berger, Loïc; Bleichrodt, Han; Eeckhoudt, Louis

    2013-05-01

    Many health risks are ambiguous in the sense that reliable and credible information about these risks is unavailable. In health economics, ambiguity is usually handled through sensitivity analysis, which implicitly assumes that people are neutral towards ambiguity. However, empirical evidence suggests that people are averse to ambiguity and react strongly to it. This paper studies the effects of ambiguity aversion on two classical medical decision problems. If there is ambiguity regarding the diagnosis of a patient, ambiguity aversion increases the decision maker's propensity to opt for treatment. On the other hand, in the case of ambiguity regarding the effects of treatment, ambiguity aversion leads to a reduction in the propensity to choose treatment.

  3. 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

  4. Image ambiguity and fluency.

    PubMed

    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: 10 ms, 50 ms, 100 ms, 500 ms, 1000 ms) 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 500 ms even 75% performed above chance level. Ambiguous artworks were found more interesting (in conditions 50 ms to 1000 ms) and were preferred over non-ambiguous stimuli at 500 ms and 1000 ms (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.

  5. 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.

  6. 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…

  7. In Defence of Ambiguity.

    ERIC Educational Resources Information Center

    Gibson, Rex

    1979-01-01

    The author argues that ambiguity in language plays an important part in moral growth and that ambiguity constitutes a rich strand in English culture. Through criticism of some moral education materials, he asserts that the context, rather than the language, of social interaction is often the key to interpreting communication. (Author/SJL)

  8. 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…

  9. 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…

  10. The Ethics of Ambiguity

    PubMed Central

    2016-01-01

    Understanding and embracing uncertainty are critical for effective teacher–learner relationships as well as for shared decision-making in the physician–patient relationship. However, ambiguity has not been given serious consideration in either the undergraduate or graduate medical curricula or in the role it plays in patient-centered care. In this article, the author examines the ethics of ambiguity and argues for a pedagogy that includes education in the importance of, and tolerance of, ambiguity that is inherent in medical education and practice. Common threads running through the ethics of ambiguity are the virtue of respect, and the development of a culture of respect is required for the successful understanding and implementation of a pedagogy of ambiguity. PMID:28725771

  11. Determinants of translation ambiguity

    PubMed Central

    Degani, Tamar; Prior, Anat; Eddington, Chelsea M.; Arêas da Luz Fontes, Ana B.; Tokowicz, Natasha

    2016-01-01

    Ambiguity in translation is highly prevalent, and has consequences for second-language learning and for bilingual lexical processing. To better understand this phenomenon, the current study compared the determinants of translation ambiguity across four sets of translation norms from English to Spanish, Dutch, German and Hebrew. The number of translations an English word received was correlated across these different languages, and was also correlated with the number of senses the word has in English, demonstrating that translation ambiguity is partially determined by within-language semantic ambiguity. For semantically-ambiguous English words, the probability of the different translations in Spanish and Hebrew was predicted by the meaning-dominance structure in English, beyond the influence of other lexical and semantic factors, for bilinguals translating from their L1, and translating from their L2. These findings are consistent with models postulating direct access to meaning from L2 words for moderately-proficient bilinguals. PMID:27882188

  12. 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

  13. Return of ambiguity attacks

    NASA Astrophysics Data System (ADS)

    Craver, Scott A.

    2002-04-01

    The ambiguity attack, or invertibility attack, was described several years ago as a potential threat to digital watermarking systems. By manipulating the invertibility of watermark embedding, one could negate or subvert the meaning of a copyright mark. These attacks were easily prevented, however, with the appropriate application of one-way functions and cryptographic hashes in watermarking protocols. New research in watermarking, however, has caused the ambiguity attack to resurface as a threat, and this time it will not be as easy averted. Recent work in public-key watermarking create scenarios in which one-way functions may be ineffective against this threat. Furthermore, there are also positive uses for ambiguity attacks, as components in watermarking protocols. This paper provides an overview of the past and possible future of these unusual attacks.

  14. 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.

  15. 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

  16. 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.

  17. 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…

  18. 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…

  19. Confronting Ambiguity in Science

    ERIC Educational Resources Information Center

    Emery, Katherine; Harlow, Danielle; Whitmer, Ali; Gaines, Steven

    2015-01-01

    People are regularly confronted with environmental and science-related issues presented to them in newspapers, on television, or even in their own doctor's office. Often the information they use to inform their decisions on matters of science may be ambiguous and contradictory. This article presents an activity that investigates how students deal…

  20. Confronting Ambiguity in Science

    ERIC Educational Resources Information Center

    Emery, Katherine; Harlow, Danielle; Whitmer, Ali; Gaines, Steven

    2015-01-01

    People are regularly confronted with environmental and science-related issues presented to them in newspapers, on television, or even in their own doctor's office. Often the information they use to inform their decisions on matters of science may be ambiguous and contradictory. This article presents an activity that investigates how students deal…

  1. Some Structural Ambiguities.

    ERIC Educational Resources Information Center

    Stageberg, Norman C.

    1958-01-01

    The identification and study of 20 syntactical patterns responsible for much of the structural ambiguity found in literary composition can develop in students an audience awareness. When they realize that such constructions as "a dull boy's knife" and "the club will be open to members from Monday to Thursday" can be misinterpreted, they take more…

  2. Ethical Ambiguity in Science.

    PubMed

    Johnson, David R; Ecklund, Elaine Howard

    2016-08-01

    Drawing on 171 in-depth interviews with physicists at universities in the United States and the UK, this study examines the narratives of 48 physicists to explain the concept of ethical ambiguity: the border where legitimate and illegitimate conduct is blurred. Researchers generally assume that scientists agree on what constitutes both egregious and more routine forms of misconduct in science. The results of this study show that scientists perceive many scenarios as ethically gray, rather than black and white. Three orientations to ethical ambiguity are considered-altruism, inconsequential outcomes, and preserving the status quo-that allow possibly questionable behavior to persist unchallenged. Each discursive strategy is rationalized as promoting the collective interest of science rather than addressing what is ethically correct or incorrect. The results of this study suggest that ethics training in science should focus not only on fabrication, falsification, and plagiarism and more routine forms of misconduct, but also on strategies for resolving ethically ambiguous scenarios where appropriate action may not be clear.

  3. Systematization of ambiguous genitalia

    PubMed Central

    Makiyan, Zograb

    2016-01-01

    ABSTRACT Sex assignment in newborns depends on the anatomy of the external genitalia, despite this stage being the final in embryogenesis. According to the current view, the genital tubercle is the embryonic precursor of penis and clitoris. It originates from mesenchymal tissue, but mesenchymal cells are arranged across the embryonal body and do not have specific androgen receptors. The nature of the signal that initiates early derivation of the indifferent genital tubercle is unknown at present. The aims of this article are to improve surgical management of intersex disorders and investigate the development of the genital tubercle. Clinical examination of 114 females with various forms of DSD revealed ambiguous (bisexual) external genitalia in 73 patients, and 51 of them underwent feminizing surgery. Intersexuality (ambiguity) in 46,XY patients results from disruptors in the pathways of sex steroid hormones or receptors; in 46,XX females arises from excessive levels of androgens. Systematization of intersex disorders distinguishes the karyotype, gonadal morphology, and genital anatomy to provide a differential diagnosis and guide appropriate surgical management. Modified feminizing clitoroplasty with preservation of the dorsal and ventral neurovascular bundles to retain erogenous sensitivity was performed in females with severe virilization (Prader degree III-V). The outgrowth of the genital tubercle and the fusion of the urethral fold proceed in an ordered fashion; but in some cases of ambiguity, there was discordance due to different pathways. Speculation about the derivation of the genital tubercle have discussed with a literature review. The genital tubercle derives from the following 3 layers: the ectodermal glans of the tubercle, the mesodermal corpora cavernosa and the endodermal urogenital groove. According to the new hypothesis, during the indifferent stages, the 5 sacral somites have to recede from their segmentation and disintegrate: the sclerotomes

  4. Ambiguities in Spoken Australian English.

    ERIC Educational Resources Information Center

    Taylor, C. V.

    1971-01-01

    Pronunciation of some sounds in Australian English causes ambiguities in cases where phonemes seem to have merged. This paper discusses some of the ambiguities arising from phonemic changes and provides examples of pronunciation variations in British and Australian English--mainly in vowels, but also in consonants and syllabification. Several…

  5. Eliminating ambiguity in digital signals

    NASA Technical Reports Server (NTRS)

    Weber, W. J., III

    1979-01-01

    Multiamplitude minimum shift keying (mamsk) transmission system, method of differential encoding overcomes problem of ambiguity associated with advanced digital-transmission techniques with little or no penalty in transmission rate, error rate, or system complexity. Principle of method states, if signal points are properly encoded and decoded, bits are detected correctly, regardless of phase ambiguities.

  6. Ambiguity aversion in rhesus macaques.

    PubMed

    Hayden, Benjamin Y; Heilbronner, Sarah R; Platt, Michael L

    2010-01-01

    People generally prefer risky options, which have fully specified outcome probabilities, to ambiguous options, which have unspecified probabilities. This preference, formalized in economics, is strong enough that people will reliably prefer a risky option to an ambiguous option with a greater expected value. Explanations for ambiguity aversion often invoke uniquely human faculties like language, self-justification, or a desire to avoid public embarrassment. Challenging these ideas, here we demonstrate that a preference for unambiguous options is shared with rhesus macaques. We trained four monkeys to choose between pairs of options that both offered explicitly cued probabilities of large and small juice outcomes. We then introduced occasional trials where one of the options was obscured and examined their resulting preferences; we ran humans in a parallel experiment on a nearly identical task. We found that monkeys reliably preferred risky options to ambiguous ones, even when this bias was costly, closely matching the behavior of humans in the analogous task. Notably, ambiguity aversion varied parametrically with the extent of ambiguity. As expected, ambiguity aversion gradually declined as monkeys learned the underlying probability distribution of rewards. These data indicate that ambiguity aversion reflects fundamental cognitive biases shared with other animals rather than uniquely human factors guiding decisions.

  7. Visual word ambiguity.

    PubMed

    van Gemert, Jan C; Veenman, Cor J; Smeulders, Arnold W M; Geusebroek, Jan-Mark

    2010-07-01

    This paper studies automatic image classification by modeling soft assignment in the popular codebook model. The codebook model describes an image as a bag of discrete visual words selected from a vocabulary, where the frequency distributions of visual words in an image allow classification. One inherent component of the codebook model is the assignment of discrete visual words to continuous image features. Despite the clear mismatch of this hard assignment with the nature of continuous features, the approach has been successfully applied for some years. In this paper, we investigate four types of soft assignment of visual words to image features. We demonstrate that explicitly modeling visual word assignment ambiguity improves classification performance compared to the hard assignment of the traditional codebook model. The traditional codebook model is compared against our method for five well-known data sets: 15 natural scenes, Caltech-101, Caltech-256, and Pascal VOC 2007/2008. We demonstrate that large codebook vocabulary sizes completely deteriorate the performance of the traditional model, whereas the proposed model performs consistently. Moreover, we show that our method profits in high-dimensional feature spaces and reaps higher benefits when increasing the number of image categories.

  8. Completion and Verification of Ambiguous Sentences

    ERIC Educational Resources Information Center

    Olson, James N.; MacKay, Donald G.

    1974-01-01

    A study testing two theories about the processing of ambiguous sentences is reported. Results suggest that parallel processing and reciprocal interactions underlie the comprehension of ambiguous sentences. (RM)

  9. 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.

  10. Ambiguity in pictorial depth.

    PubMed

    Battu, Balaraju; Kappers, Astrid M L; Koenderink, Jan J

    2007-01-01

    Pictorial space is the 3-D impression that one obtains when looking 'into' a 2-D picture. One is aware of 3-D 'opaque' objects. 'Pictorial reliefs' are the surfaces of such pictorial objects in 'pictorial space'. Photographs (or any pictures) do in no way fully specify physical scenes. Rather, any photograph is compatible with an infinite number of possible scenes that may be called 'metameric scenes'. If pictorial relief is one of these metameric scenes, the response may be considered 'veridical'. The conventional usage is more restrictive and is indeed inconsistent. Thus the observer has much freedom in arriving at such a 'veridical' response. To address this ambiguity, we determined the pictorial reliefs for eight observers, six pictures, and two psychophysical methods. We used 'methods of cross-sections' to operationalise pictorial reliefs. We find that linear regression of the depths of relief at corresponding locations in the picture for different observers often lead to very low (even insignificant) R2s. Thus the responses are idiosyncratic to a large degree. Perhaps surprisingly, we also observed that multiple regression of depth and picture coordinates at corresponding locations often lead to very high R2s. Often R2s increased from insignificant up to almost 1. Apparently, to a large extent 'depth' is irrelevant as a psychophysical variable, in the sense that it does not uniquely account for the relation of the response to the pictorial structure. This clearly runs counter to the bulk of the literature on pictorial 'depth perception'. The invariant core of interindividual perception proves to be of an 'affine' rather than a Euclidean nature; that is to say, 'pictorial space' is not simply the picture plane augmented with a depth dimension.

  11. Role ambiguity and athlete satisfaction.

    PubMed

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

    2003-05-01

    The aim of this study was to examine the relationship between athletes' perceptions of role ambiguity and satisfaction. The relationship between these multidimensional constructs was investigated at the beginning and at the end of the season, as well as from early season to end of season. Consistent with the a prioi hypothesis, concurrent analyses revealed lower perceived role ambiguity was associated with higher athlete satisfaction. Specifically, role ambiguity, as represented by the dimension Scope of Responsibilities on offence, was significantly related to the leadership facets of athlete satisfaction (i.e. ability utilization, strategy, and training/instruction) both at the beginning and at the end of the season. However, contrary to expectations, role ambiguity at the beginning of the season was not predictive of athlete satisfaction at the end of the season. The implications of the results are discussed and future research is suggested.

  12. Alcohol reduces aversion to ambiguity

    PubMed Central

    Tyszka, Tadeusz; Macko, Anna; Stańczak, Maciej

    2015-01-01

    Several years ago, Cohen et al. (1958) demonstrated that under the influence of alcohol drivers became more risk prone, although their risk perception remained unchanged. Research shows that ambiguity aversion is to some extent positively correlated with risk aversion, though not very highly (Camerer and Weber, 1992). The question addressed by the present research is whether alcohol reduces ambiguity aversion. Our research was conducted in a natural setting (a restaurant bar), where customers with differing levels of alcohol intoxication were offered a choice between a risky and an ambiguous lottery. We found that alcohol reduced ambiguity aversion and that the effect occurred in men but not women. We interpret these findings in terms of the risk-as-value hypothesis, according to which, people in Western culture tend to value risk, and suggest that alcohol consumption triggers adherence to socially and culturally valued patterns of conduct different for men and women. PMID:25642202

  13. Alcohol reduces aversion to ambiguity.

    PubMed

    Tyszka, Tadeusz; Macko, Anna; Stańczak, Maciej

    2014-01-01

    Several years ago, Cohen et al. (1958) demonstrated that under the influence of alcohol drivers became more risk prone, although their risk perception remained unchanged. Research shows that ambiguity aversion is to some extent positively correlated with risk aversion, though not very highly (Camerer and Weber, 1992). The question addressed by the present research is whether alcohol reduces ambiguity aversion. Our research was conducted in a natural setting (a restaurant bar), where customers with differing levels of alcohol intoxication were offered a choice between a risky and an ambiguous lottery. We found that alcohol reduced ambiguity aversion and that the effect occurred in men but not women. We interpret these findings in terms of the risk-as-value hypothesis, according to which, people in Western culture tend to value risk, and suggest that alcohol consumption triggers adherence to socially and culturally valued patterns of conduct different for men and women.

  14. Ambiguities analysis in SAR tomography

    NASA Astrophysics Data System (ADS)

    Wang, Ziwei; Zhang, Hong; Wang, Chao; Tang, Yixian; Zhang, Bo

    2014-10-01

    Synthetic aperture radar tomography (TomoSAR) is typically used to retrieve elevation, deformation, and other key information by separating scatters of the same slant range in multiple baseline SAR images. In this paper, we investigate two kinds of ambiguities for TomoSAR. Rank-1 ambiguity, as the first one we concerned, is due to the baseline distribution of the SAR image dataset which makes the steering matrix out of full rank. It will result in false alarms appearing in a permanent distance. However, an example using the TomoSAR imaging parameters shows this ambiguity makes no sense in most cases. The second ambiguity refers to the coherence of scatters contained in one pixel. In simulation experiment, the coherence will enhance the side lobes of the spectrum, even make the real peaks fused.

  15. Resolution Of Phase Ambiguities In QPSK

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M.

    1992-01-01

    Report discusses several techniques for resolution of phase ambiguities in detection and decoding of radio signals modulated by coherent quadrature phase-shift keying (QPSK) and offset QPSK (OQPSK). Eight ambiguities: four associated with phase of carrier signal in absence of ambiguity in direction of rotation of carrier phase, and another four associated with carrier phase in presence of phase-rotation ambiguity.

  16. 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…

  17. 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…

  18. 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…

  19. Spectral Ambiguity of Allan Variance

    NASA Technical Reports Server (NTRS)

    Greenhall, C. A.

    1996-01-01

    We study the extent to which knowledge of Allan variance and other finite-difference variances determines the spectrum of a random process. The variance of first differences is known to determine the spectrum. We show that, in general, the Allan variance does not. A complete description of the ambiguity is given.

  20. 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…

  1. 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

  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. 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…

  4. 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.

  5. 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…

  6. Implications of Ambiguity for Scientometric Measurement.

    ERIC Educational Resources Information Center

    Bookstein, A.

    2001-01-01

    The essence of Scientomatics is precise measurement. Yet the measurements made in Scientometric research are steeped in ambiguity. This article explores the nature of ambiguity in measurement, probes for mechanisms that allow regularities to be discovered in an environment in which ambiguity is pronounced, and describes Lotka's law (often used to…

  7. Where Does Sociopragmatic Ambiguity Come From?

    ERIC Educational Resources Information Center

    Burt, Susan Meredith

    Sociopragmatic ambiguity (SPA) is claimed here to differ from other, better-known types of ambiguity, in terms of its locus, cause, and effect. SPA is characteristic of whole-discourse features rather than of lexical items or phrases. The ambiguity is one of social rather than ideational or semantic meaning. It is claimed that SPA arises through…

  8. 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…

  9. 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…

  10. Resolving Phase Ambiguities In OQPSK

    NASA Technical Reports Server (NTRS)

    Nguyen, Tien M.

    1991-01-01

    Improved design for modulator and demodulator in offset-quaternary-phase-key-shifting (OQPSK) communication system enables receiver to resolve ambiguity in estimated phase of received signal. Features include unique-code-word modulation and detection and digital implementation of Costas loop in carrier-recovery subsystem. Enchances performance of carrier-recovery subsystem, reduces complexity of receiver by removing redundant circuits from previous design, and eliminates dependence of timing in receiver upon parallel-to-serial-conversion clock.

  11. 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 .

  12. 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 .

  13. Manipulation: description, identification and ambiguity.

    PubMed

    Bowers, L

    2003-06-01

    The word manipulation is frequently applied to some of the difficult-to-manage behaviours of the personality-disordered patient. However, the term is rarely defined, and a review of both the clinical and research literature shows that little has been written about its definition and identification, let alone its clinical management in both in- and outpatient settings. Recent empirical work conducted with nurses in forensic settings has demonstrated the range of behaviours that professionals refer to as 'manipulative', thus clarifying the use of the term and allowing the provision of a more precise definition. The scope of manipulation in everyday life, management practice and politics is perhaps relatively small, although manipulation can occur in all areas of human activity. Social behaviour is doubly ambiguous with respect to judgements of manipulation, as such judgements involve a moral evaluation combined with the identification of deception on the basis of little or partial evidence. The implications of this social ambiguity for clinical psychiatric practice are that professionals need to guard themselves from two polar faults: seeing manipulation everywhere; or being blind to its presence. In order to achieve a cautious moderation, staff need to hold both alternatives in mind at all times.

  14. Renormalon ambiguities in NRQCD operator matrix elements

    NASA Astrophysics Data System (ADS)

    Bodwin, Geoffrey T.; Chen, Yu-Qi

    1999-09-01

    We analyze the renormalon ambiguities that appear in factorization formulas in QCD. Our analysis contains a simple argument that the ambiguities in the short-distance coefficients and operator matrix elements are artifacts of dimensional-regularization factorization schemes and are absent in cutoff schemes. We also present a method for computing the renormalon ambiguities in operator matrix elements and apply it to a computation of the ambiguities in the matrix elements that appear in the NRQCD factorization formulas for the annihilation decays of S-wave quarkonia. Our results, combined with those of Braaten and Chen for the short-distance coefficients, provide an explicit demonstration that the ambiguities cancel in the physical decay rates. In addition, we analyze the renormalon ambiguities in the Gremm-Kapustin relation and in various definitions of the heavy-quark mass.

  15. 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 is studied for a high-resolution, large-swath SAR mapping system subjected to speckle, additive white Gaussian noise, and range and azimuthal ambiguities occurring because of the non-finite antenna pattern produced by a square aperture antenna. The effect of the azimuth antenna pattern was accounted for by calculating the aximuth ambiguity function. Range ambiguities were accounted for by adding appropriate pixels at a range separation corresponding to one pulse repetition period, but attenuated by the antenna pattern. A method of estimating the range defocussing effect which arises from the azimuth matched filter being a function of range is shown. The resulting simulated picture was compared with one degraded by speckle and noise but no ambiguities. It is concluded that azimuth ambiguities don't cause any noticeable degradation but range ambiguities might.

  16. SAR Ambiguity Study for the Cassini Radar

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Im, Eastwood; Johnson, William T. K.

    1993-01-01

    The Cassini Radar's synthetic aperture radar (SAR) ambiguity analysis is unique with respect to other spaceborne SAR ambiguity analyses owing to the non-orbiting spacecraft trajectory, asymmetric antenna pattern, and burst mode of data collection. By properly varying the pointing, burst mode timing, and radar parameters along the trajectory this study shows that the signal-to-ambiguity ratio of better than 15 dB can be achieved for all images obtained by the Cassini Radar.

  17. 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

  18. Tolerating ambiguity: ambiguous words recruit the left inferior frontal gyrus in absence of a behavioral effect.

    PubMed

    Hargreaves, Ian S; Pexman, Penny M; Pittman, Daniel J; Goodyear, Bradley G

    2011-01-01

    Many models of word recognition predict a lexical ambiguity disadvantage in semantic categorization tasks (SCTs). However, recent evidence suggests that an ambiguity disadvantage in SCT results from a bias in the decision-making phase of the task and not in the meaning-activation phase: Behavioral effects of ambiguity disappear when these decision biases are controlled (Pexman, Hino, & Lupker, 2004). The current study used event-related functional magnetic resonance imaging to examine the neural correlates of ambiguity in a task that produced no behavioral ambiguity effect (i.e., SCT with a well-defined decision category). Twenty healthy adults participated. Results showed that despite producing no behavioral effect of ambiguity, ambiguous words were associated with the recruitment of cortical structures implicated in top-down modulation of noisy activity (e.g., left inferior frontal gyrus) when compared to unambiguous words. These results are interpreted as evidence that multiple meanings are activated for ambiguous words in SCT.

  19. Perceptual Ambiguity and the Sorites

    NASA Astrophysics Data System (ADS)

    Égré, Paul

    The sorites paradox results from two equally plausible constraints on categorization in sorites series: a constraint of category switch between the first and the last items, and a constraint of similarity or consistent judgment for adjacent items. Following the work of D. Raffman [27,28] this paper argues that both constraints can be met if we assume that borderline cases pattern as ambiguous items between opposing categories. I first review some empirical evidence in favor of this view. I then examine how it bears on the tolerance principle, from a descriptive and from a normative viewpoint. In particular, I discuss ways in which the account of tolerance outlined in [6] can be related to Smith's [37] fuzzy account, as well as to the similarity-based semantics for vague predicates proposed by van Rooij [34] and explored in recent work with Cobreros et al. [4].

  20. 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),…

  1. Evidence against Competition during Syntactic Ambiguity Resolution

    ERIC Educational Resources Information Center

    van Gompel, R.P.G.; Pickering, M.J.; Pearson, J.; Liversedge, S.P.

    2005-01-01

    We report three eye-movement experiments that investigated whether alternative syntactic analyses compete during syntactic ambiguity resolution. Previous research (Traxler, Pickering, & Clifton, 1998; Van Gompel, Pickering, & Traxler, 2001) has shown that globally ambiguous sentences are easier to process than disambiguated sentences, suggesting…

  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. 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.

  5. Acute leukemias of ambiguous origin.

    PubMed

    Porwit, Anna; Béné, Marie C

    2015-09-01

    This session of the Society for Hematopathology/European Association for Haematopathology Workshop focused on acute leukemias of ambiguous origin. We provide an overview of mixed-phenotype acute leukemia (MPAL) as recognized in the current World Health Organization classification and summarize diagnostic criteria for major categories of MPAL: B/myeloid, T/myeloid, B/T, and B/T/myeloid. Most MPAL cases submitted were B/myeloid and T/myeloid MPAL, the most frequent types, but three cases of B/T MPAL were also submitted, and examples of all categories are illustrated. We emphasize that a comprehensive approach to immunophenotyping is required to accurately establish the diagnosis of MPAL. Flow cytometry immunophenotyping using a large panel of antibodies is needed as well as confirmatory immunohistochemical analysis and cytochemistry studies for myeloperoxidase and nonspecific esterase. We discuss technical issues in determining blast lineage and possible pitfalls in MPAL diagnosis. In particular, rare cases of B-acute lymphoblastic leukemia (B-ALL) can express myeloperoxidase but are otherwise consistent with B-ALL and should be treated as such. Last, we review the differential diagnosis between acute undifferentiated leukemia and acute myeloid leukemia with minimal differentiation. There was an agreement that diagnosis of MPAL can be challenging, especially if applied flow cytometry panels are not comprehensive enough. Copyright© by the American Society for Clinical Pathology.

  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. The communicative function of ambiguity in language.

    PubMed

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

    2012-03-01

    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 Dutch. Our results and theoretical analysis suggest that ambiguity is a functional property of language that allows for greater communicative efficiency. This provides theoretical and empirical arguments against recent suggestions that core features of linguistic systems are not designed for communication. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Ambiguities in 'killing' and 'letting die'.

    PubMed

    Atkinson, G M

    1983-05-01

    In a recent article Carla Kary (1980) attempts to show that there can be a significant moral difference between instances of killing and letting die. I shall maintain in Section I that Kary's argument is somewhat weakened by her failure to note an important ambiguity in the notion of killing a person. I shall also argue in Section II that a similar ambiguity affects the notion of letting someone die, and that failure to note this latter ambiguity also weakens the position developed by Robert Coburn (1980) with regard to defective newborns.

  9. 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.

  10. 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)

  11. Removing Ambiguities In Remotely Sensed Winds

    NASA Technical Reports Server (NTRS)

    Shaffer, Scott J.; Dunbar, Roy S.; Hsiao, Shuchi V.; Long, David G.

    1991-01-01

    Algorithm removes ambiguities in choices of candidate ocean-surface wind vectors estimated from measurements of radar backscatter from ocean waves. Increases accuracies of estimates of winds without requiring new instrumentation. Incorporates vector-median filtering function.

  12. 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.

  13. 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.

  14. 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

  15. Building comfort with ambiguity in nursing practice.

    PubMed

    Stilos, Kalli; Moura, Shari L; Flint, Frances

    2007-04-01

    Current nursing literature recognizes the need to honor the concept of ambiguity. Nurses experience uncertainty with handling or honoring complexity and ambiguity when confronted with times of struggle. Traditional models of care fall short as patients and families define their expectations of the healthcare system. Nurses bear witness to the discomfort caused by the unknown in their daily practice. They are challenged to address their feelings, unsure of what to anticipate, what to say, or how to respond to their patients. Uncertainty diminishes the opportunity for meaningful dialogue between nurses and other people. Nurses attempting to ease the discomfort of ambiguity by providing patients or families with reassurance, offering advice on how to fix problems, or avoiding talking about situations often express dissatisfaction. Nurses should be invited to explore ambiguity and seek understanding through dialogue and nursing knowledge. Encouraging nurses to define the meaningfulness in nursing practice that embraces human science theory will help relieve some of the ambiguity that exists in current practice. This article will explore the concept of ambiguity, highlight how nursing theory based on human science can support practice, and propose recommendations for practice.

  16. Precise Point Positioning with Partial Ambiguity Fixing.

    PubMed

    Li, Pan; Zhang, Xiaohong

    2015-06-10

    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.

  17. Probability judgments under ambiguity and conflict.

    PubMed

    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.

  18. 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

  19. Boundary Ambiguity in Remarriage: Does Ambiguity Differentiate Degree of Marital Adjustment and Interaction?

    ERIC Educational Resources Information Center

    Pasley, B. Kay; Ihinger-Tallman, Marilyn

    1989-01-01

    Examined differences between 216 spouses in remarriages classified as having low or high boundary ambiguity. Found high boundary ambiguity to be more prevalent in certain types of remarriages (stepmother families with nonresidential children). Few significant differences were found when wives were compared with wives and husbands with husbands in…

  20. How the owl resolves auditory coding ambiguity

    PubMed Central

    Mazer, James A.

    1998-01-01

    The barn owl (Tyto alba) uses interaural time difference (ITD) cues to localize sounds in the horizontal plane. Low-order binaural auditory neurons with sharp frequency tuning act as narrow-band coincidence detectors; such neurons respond equally well to sounds with a particular ITD and its phase equivalents and are said to be phase ambiguous. Higher-order neurons with broad frequency tuning are unambiguously selective for single ITDs in response to broad-band sounds and show little or no response to phase equivalents. Selectivity for single ITDs is thought to arise from the convergence of parallel, narrow-band frequency channels that originate in the cochlea. ITD tuning to variable bandwidth stimuli was measured in higher-order neurons of the owl’s inferior colliculus to examine the rules that govern the relationship between frequency channel convergence and the resolution of phase ambiguity. Ambiguity decreased as stimulus bandwidth increased, reaching a minimum at 2–3 kHz. Two independent mechanisms appear to contribute to the elimination of ambiguity: one suppressive and one facilitative. The integration of information carried by parallel, distributed processing channels is a common theme of sensory processing that spans both modality and species boundaries. The principles underlying the resolution of phase ambiguity and frequency channel convergence in the owl may have implications for other sensory systems, such as electrolocation in electric fish and the computation of binocular disparity in the avian and mammalian visual systems. PMID:9724807

  1. 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.

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

    PubMed

    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.

  3. Neural responses to category ambiguous words

    PubMed Central

    Conwell, Erin

    2015-01-01

    Category ambiguous words (like hug and swing) have the potential to complicate both learning and processing of language. However, uses of such words may be disambiguated by acoustic differences that depend on the category of use. This article uses an event-related potential (ERP) technique to ask whether adult native speakers of English show neural sensitivity to those differences. The results indicate that noun and verb tokens of ambiguous words produce differences in the amplitude of the ERP response over left anterior sites as early as 100 ms following stimulus onset and persisting for over 400 ms. Nonsense words extracted from noun and verb contexts do not show such differences. These findings suggest that the acoustic differences between noun and verb tokens of ambiguous words are perceived and processed by adults and may be part of the lexical representation of the word. PMID:25637057

  4. Incidentally Detected Situs Ambiguous in Adults

    PubMed Central

    Kim, Jae-Gyung; Kim, Gee-Hee; Park, Mi-Hee; Hur, Joon; Yu, Jin-Sok; Jung, Soo-Yeon; An, Soe-Hee

    2011-01-01

    Situs ambiguous is rare congenital anomaly in adults. In 2 adult patients who admitted for different cardiac problems, situs ambiguous with polysplenia was detected. A 42-year-old male admitted for radio frequent catheter ablation of atrial fibrillation, and he had left-sided inferior vena cava (IVC), hepatic segment of IVC interruption with hemiazygos continuation, multiple spleens and intestinal malrotation. And in a 52-year-old female case who was hospitalized due to infective endocarditis after implanting pacemaker for sick sinus syndrome, multiple spleens, left-sided stomach, bilateral liver with midline gallbladder, and left-sided IVC were found. Those findings were consistent with situs ambiguous with polysplenia, but their features were distinctive. PMID:22259667

  5. [The ambiguity of the bioethics' principles].

    PubMed

    Pardo Caballos, Antonio

    2010-01-01

    The principles of the bioethics, coined in United States at the end of the seventies and diffused in our social environment one decade later, enclose inside a semantic ambiguity that here it is analyzed in their master lines; this ambiguity oscillates between a relativistic meaning and another agreed with the classic concept of Nature; this ambiguity has been transmitted to who, being part of the field of the Hippocratic medical ethics, have adopted its terminology, and these are the immense majority of the medical class. This phenomenon is easily leading towards the abandonment of the medical ethics based on the natural law (the Hippocratic-Christian tradition), to make it finish in a more or less clear relativism. to avoid this problem, some solutions in the field of the medical ethical terminology are proposed.

  6. Resolving attachment ambiguities with multiple constraints.

    PubMed

    Spivey-Knowlton, M; Sedivy, J C

    1995-06-01

    Different theories of syntactic ambiguity resolution argue for different sources of information determining initial parsing decisions (e.g., structurally defined parsing principles, lexically specific biases, or referential pragmatics). However, a "constraint-based" approach to syntactic ambiguity resolution proposes that both lexically specific biases and referential pragmatics are used in parallel by the comprehender. Analyses of text corpora, sentence fragment completions, and self-paced reading experiments were conducted to demonstrate that both local information (lexically specific biases) and contextual information (referential presupposition) contribute to the on-line resolution of prepositional phrase attachment ambiguities. There does not appear to be a role for purely structurally defined parsing principles (i.e., minimal attachment). Present and previous evidence is consistent with a developing framework in which multiple constraints (bottom-up and top-down) interact immediately to determine initial syntactic commitments.

  7. Gene name ambiguity of eukaryotic nomenclatures.

    PubMed

    Chen, Lifeng; Liu, Hongfang; Friedman, Carol

    2005-01-15

    With more and more scientific literature published online, the effective management and reuse of this knowledge has become problematic. Natural language processing (NLP) may be a potential solution by extracting, structuring and organizing biomedical information in online literature in a timely manner. One essential task is to recognize and identify genomic entities in text. 'Recognition' can be accomplished using pattern matching and machine learning. But for 'identification' these techniques are not adequate. In order to identify genomic entities, NLP needs a comprehensive resource that specifies and classifies genomic entities as they occur in text and that associates them with normalized terms and also unique identifiers so that the extracted entities are well defined. Online organism databases are an excellent resource to create such a lexical resource. However, gene name ambiguity is a serious problem because it affects the appropriate identification of gene entities. In this paper, we explore the extent of the problem and suggest ways to address it. We obtained gene information from 21 organisms and quantified naming ambiguities within species, across species, with English words and with medical terms. When the case (of letters) was retained, official symbols displayed negligible intra-species ambiguity (0.02%) and modest ambiguities with general English words (0.57%) and medical terms (1.01%). In contrast, the across-species ambiguity was high (14.20%). The inclusion of gene synonyms increased intra-species ambiguity substantially and full names contributed greatly to gene-medical-term ambiguity. A comprehensive lexical resource that covers gene information for the 21 organisms was then created and used to identify gene names by using a straightforward string matching program to process 45,000 abstracts associated with the mouse model organism while ignoring case and gene names that were also English words. We found that 85.1% of correctly retrieved mouse

  8. 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

  9. How Does Ambiguity Affect Insurance Decisions

    DTIC Science & Technology

    1990-05-01

    Risks,"Journal of Risk and Insurance , 40, 231-243. [20] Stone, J., (1973b) "A Theory of Capacity and the Insurance of Catastrophic Risks,"Journal of Risk ... and Insurance 40, 339-355. [21] Hogarth, Robin and Kunreuther, Howard (1989a) "Risk, Ambiguity and In- surance" Journal of Risk and Uncertainty 2:5

  10. 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…

  11. 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…

  12. 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…

  13. The Ambiguity of the English Present Perfect.

    ERIC Educational Resources Information Center

    Michaelis, Laura A.

    1994-01-01

    Examines grammatical and discourse-pragmatic reflexes of the existential and resultative readings of the English present perfect and presents negative and positive arguments regarding its ambiguity. It is suggested that the resultative verb represents a formal idiom and that mastery of aspectual grammar entails knowledge of form-meaning pairings.…

  14. The Ambiguity of the English Present Perfect.

    ERIC Educational Resources Information Center

    Michaelis, Laura A.

    1994-01-01

    Examines grammatical and discourse-pragmatic reflexes of the existential and resultative readings of the English present perfect and presents negative and positive arguments regarding its ambiguity. It is suggested that the resultative verb represents a formal idiom and that mastery of aspectual grammar entails knowledge of form-meaning pairings.…

  15. 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…

  16. SPONTANEOUS CP VIOLATION AND QUARK MASS AMBIGUITIES.

    SciTech Connect

    CREUTZ,M.

    2004-09-21

    I explore the regions of quark masses where CP will be spontaneously broken in the strong interactions. The boundaries of these regions are controlled by the chiral anomaly, which manifests itself in ambiguities in the definition of non-degenerate quark masses. In particular, the concept of a single massless quark is ill defined.

  17. Exploring Situated Ambiguity in Students' Entrepreneurial Learning

    ERIC Educational Resources Information Center

    Kubberød, Elin; Pettersen, Inger Beate

    2017-01-01

    Purpose: Building on entrepreneurial learning research, the purpose of this paper is to argue that the students participating in foreign entrepreneurial education programmes can have realistic entrepreneurial learning experiences. This research addresses two specific questions: how situated ambiguity induced by a foreign culture may contribute to…

  18. 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…

  19. Feature-based attention resolves depth ambiguity.

    PubMed

    Yu, D; Levinthal, B; Franconeri, S L

    2016-09-07

    Perceiving the world around us requires that we resolve ambiguity. This process is often studied in the lab using ambiguous figures whose structures can be interpreted in multiple ways. One class of figures contains ambiguity in its depth relations, such that either of two surfaces could be seen as being the "front" of an object. Previous research suggests that selectively attending to a given location on such objects can bias the perception of that region as the front. This study asks whether selectively attending to a distributed feature can also bias that region toward the front. Participants viewed a structure-from-motion display of a rotating cylinder that could be perceived as rotating clockwise or counterclockwise (as imagined viewing from the top), depending on whether a set of red or green moving dots were seen as being in the front. A secondary task encouraged observers to globally attend to either red or green. Results from both Experiment 1 and 2 showed that the dots on the cylinder that shared the attended feature, and its corresponding surface, were more likely to be seen as being in the front, as measured by participants' clockwise versus counterclockwise percept reports. Feature-based attention, like location-based attention, is capable of biasing competition among potential interpretations of figures with ambiguous structure in depth.

  20. The Function of Ambiguity in Child Crises

    ERIC Educational Resources Information Center

    Stein, Myron

    1970-01-01

    Discusses the function of ambiguity" (an attitude of hatibual uncertainty, vagueness, and imprecision of communication) in crisis situations involving adult-child interchanges. Makes suggestions for medical and psychiatric counselors. Paper was presented at the meeting of the American Association of Psychiatric Clinics for Children, Boston,…

  1. Infants Interpret Ambiguous Requests for Absent Objects

    ERIC Educational Resources Information Center

    Saylor, Megan M.; Ganea, Patricia

    2007-01-01

    The current studies investigated 2 skills involved in 14- to 20-month-olds' ability to interpret ambiguous requests for absent objects: tracking others' experiences (Study 1) and representing links between speakers and object features across present and absent reference episodes (Study 2). In the basic task, 2 experimenters played separately with…

  2. A Statistical Approach for Ambiguous Sequence Mappings

    USDA-ARS?s Scientific Manuscript database

    When attempting to map RNA sequences to a reference genome, high percentages of short sequence reads are often assigned to multiple genomic locations. One approach to handling these “ambiguous mappings” has been to discard them. This results in a loss of data, which can sometimes be as much as 45% o...

  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 problem—the existence of well-behaved regularization of the constraints—is 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 dimensions—due to the difficulties associated to the definition of the physical inner product—it 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

  4. Regularization ambiguities in loop quantum gravity

    SciTech Connect

    Perez, Alejandro

    2006-02-15

    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 problem--the existence of well-behaved regularization of the constraints--is 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 dimensions - due to the difficulties associated to the definition of the physical inner product - it 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

  5. 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.

  6. An Investigation into Ambiguity Tolerance in Iranian Senior EFL Undergraduates

    ERIC Educational Resources Information Center

    Marzban, Amin; Barati, Hossein; Moinzadeh, Ahmad

    2012-01-01

    The present study aimed to explore how tolerant of ambiguity Iranian EFL learners at university level are and if gender plays a role in this regard. To this end, upon filling in the revised SLTAS scale of ambiguity tolerance 194 male and female Iranian teacher trainees were assigned to three ambiguity tolerance groups; namely, high, moderate and…

  7. 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…

  8. A New Method For DGPS Ambiguity Resolution

    NASA Astrophysics Data System (ADS)

    Pieregentili, Fabrizio; Cordelli, Emiliano

    This paper deals with the problem of determining the baseline vector between two GPS receivers in single frequency (L1) using the basic principles of interferometric Differential GPS, therefore using the interferometric relations between the two receivers and the satellites visible to both receivers. As a preliminary step, ambiguity identification was solved using the results provided by the Kalman filter; these results were optimized by evaluating the Dilution Of Precision indexes for satellites in view of the receivers. Results achieved by applying this first procedure to data collected are discussed. To increase the accuracy of the results, a new, computationally fast algorithm for carrier phase ambiguity resolution on data collected from static and dynamics acquisitions was developed, implemented and tested. The new algorithm permitted an increase of accuracy of about two orders of magnitude with respect to results given by filtered Double Difference in the resolution of baseline vector.

  9. Evolution without evolution and without ambiguities

    NASA Astrophysics Data System (ADS)

    Marletto, C.; Vedral, V.

    2017-02-01

    In quantum theory it is possible to explain time, and dynamics, in terms of entanglement. This is the timeless approach to time, which assumes that the universe is in a stationary state, where two noninteracting subsystems, the "clock" and the "rest," are entangled. As a consequence, by choosing a suitable observable of the clock, the relative state of the rest of the universe evolves unitarily with respect to the variable labeling the clock observable's eigenstates, which is then interpreted as time. This model for an "evolution without evolution" (Page and Wootters, 1983), albeit elegant, has never been developed further, because it was criticized for generating severe ambiguities in the dynamics of the rest of the universe. In this paper we show that there are no such ambiguities; we also update the model, making it amenable to possible new applications.

  10. Are "drink responsibly" alcohol campaigns strategically ambiguous?

    PubMed

    Smith, Sandi W; Atkin, Charles K; Roznowski, JoAnn

    2006-01-01

    This article applies the concept of strategic ambiguity in examining viewer responses to brewer-sponsored "responsible drinking" television advertising campaigns. Strategically ambiguous messages are designed to engender diverse interpretations between varied audience segments, and these different selective perceptions should translate into relatively uniform positive corporate images. In this study, teenage and young adult respondents were shown a series of television spots from two leading alcohol companies. As predicted, there was a high degree of diversity in meanings of message content and campaign purpose derived by viewers, particularly among less sophisticated teenagers. Moreover, evaluative ratings of messages and sponsors were generally favorable and more uniform than interpretive responses. The research demonstrates how seemingly prohealth messages can serve to subtly advance both industry sales and public relations interests.

  11. 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.

  12. Occasion setting in Pavlovian ambiguous target discriminations.

    PubMed

    Bueno, José Lino Oliveira; Holland, Peter C

    2008-11-01

    Rats were trained in a Pavlovian serial ambiguous target discrimination, in which a target cue was reinforced if it was preceded by one stimulus (P-->T+) but was not reinforced if it was preceded by another stimulus (N-->T-). Test performance indicated that stimulus control by these features was weaker than that acquired by features trained within separate serial feature positive (P-->T+, T-) and serial feature negative (N-->W-, W+) discriminations. The form of conditioned responding and the patterns of transfer observed suggested that the serial ambiguous target discrimination was solved by occasion setting. The data are discussed in terms of the use of retrospective coding strategies when solving Pavlovian serial conditional discriminations, and the acquisition of special properties by both feature and target stimuli.

  13. Hippocampal Processing of Ambiguity Enhances Fear Memory.

    PubMed

    Amadi, Ugwechi; Lim, Seh Hong; Liu, Elizabeth; Baratta, Michael V; Goosens, Ki A

    2017-02-01

    Despite the ubiquitous use of Pavlovian fear conditioning as a model for fear learning, the highly predictable conditions used in the laboratory do not resemble real-world conditions, in which dangerous situations can lead to unpleasant outcomes in unpredictable ways. In the current experiments, we varied the timing of aversive events after predictive cues in rodents and discovered that temporal ambiguity of aversive events greatly enhances fear. During fear conditioning with unpredictably timed aversive events, pharmacological inactivation of the dorsal hippocampus or optogenetic silencing of cornu ammonis 1 cells during aversive negative prediction errors prevented this enhancement of fear without affecting fear learning for predictable events. Dorsal hippocampal inactivation also prevented ambiguity-related enhancement of fear during auditory fear conditioning under a partial-reinforcement schedule. These results reveal that information about the timing and occurrence of aversive events is rapidly acquired and that unexpectedly timed or omitted aversive events generate hippocampal signals to enhance fear learning.

  14. Ambiguity and Uncertainty in Probabilistic Inference.

    DTIC Science & Technology

    1983-09-01

    1961)demonstrated, this poses problems for theories of probability operationalized via choices amongst gambles. A descriptive model of how people make...judgments under ambiguity in tasks where data come from a source of limited, but not exactly known reliability, is proposed. The model assumes an...have been.ŝK The latter is modeled as the result of a mental simulation process that incorporates the unreliability of the source and one’s attitude

  15. Resolving Ambiguity in Nonmonotonic Inheritance Hierarchies

    DTIC Science & Technology

    1991-08-01

    this case, specificity cannot resolve the ambiguity w.r.t. platypus at mammal, and r 2 supports both of the assertions marked (***): that platypuses ...eoss jo~yer Figure 2: Is a platypus a mammal? Figure 3: A blue whale is an aquatic creature. eater does not defeat either the assertion that Joe is a...derived conclusion that platypuses are mammals is directly opposed by the (equally legitimate) conclusion that platypuses are not mammals. In this case

  16. Phonological ambiguity modulates resolution of semantic ambiguity during reading: An fMRI study of Hebrew.

    PubMed

    Bitan, Tali; Kaftory, Asaf; Meiri-Leib, Adi; Eviatar, Zohar; Peleg, Orna

    2017-10-01

    The current fMRI study examined the role of phonology in the extraction of meaning from print in each hemisphere by comparing homophonic and heterophonic homographs (ambiguous words in which both meanings have the same or different sounds respectively, e.g., bank or tear). The analysis distinguished between the first phase, in which participants read ambiguous words without context, and the second phase in which the context resolves the ambiguity. Native Hebrew readers were scanned during semantic relatedness judgments on pairs of words in which the first word was either a homophone or a heterophone and the second word was related to its dominant or subordinate meaning. In Phase 1 there was greater activation for heterophones in left inferior frontal gyrus (IFG), pars opercularis, and more activation for homophones in bilateral IFG pars orbitalis, suggesting that resolution of the conflict at the phonological level has abolished the semantic ambiguity for heterophones. Reduced activation for all ambiguous words in temporo-parietal regions suggests that although ambiguity enhances controlled lexical selection processes in frontal regions it reduces reliance on bottom-up mapping processes. After presentation of the context, a larger difference between the dominant and subordinate meaning was found for heterophones in all reading-related regions, suggesting a greater engagement for heterophones with the dominant meaning. Altogether these results are consistent with the prominent role of phonological processing in visual word recognition. Finally, despite differences in hemispheric asymmetry between homophones and heterophones, ambiguity resolution, even toward the subordinate meaning, is largely left lateralized. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  17. 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

  18. 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

  19. Remindings influence the interpretation of ambiguous stimuli.

    PubMed

    Tullis, Jonathan G; Braverman, Michael; Ross, Brian H; Benjamin, Aaron S

    2014-02-01

    Remindings-stimulus-guided retrievals of prior events-may help us interpret ambiguous events by linking the current situation to relevant prior experiences. Evidence suggests that remindings play an important role in interpreting complex ambiguous stimuli (Ross & Bradshaw Memory & Cognition, 22, 591-605, 1994); here, we evaluate whether remindings will influence word interpretation and memory in a new paradigm. Learners studied words on distinct visual backgrounds and generated a sentence for each word. Homographs were preceded by a biasing cue on the same background three items earlier, preceded by a biasing cue on a different background three items earlier, or followed by a biasing cue on the same background three items later. When biasing cues preceded the homographs on the same backgrounds as the homographs, the meanings of the homographs in learner-generated sentences were consistent with the biasing cues more often than in the other two conditions. These results show that remindings can influence word interpretation. In addition, later memory for the homographs and cues was greater when the meaning of the homograph in the sentence was consistent with the earlier biasing cue, suggesting that remindings enhanced mnemonic performance. Remindings play an important role in how we interpret ambiguous stimuli and enhance memory for the involved material.

  20. Generating Ambiguous Figure-Ground Images.

    PubMed

    Kuo, Ying-Miao; Chu, Hung-Kuo; Chi, Ming-Te; Lee, Ruen-Rone; Lee, Tong-Yee

    2016-02-26

    Ambiguous figure-ground images, mostly represented as binary images, are fascinating as they present viewers a visual phenomena of perceiving multiple interpretations from a single image. In one possible interpretation, the white region is seen as a foreground figure while the black region is treated as shapeless background. Such perception can reverse instantly at any moment. In this paper, we investigate the theory behind this ambiguous perception and present an automatic algorithm to generate such images. We model the problem as a binary image composition using two object contours and approach it through a three-stage pipeline. The algorithm first performs a partial shape matching to find a good partial contour matching between objects. This matching is based on a content-aware shape matching metric, which captures features of ambiguous figure-ground images. Then we combine matched contours into a compound contour using an adaptive contour deformation, followed by computing an optimal cropping window and image binarization for the compound contour that maximize the completeness of object contours in the final composition. We have tested our system using a wide range of input objects and generated a large number of convincing examples with or without user guidance. The efficiency of our system and quality of results are verified through an extensive experimental study.

  1. 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

  2. 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.

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

    PubMed

    Osmont, Anaïs; Cassotti, Mathieu; Agogué, Marine; Houdé, 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.

  4. 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

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

    PubMed

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

    2014-01-01

    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.

  6. 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.

  7. Disambiguation in the biomedical domain: the role of ambiguity type.

    PubMed

    Stevenson, Mark; Guo, Yikun

    2010-12-01

    Word Sense Disambiguation (WSD), the automatic identification of the meanings of ambiguous terms in a document, is an important stage in text processing. We describe a WSD system that has been developed specifically for the types of ambiguities found in biomedical documents. This system uses a range of knowledge sources. It employs both linguistic features, such as local collocations, and features derived from domain-specific knowledge sources, the Unified Medical Language System (UMLS) and Medical Subject Headings (MeSH). This system is applied to three types of ambiguities found in Medline abstracts: ambiguous terms, abbreviations with multiple expansions and names that are ambiguous between genes. The WSD system is applied to the standard NLM-WSD data set, which consists of ambiguous terms from Medline abstracts, and was found to perform well in comparison with previously reported results. The system's performance and the contribution of each knowledge source depends upon the type of lexical ambiguity. 87.9% of the ambiguous terms are correctly disambiguated using a combination of linguistic features and MeSH terms, 99% of abbreviations are disambiguated by combining all knowledge sources, while 97.2% of ambiguous gene names are disambiguated using the MeSH terms alone. Analysis reveals that these differences are caused by the nature of each ambiguity type. These results should be taken into account when deciding which information to use for WSD and the level of performance that can be expected. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Sublexical ambiguity effect in reading Chinese disyllabic compounds.

    PubMed

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

    2011-05-01

    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 reading a disyllabic compound. The sublexical ambiguity of the first character was manipulated while the orthographic neighborhood sizes of the first and second character (NS1, NS2) were controlled. Subjective rating of number of meanings corresponding to a character was used as an index of sublexical ambiguity. Results showed that low sublexical ambiguity words elicited a more negative N400 than high sublexical ambiguity words when words were centrally presented. Similar patterns were found when words were presented to the left VF. Interestingly, different patterns were observed for pseudowords. With left VF presentation, high sublexical ambiguity psudowords showed a more negative N400 than low sublexical ambiguity pseudowords. In contrast, with right VF presentation, low sublexical ambiguity pseudowords showed a more negative N400 than high sublexical ambiguity pseudowords. These findings indicate that a level of morphological representation between form and meaning needs to be established and refined in Chinese. In addition, hemispheric asymmetries in the use of word information in ambiguity resolution should be taken into account, even at sublexical level.

  9. Studies in linguistic ambiguity and insecurity.

    PubMed

    Baxter, M; Bucci, W

    1981-06-01

    This article focuses on problems of cross-culture communication between patients and psychiatrists of varying socio-linguistic and foreign language backgrounds, in an in-patient psychiatric community facility. Issues of diagnosis, integration into the ward treatment program, and progress in the course of treatment can in some cases be traced to specific socio-linguistic problems, which have previously gone undiagnosed. The clinical impact of three types of communication breakdowns are evaluated: (1) overt language differences; (2) linguistic ambiguity; and (3) linguistic insecurity. A need exists for further research in identification and assessment of language insecurity, and for modification of therapeutic procedures to deal with inter-dialectic communication difficulties.

  10. Ambiguity aversion in schizophrenia: An fMRI study of decision-making under risk and ambiguity.

    PubMed

    Fujino, Junya; Hirose, Kimito; Tei, Shisei; Kawada, Ryosaku; Tsurumi, Kosuke; Matsukawa, Noriko; Miyata, Jun; Sugihara, Genichi; Yoshihara, Yujiro; Ideno, Takashi; Aso, Toshihiko; Takemura, Kazuhisa; Fukuyama, Hidenao; Murai, Toshiya; Takahashi, Hidehiko

    2016-12-01

    When making decisions in everyday life, we often have to choose between uncertain outcomes. Economic studies have demonstrated that healthy people tend to prefer options with known probabilities (risk) than those with unknown probabilities (ambiguity), which is referred to as "ambiguity aversion." However, it remains unclear how patients with schizophrenia behave under ambiguity, despite growing evidence of their altered decision-making under uncertainty. In this study, combining economic tools and functional magnetic resonance imaging (fMRI), we assessed the attitudes toward risk/ambiguity and investigated the neural correlates during decision-making under risk/ambiguity in schizophrenia. Although no significant difference in attitudes under risk was observed, patients with schizophrenia chose ambiguity significantly more often than the healthy controls. Attitudes under risk and ambiguity did not correlate across patients with schizophrenia. Furthermore, unlike in the healthy controls, activation of the left lateral orbitofrontal cortex was not increased during decision-making under ambiguity compared to under risk in schizophrenia. These results suggest that ambiguity aversion, a well-established subjective bias, is attenuated in patients with schizophrenia, highlighting the need to distinguish between risk and ambiguity when assessing decision-making under these situations. Our findings, comprising important clinical implications, contribute to improved understanding of the mechanisms underlying altered decision-making in patients with schizophrenia.

  11. Deep Label Distribution Learning With Label Ambiguity

    NASA Astrophysics Data System (ADS)

    Gao, Bin-Bin; Xing, Chao; Xie, Chen-Wei; Wu, Jianxin; Geng, Xin

    2017-06-01

    Convolutional Neural Networks (ConvNets) have achieved excellent recognition performance in various visual recognition tasks. A large labeled training set is one of the most important factors for its success. However, it is difficult to collect sufficient training images with precise labels in some domains such as apparent age estimation, head pose estimation, multi-label classification and semantic segmentation. Fortunately, there is ambiguous information among labels, which makes these tasks different from traditional classification. Based on this observation, we convert the label of each image into a discrete label distribution, and learn the label distribution by minimizing a Kullback-Leibler divergence between the predicted and ground-truth label distributions using deep ConvNets. The proposed DLDL (Deep Label Distribution Learning) method effectively utilizes the label ambiguity in both feature learning and classifier learning, which help prevent the network from over-fitting even when the training set is small. Experimental results show that the proposed approach produces significantly better results than state-of-the-art methods for age estimation and head pose estimation. At the same time, it also improves recognition performance for multi-label classification and semantic segmentation tasks.

  12. [Breast feeding: knowledge, attitudes and sociocultural ambiguity].

    PubMed

    Paricio Talayero, J M; Santos Serrano, L; Fernández Feijoo, A; Martí Barranco, E; Bernal Ferrer, A; Ferriol Camacho, M; Sánchez Palomares, M; Lucas Abad, M L

    1999-10-15

    Found sociocultural attitude with regard to breast-feeding (BF) between the sanitary (SP) and no sanitary personnel (NSP) of health centers. Descriptive, cross-sectional study. 4 health centres and 3 hospitals of Valencia. 442 workers of these centres. Structured questionnaire. 88% of SP and 76% of NSP (p < 0.05) believed that BF has many advantages comparing with artificial-feeding in a developed country. SP said more advantages of BF than NSP (p < 0.0001). Most renowned advantages were immunological, affective relationship and comfort. Main inconveniences were dependence, work reasons, aesthetic nature and insecurity in the ingested amount. 56% of SP and 86% of NSP (p < 0.0001) believed milk's analysis necessary. 56% women and 38% men (p < 0.001) didn't see correct give BF in public. Men were more concerned than women (p < 0.05) for local problems of chest, aesthetic results, milk's quality and transmission of illnesses. It's necessary to support knowledge and re-evaluating the trust in the nutritious capacity of maternal milk between the personnel of health centers and hospitals. Generic ambiguity toward functions of feminine breast exists and public'BF isn't acceptable. It's necessary recover socioculturally the image of BF and keep in mind the existent ambiguity upon designing campaigns of promotion.

  13. Commentary: ambiguity and uncertainty: neglected elements of medical education curricula?

    PubMed

    Luther, Vera P; Crandall, Sonia J

    2011-07-01

    Despite significant advances in scientific knowledge and technology, ambiguity and uncertainty are still intrinsic aspects of contemporary medicine. To practice confidently and competently, a physician must learn rational approaches to complex and ambiguous clinical scenarios and must possess a certain degree of tolerance of ambiguity. In this commentary, the authors discuss the role that ambiguity and uncertainty play in medicine and emphasize why openly addressing these topics in the formal medical education curriculum is critical. They discuss key points from original research by Wayne and colleagues and their implications for medical education. Finally, the authors offer recommendations for increasing medical student tolerance of ambiguity and uncertainty, including dedicating time to attend candidly to ambiguity and uncertainty as a formal part of every medical school curriculum.

  14. The development of preschoolers' appreciation of communicative ambiguity.

    PubMed

    Nilsen, Elizabeth S; Graham, Susan A

    2012-01-01

    Using a longitudinal design, preschoolers' appreciation of a listener's knowledge of the location of a hidden sticker after the listener was provided with an ambiguous or unambiguous description was assessed. Preschoolers (N=34) were tested at 3 time points, each 6 months apart (4, 4½, and 5 years). Eye gaze measures demonstrated that preschoolers were sensitive to communicative ambiguity, even when the situation was unambiguous from their perspective. Preschoolers' explicit evaluations of ambiguity were characterized by an initial appreciation of message clarity followed by an appreciation of message ambiguity. Children's inhibitory control skills at 4 years old related to their explicit detection of ambiguity at later ages. Results are discussed in terms of the developmental progression of preschoolers' awareness of communicative ambiguity.

  15. Ambiguity resolution in systems using Omega for position location

    NASA Technical Reports Server (NTRS)

    Frenkel, G.; Gan, D. G.

    1974-01-01

    The lane ambiguity problem prevents the utilization of the Omega system for many applications such as locating buoys and balloons. The method of multiple lines of position introduced herein uses signals from four or more Omega stations for ambiguity resolution. The coordinates of the candidate points are determined first through the use of the Newton iterative procedure. Subsequently, a likelihood function is generated for each point, and the ambiguity is resolved by selecting the most likely point. The method was tested through simulation.

  16. Ambiguous Loss Experienced by Transnational Mexican Immigrant Families.

    PubMed

    Solheim, Catherine; Zaid, Samantha; Ballard, Jaime

    2016-06-01

    In this study, an ambiguous loss framework as described by Boss (1999, Ambiguous loss: Learning to live with unresolved grief, First Harvard University Press, Cambridge, MA) was used to examine and understand the family experiences of Mexican immigrant agricultural workers in Minnesota. Transcripts from interviews with 17 workers in Minnesota and 17 family members in Mexico were analyzed using qualitative methodology to identify experiences of ambiguous loss in the participants' narratives. Key dimensions of ambiguous loss identified in the transcripts include: psychological family, feelings of chronic/recurring loss, finding support, and meaning making. In the category of psychological family, participants in both Mexico and the United States mourned the physical absence of their family members and experienced ambiguity regarding family responsibilities, but worked to maintain their psychological roles within the family. In the category of chronic/recurring loss, participants in both countries experienced chronic worry from not knowing if family members were safe, ambiguity regarding when the immigrant would return, and chronic stressors that compounded these feelings of loss. Participants in both countries coped with both real and ambiguous losses by accessing family support and by using ambiguous communication to minimize worry. Participants in Mexico also accessed work and community-based support. Participants in both countries made meaning of the ambiguous loss by identifying ways their lives were improved and goals were met as a result of the immigration for agricultural work in Minnesota. © 2015 Family Process Institute.

  17. Ambiguous science and the visual representation of the real

    NASA Astrophysics Data System (ADS)

    Newbold, Curtis Robert

    The emergence of visual media as prominent and even expected forms of communication in nearly all disciplines, including those scientific, has raised new questions about how the art and science of communication epistemologically affect the interpretation of scientific phenomena. In this dissertation I explore how the influence of aesthetics in visual representations of science inevitably creates ambiguous meanings. As a means to improve visual literacy in the sciences, I call awareness to the ubiquity of visual ambiguity and its importance and relevance in scientific discourse. To do this, I conduct a literature review that spans interdisciplinary research in communication, science, art, and rhetoric. Furthermore, I create a paradoxically ambiguous taxonomy, which functions to exploit the nuances of visual ambiguities and their role in scientific communication. I then extrapolate the taxonomy of visual ambiguity and from it develop an ambiguous, rhetorical heuristic, the Tetradic Model of Visual Ambiguity. The Tetradic Model is applied to a case example of a scientific image as a demonstration of how scientific communicators may increase their awareness of the epistemological effects of ambiguity in the visual representations of science. I conclude by demonstrating how scientific communicators may make productive use of visual ambiguity, even in communications of objective science, and I argue how doing so strengthens scientific communicators' visual literacy skills and their ability to communicate more ethically and effectively.

  18. P300 and Decision Making under Risk and Ambiguity.

    PubMed

    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.

  19. Neural representation of subjective value under risk and ambiguity.

    PubMed

    Levy, Ifat; Snell, Jason; Nelson, Amy J; Rustichini, Aldo; Glimcher, Paul W

    2010-02-01

    Risk and ambiguity are two conditions in which the consequences of possible outcomes are not certain. Under risk, the probabilities of different outcomes can be estimated, whereas under ambiguity, even these probabilities are not known. Although most people exhibit at least some aversion to both risk and ambiguity, the degree of these aversions is largely uncorrelated across subjects, suggesting that risk aversion and ambiguity aversion are distinct phenomena. Previous studies have shown differences in brain activations for risky and ambiguous choices and have identified neural mechanisms that may mediate transitions from conditions of ambiguity to conditions of risk. Unknown, however, is whether the value of risky and ambiguous options is necessarily represented by two distinct systems or whether a common mechanism can be identified. To answer this question, we compared the neural representation of subjective value under risk and ambiguity. fMRI was used to track brain activation while subjects made choices regarding options that varied systematically in the amount of money offered and in either the probability of obtaining that amount or the level of ambiguity around that probability. A common system, consisting of at least the striatum and the medial prefrontal cortex, was found to represent subjective value under both conditions.

  20. 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

  1. 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.

  2. 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.

  3. [Ambiguity role of neutrophils in oncogenesis].

    PubMed

    Mal'tseva, V N; Safronova, V G

    2009-01-01

    The review is focused on the participation of polymorphonuclear granulocytes (neutrophils) in development and spreading of a tumor. We consider both the well known functions of neutrophils (degranulation, production of reactive oxygen species (ROS)) and the recently shown one (presentation of an antigene). The special attention is focused on the ambiguity of the neutrophil role in oncogenesis. The dominant view is that neutrophils display exclusively antitumor properties. The update information testifies about protumoral activity of neutrophils: they migrate to a tumor and promote angiogenesis and metastasis at late stages of the tumor. It is interesting that certain components of neutrophil cytotoxic arsenal (ROS, cytokines, specific enzymes) participate both in antitumoral defenses of an organism and protumoral activity.

  4. Phonetic recoding of phonologically ambiguous printed words.

    PubMed

    Frost, R; Kampf, M

    1993-01-01

    Speech detection and matching simultaneously presented printed and spoken words were used to examine phonologic and phonetic processing of Hebrew heterophonic homographs. Subjects detected a correspondence between an ambiguous letter string and the amplitude envelopes of both dominant and subordinate phonological alternatives. Similar effects were obtained when the homographs were phonologically disambiguated by adding vowel marks. The matching of the unpointed printed forms of heterophonic homographs to the dominant and subordinate spoken alternatives presented auditorily was as fast as matching the pointed unambiguous forms to the respective spoken words. This outcome was not obtained when print and speech were not presented simultaneously. These results suggest that printed heterophonic homographs activate the two spoken alternatives they represent and provide further confirmation for fast phonetic recoding in reading.

  5. 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…

  6. Children's Comprehension of Two Types of Syntactic Ambiguity

    ERIC Educational Resources Information Center

    Zimmer, Elly Jane

    2017-01-01

    This study asks whether children accept both interpretations of ambiguous sentences with contexts supporting each option. Twenty-six 3- to 5-year-old English-speaking children and a control group of 30 English-speaking adults participated in a truth value judgment task. As a step towards evaluating the complexity of syntactic ambiguity, the…

  7. Persistence of Initial Misanalysis with No Referential Ambiguity

    ERIC Educational Resources Information Center

    Nakamura, Chie; Arai, Manabu

    2016-01-01

    Previous research reported that in processing structurally ambiguous sentences comprehenders often preserve an initial incorrect analysis even after adopting a correct analysis following structural disambiguation. One criticism is that the sentences tested in previous studies involved referential ambiguity and allowed comprehenders to make…

  8. 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…

  9. Inevitable ambiguity in perturbation around flat space-time

    SciTech Connect

    Ichinose, S. ); Kaminaga, Y. )

    1989-12-15

    Perturbation of general-relativistic predictions around flat geometry, in general, introduces inevitable ambiguity. The ambiguity reflects the geometrical nature of general relativity and is never a difficulty of it. We explain it by taking a concrete example of the radar-echo experiment.

  10. 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…

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

    NASA Astrophysics Data System (ADS)

    Banville, Simon

    2016-05-01

    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.

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. Comments on Regularization Ambiguities and Local Gauge Symmetries

    NASA Astrophysics Data System (ADS)

    Casana, R.; Pimentel, B. M.

    We study the regularization ambiguities in an exact renormalized (1 +1)-dimensional field theory. We show a relation between the regularization ambiguities and the coupling parameters of the theory as well as their role in the implementation of a local gauge symmetry at quantum level.

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. Persistence of Initial Misanalysis with No Referential Ambiguity

    ERIC Educational Resources Information Center

    Nakamura, Chie; Arai, Manabu

    2016-01-01

    Previous research reported that in processing structurally ambiguous sentences comprehenders often preserve an initial incorrect analysis even after adopting a correct analysis following structural disambiguation. One criticism is that the sentences tested in previous studies involved referential ambiguity and allowed comprehenders to make…

  5. The Politics of Poor Relief: A Study in Ambiguities.

    ERIC Educational Resources Information Center

    Holden, Matthew, Jr.

    The essay addresses both the question of poverty and the scope of political science. The study of poverty demands a transeconomic approach because the act of making an economic choice is fundamentally political, but the act is likely to be ambiguous and that ambiguity is peculiarly revealed in the politics of poor relief. While the idea of…

  6. Children's Comprehension of Two Types of Syntactic Ambiguity

    ERIC Educational Resources Information Center

    Zimmer, Elly Jane

    2017-01-01

    This study asks whether children accept both interpretations of ambiguous sentences with contexts supporting each option. Twenty-six 3- to 5-year-old English-speaking children and a control group of 30 English-speaking adults participated in a truth value judgment task. As a step towards evaluating the complexity of syntactic ambiguity, the…

  7. Rules for clinical diagnosis in babies with ambiguous genitalia.

    PubMed

    Low, Y; Hutson, J M

    2003-08-01

    Intersex disorders are rare and complex; yet, in each case of genital ambiguity, accurate and expeditious management is required of the clinician. This article reviews the embryology of sexual differentiation, from which some 'rules' of diagnosis are derived. A simplified approach to the interpretation of clinical signs in ambiguous genitalia is presented and discussed.

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  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. Optical Spatial integration methods for ambiguity function generation

    NASA Technical Reports Server (NTRS)

    Tamura, P. N.; Rebholz, J. J.; Daehlin, O. T.; Lee, T. C.

    1981-01-01

    A coherent optical spatial integration approach to ambiguity function generation is described. It uses one dimensional acousto-optic Bragg cells as input tranducers in conjunction with a space variant linear phase shifter, a passive optical element, to generate the two dimensional ambiguity function in one exposure. Results of a real time implementation of this system are shown.

  14. 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…

  15. Genetic code ambiguity confers a selective advantage on Acinetobacter baylyi.

    PubMed

    Bacher, Jamie M; Waas, William F; Metzgar, David; de Crécy-Lagard, Valérie; Schimmel, Paul

    2007-09-01

    A primitive genetic code, composed of a smaller set of amino acids, may have expanded via recursive periods of genetic code ambiguity that were followed by specificity. Here we model a step in this process by showing how genetic code ambiguity could result in an enhanced growth rate in Acinetobacter baylyi.

  16. Genetic Code Ambiguity Confers a Selective Advantage on Acinetobacter baylyi▿

    PubMed Central

    Bacher, Jamie M.; Waas, William F.; Metzgar, David; de Crécy-Lagard, Valérie; Schimmel, Paul

    2007-01-01

    A primitive genetic code, composed of a smaller set of amino acids, may have expanded via recursive periods of genetic code ambiguity that were followed by specificity. Here we model a step in this process by showing how genetic code ambiguity could result in an enhanced growth rate in Acinetobacter baylyi. PMID:17616603

  17. Ambiguity Tolerance and Perceptual Learning Styles of Chinese EFL Learners

    ERIC Educational Resources Information Center

    Li, Haishan; He, Qingshun

    2016-01-01

    Ambiguity tolerance and perceptual learning styles are the two influential elements showing individual differences in EFL learning. This research is intended to explore the relationship between Chinese EFL learners' ambiguity tolerance and their preferred perceptual learning styles. The findings include (1) the learners are sensitive to English…

  18. 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…

  19. Semantic Ambiguity and the Process of Generating Meaning From Print

    ERIC Educational Resources Information Center

    Pexman, Penny M.; Hino, Yasushi; Lupker, Stephen J.

    2004-01-01

    An ambiguity disadvantage (slower responses for ambiguous words, e.g., bank, than for unambiguous words) has been reported in semantic tasks (L. R. Gottlob, S. D. Goldinger, G. O. Stone, & G. C. Van Orden, 1999; Y. Hino, S. J. Lupker, & P. M. Pexman, 2002; C. D. Piercey & S. Joordens, 2000) and has been attributed to the meaning activation…

  20. 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…

  1. Absence of the Gribov ambiguity in a quadratic gauge

    NASA Astrophysics Data System (ADS)

    Raval, Haresh

    2016-05-01

    The Gribov ambiguity exists in various gauges. Algebraic gauges are likely to be ambiguity free. However, algebraic gauges are not Lorentz invariant, which is their fundamental flaw. In addition, they are not generally compatible with the boundary conditions on the gauge fields, which are needed to compactify the space i.e., the ambiguity continues to exist on a compact manifold. Here we discuss a quadratic gauge fixing, which is Lorentz invariant. We consider an example of a spherically symmetric gauge field configuration in which we prove that this Lorentz invariant gauge removes the ambiguity on a compact manifold {S}^3, when a proper boundary condition on the gauge configuration is taken into account. Thus, we provide one example where the ambiguity is absent on a compact manifold in the algebraic gauge. We also show that the BRST invariance is preserved in this gauge.

  2. Ambiguity aversion and household portfolio choice puzzles: Empirical evidence*

    PubMed Central

    Dimmock, Stephen G.; Kouwenberg, Roy; Mitchell, Olivia S.; Peijnenburg, Kim

    2017-01-01

    We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks. PMID:28458446

  3. Method of resolving radio phase ambiguity in satellite orbit determination

    NASA Technical Reports Server (NTRS)

    Councelman, Charles C., III; Abbot, Richard I.

    1989-01-01

    For satellite orbit determination, the most accurate observable available today is microwave radio phase, which can be differenced between observing stations and between satellites to cancel both transmitter- and receiver-related errors. For maximum accuracy, the integer cycle ambiguities of the doubly differenced observations must be resolved. To perform this ambiguity resolution, a bootstrapping strategy is proposed. This strategy requires the tracking stations to have a wide ranging progression of spacings. By conventional 'integrated Doppler' processing of the observations from the most widely spaced stations, the orbits are determined well enough to permit resolution of the ambiguities for the most closely spaced stations. The resolution of these ambiguities reduces the uncertainty of the orbit determination enough to enable ambiguity resolution for more widely spaced stations, which further reduces the orbital uncertainty. In a test of this strategy with six tracking stations, both the formal and the true errors of determining Global Positioning System satellite orbits were reduced by a factor of 2.

  4. Intolerance for approach of ambiguity in social anxiety disorder.

    PubMed

    Kuckertz, Jennie M; Strege, Marlene V; Amir, Nader

    2017-06-01

    Previous research has utilised the approach-avoidance task (AAT) to measure approach and avoidance action tendencies in socially anxious individuals. "Neutral" social stimuli may be perceived as ambiguous and hence threatening to socially anxious individuals, however it is unclear whether this results in difficulty approaching ambiguous ("neutral") versus unambiguous threat (e.g. disgust) faces (i.e. intolerance of ambiguity). Thirty participants with social anxiety disorder (SADs) and 29 non-anxious controls completed an implicit AAT in which they were instructed to approach or avoid neutral and disgust faces (i.e. pull or push a joystick) based on colour of the picture border. Results indicated that SADs demonstrated greater difficulty approaching neutral relative to disgust faces. Moreover, intolerance for approach of ambiguity predicted social anxiety severity while controlling for the effects of trait anxiety and depression. Our results provide further support for the role of intolerance of ambiguity in SAD.

  5. Ambiguity aversion and household portfolio choice puzzles: Empirical evidence.

    PubMed

    Dimmock, Stephen G; Kouwenberg, Roy; Mitchell, Olivia S; Peijnenburg, Kim

    2016-03-01

    We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks.

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

    PubMed

    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 "fronto-parietal-striatal" 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).

  7. 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 “fronto—parietal—striatal” 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

  8. Actively learning object names across ambiguous situations.

    PubMed

    Kachergis, George; Yu, Chen; Shiffrin, Richard M

    2013-01-01

    Previous research shows that people can use the co-occurrence of words and objects in ambiguous situations (i.e., containing multiple words and objects) to learn word meanings during a brief passive training period (Yu & Smith, 2007). However, learners in the world are not completely passive but can affect how their environment is structured by moving their heads, eyes, and even objects. These actions can indicate attention to a language teacher, who may then be more likely to name the attended objects. Using a novel active learning paradigm in which learners choose which four objects they would like to see named on each successive trial, this study asks whether active learning is superior to passive learning in a cross-situational word learning context. Finding that learners perform better in active learning, we investigate the strategies and discover that most learners use immediate repetition to disambiguate pairings. Unexpectedly, we find that learners who repeat only one pair per trial--an easy way to infer this pair-perform worse than those who repeat multiple pairs per trial. Using a working memory extension to an associative model of word learning with uncertainty and familiarity biases, we investigate individual differences that correlate with these assorted strategies.

  9. Rotational Study of Ambiguous Taxonomic Classified Asteroids

    NASA Astrophysics Data System (ADS)

    Linder, Tyler R.; Sanchez, Rick; Wuerker, Wolfgang; Clayson, Timothy; Giles, Tucker

    2017-01-01

    The Sloan Digital Sky Survey (SDSS) moving object catalog (MOC4) provided the largest ever catalog of asteroid spectrophotometry observations. Carvano et al. (2010), while analyzing MOC4, discovered that individual observations of asteroids which were observed multiple times did not classify into the same photometric-based taxonomic class. A small subset of those asteroids were classified as having both the presence and absence of a 1um silicate absorption feature. If these variations are linked to differences in surface mineralogy, the prevailing assumption that an asteroid’s surface composition is predominantly homogenous would need to be reexamined. Furthermore, our understanding of the evolution of the asteroid belt, as well as the linkage between certain asteroids and meteorite types may need to be modified.This research is an investigation to determine the rotational rates of these taxonomically ambiguous asteroids. Initial questions to be answered:Do these asteroids have unique or nonstandard rotational rates?Is there any evidence in their light curve to suggest an abnormality?Observations were taken using PROMPT6 a 0.41-m telescope apart of the SKYNET network at Cerro Tololo Inter-American Observatory (CTIO). Observations were calibrated and analyzed using Canopus software. Initial results will be presented at AAS.

  10. Formant Pattern Ambiguity of Vowel Sounds.

    PubMed

    Maurer; d'Heureuse; Landis

    1999-01-01

    The formant frequencies of a particular vowel vary according to the speaker group and to coarticulation. Therefore, overlapping formant patterns of different vowels are commonly related to sex and age differences and to coarticulation, and are considered to concern mainly the F(1) -F(2) pattern of adjacent vowels. However, several studies have reported indications of a correlation between the lower formant frequencies and F(0), as well as of the appearance of different formant numbers relevant to vowel identity. As a consequence, the overlap between formant patterns of different vowels might be more substantial than has traditionally been assumed. Within the present study, therefore, the extent to which a given formant pattern can represent different vowels was investigated for natural Swiss German vowels produced monotonously and in isolation by men, women and children at F(0) of 85-870 Hz. Similar formant patterns were found for vocalizations of different vowels with both small and large phonetic distances, and within the entire frequency ranges of the formants relevant for phoneme identity. For vowel sounds displaying ambiguous formant patterns, the main spectral characteristics related to differences in their perceptual identity were found to concern F(0) and relative formant amplitudes. Results are given in exemplary vowel series, and consequences for the psychophysics of the vowel are discussed.

  11. Formant pattern ambiguity of vowel sounds.

    PubMed

    Maurer, D; D'Heureuse, C; Landis, T

    2000-01-01

    The formant frequencies of a particular vowel vary according to the speaker group and to coarticulation. Therefore, overlapping formant patterns of different vowels are commonly related to sex and age differences and to coarticulation, and are considered to concern mainly the F1-F2 pattern of adjacent vowels. However, several studies have reported indications of a correlation between the lower formant frequencies and F0, as well as of the appearance of different formant numbers relevant to vowel identity. As a consequence, the overlap between formant patterns of different vowels might be more substantial than has traditionally been assumed. Within the present study, therefore, the extent to which a given formant pattern can represent different vowels was investigated for natural Swiss German vowels produced monotonously and in isolation by men, women and children at F0 of 85-870 Hz. Similar formant patterns were found for vocalizations of different vowels with both small and large phonetic distances, and within the entire frequency ranges of the formants relevant for phoneme identity. For vowel sounds displaying ambiguous formant patterns, the main spectral characteristics related to differences in their perceptual identity were found to concern F0 and relative formant amplitudes. Results are given in exemplary vowel series, and consequences for the psychophysics of the vowel are discussed.

  12. 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.

  13. Semantic ambiguity within and across languages: an integrative review.

    PubMed

    Degani, Tamar; Tokowicz, Natasha

    2010-07-01

    Semantic ambiguity often occurs within a language (e.g., the word "organ" in English means both a body part and a musical instrument), but it can also cross a language boundary, such that a given word form is shared in two languages, but its meanings are different (e.g., the word "angel" means "sting" in Dutch). Bilingual individuals are therefore faced not only with ambiguity in each of their languages, but also with ambiguity across languages. The current review focuses on studies that explored such cross-language ambiguity and examines how the results from these studies can be integrated with what we have learned about within-language ambiguity resolution. In particular, this review examines how interactions of frequency and context manifest themselves in ambiguity that crosses a language boundary and call for the inclusion of language context as a contributing factor. An extension of the monolingual reordered access model (Duffy, Morris, & Rayner, 1988) is outlined to discuss the interactions between these factors. Furthermore, the effects of the similarity between the two meanings, task differences, and individual differences are explored. This review highlights the need for studies that test within- and cross-language ambiguity in the same individuals before strong conclusions can be made about the nature of interactions between frequency, semantic context, and language context.

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

    PubMed

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

    2016-01-01

    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.

  15. Neuropsychology of Aesthetic Judgment of Ambiguous and Non-Ambiguous Artworks.

    PubMed

    Boccia, Maddalena; Barbetti, Sonia; Piccardi, Laura; Guariglia, Cecilia; Giannini, Anna Maria

    2017-03-18

    Several affective and cognitive processes have been found to be pivotal in affecting aesthetic experience of artworks and both neuropsychological as well as psychiatric symptoms have been found to affect artistic production. However, there is a paucity of studies directly investigating effects of brain lesions on aesthetic judgment. Here, we assessed the effects of unilateral brain damage on aesthetic judgment of artworks showing part/whole ambiguity. We asked 19 unilaterally brain-damaged patients (10 left and 9 right brain damaged patients, respectively LBDP and RBDP) and 20 age- and education-matched healthy individuals (controls, C) to rate 10 Arcimboldo's ambiguous portraits (AP), 10 realistic Renaissance portraits (RP), 10 still life paintings (SL), and 10 Arcimboldo's modified portraits where only objects/parts are detectable (AO). They were also administered a Navon task, a facial recognition test, and evaluated on visuo-perceptual and visuo-constructional abilities. Patients included in the study did not show any deficits that could affect the capability to explore and enjoy artworks. SL and RP was not affected by brain damage regardless of its laterality. On the other hand, we found that RBDP liked AP more than the C participants. Furthermore, we found a positive correlation between aesthetic judgment of AP and visuo-perceptual skills even if the single case analyses failed to find a systematic association between neuropsychological deficits and aesthetic judgment of AP. On the whole, the present data suggest that a right hemisphere lesion may affect aesthetic judgment of ambiguous artworks, even in the absence of exploration or constructional deficits.

  16. Neuropsychology of Aesthetic Judgment of Ambiguous and Non-Ambiguous Artworks

    PubMed Central

    Boccia, Maddalena; Barbetti, Sonia; Piccardi, Laura; Guariglia, Cecilia; Giannini, Anna Maria

    2017-01-01

    Several affective and cognitive processes have been found to be pivotal in affecting aesthetic experience of artworks and both neuropsychological as well as psychiatric symptoms have been found to affect artistic production. However, there is a paucity of studies directly investigating effects of brain lesions on aesthetic judgment. Here, we assessed the effects of unilateral brain damage on aesthetic judgment of artworks showing part/whole ambiguity. We asked 19 unilaterally brain-damaged patients (10 left and 9 right brain damaged patients, respectively LBDP and RBDP) and 20 age- and education-matched healthy individuals (controls, C) to rate 10 Arcimboldo’s ambiguous portraits (AP), 10 realistic Renaissance portraits (RP), 10 still life paintings (SL), and 10 Arcimboldo’s modified portraits where only objects/parts are detectable (AO). They were also administered a Navon task, a facial recognition test, and evaluated on visuo-perceptual and visuo-constructional abilities. Patients included in the study did not show any deficits that could affect the capability to explore and enjoy artworks. SL and RP was not affected by brain damage regardless of its laterality. On the other hand, we found that RBDP liked AP more than the C participants. Furthermore, we found a positive correlation between aesthetic judgment of AP and visuo-perceptual skills even if the single case analyses failed to find a systematic association between neuropsychological deficits and aesthetic judgment of AP. On the whole, the present data suggest that a right hemisphere lesion may affect aesthetic judgment of ambiguous artworks, even in the absence of exploration or constructional deficits. PMID:28335460

  17. Role ambiguity among women providing care for ex-husbands.

    PubMed

    Cooney, Teresa M; Proulx, Christine M; Snyder-Rivas, Linley A; Benson, Jacquelyn J

    2014-01-01

    Twenty-one women were interviewed regarding their caregiving experiences for ill or dying ex-husbands. Emergent in the analyses was the variety of ways in which they experienced role ambiguity as ex-wife caregivers. This article describes the role ambiguity ex-wife caregivers encountered interpersonally through interactions with network members, institutionally in dealing with professionals and the workplace, and intrapersonally in confusion over their roles and feelings. Consequences of role ambiguity are discussed, and recommendations for policy and practice are made in light of the aging population, changing family forms, and women's care roles.

  18. Ambiguity in Tactile Apparent Motion Perception

    PubMed Central

    Liaci, Emanuela; Bach, Michael; Tebartz van Elst, Ludger; Heinrich, Sven P.; Kornmeier, Jürgen

    2016-01-01

    Background In von Schiller’s Stroboscopic Alternative Motion (SAM) stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio (“AR”, i.e. the relation between vertical and horizontal dot distances). Further, with equal horizontal and vertical dot distances (AR = 1) perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion. Methods We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants’ forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames. Results Increasing the tactile SAM’s AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias. Discussion Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual

  19. Statistical Resolution of Ambiguous HLA Typing Data

    PubMed Central

    Listgarten, Jennifer; Brumme, Zabrina; Kadie, Carl; Xiaojiang, Gao; Walker, Bruce; Carrington, Mary; Goulder, Philip; Heckerman, David

    2008-01-01

    High-resolution HLA typing plays a central role in many areas of immunology, such as in identifying immunogenetic risk factors for disease, in studying how the genomes of pathogens evolve in response to immune selection pressures, and also in vaccine design, where identification of HLA-restricted epitopes may be used to guide the selection of vaccine immunogens. Perhaps one of the most immediate applications is in direct medical decisions concerning the matching of stem cell transplant donors to unrelated recipients. However, high-resolution HLA typing is frequently unavailable due to its high cost or the inability to re-type historical data. In this paper, we introduce and evaluate a method for statistical, in silico refinement of ambiguous and/or low-resolution HLA data. Our method, which requires an independent, high-resolution training data set drawn from the same population as the data to be refined, uses linkage disequilibrium in HLA haplotypes as well as four-digit allele frequency data to probabilistically refine HLA typings. Central to our approach is the use of haplotype inference. We introduce new methodology to this area, improving upon the Expectation-Maximization (EM)-based approaches currently used within the HLA community. Our improvements are achieved by using a parsimonious parameterization for haplotype distributions and by smoothing the maximum likelihood (ML) solution. These improvements make it possible to scale the refinement to a larger number of alleles and loci in a more computationally efficient and stable manner. We also show how to augment our method in order to incorporate ethnicity information (as HLA allele distributions vary widely according to race/ethnicity as well as geographic area), and demonstrate the potential utility of this experimentally. A tool based on our approach is freely available for research purposes at http://microsoft.com/science. PMID:18392148

  20. The recency effect in the perception of ambiguous figures.

    PubMed

    Wilton, R N

    1985-01-01

    After a failure to obtain a recency effect in the perception of ambiguous figures three experiments were carried out to determine the conditions which govern the effect. It was found that the duration of the stimulus which precedes the ambiguous figure (the most recent stimulus) was important. Also of importance was the interval between the next-to-most-recent stimulus and the ambiguous figure. The effect of manipulating these variables was such that sometimes no recency effect was obtained, implying that their state is sometimes critical for the effect. Variations in the duration of the ambiguous stimulus did not cause the recency effect to vary. Recommendations are made for the demonstration of a reliable recency effect.

  1. Performance analysis of multiple PRF technique for ambiguity resolution

    NASA Technical Reports Server (NTRS)

    Chang, C. Y.; Curlander, J. C.

    1992-01-01

    For short wavelength spaceborne synthetic aperture radar (SAR), ambiguity in Doppler centroid estimation occurs when the azimuth squint angle uncertainty is larger than the azimuth antenna beamwidth. Multiple pulse recurrence frequency (PRF) hopping is a technique developed to resolve the ambiguity by operating the radar in different PRF's in the pre-imaging sequence. Performance analysis results of the multiple PRF technique are presented, given the constraints of the attitude bound, the drift rate uncertainty, and the arbitrary numerical values of PRF's. The algorithm performance is derived in terms of the probability of correct ambiguity resolution. Examples, using the Shuttle Imaging Radar-C (SIR-C) and X-SAR parameters, demonstrate that the probability of correct ambiguity resolution obtained by the multiple PRF technique is greater than 95 percent and 80 percent for the SIR-C and X-SAR applications, respectively. The success rate is significantly higher than that achieved by the range cross correlation technique.

  2. 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.

  3. Performance analysis of multiple PRF technique for ambiguity resolution

    NASA Technical Reports Server (NTRS)

    Chang, C. Y.; Curlander, J. C.

    1992-01-01

    For short wavelength spaceborne synthetic aperture radar (SAR), ambiguity in Doppler centroid estimation occurs when the azimuth squint angle uncertainty is larger than the azimuth antenna beamwidth. Multiple pulse recurrence frequency (PRF) hopping is a technique developed to resolve the ambiguity by operating the radar in different PRF's in the pre-imaging sequence. Performance analysis results of the multiple PRF technique are presented, given the constraints of the attitude bound, the drift rate uncertainty, and the arbitrary numerical values of PRF's. The algorithm performance is derived in terms of the probability of correct ambiguity resolution. Examples, using the Shuttle Imaging Radar-C (SIR-C) and X-SAR parameters, demonstrate that the probability of correct ambiguity resolution obtained by the multiple PRF technique is greater than 95 percent and 80 percent for the SIR-C and X-SAR applications, respectively. The success rate is significantly higher than that achieved by the range cross correlation technique.

  4. Absence of the Gribov ambiguity in a special algebraic gauge

    NASA Astrophysics Data System (ADS)

    Raval, Haresh

    2016-11-01

    The Gribov ambiguity exists in various gauges except algebraic gauges. However in general, algebraic gauges are not Lorentz invariant, which is their fundamental flaw. Here we discuss a quadratic gauge fixing, which is Lorentz invariant. We show that nontrivial copies can not occur in this gauge. We then provide an example of spherically symmetric gauge field configuration and prove that with a proper boundary condition on the configuration, this gauge removes the ambiguity on a compact manifold S^3.

  5. Comparing Tolerance of Ambiguity in Veterinary and Medical Students.

    PubMed

    Hancock, Jason; Hammond, Jennifer A; Roberts, Martin; Mattick, Karen

    2017-01-01

    Current guidelines suggest that educators in both medical and veterinary professions should do more to ensure that students can tolerate ambiguity. Designing curricula to achieve this requires the ability to measure and understand differences in ambiguity tolerance among and within professional groups. Although scales have been developed to measure tolerance of ambiguity in both medical and veterinary professions, no comparative studies have been reported. We compared the tolerance of ambiguity of medical and veterinary students, hypothesizing that veterinary students would have higher tolerance of ambiguity, given the greater patient diversity and less well-established evidence base underpinning practice. We conducted a secondary analysis of questionnaire data from first- to fourth-year medical and veterinary students. Tolerance of ambiguity scores were calculated and compared using the TAMSAD scale (29 items validated for the medical student population), the TAVS scale (27 items validated for the veterinary student population), and a scale comprising the 22 items common to both scales. Using the TAMSAD and TAVS scales, medical students had a significantly higher mean tolerance of ambiguity score than veterinary students (56.1 vs. 54.1, p<.001 and 60.4 vs. 58.5, p=.002, respectively) but no difference was seen when only the 22 shared items were compared (56.1 vs. 57.2, p=.513). The results do not support our hypothesis and highlight that different findings can result when different tools are used. Medical students may have slightly higher tolerance of ambiguity than veterinary students, although this depends on the scale used.

  6. PRF Ambiguity Detrmination for Radarsat ScanSAR System

    NASA Technical Reports Server (NTRS)

    Jin, Michael Y.

    1998-01-01

    PRF ambiguity is a potential problem for a spaceborne SAR operated at high frequencies. For a strip mode SAR, there were several approaches to solve this problem. This paper, however, addresses PRF ambiguity determination algorithms suitable for a burst mode SAR system such as the Radarsat ScanSAR. The candidate algorithms include the wavelength diversity algorithm, range look cross correlation algorithm, and multi-PRF algorithm.

  7. Practitioner perfectionism: relationship to ambiguity tolerance and work satisfaction.

    PubMed

    Wittenberg, K J; Norcross, J C

    2001-12-01

    Perfectionism among psychological practitioners is a common phenomenon, but a neglected topic in the research literature. This article presents data indicating that perfectionism is negatively related to both tolerance of ambiguity and satisfaction of conducting psychotherapy in a sample of 197 doctoral-level, private-practice psychologists. Results demonstrated that high, socially prescribed perfectionism and low tolerance of ambiguity are associated with reduced enjoyment of conducting psychotherapy. Several methods to self-evaluate and moderate perfectionism in clinicians are offered.

  8. PRF Ambiguity Detrmination for Radarsat ScanSAR System

    NASA Technical Reports Server (NTRS)

    Jin, Michael Y.

    1998-01-01

    PRF ambiguity is a potential problem for a spaceborne SAR operated at high frequencies. For a strip mode SAR, there were several approaches to solve this problem. This paper, however, addresses PRF ambiguity determination algorithms suitable for a burst mode SAR system such as the Radarsat ScanSAR. The candidate algorithms include the wavelength diversity algorithm, range look cross correlation algorithm, and multi-PRF algorithm.

  9. Estimating ambiguity preferences and perceptions in multiple prior models: Evidence from the field.

    PubMed

    Dimmock, Stephen G; Kouwenberg, Roy; Mitchell, Olivia S; Peijnenburg, Kim

    2015-12-01

    We develop a tractable method to estimate multiple prior models of decision-making under ambiguity. In a representative sample of the U.S. population, we measure ambiguity attitudes in the gain and loss domains. We find that ambiguity aversion is common for uncertain events of moderate to high likelihood involving gains, but ambiguity seeking prevails for low likelihoods and for losses. We show that choices made under ambiguity in the gain domain are best explained by the α-MaxMin model, with one parameter measuring ambiguity aversion (ambiguity preferences) and a second parameter quantifying the perceived degree of ambiguity (perceptions about ambiguity). The ambiguity aversion parameter α is constant and prior probability sets are asymmetric for low and high likelihood events. The data reject several other models, such as MaxMin and MaxMax, as well as symmetric probability intervals. Ambiguity aversion and the perceived degree of ambiguity are both higher for men and for the college-educated. Ambiguity aversion (but not perceived ambiguity) is also positively related to risk aversion. In the loss domain, we find evidence of reflection, implying that ambiguity aversion for gains tends to reverse into ambiguity seeking for losses. Our model's estimates for preferences and perceptions about ambiguity can be used to analyze the economic and financial implications of such preferences.

  10. Estimating ambiguity preferences and perceptions in multiple prior models: Evidence from the field

    PubMed Central

    Dimmock, Stephen G.; Kouwenberg, Roy; Mitchell, Olivia S.; Peijnenburg, Kim

    2016-01-01

    We develop a tractable method to estimate multiple prior models of decision-making under ambiguity. In a representative sample of the U.S. population, we measure ambiguity attitudes in the gain and loss domains. We find that ambiguity aversion is common for uncertain events of moderate to high likelihood involving gains, but ambiguity seeking prevails for low likelihoods and for losses. We show that choices made under ambiguity in the gain domain are best explained by the α-MaxMin model, with one parameter measuring ambiguity aversion (ambiguity preferences) and a second parameter quantifying the perceived degree of ambiguity (perceptions about ambiguity). The ambiguity aversion parameter α is constant and prior probability sets are asymmetric for low and high likelihood events. The data reject several other models, such as MaxMin and MaxMax, as well as symmetric probability intervals. Ambiguity aversion and the perceived degree of ambiguity are both higher for men and for the college-educated. Ambiguity aversion (but not perceived ambiguity) is also positively related to risk aversion. In the loss domain, we find evidence of reflection, implying that ambiguity aversion for gains tends to reverse into ambiguity seeking for losses. Our model’s estimates for preferences and perceptions about ambiguity can be used to analyze the economic and financial implications of such preferences. PMID:26924890

  11. Preferences for 'New' Treatments Diminish in the Face of Ambiguity.

    PubMed

    Harrison, Mark; Marra, Carlo A; Bansback, Nick

    2016-05-12

    New products usually offer advantages over existing products, but in health care, most new drugs are 'me-too', comparable in effectiveness and side effects to existing drugs, but with a more ambiguous evidence base around adverse effects. Despite this, new treatments drive increased health care spending, suggesting a preference for 'newness' in this setting. We explore (1) whether preferences for treatments labeled 'new' exist and (2) persist once the ambiguity in the evidence base reflecting newness is described. We use a Canadian general population sample (n = 2837) characterized by their innovativeness in adopting new products in normal markets. We found that innovators/early adopters (n = 173) had significant preferences for 'newer' treatments (B = 0.162, p = 0.038) irrespective of comparable benefits and side effects and all respondents had significant preferences for less ambiguity in benefit/side effect estimates. Notably, when 'newness' was combined with ambiguity, no significant preferences for new treatments were observed regardless of respondent innovativeness. We conclude that preferences for new products exist for some people in health care markets but disappear when the implication of ambiguity in the evidence base for new treatments is communicated. Physicians should avoid describing treatments as 'new' or be mindful to qualify the implications of 'new' treatments in terms of evidence ambiguity. Copyright © 2016 John Wiley & Sons, Ltd.

  12. GNSS antenna array-aided CORS ambiguity resolution

    NASA Astrophysics Data System (ADS)

    Li, Bofeng; Teunissen, Peter J. G.

    2014-04-01

    Array-aided precise point positioning is a measurement concept that uses GNSS data, from multiple antennas in an array of known geometry, to realize improved GNSS parameter estimation proposed by Teunissen (IEEE Trans Signal Process 60:2870-2881, 2012). In this contribution, the benefits of array-aided CORS ambiguity resolution are explored. The mathematical model is formulated to show how the platform-array data can be reduced and how the variance matrix of the between-platform ambiguities can profit from the increased precision of the reduced platform data. The ambiguity resolution performance will be demonstrated for varying scenarios using simulation. We consider single-, dual- and triple-frequency scenarios of geometry-based and geometry-free models for different number of antennas and different standard deviations of the ionosphere-weighted constraints. The performances of both full and partial ambiguity resolution (PAR) are presented for these different scenarios. As the study shows, when full advantage is taken of the array antennas, both full and partial ambiguity resolution can be significantly improved, in some important cases even enabling instantaneous ambiguity resolution. PAR widelaning and its suboptimal character are hereby also illustrated.

  13. Referential Ambiguity in the Narrative Productions of African American Adults.

    PubMed

    Wainwright, Angela Bradford; Cannito, Michael P

    2015-11-01

    The purpose of this study was to examine the production of referential ambiguities in two contrasting narrative conditions among age-defined groups of healthy African American women. Twenty middle-aged adults (M = 51 years) and 20 older adults (M = 72 years) produced a complex story retelling and a personal narrative. All narratives were transcribed orthographically, parsed into T-units, and analyzed for surface structure markings of referents and the presence of ambiguities. The results demonstrated that older adults produced more ambiguities than middle-aged adults, were more compromised with task complexity, used more role or relation designations to refer to story characters while underusing proper names, and exhibited significant lexical retrieval deficits during ongoing narrative production. Middle-aged adults produced more proper names, but were also challenged by the complexity of the story-retelling task. Moreover, the results showed that older adults produced more African American English variants than middle-aged adults. This investigation revealed a pattern of age-related ambiguities during narrative production. The results demonstrated that lexical retrieval from long-term semantic memory was an important predictor of ambiguity, whereas African American English contributed negligibly. These results show that referential ambiguities may be a robust characteristic of cognitive-linguistic changes that occur with typical aging.

  14. Affective ambiguity for a group recruits ventromedial prefrontal cortex.

    PubMed

    Simmons, Alan; Stein, Murray B; Matthews, Scott C; Feinstein, Justin S; Paulus, Martin P

    2006-01-15

    Affective appraisal often involves processing complex and ambiguous stimuli, such as the mood of a group people. However, affective neuroimaging research often uses individual faces as stimuli when exploring the neural circuitry involved in social appraisal. Results from studies using single face paradigms may not generalize to settings where multiple faces are simultaneously processed. The goal of the current study was to use a novel task that presents groups of affective faces to probe the medial prefrontal cortex (PFC), a region that is critically involved in appraisal of ambiguous affective stimuli, in healthy volunteers. In the current study, 27 subjects performed the Wall of Faces (WOF) task in which multiple matrices of faces were briefly presented during functional MRI. Subjects were asked to decide whether there were more angry or happy faces (emotional decision) or whether there were more male or female faces (gender decision). In each condition, the array contained either an equal (ambiguous trials) or an unequal (unambiguous trials) distribution of one affect or gender. Ambiguous trials relative to unambiguous trials activated regions implicated in conflict monitoring and cognitive control, including the dorsal anterior cingulate cortex (ACC), dorsolateral PFC, and posterior parietal cortex. When comparing ambiguous affective decisions with ambiguous gender decisions, the ventromedial PFC (including the ventral ACC) was significantly more active. This supports the dissociation of the ACC into dorsal cognitive and ventral affective divisions, and suggests that the ventromedial PFC may play a critical role in appraising affective tone in a complex display of multiple human faces.

  15. 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,…

  16. 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,…

  17. Evidence of the properties of an ambiguity tolerance measure: the Multiple Stimulus Types Ambiguity Tolerance Scale-II (MSTAT-II).

    PubMed

    McLain, David L

    2009-12-01

    Despite widespread interest in ambiguity tolerance and other information-related individual differences, existing measures of ambiguity tolerance are conceptually disparate and are often psychometrically weak. This paper presents evidence of reliability and validity for a 13-item measure of ambiguity tolerance (MSTAT-II) based on a definition of ambiguity tolerance as an orientation, ranging from aversion to attraction, toward stimuli that are complex, unfamiliar, and insoluble. The MSTAT-II addresses each basic type of ambiguous stimulus, contains fewer items than many other scales, and reduces references to specific contexts and objects not directly related to ambiguity. Data from three studies using diverse samples and measures, including other popular ambiguity tolerance scales, were examined, and the results suggest the MSTAT-II may improve upon other paper-and-pencil measures of ambiguity tolerance.

  18. 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

  19. 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

  20. Role conflict, role ambiguity, and job satisfaction in nurse executives.

    PubMed

    Tarrant, Theresa; Sabo, Carolyn E

    2010-01-01

    This article reports the results of a cross-sectional correlational survey design of nurse executives' (NEs') views on role conflict, role ambiguity, job satisfaction, and depression. A total of 380 surveys were returned from 1000 randomly selected participants. Four instruments were utilized, 1 for demographic data and 3 established instruments. Results indicated that the respondents had low to moderate amounts of role ambiguity, high levels of job satisfaction, low levels of depression, a negative relationship between role conflict and role ambiguity and job satisfaction, and a positive relationship between role conflict and depression. Furthermore, although levels of role conflict are decreasing, levels of role ambiguity are increasing. Neither educational level nor age was related to the dependent variables. Role conflict and role ambiguity are both forms of role stress. This study indicates that stress levels are not overwhelming to the NE and may be encouraging development of required skills. Healthcare organizations will continue to evolve and increase in complexity putting pressure on NEs in their many roles. Although this study did not consider strategies for coping with stress, this important avenue needs to be considered as NEs move forward with more extensive roles in the leadership of our healthcare system.

  1. Auditory scene analysis: the sweet music of ambiguity.

    PubMed

    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.

  2. Neural correlates of semantic competition during processing of ambiguous words.

    PubMed

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

    2009-05-01

    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.

  3. Ambiguity and the 'mental eye' in pictorial relief.

    PubMed

    Koenderink, J J; van Doorn, A J; Kappers, A M; Todd, J T

    2001-01-01

    Photographs of scenes do not determine scenes in the sense that infinitely many different scenes could have given rise to any given photograph. In psychophysical experiments, observers have (at least partially) to resolve these ambiguities. The ambiguities also allow them to vary their response within the space of 'veridical' responses. Such variations may well be called 'the beholder's share' since they do not depend causally on the available depth cues. We determined the pictorial relief for four observers, four stimuli, and four different tasks. In all cases we addressed issues of reliability (scatter on repeated trials) and consistency (how well the data can be explained via a smooth surface, any surface). All data were converted to depth maps which allows us to compare the relief from the different operationalisations. As expected, pictorial relief can differ greatly either between observers (same stimulus, same task) or between operationalisations (same observer, same stimulus). However, when we factor out the essential ambiguity, these differences almost completely vanish and excellent agreement over tasks and observers pertains. Thus, observers often resolve the ambiguity in idiosyncratic ways, but mutually agree--even over tasks--in so far as their responses are causally dependent on the depth cues. A change of task often induces a change in 'mental perspective'. In such cases, the observers switch the 'beholder's share', which resolves the essential ambiguity through a change in viewpoint of their 'mental eye'.

  4. Artificially ambiguous genetic code confers growth yield advantage

    PubMed Central

    Pezo, V.; Metzgar, D.; Hendrickson, T. L.; Waas, W. F.; Hazebrouck, S.; Döring, V.; Marlière, P.; Schimmel, P.; de Crécy-Lagard, V.

    2004-01-01

    A primitive genetic code is thought to have encoded statistical, ambiguous proteins in which more than one amino acid was inserted at a given codon. The relative vitality of organisms bearing ambiguous proteins and the kinds of pressures that forced development of the highly specific modern genetic code are unknown. Previous work demonstrated that, in the absence of selective pressure, enforced ambiguity in cells leads to death or to sequence reversion to eliminate the ambiguous phenotype. Here, we report the creation of a nonreverting strain of bacteria that produced statistical proteins. Ablating the editing activity of isoleucyl-tRNA synthetase resulted in an ambiguous code in which, through supplementation of a limited supply of isoleucine with an alternative amino acid that was noncoding, the mutant generating statistical proteins was favored over the wild-type isogenic strain. Such organisms harboring statistical proteins could have had an enhanced adaptive capacity and could have played an important role in the early development of living systems. PMID:15163798

  5. Ambiguity and context processing in human predictive learning.

    PubMed

    Callejas-Aguilera, José E; Rosas, Juan M

    2010-10-01

    Two experiments explored the role of ambiguity on context processing by using relative stimulus validity designs in human predictive learning. Two groups of participants were trained with 2 stimulus compounds (XY and XZ). In Group TD (true discrimination), compound XY was always followed by the outcome, whereas compound XZ was never followed by it. In Group PD (pseudodiscrimination) the presentation of each compound was followed by the outcome in half of the trials. Experiment 1 found that pseudodiscrimination facilitated context dependency of reliable predictors regardless of whether they were trained in the same context in which pseudodiscrimination took place or in an alternative context in which true discrimination was conducted. Experiment 2 found context dependency of reliable predictors trained and tested in PD contexts, suggesting that the ambiguity in the meaning of the cues produced by pseudodiscrimination training is at least partially responsible for the context switch effects found in ambiguous situations in human predictive learning.

  6. Role ambiguity in nursing: undergraduate students' struggle for direction.

    PubMed

    Gagan, Alex

    2002-06-01

    An experience common to many undergraduate nursing students, particularly whilst on placement in the clinical area, is a sense of aimlessness, lack of direction and standard role, and an overall ambiguity about what nursing is and does. Research in the nursing literature contributes to and supports the concept of the lack of clarity of the nursing role. Whilst the discourse of nursing is diverse and covers many aspects of nursing, a number of core issues may be seen to emerge. These contribute to form a concept that may be identified as the ambiguity of nursing. This paper identifies those issues and represents this concept of role ambiguity. These issues include the concept of caring and the apparent lack of clarity over what this actually is in a nursing context.

  7. 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.

  8. 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.

  9. Doppler centroid estimation ambiguity for synthetic aperture radars

    NASA Technical Reports Server (NTRS)

    Chang, C. Y.; Curlander, J. C.

    1989-01-01

    A technique for estimation of the Doppler centroid of an SAR in the presence of large uncertainty in antenna boresight pointing is described. Also investigated is the image degradation resulting from data processing that uses an ambiguous centroid. Two approaches for resolving ambiguities in Doppler centroid estimation (DCE) are presented: the range cross-correlation technique and the multiple-PRF (pulse repetition frequency) technique. Because other design factors control the PRF selection for SAR, a generalized algorithm is derived for PRFs not containing a common divisor. An example using the SIR-C parameters illustrates that this algorithm is capable of resolving the C-band DCE ambiguities for antenna pointing uncertainties of about 2-3 deg.

  10. Synthetic aperture radar range - Azimuth ambiguity design and constraints

    NASA Technical Reports Server (NTRS)

    Mehlis, J. G.

    1980-01-01

    Problems concerning the design of a system for mapping a planetary surface with a synthetic aperture radar (SAR) are considered. Given an ambiguity level, resolution, and swath width, the problems are related to the determination of optimum antenna apertures and the most suitable pulse repetition frequency (PRF). From the set of normalized azimuth ambiguity ratio curves, the designer can arrive at the azimuth antenna length, and from the sets of normalized range ambiguity ratio curves, he can arrive at the range aperture length or pulse repetition frequency. A procedure based on this design method is shown in an example. The normalized curves provide results for a SAR using a uniformly or cosine weighted rectangular antenna aperture.

  11. 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.

  12. Phase ambiguity resolution for offset QPSK modulation systems

    NASA Astrophysics Data System (ADS)

    Nguyen, Tien M.

    1991-06-01

    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.

  13. 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.

  14. Ambiguity of structure determination from a minimum of diffraction intensities.

    PubMed

    Al-Asadi, Ahmed; Leggas, Dimitri; Tsodikov, Oleg V

    2014-07-01

    Although the ambiguity of the crystal structures determined directly from diffraction intensities has been historically recognized, it is not well understood in quantitative terms. Bernstein's theorem has recently been used to obtain the number of one-dimensional crystal structures of equal point atoms, given a minimum set of diffraction intensities. By a similar approach, the number of two- and three-dimensional crystal structures that can be determined from a minimum intensity data set is estimated herein. The ambiguity of structure determination from the algebraic minimum of data increases at least exponentially fast with the increasing structure size. Substituting lower-resolution intensities by higher-resolution ones in the minimum data set has little or no effect on this ambiguity if the number of such substitutions is relatively small.

  15. Doppler centroid estimation ambiguity for synthetic aperture radars

    NASA Technical Reports Server (NTRS)

    Chang, C. Y.; Curlander, J. C.

    1989-01-01

    A technique for estimation of the Doppler centroid of an SAR in the presence of large uncertainty in antenna boresight pointing is described. Also investigated is the image degradation resulting from data processing that uses an ambiguous centroid. Two approaches for resolving ambiguities in Doppler centroid estimation (DCE) are presented: the range cross-correlation technique and the multiple-PRF (pulse repetition frequency) technique. Because other design factors control the PRF selection for SAR, a generalized algorithm is derived for PRFs not containing a common divisor. An example using the SIR-C parameters illustrates that this algorithm is capable of resolving the C-band DCE ambiguities for antenna pointing uncertainties of about 2-3 deg.

  16. Synthetic aperture radar range - Azimuth ambiguity design and constraints

    NASA Technical Reports Server (NTRS)

    Mehlis, J. G.

    1980-01-01

    Problems concerning the design of a system for mapping a planetary surface with a synthetic aperture radar (SAR) are considered. Given an ambiguity level, resolution, and swath width, the problems are related to the determination of optimum antenna apertures and the most suitable pulse repetition frequency (PRF). From the set of normalized azimuth ambiguity ratio curves, the designer can arrive at the azimuth antenna length, and from the sets of normalized range ambiguity ratio curves, he can arrive at the range aperture length or pulse repetition frequency. A procedure based on this design method is shown in an example. The normalized curves provide results for a SAR using a uniformly or cosine weighted rectangular antenna aperture.

  17. Range ambiguity resolution for high PRF pulse-Doppler radar

    NASA Astrophysics Data System (ADS)

    Postema, G. B.

    The range ambiguity resolution for high 'PRF pulse-Doppler radars can be resolved using a simple algorithm based on residue arithmetic. The unambiguous range is found from R = T + R(a), where T is the output of a look-up table and R(a) is one of the measured ambiguous ranges. This formula is easily extended to multiple PRF ranging systems, where three or more measurements are required for the ambiguity resolution. Target obscuration in clutter reduces the visibility and leads, especially in dense target environments, to ghost ranges. It is shown that long range coverage requires a small resolved pulse length and PRFs as low as practical in the intended clutter and target environment. Special attention is given to the generation of sparsely populated look-up tables that reduce the ghosting problem. A practical example for an S-band surveillance radar is presented.

  18. 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.

  19. On InSAR Ambiguity Resolution For Deformation Monitoring

    NASA Astrophysics Data System (ADS)

    Teunissen, P.

    2006-01-01

    Integer carrier phase ambiguity resolution is the key to fast and highprecision satellite positioning and navigation. It applies to a great variety of current and future models of GPS, modernized GPS and Galileo. It also applies to stacked radar interferometry for deformation monitoring, see e.g. [Hanssen, et al, 2001]. In this contribution we apply the integer least-squares' principle to the rank defect model of stacked InSAR carrier phase data. We discuss two ways of dealing with the rank defect for ambiguity resolution. One is based on the use of a priori data, the other is based on the use of an interval constraint on the deformation rate.

  20. 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.

  1. Objective scatterometer wind ambiguity removal using smoothness and dynamical constraints

    NASA Technical Reports Server (NTRS)

    Hoffman, R. N.

    1984-01-01

    In the present investigation, a variational analysis method (VAM) is used to remove the ambiguity of the Seasat-A Satellite Scatterometer (SASS) winds. At each SASS data point, two, three, or four wind vectors (termed ambiguities) are retrieved. It is pointed out that the VAM is basically a least squares method for fitting data. The problem may be nonlinear. The best fit to the data and constraints is obtained on the basis of a minimization of the objective function. The VAM was tested and tuned at 12 h GMT Sept. 10, 1978. Attention is given to a case study involving an intense cyclone centered south of Japan at 138 deg E.

  2. Improving integer ambiguity resolution for GLONASS precise orbit determination

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Ge, Maorong; Shi, Chuang; Lou, Yidong; Wickert, Jens; Schuh, Harald

    2016-08-01

    The frequency division multiple access adopted in present GLONASS introduces inter-frequency bias (IFB) at the receiver-end both in code and phase observables, which makes GLONASS ambiguity resolution rather difficult or even not available, especially for long baselines up to several thousand kilometers. This is one of the major reasons that GLONASS could hardly reach the orbit precision of GPS, both in terms of consistency among individual International GNSS Service (IGS) analysis centers and discontinuity at the overlapping day boundaries. Based on the fact that the GLONASS phase IFB is similar on L1 and L2 bands in unit of length and is a linear function of the frequency number, several approaches have been developed to estimate and calibrate the IFB for integer ambiguity resolution. However, they are only for short and medium baselines. In this study, a new ambiguity resolution approach is developed for GLONASS global networks. In the approach, the phase ambiguities in the ionosphere-free linear combination are directly transformed with a wavelength of about 5.3 cm, according to the special frequency relationship of GLONASS L1 and L2 signals. After such transformation, the phase IFB rate can be estimated and corrected precisely and then the corresponding double-differenced ambiguities can be directly fixed to integers even for baselines up to several thousand kilometers. To evaluate this approach, experimental validations using one-month data of a global network with 140 IGS stations was carried out for GLONASS precise orbit determination. The results show that the GLONASS double-difference ambiguity resolution for long baselines could be achieved with an average fixing-rate of 91.4 %. Applying the fixed ambiguities as constraints, the GLONASS orbit overlapping RMS at the day boundaries could be reduced by 37.2 % in ideal cases and with an averaged reduction of about 21.4 %, which is comparable with that by the GPS ambiguity resolution. The orbit improvement is

  3. 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…

  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. Ambiguity of Visual Design and Meaning in TV's "Battlestar Galactica."

    ERIC Educational Resources Information Center

    Roth, Lane

    "Battlestar Galactica," ABC-TV's prime-time science fiction series for 1978-79, illustrates how popular, mass media entertainment can communicate contradictory meanings that correlate with unresolved cultural tensions. The ambiguity of visual design is especially confusing because it is contrapuntal to the simplicity and clarity of the…

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

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  7. Sources of sentence constraint on lexical ambiguity resolution.

    PubMed

    Vu, H; Kellas, G; Paul, S T

    1998-09-01

    Results from a series of naming experiments demonstrated that major lexical categories of simple sentences can provide sources of constraint on the interpretation of ambiguous words (homonyms). Manipulation of verb (Experiment 1) or subject noun (Experiment 2) specificity produced contexts that were empirically rated as being strongly biased or ambiguous. Priming was demonstrated for target words related to both senses of a homonym following ambiguous sentences, but only contextually appropriate target words were primed following strongly biased dominant or subordinate sentences. Experiment 3 showed an increase in the magnitude of priming when multiple constraints on activation converged. Experiments 4 and 5 eliminated combinatorial intralexical priming as an alternative explanation. Instead, it was demonstrated that each constraint was influential only insofar as it contributed to the overall semantic representation of the sentence. When the multiple sources of constraint were retained but the sentence-level representation was changed (Experiment 4) or eliminated (Experiment 5), the results of Experiments 1, 2, and 3 and were not replicated. Experiment 6 examined the issue of homonym exposure duration by using an 80-msec stimulus onset asynchrony. The results replicated the previous experiments. The overall evidence indicates that a sentence context can be made strongly and immediately constraining by the inclusion of specific fillers for salient lexical categories. The results are discussed within a constraint-based, context-sensitive model of lexical ambiguity resolution.

  8. 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…

  9. 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 either…

  10. 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…

  11. 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…

  12. 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…

  13. Absence of Real Evidence against Competition during Syntactic Ambiguity Resolution

    ERIC Educational Resources Information Center

    Green, Matthew J.; Mitchell, Don C.

    2006-01-01

    Using evidence from eye-tracking studies, Van Gompel, Pickering, Pearson, and Liversedge (2005) have argued against currently implemented constraint-based models of syntactic ambiguity resolution. The case against these competition models is based on a mismatch between reported patterns of reading data and the putative predictions of the models.…

  14. 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…

  15. 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…

  16. 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…

  17. Computational Consequences of Agreement and Ambiguity in Natural Language

    DTIC Science & Technology

    1988-11-01

    qualities with preceding vowels ; this phenomenon occurs widely in such diverse languages as Finnish, Arabic, Hebrew , and the Australian language...relation to our NP-completeness result below in section 4. Computation, agreement, and ambiguity 5 suffix ending such as Ui forces agreement in vowel

  18. 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.

  19. 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…

  20. 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…

  1. Ambiguity, Accessibility, and a Division of Labor for Communicative Success

    PubMed Central

    Ferreira, Victor S.

    2009-01-01

    People talk to be understood, and so they should produce utterances that are easy for their listeners to understand. I begin this chapter by describing evidence showing that speakers rarely avoid sentences that are ambiguous, even though ambiguity is a factor that is well known to cause difficulty for listeners. Instead, speakers seem to choose utterances that are especially easy for them to say, specifically by producing more accessible, easy-to-think-of material sooner, and less accessible, harder-to-think-of material later. If speakers produce utterances that are easy to say but not utterances that are easy to understand, how is it that we understand each other? A third line of evidence shows that even when sentences are structurally ambiguous, they’re likely to include enough information for comprehenders to figure out what they mean. This suggests that speakers produce ambiguous utterances simply because they can -- because the grammar of their language will only let them produce utterances that are unambiguous enough to be understood most of the time anyway. And so, we understand each other because speakers produce utterances efficiently even if they’re not optimally understandable; addressees do what they need to to understand their speakers; and the grammar makes sure everything works out properly. PMID:19710948

  2. 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…

  3. Ambiguity Tolerance of Therapists and Process Changes of Their Clients

    ERIC Educational Resources Information Center

    Tucker, Robin C.; Snyder, William U.

    1974-01-01

    The study investigated the relationships between student-therapists' tolerance for ambiguity in visual perception tasks and (a)the positive affect displayed toward them by their clients, (b)measures of improvement in clients' self self-reference statements, and (c)measures of improvement in clients'"adjustment". (Author)

  4. Managing ambiguity in reference generation: the role of surface structure.

    PubMed

    Khan, Imtiaz H; van Deemter, Kees; Ritchie, Graeme

    2012-04-01

    This article explores the role of surface ambiguities in referring expressions, and how the risk of such ambiguities should be taken into account by an algorithm that generates referring expressions, if these expressions are to be optimally effective for a hearer. We focus on the ambiguities that arise when adjectives occur in coordinated structures. The central idea is to use statistical information about lexical co-occurrence to estimate which interpretation of a phrase is most likely for human readers, and to avoid generating phrases where misunderstandings are likely. Various aspects of the problem were explored in three experiments in which responses by human participants provided evidence about which reading was most likely for certain phrases, which phrases were deemed most suitable for particular referents, and the speed at which various phrases were read. We found a preference for ''clear'' expressions to ''unclear'' ones, but if several of the expressions are ''clear,'' then brief expressions are preferred over non-brief ones even though the brief ones are syntactically ambiguous and the non-brief ones are not; the notion of clarity was made precise using Kilgarriff's Word Sketches. We outline an implemented algorithm that generates noun phrases conforming to our hypotheses.

  5. 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…

  6. 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…

  7. 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. PsycINFO Database Record (c) 2013 APA, all rights reserved

  8. Intolerance of Ambiguity and Political Orientation among Israeli University Students.

    ERIC Educational Resources Information Center

    Fibert, Zigi; Ressler, William Harris

    1998-01-01

    Explores relations between political orientation and cognitive style among Israeli university students. Finds that intolerance of ambiguity contributed significantly to political orientation and that the political Left showed more complex cognitive styles than the Right. Notes implications for testing competing hypotheses about cognitive style and…

  9. Children's Interpretation of Ambiguous Focus in Sentences with "Only"

    ERIC Educational Resources Information Center

    Paterson, Kevin B.; Liversedge, Simon P.; White, Diane; Filik, Ruth; Jaz, Kristina

    2006-01-01

    We report 3 studies investigating children's and adults' interpretation of ambiguous focus in sentences containing the focus-sensitive quantifier only. In each experiment, child and adult participants compared sentences with only in a preverbal position and counterpart sentences without only against a series of pictures depicting events that…

  10. 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…

  11. Some Pragmatic Features of Lexical Ambiguity and Simple Riddles.

    ERIC Educational Resources Information Center

    Weiner, E. Judith; DePalma, Paul

    1993-01-01

    Describes a category of riddles based on lexical ambiguity and uses category theory to illustrate the function of the accessibility hierarchy in riddling. A discussion of riddles and parallelism (the tendency to stay on the same syntactic, semantic, pragmatic track while processing language) shows how parallelism partially accounts for how the…

  12. Role Ambiguity in Institutional Marketing and Enrollment Management.

    ERIC Educational Resources Information Center

    Muston, Ray A.

    1985-01-01

    Academic and student services officers from the largest 61 state university users of American College Testing (ACT) data systems were surveyed. The study revealed a high degree of role ambiguity and organizational resistance to enrollment management strategies. A need for clarity and coordination in organizational performance is demonstrated.…

  13. Children's Comprehension of Referential Communication: Decoding Ambiguous Messages.

    ERIC Educational Resources Information Center

    Bearison, David J.; Levey, Linda M.

    A sample of 90 children drawn from kindergarten, second grade, and fourth grade participated in a study of ability to decode ambiguous and unambiguous verbal messages. Subjects were read 12 message stems, each followed by a question pertaining to the contents of the stem. For half of the messages, the meaning of the questions was unambiguous; for…

  14. How do adults and children process referentially ambiguous pronouns?

    PubMed

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

    2004-02-01

    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 those in the sentence. For adults, behavioural data, responses and reaction times indicate that pronouns are referentially ambiguous. Adults' eye movements show a competition between the looks to sentence-internal and -external referents for pronouns, but not for reflexives. Children overwhelmingly prefer the sentence-internal referent in the off-line picture selection task. However, their eye movements reveal implicit awareness of referential ambiguity that develops earlier than their explicit knowledge in the picture selection task. This discrepancy between performance on a looking measure and a pointing measure in the children's processing system is explained by a general dissociation between implicit and explicit knowledge proposed in recent literature on cognitive development.

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

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  16. The Development of Preschoolers' Appreciation of Communicative Ambiguity

    ERIC Educational Resources Information Center

    Nilsen, Elizabeth S.; Graham, Susan A.

    2012-01-01

    Using a longitudinal design, preschoolers' appreciation of a listener's knowledge of the location of a hidden sticker after the listener was provided with an ambiguous or unambiguous description was assessed. Preschoolers (N = 34) were tested at 3 time points, each 6 months apart (4, 4 1/2, and 5 years). Eye gaze measures demonstrated that…

  17. Syntactic Structure Guides Prosody in Temporarily Ambiguous Sentences

    ERIC Educational Resources Information Center

    Anderson, Catherine; Carlson, Katy

    2010-01-01

    A pair of speaking and listening studies investigated the prosody of sentences with temporary Object/Clause and Late/Early Closure ambiguities. Speakers reliably produced prosodic cues that allowed listeners to disambiguate Late/Early Closure sentences, but only infrequently produced prosody that disambiguated Object/Clause sentences, as shown by…

  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. 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…

  1. Why Ambiguity Detection Is a Predictor of Early Reading Skill

    ERIC Educational Resources Information Center

    Wankoff, Lorain Szabo; Cairns, Helen Smith

    2009-01-01

    This study was designed to determine the contributions of metalinguistic skill and psycholinguistic processing ability to children's ability to detect the ambiguity of sentences and the relationship among all three factors to early reading ability. A total of 20 first graders and 20 second graders were given tasks testing the following abilities:…

  2. 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.

  3. 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…

  4. Persistence of Initial Misanalysis With No Referential Ambiguity.

    PubMed

    Nakamura, Chie; Arai, Manabu

    2016-05-01

    Previous research reported that in processing structurally ambiguous sentences comprehenders often preserve an initial incorrect analysis even after adopting a correct analysis following structural disambiguation. One criticism is that the sentences tested in previous studies involved referential ambiguity and allowed comprehenders to make inferences about the initial interpretation using pragmatic information, suggesting the possibility that the initial analysis persisted due to comprehenders' pragmatic inference but not to their failure to perform complete reanalysis of the initial misanalysis. Our study investigated this by testing locally ambiguous relative clause sentences in Japanese, in which the initial misinterpretation contradicts the correct interpretation. Our study using a self-paced reading technique demonstrated evidence for the persistence of the initial analysis with this structure. The results from an eye-tracking study further suggested that the phenomenon directly reflected the amount of support given to the initial incorrect analysis prior to disambiguating information: The more supported the incorrect main clause analysis was, the more likely comprehenders were to preserve the analysis even after the analysis was falsified. Our results thus demonstrated that the preservation of the initial analysis occurs not due to referential ambiguities but to comprehenders' difficulty to fully revise the highly supported initial interpretation.

  5. A note on the ambiguity of troposcatter aircraft interference patterns

    NASA Astrophysics Data System (ADS)

    Cook, C. E.; Hanlon, E. A.

    1980-09-01

    Earlier investigators of troposcatter propagation phenomena have suggested that aircraft-created interference patterns observed at the receiving site can be used to measure aircraft motion within and near the common volume region. A simplified signal and scattering model is used to show that these interference signatures are ambiguous unless prior knowledge of the aircraft trajectory is available.

  6. 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.

  7. Phrase Length and Prosody in On-Line Ambiguity Resolution

    ERIC Educational Resources Information Center

    Webman-Shafran, Ronit; Fodor, Janet Dean

    2016-01-01

    We investigated the processing of ambiguous double-PP constructions in Hebrew. Selection restrictions forced the first prepositional phrase (PP1) to attach low, but PP2 could attach maximally high to VP or maximally low to the NP inside PP1. A length contrast in PP2 was also examined. This construction affords more potential locations for prosodic…

  8. 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…

  9. The Development of Preschoolers' Appreciation of Communicative Ambiguity

    ERIC Educational Resources Information Center

    Nilsen, Elizabeth S.; Graham, Susan A.

    2012-01-01

    Using a longitudinal design, preschoolers' appreciation of a listener's knowledge of the location of a hidden sticker after the listener was provided with an ambiguous or unambiguous description was assessed. Preschoolers (N = 34) were tested at 3 time points, each 6 months apart (4, 4 1/2, and 5 years). Eye gaze measures demonstrated that…

  10. 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…

  11. Phrase Length and Prosody in On-Line Ambiguity Resolution

    ERIC Educational Resources Information Center

    Webman-Shafran, Ronit; Fodor, Janet Dean

    2016-01-01

    We investigated the processing of ambiguous double-PP constructions in Hebrew. Selection restrictions forced the first prepositional phrase (PP1) to attach low, but PP2 could attach maximally high to VP or maximally low to the NP inside PP1. A length contrast in PP2 was also examined. This construction affords more potential locations for prosodic…

  12. 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…

  13. Syntactic Structure Guides Prosody in Temporarily Ambiguous Sentences

    ERIC Educational Resources Information Center

    Anderson, Catherine; Carlson, Katy

    2010-01-01

    A pair of speaking and listening studies investigated the prosody of sentences with temporary Object/Clause and Late/Early Closure ambiguities. Speakers reliably produced prosodic cues that allowed listeners to disambiguate Late/Early Closure sentences, but only infrequently produced prosody that disambiguated Object/Clause sentences, as shown by…

  14. 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…

  15. Disclosing ambiguous gene aliases by automatic literature profiling.

    PubMed

    Coimbra, Roney S; Vanderwall, Dana E; Oliveira, Guilherme C

    2010-12-22

    Retrieving pertinent information from biological scientific literature requires cutting-edge text mining methods which may be able to recognize the meaning of the very ambiguous names of biological entities. Aliases of a gene share a common vocabulary in their respective collections of PubMed abstracts. This may be true even when these aliases are not associated with the same subset of documents. This gene-specific vocabulary defines a unique fingerprint that can be used to disclose ambiguous aliases. The present work describes an original method for automatically assessing the ambiguity levels of gene aliases in large gene terminologies based exclusively in the content of their associated literature. The method can deal with the two major problems restricting the usage of current text mining tools: 1) different names associated with the same gene; and 2) one name associated with multiple genes, or even with non-gene entities. Important, this method does not require training examples. Aliases were considered "ambiguous" when their Jaccard distance to the respective official gene symbol was equal or greater than the smallest distance between the official gene symbol and one of the three internal controls (randomly picked unrelated official gene symbols). Otherwise, they were assigned the status of "synonyms". We evaluated the coherence of the results by comparing the frequencies of the official gene symbols in the text corpora retrieved with their respective "synonyms" or "ambiguous" aliases. Official gene symbols were mentioned in the abstract collections of 42 % (70/165) of their respective synonyms. No official gene symbol occurred in the abstract collections of any of their respective ambiguous aliases. In overall, querying PubMed with official gene symbols and "synonym" aliases allowed a 3.6-fold increase in the number of unique documents retrieved. These results confirm that this method is able to distinguish between synonyms and ambiguous gene aliases based

  16. Using virtual reality for evaluation of fetal ambiguous genitalia.

    PubMed

    Verwoerd-Dikkeboom, C M; Koning, A H J; Groenenberg, I A L; Smit, B J; Brezinka, C; Van Der Spek, P J; Steegers, E A P

    2008-09-01

    The utility of a virtual reality system was examined in the visualization of three-dimensional (3D) ultrasound images of fetal ambiguous genitalia. In 2005, fetal ambiguous genitalia were diagnosed in four patients referred to our department for prenatal ultrasound assessment. The patients were examined by two-dimensional (2D) and 3D ultrasound and, subsequently, the volumes obtained on 3D ultrasound were visualized in the BARCO I-Space virtual reality system. This system projects stereoscopic images on three walls and the floor of a small 'room', allowing several viewers to see a 3D 'hologram' of the data being visualized. The results of 2D and 3D ultrasound examination and the virtual reality images of the I-Space were compared with diagnoses made postpartum. In all cases, prenatal diagnosis was unclear based on 2D ultrasound alone. Surface rendering of 3D data provided an impression of ambiguity, but diagnosis based on these data proved incorrect at birth in three cases. Conclusions based on the evaluation of 3D volumes in virtual reality best fitted the postpartum diagnosis in all cases. This study suggests that by evaluation of the genitals in the I-Space, a better impression of genital ambiguity can be established. Binocular depth perception appeared particularly useful in distinguishing either a micropenis or enlarged clitoris from labia minora, since it helps in the estimation of size and position. Therefore, we see potential for the application of virtual reality not only for the evaluation of fetal ambiguous genitalia, but in all those cases where depth perception would improve the visualization of anatomical structures.

  17. Biological nomenclatures: a source of lexical knowledge and ambiguity.

    PubMed

    Tuason, O; Chen, L; Liu, H; Blake, J A; Friedman, C

    2004-01-01

    There has been increased work in developing automated systems that involve natural language processing (NLP) to recognize and extract genomic information from the literature. Recognition and identification of biological entities is a critical step in this process. NLP systems generally rely on nomenclatures and ontological specifications as resources for determining the names of the entities, assigning semantic categories that are consistent with the corresponding ontology, and assignment of identifiers that map to well-defined entities within a particular nomenclature. Although nomenclatures and ontologies are valuable for text processing systems, they were developed to aid researchers and are heterogeneous in structure and semantics. A uniform resource that is automatically generated from diverse resources, and that is designed for NLP purposes would be a useful tool for the field, and would further database interoperability. This paper presents work towards this goal. We have automatically created lexical resources from four model organism nomenclature systems (mouse, fly, worm, and yeast), and have studied performance of the resources within an existing NLP system, GENIES. Using nomenclatures is not straightforward because issues concerning ambiguity, synonymy, and name variations are quite challenging. In this paper we focus mainly on ambiguity. We determined that the number of ambiguous gene names within the individual nomenclatures, across the four nomenclatures, and with general English ranged from 0%-10.18%, 1.187%-20.30%, and 0%-2.49% respectively. When actually processing text, we found the rate of ambiguous occurrences (not counting ambiguities stemming from English words) to range from 2.4%-32.9% depending on the organisms considered.

  18. Improved PPP ambiguity resolution by COES FCB estimation

    NASA Astrophysics Data System (ADS)

    Li, Yihe; Gao, Yang; Shi, Junbo

    2016-05-01

    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.

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

    PubMed

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

    2015-10-01

    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.

  20. An Example and Analysis for Ambiguity Resolution in the Indoor ZigBee Positioning System

    NASA Astrophysics Data System (ADS)

    Janicka, Joanna; Rapinski, Jacek

    2017-06-01

    This paper presents ambiguity resolution in the range-based ZigBee positioning system. The system is using the phase shift measurements to determine the distances between user and anchors. In this paper, the ambiguity is defined as the number of full reps of a certain distance added to the measurement result. The way of resolving ambiguities in the positioning system is described and an experiment results are presented. Featured algorithm is successful in finding ambiguities and correct location of the user.

  1. Rapid PPP ambiguity resolution using GPS+GLONASS observations

    NASA Astrophysics Data System (ADS)

    Liu, Yanyan; Ye, Shirong; Song, Weiwei; Lou, Yidong; Gu, Shengfeng

    2017-04-01

    Integer ambiguity resolution (IAR) in precise point positioning (PPP) using GPS observations has been well studied. The main challenge remaining is that the first ambiguity fixing takes about 30 min. This paper presents improvements made using GPS+GLONASS observations, especially improvements in the initial fixing time and correct fixing rate compared with GPS-only solutions. As a result of the frequency division multiple access strategy of GLONASS, there are two obstacles to GLONASS PPP-IAR: first and most importantly, there is distinct code inter-frequency bias (IFB) between satellites, and second, simultaneously observed satellites have different wavelengths. To overcome the problem resulting from GLONASS code IFB, we used a network of homogeneous receivers for GLONASS wide-lane fractional cycle bias (FCB) estimation and wide-lane ambiguity resolution. The integer satellite clock of the GPS and GLONASS was then estimated with the wide-lane FCB products. The effect of the different wavelengths on FCB estimation and PPP-IAR is discussed in detail. We used a 21-day data set of 67 stations, where data from 26 stations were processed to generate satellite wide-lane FCBs and integer clocks and the other 41 stations were selected as users to perform PPP-IAR. We found that GLONASS FCB estimates are qualitatively similar to GPS FCB estimates. Generally, 98.8% of a posteriori residuals of wide-lane ambiguities are within ± 0.25 cycles for GPS, and 96.6% for GLONASS. Meanwhile, 94.5 and 94.4% of narrow-lane residuals are within 0.1 cycles for GPS and GLONASS, respectively. For a critical value of 2.0, the correct fixing rate for kinematic PPP is only 75.2% for GPS alone and as large as 98.8% for GPS+GLONASS. The fixing percentage for GPS alone is only 11.70 and 46.80% within 5 and 10 min, respectively, and improves to 73.71 and 95.83% when adding GLONASS. Adding GLONASS thus improves the fixing percentage significantly for a short time span. We also used global ionosphere

  2. Rapid PPP ambiguity resolution using GPS+GLONASS observations

    NASA Astrophysics Data System (ADS)

    Liu, Yanyan; Ye, Shirong; Song, Weiwei; Lou, Yidong; Gu, Shengfeng

    2017-01-01

    Integer ambiguity resolution (IAR) in precise point positioning (PPP) using GPS observations has been well studied. The main challenge remaining is that the first ambiguity fixing takes about 30 min. This paper presents improvements made using GPS+GLONASS observations, especially improvements in the initial fixing time and correct fixing rate compared with GPS-only solutions. As a result of the frequency division multiple access strategy of GLONASS, there are two obstacles to GLONASS PPP-IAR: first and most importantly, there is distinct code inter-frequency bias (IFB) between satellites, and second, simultaneously observed satellites have different wavelengths. To overcome the problem resulting from GLONASS code IFB, we used a network of homogeneous receivers for GLONASS wide-lane fractional cycle bias (FCB) estimation and wide-lane ambiguity resolution. The integer satellite clock of the GPS and GLONASS was then estimated with the wide-lane FCB products. The effect of the different wavelengths on FCB estimation and PPP-IAR is discussed in detail. We used a 21-day data set of 67 stations, where data from 26 stations were processed to generate satellite wide-lane FCBs and integer clocks and the other 41 stations were selected as users to perform PPP-IAR. We found that GLONASS FCB estimates are qualitatively similar to GPS FCB estimates. Generally, 98.8% of a posteriori residuals of wide-lane ambiguities are within ± 0.25 cycles for GPS, and 96.6% for GLONASS. Meanwhile, 94.5 and 94.4% of narrow-lane residuals are within 0.1 cycles for GPS and GLONASS, respectively. For a critical value of 2.0, the correct fixing rate for kinematic PPP is only 75.2% for GPS alone and as large as 98.8% for GPS+GLONASS. The fixing percentage for GPS alone is only 11.70 and 46.80% within 5 and 10 min, respectively, and improves to 73.71 and 95.83% when adding GLONASS. Adding GLONASS thus improves the fixing percentage significantly for a short time span. We also used global ionosphere

  3. 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…

  4. 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,…

  5. 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,…

  6. Identification and Definition of Lexically Ambiguous Words in Statistics by Tutors and Students

    ERIC Educational Resources Information Center

    Richardson, Alice M.; Dunn, Peter K.; Hutchins, Rene

    2013-01-01

    Lexical ambiguity arises when a word from everyday English is used differently in a particular discipline, such as statistics. This paper reports on a project that begins by identifying tutors' perceptions of words that are potentially lexically ambiguous to students, in two different ways. Students' definitions of nine lexically ambiguous words…

  7. 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.

  8. 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…

  9. Instructor Strategic Ambiguity: Delineation of the Construct and Development of a Measure

    ERIC Educational Resources Information Center

    Klyukovski, Andrei A.; Medlock-Klyukovski, Amanda L.

    2016-01-01

    This article presents research to delineate the construct of instructor strategic ambiguity (ISA) and develop a measure. The first study analyzed instructor uses of ambiguity, identified 18 strategies, and classified them into four categories. The second study developed an Instructor Strategic Ambiguity Measure (ISAM) for the college classroom.…

  10. Performance management and goal ambiguity: managerial implications in a single payer system.

    PubMed

    Calciolari, Stefano; Cantù, Elena; Fattore, Giovanni

    2011-01-01

    Goal ambiguity influences the effectiveness of performance management systems to drive organizations toward enhanced results. The literature analyzes the antecedents of goal ambiguity and shows the influence of goal ambiguity on the performance of U.S. federal agencies. However, no study has analyzed goal ambiguity in other countries or in health care systems. This study has three aims: to test the validity of a measurement instrument for goal ambiguity, to investigate its main antecedents, and to explore the relationship between goal ambiguity and organizational performance in a large, public, Beveridge-type health care system. A nationwide survey of general managers of the Italian national health system was performed. A factor analysis was used to validate the mono-dimensionality of an instrument that measured goal ambiguity. Structural equation modeling was used to test both the antecedents and the influence of goal ambiguity on organizational performance. Data from 135 health care organizations (53% response rate) were available for analysis. The results confirm the mono-dimensionality of the instrument, the existence of two environmental sources of ambiguity (political endorsement and governance commitment), and the negative relationship between goal ambiguity and organizational performance. Goal ambiguity matters because it may hamper organizational performance. Therefore, performance should be fostered by reducing goal ambiguity (e.g., goal-setting model, funding arrangements, and political support). Mutatis mutandis, our results may apply to public health care systems of other countries or other "public interest" sectors, such as social care and education.

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

    PubMed

    Le Sourn-Bissaoui, Sandrine; Caillies, Stéphanie; Bernard, Stéphane; Deleau, Michel; Brulé, 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.

  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. The ambiguity of simplicity in quantum and classical simulation

    NASA Astrophysics Data System (ADS)

    Aghamohammadi, Cina; Mahoney, John R.; Crutchfield, James P.

    2017-04-01

    A system's perceived simplicity depends on whether it is represented classically or quantally. This is not so surprising, as classical and quantum physics are descriptive frameworks built on different assumptions that capture, emphasize, and express different properties and mechanisms. What is surprising is that, as we demonstrate, simplicity is ambiguous: the relative simplicity between two systems can change sign when moving between classical and quantum descriptions. Here, we associate simplicity with small model-memory. We see that the notions of absolute physical simplicity at best form a partial, not a total, order. This suggests that appeals to principles of physical simplicity, via Ockham's Razor or to the ;elegance; of competing theories, may be fundamentally subjective. Recent rapid progress in quantum computation and quantum simulation suggest that the ambiguity of simplicity will strongly impact statistical inference and, in particular, model selection.

  14. Ambiguity of care in the experience of drug consumers.

    PubMed

    Sena, Edite Lago da Silva; Araújo, Mitze Lopes; Ribeiro, Bárbara Santos; Santos, Vanessa Thamyris Carvalho Dos; Malhado, Sâmia de Carliris Barbosa; Soares, Carine de Jesus; Carvalho, Patrícia Anjos Lima de

    2017-07-20

    To understand the perception of users of a Psychosocial Care Center about care in the context of drug use. Study based on the Phenomenology of Maurice Merleau-Ponty, developed in the Center for Psychosocial Care Alcohol and Other Drugs. The data has been submitted to the Analytical Technique of Ambiguity. The drug use sometimes provides the consumer with pleasurable feelings, sometimes contributing to the occurrence of biopsychosocial harm and/or new possibilities for relationship with the drug. The drug use is an ambiguous process, which corresponds to the perception of different care profiles in the relationship between the consumer and the drug. It is up to the health professionals to recognize the diverse possibilities of care and to favor the construction of therapeutic projects based on listening and respecting the needs of drug users.

  15. Covariant gauges without Gribov ambiguities in Yang-Mills theories

    NASA Astrophysics Data System (ADS)

    Serreau, J.; Tissier, M.; Tresmontant, A.

    2014-06-01

    We propose a one-parameter family of nonlinear covariant gauges which can be formulated as an extremization procedure that may be amenable to lattice implementation. At high energies, where the Gribov ambiguities can be ignored, this reduces to the Curci-Ferrari-Delbourgo-Jarvis gauges. We further propose a continuum formulation in terms of a local action which is free of Gribov ambiguities and avoids the Neuberger zero problem of the standard Faddeev-Popov construction. This involves an averaging over Gribov copies with a nonuniform weight, which introduces a new gauge-fixing parameter. We show that the proposed gauge-fixed action is perturbatively renormalizable in four dimensions and we provide explicit expressions of the renormalization factors at one loop. We discuss the possible implications of the present proposal for the calculation of Yang-Mills correlators.

  16. Imageability and ambiguity effects in speeded naming: convergence and divergence.

    PubMed

    Woollams, Anna M

    2005-09-01

    A current area of controversy within the literature on visual word recognition concerns the extent to which semantic information influences the computation of phonology. Experiment 1 revealed that both the imageability effect and the ambiguity advantage seen in the speeded naming task are confined to words with atypical mappings between spelling and sound. Nonetheless, it is possible that either of these effects may arise from the operation of the direct rather than the semantic pathway. Experiment 2 therefore included nonword fillers in order to minimize semantic reliance during speeded naming. This manipulation removed the imageability effect, indicating a semantic locus, but the ambiguity advantage remained, suggesting a nonsemantic locus. These results are considered in the context of computational models that incorporate a semantic level of representation.

  17. On InSAR ambiguity resolution for deformation monitoring

    NASA Astrophysics Data System (ADS)

    Teunissen, P. J. T.

    Integer carrier phase ambiguity resolution is the key to fast and high-precision satellite positioning and navigation. It applies to a great variety of current and future models of GPS, modernized GPS and Galileo. It also applies to stacked radar interferometry for deformation monitoring, see e.g. [Hanssen, et al., 2001]. In this contribution we apply the integer least-squares' principle to the rank defect model of stacked InSAR carrier phase data. We discuss two ways of dealing with the rank defect for ambiguity resolution. One is based on the use of a priori data, the other is based on the use of an interval constraint on the deformation rate.

  18. Biased Interpretation of Ambiguous Social Scenarios in Anorexia Nervosa.

    PubMed

    Cardi, Valentina; Turton, Robert; Schifano, Sylvia; Leppanen, Jenni; Hirsch, Colette R; Treasure, Janet

    2017-01-01

    Patients with anorexia nervosa experience increased sensitivity to the risk of social rejection. The aims of this study were to assess the interpretation of ambiguous social scenarios depicting the risk of rejection and to examine the relationship between interpretation biases and clinical symptoms. Thirty-five women with anorexia nervosa and 30 healthy eaters completed clinical questionnaires, alongside a sentence completion task. This task required participants to generate completions to ambiguous social scenarios and to endorse their best completion. Responses were rated as being negative, neutral or positive. Patients endorsed more negative interpretations and fewer neutral and positive interpretations compared with healthy eaters. The frequency of endorsed negative interpretations correlated with depression, anxiety and fear of weight gain and body disturbance. A negative interpretation bias towards social stimuli is present in women with anorexia nervosa and correlates with clinical symptoms. Interventions aimed at reducing this bias could improve illness prognosis. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

  19. Interpretation bias in responses to ambiguous cues in pain patients.

    PubMed

    Pincus, T; Pearce, S; McClelland, A; Farley, S; Vogel, S

    1994-05-01

    Pain patients and control subjects responses to ambiguous cues were compared in two separate investigations. In the first, pain patients, control subjects and physiotherapists were asked to produce a list of spontaneous associations to ambiguous cues (such as terminal and growth). To control for mood effects the experiment was repeated with three more groups: Pain patients, osteopaths and a control group. Measures of anxiety and depression were incorporated in the analysis. Results indicate that pain patients systematically produce more pain related associations than the other groups, and that this effect is independent of anxiety and depression levels. The discussion concentrates on the implications of these findings both for the theory of pain processing and for clinical interventions.

  20. Punctuated equilibrium based on a locally ambiguous niche.

    PubMed

    Gunji, Yukio-Pegio; Sakiyama, Tomoko; Murakami, Hisashi

    2014-09-01

    Punctuated equilibrium, recently regarded as the power law distribution of lifespan, is estimated with respect to self-organized criticality. Previous explanations were based on a global property, such as the selection of species depending on their fitness, however a particular entity defined through such global property cannot be relevant to the notion of "self". Here, we introduce local ambiguity of a niche with respect to function and define a function network by using two types of maps. Due to the local complex structure of the function network, motif and lateral connections, some species are easily replaced by others, and other species have long lives. Punctuated equilibrium can, therefore, be explained by local ambiguous interaction, which suggests the notion of self and supports the idea of self-organized criticality.

  1. Learning and Generalization under Ambiguity: An fMRI Study

    PubMed Central

    Chumbley, J. R.; Flandin, G.; Bach, D. R.; Daunizeau, J.; Fehr, E.; Dolan, R. J.; Friston, K. J.

    2012-01-01

    Adaptive behavior often exploits generalizations from past experience by applying them judiciously in new situations. This requires a means of quantifying the relative importance of prior experience and current information, so they can be balanced optimally. In this study, we ask whether the brain generalizes in an optimal way. Specifically, we used Bayesian learning theory and fMRI to test whether neuronal responses reflect context-sensitive changes in ambiguity or uncertainty about experience-dependent beliefs. We found that the hippocampus expresses clear ambiguity-dependent responses that are associated with an augmented rate of learning. These findings suggest candidate neuronal systems that may be involved in aberrations of generalization, such as over-confidence. PMID:22275857

  2. Decoding of depth and motion in ambiguous binocular perception.

    PubMed

    Sakai, Ko; Ogiya, Mitsuharu; Hirai, Yuzo

    2011-07-01

    We have shown previously that random dots with an interocular time delay (ITD), the time difference of the onset of dots between the two eyes, yield both apparent depth and motion, although depth and velocity are covariant and, thus, ITD is inherently ambiguous. The depth of random dots with ITD was proportional to ITD, suggesting that the visual system assumes a constant velocity of the dots and determines depth on the basis of this constant velocity. We performed psychophysical experiments to investigate whether subjects perceive a constant velocity with a variety of ITDs in random dots aligned along a single vertical line that ensures neither apparent motion nor accidental disparity between the dots. The results showed that subjects perceive a constant velocity for a variety of ITDs with simultaneous perception of depth in proportion to ITD, indicating the priority of depth over velocity in ambiguous binocular perception derived from ITD. © 2011 Optical Society of America

  3. Ambiguity in Ensemble Forecasting: Evolution, Estimate Validation and Value

    DTIC Science & Technology

    2009-09-01

    I labored through my research and writing this dissertation. First, I could not have accomplished this daunting achievement without the love and...practical approach to estimating ambiguity. The explanation of the practical methods follows that given in Eckel and Allen (2009) for ease of writing ...representation of model uncertainties in the ECMWF Ensemble Prediction System. Quart. J. Roy. Meteor. Soc., 125, 2887–2907. Burgers, G., P. Jan van Leeuwen

  4. Neural correlates of semantic ambiguity processing during context verification.

    PubMed

    Hoenig, Klaus; Scheef, Lukas

    2009-04-15

    Understanding the relevant meaning of a word with different meanings (homonym) in a given context requires activation of the neural representations of the relevant meaning and inhibition of the irrelevant meaning. The cognitive demand of such disambiguation is highest when the dominant, yet contextually irrelevant meaning of a polar homonym must be suppressed. This central process (semantic inhibition) for lexico-semantic ambiguity resolution was monitored with fMRI during semantic context verifications. Twenty-two healthy volunteers decided whether congruent or incongruent target words fitted into the contexts established by preceding sentences. Half of the sentences ended with a homonym, thereby allowing to cross the factors ambiguity and semantic congruency. BOLD increases related to the inhibitory attentional control over non-selected meanings during ambiguity processing occurred in a brain network including left dorsolateral prefrontal cortex (DLPFC), bilateral angular gyrus (AG), bilateral anterior superior temporal gyrus (aSTG) as well as right ventromedial temporal lobe. In left DLPFC (BA 46/9) and left AG (BA 39) BOLD activity to target words of the incongruent-ambiguous condition correlated with the individual amount of semantic interference experienced by the subjects. BOLD increases of incongruent versus congruent semantic verifications occurred in bilateral inferior frontal gyrus. The results of the present study suggest a specific role of left DLPFC and AG in the resolution of semantic interference from contextually inappropriate homonym meanings. These fronto-parietal areas might exert inhibitory control over temporal regions in service of attentional selection between relevant and irrelevant homonym meanings, by creating a sufficient activation difference between their respective representations.

  5. Ambiguities: residents' experience of 'nursing home as my home'.

    PubMed

    Nakrem, Sigrid; Vinsnes, Anne G; Harkless, Gene E; Paulsen, Bård; Seim, Arnfinn

    2013-09-01

    Residential care in nursing homes continues to be necessary for those individuals who are no longer able to live at home. Uncovering what nursing home residents' view as quality of care in nursing homes will help further understanding of how best to provide high quality, person-centred care. To describe residents' experiences of living in a nursing home related to quality of care. The study utilises a descriptive exploratory design. In-depth interviews were undertaken with 15 residents who were not cognitively impaired, aged 65 and over and living in one of four nursing homes. The interviews were transcribed verbatim and analysed by categorising of meaning. Residents perceived the nursing home as their home, but at the same time not 'a home'. This essential ambiguity created the tension from which the categories of perceptions of quality emerged. Four main categories of quality of care experience were identified: 'Being at home in a nursing home', 'Paying the price for 24-hour care', 'Personal habits and institutional routines', and 'Meaningful activities for a meaningful day'. Ambiguities concerning the nursing home as a home and place to live, a social environment in which the residents experience most of their social life and the institution where professional health service is provided were uncovered. High-quality care was when ambiguities were managed well and a home could be created within the institution. Implication for practice. Achieving quality care in nursing homes requires reconciling the ambiguities of the nursing home as a home. This implies helping residents to create a private home distinct from the professional home, allowing residents' personal habits to guide institutional routines and supporting meaningful activities. Using these resident developed quality indicators is an important step in improving nursing home services. © 2012 Blackwell Publishing Ltd.

  6. Decision making and ambiguity in auditory stream segregation.

    PubMed

    Deike, Susann; Heil, Peter; Böckmann-Barthel, Martin; Brechmann, André

    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 (ΔF). Sequences with seven different ΔF were tested. We found that the initial decision time varied non-monotonically with ΔF 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.

  7. Decision making and ambiguity in auditory stream segregation

    PubMed Central

    Deike, Susann; Heil, Peter; Böckmann-Barthel, Martin; Brechmann, André

    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 (ΔF). Sequences with seven different ΔF were tested. We found that the initial decision time varied non-monotonically with ΔF 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

  8. Infants' Use of Shared Linguistic Information to Clarify Ambiguous Requests

    ERIC Educational Resources Information Center

    Ganea, Patricia A.; Saylor, Megan M.

    2007-01-01

    Do infants use past linguistic information to interpret an ambiguous request for an object? When infants in this research were shown 2 objects, and asked for 1 with an indefinite request (e.g., "Can you get it for me?"), both 15- and 18-month-olds used the speaker's previous reference to an absent object to interpret the request. The 18-month-olds…

  9. Resolution of ambiguous radar measurements using a floating bin correlator

    NASA Astrophysics Data System (ADS)

    Addison, E. R.; Frost, E. L.

    It is pointed out that the Chinese Remainder Theorem (Mooney and Skillman, 1970) can be used to yield unambiguous measurements by comparing outputs allocated to fixed integer number bins using integer arithmetic to modulo to the correct bin number. In general, targets straddling two or more bins or the assignment of an incorrect bin number will yield incorrect parameter values. An ambiguity resolution technique using multiple pulse repetition frequency (PRF) data and a sliding floating point window or 'floating bin' to correlate ambiguous centroided Doppler measurements is proposed. An advantage of the technique is that false targets are much less prevalent than in classical techniques. What is more, the same technique may be employed to resolve ambiguous range wherein centroided range measurements are moduloed with the pulse repetition interval associated with each PRF. Results demonstrate that this method is better than conventional approaches in that the number of false targets produced is significantly lower while simultaneoulsy providing a high probability of correlation. In addition, the correlation can be effected in real time.

  10. Ambiguity and variability of database and software names in bioinformatics.

    PubMed

    Duck, Geraint; Kovacevic, Aleksandar; Robertson, David L; Stevens, Robert; Nenadic, Goran

    2015-01-01

    There are numerous options available to achieve various tasks in bioinformatics, but until recently, there were no tools that could systematically identify mentions of databases and tools within the literature. In this paper we explore the variability and ambiguity of database and software name mentions and compare dictionary and machine learning approaches to their identification. Through the development and analysis of a corpus of 60 full-text documents manually annotated at the mention level, we report high variability and ambiguity in database and software mentions. On a test set of 25 full-text documents, a baseline dictionary look-up achieved an F-score of 46 %, highlighting not only variability and ambiguity but also the extensive number of new resources introduced. A machine learning approach achieved an F-score of 63 % (with precision of 74 %) and 70 % (with precision of 83 %) for strict and lenient matching respectively. We characterise the issues with various mention types and propose potential ways of capturing additional database and software mentions in the literature. Our analyses show that identification of mentions of databases and tools is a challenging task that cannot be achieved by relying on current manually-curated resource repositories. Although machine learning shows improvement and promise (primarily in precision), more contextual information needs to be taken into account to achieve a good degree of accuracy.

  11. 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.

  12. Data compression for complex ambiguity function for emitter location

    NASA Astrophysics Data System (ADS)

    Pourhomayoun, Mohammed; Fowler, Mark L.

    2010-08-01

    The Complex Ambiguity Function (CAF) used in emitter location measurement is a 2-dimensional complex-valued function of time-difference-of-arrival (TDOA) and frequency-difference-of-arrival (FDOA). In classical TDOA/FDOA systems, pairs of sensors share data (using compression) to compute the CAF, which is then used to estimate the TDOA/FDOA for each pair; the sets of TDOA/FDOA measurements are then transmitted to a common site where they are fused into an emitter location. However, in some recently published methods for improved emitter location methods, it has been proposed that after each pair of sensors computes the CAF it is the entire CAFs that should be shared rather than the extracted TDOA/FDOA estimates. This leads to a need for methods to compress the CAFs. Because a CAF is a 2-D functions it can be thought of as a form of image - albeit, a complex-valued image. We apply and appropriately modify the Embedded Zerotree Wavelet (EZW) to compress the Ambiguity Function. Several techniques are analyzed to exploit the correlation between the imaginary part and real part of Ambiguity Function and comparisons are made between the approaches. The impact of such compression on the overall location accuracy is assessed via simulations.

  13. Teaching weight to explicitly address language ambiguities and conceptual difficulties

    NASA Astrophysics Data System (ADS)

    Taibu, Rex; Schuster, David; Rudge, David

    2017-06-01

    Language ambiguities in concept meanings can exacerbate student learning difficulties and conceptual understanding of physics concepts. This is especially true for the concept of "weight," which has multiple meanings in both scientific and everyday usage. The term weight has been defined in several different ways, with nuances, but in textbooks and teaching the term is almost always defined in one of two ways: operationally either as the contact force between an object and a measuring scale or as the gravitational force on an object due to some other body such as Earth. The use of the same name for different concepts leads to much confusion, especially in accelerating situations, and to conflicting notions of "weightlessness" in free fall situations. In the present paper, we share an innovative approach that initially avoids the term weight entirely while teaching the physics of each situation, and then teaches the language ambiguities explicitly. We developed an instructional module with this approach and implemented it over two terms in three sections of an introductory physics course for preservice elementary teachers. Learning gains for content understanding were assessed using pretests and post-tests. Participants achieved remarkably high gains for both static and accelerating situations. Surveys pre- and postinstruction showed substantially improved appreciation of language issues and ambiguities associated with weight, weightlessness, and free fall. Interviews with instructors teaching the module provided additional insight into the advantages and teaching demands of the new approach.

  14. REDUCING AMBIGUITY IN THE FUNCTIONAL ASSESSMENT OF PROBLEM BEHAVIOR.

    PubMed

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

    2015-02-01

    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.

  15. 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

  16. Acute stress affects risk taking but not ambiguity aversion.

    PubMed

    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.

  17. 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

  18. Tolerance of ambiguity: text analytic vs self-report measures in two nonclinical groups.

    PubMed

    Leichsenring, Falk; Steuernagel, Elke; Steuernagel, Jens; Meyer, H A

    2007-06-01

    Avoidance of ambiguity can be examined by both text analytic and self-report methods. In previous studies using text analytic methods, clinical groups showed a higher avoidance of ambiguity than nonclinical subjects. In nonclinical subjects, however, higher avoidance of ambiguity did not correlate with emotional processes. In these studies, higher avoidance of ambiguity was assessed by a text analytic method (DoTA), which was applied to the Holtzman Inkblot Technique. However, the Inkblot Technique may not activate those cognitive-affective structures in nonclinical subjects required to elicit higher avoidance of ambiguity. Thus, the following discrepant results can be predicted: in nonclinical subjects, DoTA indicators of higher avoidance of ambiguity based on Holtzman Inkblot Technique do not show correlations with self-report measures of higher avoidance of ambiguity such as the Ambiguity Tolerance Questionnaire, the Inventory for the Measurement of Tolerance of Ambiguity (Reis inventory), or self-report measures of related traits of personality such as the Giessen Test. Self-report measures of higher avoidance of ambiguity should show such correlations. Two studies were carried out to test these hypotheses. In Study 1, 80 nonclinical subjects (48 women, M age = 34.5 yr.) were examined using the DoTA text analytic method, the Ambiguity Tolerance Questionnaire-14 and the Giessen Test. In Study 2, 82 nonclinical subjects (43 women, M age = 34.0 yr.) were tested using the Reis inventory. The results obtained in these subjects are consistent with the hypothe-

  19. A method of undifferenced ambiguity resolution for GPS+GLONASS precise point positioning.

    PubMed

    Yi, Wenting; Song, Weiwei; Lou, Yidong; Shi, Chuang; Yao, Yibin

    2016-05-25

    Integer ambiguity resolution is critical for achieving positions of high precision and for shortening the convergence time of precise point positioning (PPP). However, GLONASS adopts the signal processing technology of frequency division multiple access and results in inter-frequency code biases (IFCBs), which are currently difficult to correct. This bias makes the methods proposed for GPS ambiguity fixing unsuitable for GLONASS. To realize undifferenced GLONASS ambiguity fixing, we propose an undifferenced ambiguity resolution method for GPS+GLONASS PPP, which considers the IFCBs estimation. The experimental result demonstrates that the success rate of GLONASS ambiguity fixing can reach 75% through the proposed method. Compared with the ambiguity float solutions, the positioning accuracies of ambiguity-fixed solutions of GLONASS-only PPP are increased by 12.2%, 20.9%, and 10.3%, and that of the GPS+GLONASS PPP by 13.0%, 35.2%, and 14.1% in the North, East and Up directions, respectively.

  20. Development of a New Scale to Measure Ambiguity Tolerance in Veterinary Students.

    PubMed

    Hammond, Jennifer A; Hancock, Jason; Martin, Margaret S; Jamieson, Susan; Mellor, Dominic J

    The ability to cope with ambiguity and feelings of uncertainty is an essential part of professional practice. Research with physicians has identified that intolerance of ambiguity or uncertainty is linked to stress, and some authors have hypothesized that there could be an association between intolerance of ambiguity and burnout. We describe the adaptation of the TAMSAD (Tolerance of Ambiguity in Medical Students and Doctors) scale for use with veterinary students. Exploratory factor analysis supports a uni-dimensional structure for the Ambiguity tolerance construct. Although internal reliability of the 29-item TAMSAD scale is reasonable (α=.50), an alternative 27-item scale (drawn from the original 41 items used to develop TAMSAD) shows higher internal reliability for veterinary students (α=.67). We conclude that there is good evidence to support the validity of this latter TAVS (Tolerance of Ambiguity in Veterinary Students) scale to study ambiguity tolerance in veterinary students.

  1. Children's use of phonological information in ambiguity resolution: a view from Mandarin Chinese.

    PubMed

    Zhou, Peng; Su, Yi Esther; Crain, Stephen; Gao, Liqun; Zhan, Likan

    2012-09-01

    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 1 used eye-tracking to assess children's use of stress in resolving structural ambiguities. Experiment 2 took advantage of special properties of Mandarin to investigate whether children can use intonational cues to resolve ambiguities involving speech acts. The results of our experiments show that children's use of prosodic information in ambiguity resolution varies depending on the type of ambiguity involved. Children can use prosodic information more effectively to resolve speech act ambiguities than to resolve structural ambiguities. This finding suggests that the mapping between prosody and semantics/pragmatics in young children is better established than the mapping between prosody and syntax.

  2. A method of undifferenced ambiguity resolution for GPS+GLONASS precise point positioning

    NASA Astrophysics Data System (ADS)

    Yi, Wenting; Song, Weiwei; Lou, Yidong; Shi, Chuang; Yao, Yibin

    2016-05-01

    Integer ambiguity resolution is critical for achieving positions of high precision and for shortening the convergence time of precise point positioning (PPP). However, GLONASS adopts the signal processing technology of frequency division multiple access and results in inter-frequency code biases (IFCBs), which are currently difficult to correct. This bias makes the methods proposed for GPS ambiguity fixing unsuitable for GLONASS. To realize undifferenced GLONASS ambiguity fixing, we propose an undifferenced ambiguity resolution method for GPS+GLONASS PPP, which considers the IFCBs estimation. The experimental result demonstrates that the success rate of GLONASS ambiguity fixing can reach 75% through the proposed method. Compared with the ambiguity float solutions, the positioning accuracies of ambiguity-fixed solutions of GLONASS-only PPP are increased by 12.2%, 20.9%, and 10.3%, and that of the GPS+GLONASS PPP by 13.0%, 35.2%, and 14.1% in the North, East and Up directions, respectively.

  3. 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

  4. Decision-Making under Ambiguity Is Modulated by Visual Framing, but Not by Motor vs. Non-Motor Context. Experiments and an Information-Theoretic Ambiguity Model

    PubMed Central

    Grau-Moya, Jordi; Ortega, Pedro A.; Braun, Daniel A.

    2016-01-01

    A number of recent studies have investigated differences in human choice behavior depending on task framing, especially comparing economic decision-making to choice behavior in equivalent sensorimotor tasks. Here we test whether decision-making under ambiguity exhibits effects of task framing in motor vs. non-motor context. In a first experiment, we designed an experience-based urn task with varying degrees of ambiguity and an equivalent motor task where subjects chose between hitting partially occluded targets. In a second experiment, we controlled for the different stimulus design in the two tasks by introducing an urn task with bar stimuli matching those in the motor task. We found ambiguity attitudes to be mainly influenced by stimulus design. In particular, we found that the same subjects tended to be ambiguity-preferring when choosing between ambiguous bar stimuli, but ambiguity-avoiding when choosing between ambiguous urn sample stimuli. In contrast, subjects’ choice pattern was not affected by changing from a target hitting task to a non-motor context when keeping the stimulus design unchanged. In both tasks subjects’ choice behavior was continuously modulated by the degree of ambiguity. We show that this modulation of behavior can be explained by an information-theoretic model of ambiguity that generalizes Bayes-optimal decision-making by combining Bayesian inference with robust decision-making under model uncertainty. Our results demonstrate the benefits of information-theoretic models of decision-making under varying degrees of ambiguity for a given context, but also demonstrate the sensitivity of ambiguity attitudes across contexts that theoretical models struggle to explain. PMID:27124723

  5. Decision-Making under Ambiguity Is Modulated by Visual Framing, but Not by Motor vs. Non-Motor Context. Experiments and an Information-Theoretic Ambiguity Model.

    PubMed

    Grau-Moya, Jordi; Ortega, Pedro A; Braun, Daniel A

    2016-01-01

    A number of recent studies have investigated differences in human choice behavior depending on task framing, especially comparing economic decision-making to choice behavior in equivalent sensorimotor tasks. Here we test whether decision-making under ambiguity exhibits effects of task framing in motor vs. non-motor context. In a first experiment, we designed an experience-based urn task with varying degrees of ambiguity and an equivalent motor task where subjects chose between hitting partially occluded targets. In a second experiment, we controlled for the different stimulus design in the two tasks by introducing an urn task with bar stimuli matching those in the motor task. We found ambiguity attitudes to be mainly influenced by stimulus design. In particular, we found that the same subjects tended to be ambiguity-preferring when choosing between ambiguous bar stimuli, but ambiguity-avoiding when choosing between ambiguous urn sample stimuli. In contrast, subjects' choice pattern was not affected by changing from a target hitting task to a non-motor context when keeping the stimulus design unchanged. In both tasks subjects' choice behavior was continuously modulated by the degree of ambiguity. We show that this modulation of behavior can be explained by an information-theoretic model of ambiguity that generalizes Bayes-optimal decision-making by combining Bayesian inference with robust decision-making under model uncertainty. Our results demonstrate the benefits of information-theoretic models of decision-making under varying degrees of ambiguity for a given context, but also demonstrate the sensitivity of ambiguity attitudes across contexts that theoretical models struggle to explain.

  6. Combined GPS/GLONASS precise point positioning with fixed GPS ambiguities.

    PubMed

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

    2014-09-18

    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.

  7. 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

  8. In defense of competition during syntactic ambiguity resolution.

    PubMed

    Vosse, Theo; Kempen, Gerard

    2009-02-01

    In a recent series of publications (Traxler et al. J Mem Lang 39:558-592, 1998; Van Gompel et al. J Mem Lang 52:284-307, 2005; see also Van Gompel et al. (In: Kennedy, et al.(eds) Reading as a perceptual process, Oxford, Elsevier pp 621-648, 2000); Van Gompel et al. J Mem Lang 45:225-258, 2001) eye tracking data are reported showing that globally ambiguous (GA) sentences are read faster than locally ambiguous (LA) counterparts. They argue that these data rule out "constraint-based" models where syntactic and conceptual processors operate concurrently and syntactic ambiguity resolution is accomplished by competition. Such models predict the opposite pattern of reading times. However, this argument against competition is valid only in conjunction with two standard assumptions in current constraint-based models of sentence comprehension: (1) that syntactic competitions (e.g., Which is the best attachment site of the incoming constituent?) are pooled together with conceptual competitions (e.g., Which attachment site entails the most plausible meaning?), and (2) that the duration of a competition is a function of the overall (pooled) quality score obtained by each competitor. We argue that it is not necessary to abandon competition as a successful basis for explaining parsing phenomena and that the above-mentioned reading time data can be accounted for by a parallel-interactive model with conceptual and syntactic processors that do not pool their quality scores together. Within the individual linguistic modules, decision-making can very well be competition-based.

  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. Ambiguous genitalia: what prenatal genetic testing is practical?

    PubMed

    Adam, Margaret P; Fechner, Patricia Y; Ramsdell, Linda A; Badaru, Angela; Grady, Richard E; Pagon, Roberta A; McCauley, Elizabeth; Cheng, Edith Y; Parisi, Melissa A; Shnorhavorian, Margarett

    2012-06-01

    Concern for ambiguous genitalia or chromosome-phenotype discordance detected in a prenatal setting has increased over the last two decades. Practitioners faced with this prenatal finding have a variety of genetic tests available to them; however, it is unclear to what extent prenatal testing for disorders of sex development (DSD) is useful or practical. We undertook a retrospective review of the medical records of 140 individuals evaluated through the DSD clinic at Seattle Children's Hospital with birthdates from 01/01/1994 through 08/16/2011 to determine the rate of prenatal detection of ambiguous genitalia in individuals with DSD, what prenatal diagnostic workup was undertaken, and the postnatal outcome, including whether a postnatal genetic diagnosis was confirmed. Of all 140 subjects, 34 (24%) were identified prenatally. The most common postnatal diagnoses were penoscrotal hypospadias with transposition of the scrotum with no known genetic cause (24/140; 17%) and 21-hydroxylase deficiency (20/140; 14%). Apart from these, no single diagnosis comprised more than a few cases. Prenatal diagnostic testing varied widely, from no tests to multiple molecular tests with amniotic fluid hormone concentrations. In the absence of other fetal anomalies or growth retardation on ultrasound, prenatal karyotype with fluorescence in situ hybridization for the SRY gene is the most useful test when ambiguous genitalia is suspected. Further prenatal testing for Smith-Lemli-Opitz syndrome in 46,XY individuals and congenital adrenal hyperplasia in 46,XX individuals may be considered. However, targeted molecular testing for rare DSD conditions in the absence of a family history of DSD has a low yield. Copyright © 2012 Wiley Periodicals, Inc.

  11. 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

  12. Perceived ambiguity about cancer prevention recommendations: relationship to perceptions of cancer preventability, risk, and worry.

    PubMed

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

    2006-01-01

    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.

  13. Resolving the sign ambiguity in the singular value decomposition.

    SciTech Connect

    Bro, Rasmus; Acar, Evrim; Kolda, Tamara Gibson

    2007-10-01

    Many modern data analysis methods involve computing a matrix singular value decomposition (SVD) or eigenvalue decomposition (EVD). Principal components analysis is the time-honored example, but more recent applications include latent semantic indexing, hypertext induced topic selection (HITS), clustering, classification, etc. Though the SVD and EVD are well-established and can be computed via state-of-the-art algorithms, it is not commonly mentioned that there is an intrinsic sign indeterminacy that can significantly impact the conclusions and interpretations drawn from their results. Here we provide a solution to the sign ambiguity problem and show how it leads to more sensible solutions.

  14. 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.

  15. Treatment motivation: An attempt for clarification of an ambiguous concept.

    PubMed

    Drieschner, Klaus H; Lammers, Sylvia M M; van der Staak, Cees P F

    2004-01-01

    Although the concept of treatment motivation is generally regarded as highly relevant, it has since long been surrounded by conceptual confusion, resulting in miscommunication, ambiguous measures, and contradictory conclusions of research. This article provides an analysis of three major sources of confusion in the conceptualization of treatment motivation: (a) negligence of the concepts' intrinsic relationship with behavior, (b) entanglement of the concept with its determining factors and behavioral consequences, and (c) conceptualization in a stage model. Following the conceptual analysis, causes of the problems and implications for clinical praxis and research are considered. Finally, a more adequate conceptualization of treatment motivation is proposed and suggestions for future research are made.

  16. New Ambiguity in Probing CP Violation in Neutrino Oscillations.

    PubMed

    Miranda, O G; Tórtola, M; Valle, J W F

    2016-08-05

    If neutrinos get mass via the seesaw mechanism the mixing matrix describing neutrino oscillations can be effectively nonunitary. We show that in this case the neutrino appearance probabilities involve a new CP phase ϕ associated with nonunitarity. This leads to an ambiguity in extracting the "standard" three-neutrino phase δ_{CP}, which can survive even after neutrino and antineutrino channels are combined. Its existence should be taken into account in the planning of any oscillation experiment aiming at a robust measurement of δ_{CP}.

  17. 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.

  18. New Ambiguity in Probing C P Violation in Neutrino Oscillations

    NASA Astrophysics Data System (ADS)

    Miranda, O. G.; Tórtola, M.; Valle, J. W. F.

    2016-08-01

    If neutrinos get mass via the seesaw mechanism the mixing matrix describing neutrino oscillations can be effectively nonunitary. We show that in this case the neutrino appearance probabilities involve a new C P phase ϕ associated with nonunitarity. This leads to an ambiguity in extracting the "standard" three-neutrino phase δC P, which can survive even after neutrino and antineutrino channels are combined. Its existence should be taken into account in the planning of any oscillation experiment aiming at a robust measurement of δC P.

  19. Spatial average ambiguity function for array radar with stochastic signals

    NASA Astrophysics Data System (ADS)

    Zha, Guofeng; Wang, Hongqiang; Cheng, Yongqiang; Qin, Yuliang

    2016-03-01

    For analyzing the spatial resolving performance of multi-transmitter single-receiver (MTSR) array radar with stochastic signals, the spatial average ambiguity function (SAAF) is introduced based on the statistical average theory. The analytic expression of SAAF and the corresponding resolutions in vertical range and in horizontal range are derived. Since spatial resolving performance is impacted by many parameters including signal modulation schemes, signal bandwidth, array aperture's size and target's spatial position, comparisons are implemented to analyze these influences. Simulation results are presented to validate the whole analysis.

  20. 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.

  1. From expert generalists to ambiguity masters: using ambiguity tolerance theory to redefine the practice of rural nurses.

    PubMed

    Knight, Kaye; Kenny, Amanda; Endacott, Ruth

    2016-06-01

    To redefine the practice of rural nurses and describe a model that conceptualises the capabilities and characteristics required in the rural environment. The way in which the practice of rural nurses has been conceptualised is problematic. Definitions of rural nursing have been identified primarily through the functional context of rural health service delivery. The expert generalist term has provided a foundation theory for rural nurses with understandings informed by the scope of practice needed to meet service delivery requirements. However, authors exploring intrinsic characteristics of rural nurses have challenged this definition, as it does not adequately address the deeper, intangible complexities of practice required in the rural context. Despite this discourse, an alternative way to articulate the distinctive nature of rural nursing practice has eluded authors in Australia and internationally. A theoretical paper based on primary research. The development of the model was informed by the findings of a study that explored the nursing practice of managing telephone presentations in rural health services in Victoria, Australia. The study involved policy review from State and Federal governments, nursing and medical professional bodies, and five rural health services; semi-structured interviews with eight Directors of Nursing, seven registered nurses and focus group interviews with eight registered nurses. An ambiguity tolerance model drawn from corporate global entrepreneurship theory was adapted to explain the findings of the study. The adapted model presents capabilities and characteristics used by nurses to successfully manage the ambiguity of providing care in the rural context. Redefining the practice of rural nurses, through an adapted theory of ambiguity tolerance, highlights nursing characteristics and capabilities required in the rural context. This perspective offers new ways of thinking about the work of rural nurses, rural nurse policy, education

  2. Noun-verb ambiguity in chronic undifferentiated schizophrenia.

    PubMed

    Goldfarb, Robert; Bekker, Natalie

    2009-01-01

    This study investigated noun-verb retrieval patterns of 30 adults with chronic undifferentiated schizophrenia and 67 typical adults, to determine if schizophrenia affected nouns (associated with temporal lobe function) differently from verbs (associated with frontal lobe function). Stimuli were homophonic homographic homonyms, balanced according to frequency of occurrence, where N>V, Nambiguous noun-verb preference to differentiate the language of schizophrenia from the language of typical adults; and (c) evidence of ambiguous noun-verb preference to differentiate the language of schizophrenia from fluent aphasia.

  3. Flow Ambiguity: A Path Towards Classically Driven Blind Quantum Computation

    NASA Astrophysics Data System (ADS)

    Mantri, Atul; Demarie, Tommaso F.; Menicucci, Nicolas C.; Fitzsimons, Joseph F.

    2017-07-01

    Blind quantum computation protocols allow a user to delegate a computation to a remote quantum computer in such a way that the privacy of their computation is preserved, even from the device implementing the computation. To date, such protocols are only known for settings involving at least two quantum devices: either a user with some quantum capabilities and a remote quantum server or two or more entangled but noncommunicating servers. In this work, we take the first step towards the construction of a blind quantum computing protocol with a completely classical client and single quantum server. Specifically, we show how a classical client can exploit the ambiguity in the flow of information in measurement-based quantum computing to construct a protocol for hiding critical aspects of a computation delegated to a remote quantum computer. This ambiguity arises due to the fact that, for a fixed graph, there exist multiple choices of the input and output vertex sets that result in deterministic measurement patterns consistent with the same fixed total ordering of vertices. This allows a classical user, computing only measurement angles, to drive a measurement-based computation performed on a remote device while hiding critical aspects of the computation.

  4. Intolerance of uncertainty correlates with insula activation during affective ambiguity

    PubMed Central

    Simmons, Alan; Matthews, Scott C.; Paulus, Martin P.; Stein, Murray B.

    2009-01-01

    Intolerance of uncertainty (IU), or the increased affective response to situations with uncertain outcomes, is an important component process of anxiety disorders. Increased IU is observed in panic disorder (PD), obsessive compulsive disorder (OCD) and generalized anxiety disorder (GAD), and is thought to relate to dysfunctional behaviors and thought patterns in these disorders. Identifying what brain systems are associated with IU would contribute to a comprehensive model of anxiety processing, and increase our understanding of the neurobiology of anxiety disorders. Here, we used a behavioral task, Wall of Faces (WOF), during functional magnetic resonance imaging (fMRI), which probes both affect and ambiguity, to examine the neural circuitry of IU in fourteen (10 females) college age (18.8 yrs) subjects. All subjects completed the Intolerance of Uncertainty Scale (IUS), Anxiety Sensitivity Index (ASI), and a measure of neuroticism (i.e. the NEO-N). IUS scores but neither ASI nor NEO-N scores, correlated positively with activation in bilateral insula during affective ambiguity. Thus, the experience of IU during certain types of emotion processing may relate to the degree to which bilateral insula processes uncertainty. Previously observed insula hyperactivity in anxiety disorder individuals may therefore be directly linked to altered processes of uncertainty. PMID:18079060

  5. 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

  6. 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.

  7. Vaccine hesitancy: clarifying a theoretical framework for an ambiguous notion.

    PubMed

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

    2015-02-25

    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.

  8. Auditory cortex encodes the perceptual interpretation of ambiguous sound.

    PubMed

    Kilian-Hütten, Niclas; Valente, Giancarlo; Vroomen, Jean; Formisano, Elia

    2011-02-02

    The confounding of physical stimulus characteristics and perceptual interpretations of stimuli poses a problem for most neuroscientific studies of perception. In the auditory domain, this pertains to the entanglement of acoustics and percept. Traditionally, most study designs have relied on cognitive subtraction logic, which demands the use of one or more comparisons between stimulus types. This does not allow for a differentiation between effects due to acoustic differences (i.e., sensation) and those due to conscious perception. To overcome this problem, we used functional magnetic resonance imaging (fMRI) in humans and pattern-recognition analysis to identify activation patterns that encode the perceptual interpretation of physically identical, ambiguous sounds. We show that it is possible to retrieve the perceptual interpretation of ambiguous phonemes-information that is fully subjective to the listener-from fMRI measurements of brain activity in auditory areas in the superior temporal cortex, most prominently on the posterior bank of the left Heschl's gyrus and sulcus and in the adjoining left planum temporale. These findings suggest that, beyond the basic acoustic analysis of sounds, constructive perceptual processes take place in these relatively early cortical auditory networks. This disagrees with hierarchical models of auditory processing, which generally conceive of these areas as sets of feature detectors, whose task is restricted to the analysis of physical characteristics and the structure of sounds.

  9. Removal of pedestals and directional ambiguity of optical anemometer signals.

    PubMed

    Durst, F; Zaré, M

    1974-11-01

    Laser Doppler anemometry permits, in principle, the measurement of both magnitude and direction of components of a particle's velocity vector. Most exiting anemometers, however, permit measurements only with a directional ambiguity of 180 degrees , resulting in errors in certain flow fields. Available methods of eliminating the directional ambiguity of Laser Doppler anemometers are reviewed, covering frequency shifting of the incident and scattered light beams, the use of beams with different polarization properties, and employment of multicolor laser beams. The advantages and disadvantages of existing methods are summarized, and suggestions for alterations are made. Different techniques used to remove the pedestal of laser Doppler anemometer signals are also reviewed. Optical techniques should be employed in any advanced optical anemometer system to avoid dynamic range limitations by electronic bandpass filters. Suggestions are made for advanced optical anemometers employing multielement avalanche photodiodes that can be used for simultaneous measurements of two velocity components. These anemometers incorporate devices to sense the direction of the velocity components and to eliminate optically the pedestal of laser Doppler signals.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Ambiguity between self and other: Individual differences in action attribution.

    PubMed

    de Bézenac, Christophe E; Sluming, Vanessa; O'Sullivan, Noreen; Corcoran, Rhiannon

    2015-09-01

    Individuals differ in their ability to attribute actions to self or other. This variance is thought to explain, in part, the experience of voice-hearing. Misattribution can also be context-driven. For example, causal ambiguity can arise when the actions of two or more individuals are coordinated and produce similar effects (e.g., music-making). Experience in such challenging contexts may refine skills of action attribution. Forty participants completed a novel finger-tapping task which parametrically manipulated the proportion of control that 'self' versus 'other' possessed over resulting auditory tones. Results showed that action misattribution peaked in the middle of the self-to-other continuum and was biased towards other. This pattern was related to both high hallucination-proneness and to low musical-experience. Findings suggest not only that causal ambiguity plays a key role in agency but also that action attribution abilities may improve with practice, potentially providing an avenue for remediation of the positive symptoms of schizophrenia. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. 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 [-π, π], 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.

  16. Intolerance of uncertainty correlates with insula activation during affective ambiguity.

    PubMed

    Simmons, Alan; Matthews, Scott C; Paulus, Martin P; Stein, Murray B

    2008-01-10

    Intolerance of uncertainty (IU), or the increased affective response to situations with uncertain outcomes, is an important component process of anxiety disorders. Increased IU is observed in panic disorder (PD), obsessive compulsive disorder (OCD) and generalized anxiety disorder (GAD), and is thought to relate to dysfunctional behaviors and thought patterns in these disorders. Identifying what brain systems are associated with IU would contribute to a comprehensive model of anxiety processing, and increase our understanding of the neurobiology of anxiety disorders. Here, we used a behavioral task, Wall of Faces (WOFs), during functional magnetic resonance imaging (fMRI), which probes both affect and ambiguity, to examine the neural circuitry of IU in 14 (10 females) college age (18.8 years) subjects. All subjects completed the Intolerance of Uncertainty Scale (IUS), Anxiety Sensitivity Index (ASI), and a measure of neuroticism (i.e. the NEO-N). IUS scores but neither ASI nor NEO-N scores, correlated positively with activation in bilateral insula during affective ambiguity. Thus, the experience of IU during certain types of emotion processing may relate to the degree to which bilateral insula processes uncertainty. Previously observed insula hyperactivity in anxiety disorder individuals may therefore be directly linked to altered processes of uncertainty.

  17. 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

  18. 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.

  19. Lexical and Prosodic Effects on Syntactic Ambiguity Resolution in Aphasia

    PubMed Central

    DeDe, Gayle

    2012-01-01

    The purpose of this study was to determine whether and when individuals with aphasia and healthy controls use lexical and prosodic information during on-line sentence comprehension. Individuals with aphasia and controls (n = 12 per group) participated in a self-paced listening experiment. The stimuli were early closure sentences, such as “While the parents watched(,) the child sang a song.” Both lexical and prosodic cues were manipulated. The cues were biased toward the subject- or object- of the ambiguous noun phrase (the child). Thus, there were two congruous conditions (in which both lexical cues and prosodic cues were consistent) and two incongruous conditions (in which lexical and prosodic cues conflicted). The results showed that the people with aphasia had longer listening times for the ambiguous noun phrase (the child) when the cues were conflicting, rather than consistent. The controls showed effects earlier in the sentence, at the subordinate verb (watched or danced). Both groups showed evidence of reanalysis at the main verb (sang). These effects demonstrate that the aphasic group was sensitive to the lexical and prosodic cues, but used them on a delayed time course relative to the control group. PMID:22143353

  20. 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.

  1. At the crossroads of race: racial ambiguity and biracial identification influence psychological essentialist thinking.

    PubMed

    Young, Danielle M; Sanchez, Diana T; Wilton, Leigh S

    2013-10-01

    Racial essentialism refers to the widely held belief that race is a biological, stable, and natural category. Although research finds very little evidence that race has biological underpinnings, racial essentialist beliefs persist and are linked to negative outgroup consequences. This study initially demonstrates that label and visual ambiguity concurrently inform racial categorization. It then tests whether exposure to racially ambiguous targets (a) challenges essentialism when ambiguous targets are labeled with biracial categories and (b) reinforces essentialism when ambiguous targets identify with monoracial categories. The results showed that White perceivers (N = 84) who were exposed to racially ambiguous, biracially labeled targets showed reductions in their essentialist thinking about race, whereas perceivers who were exposed to racially ambiguous, monoracially labeled targets showed increases in their essentialist beliefs. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  2. The effect of context on responses to racially ambiguous faces: changes in perception and evaluation

    PubMed Central

    2015-01-01

    Reactions to individuals who possess features associated with multiple racial groups may be particularly susceptible to external contextual influences, leading to meaningfully different racial perceptions and judgments in different situations. In the present study, we found that an extrinsic race-label cue not only changed evaluative associations activated by a racially ambiguous face, but also changed quickly occurring neural responses sensitive to racial perception. Behaviorally, prototypical Black faces and racially ambiguous faces labeled as Black activated more negative implicit associations than prototypical White faces and racially ambiguous faces labeled as White. Neurally, prototypical faces and racially ambiguous faces cued with the same race elicited similar responses. Specifically, prototypical Black and racially ambiguous faces labeled as Black elicited larger P200s but smaller N200s than prototypical White and racially ambiguous faces labeled as White. These results show that racial perception can be changed by an external cue and this, in turn, influences subsequent evaluative reactions. PMID:25344946

  3. Using uniformat and gene[rate] to Analyze Data with Ambiguities in Population Genetics.

    PubMed

    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.

  4. 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.

  5. 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.

  6. 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.

  7. Laser Doppler velocity measurement without directional ambiguity by using frequency shifted incident beams

    NASA Technical Reports Server (NTRS)

    Mazumder, M. K.

    1970-01-01

    Laser Doppler heterodyning system for velocity measurements without directional ambiguity, employing incident beams of different frequencies through rotating diffraction grating or Bragg cell application

  8. Downsizing and reorganization: demands, challenges and ambiguity for registered nurses.

    PubMed

    Hertting, Anna; Nilsson, Kerstin; Theorell, Töres; Larsson, Ullabeth Sätterlund

    2004-01-01

    The 1990s were characterized by substantial financial cuts, and related staff redundancies and reorganizations in the Swedish health care sector. A large hospital in Sweden was selected for the study, in which downsizing had occurred between 1995 and 1997. The number of staff in the hospital was reduced by an average of 20%, and 10% were relocated to other departments. The aims of this study were to explore registered nurses' experiences of psychosocial 'stressors' and 'motivators', and how they handled their work situations, following a period of personnel reductions and ongoing reorganization. Interviews were undertaken with 14 nurses working in one Swedish hospital. Nurses were interviewed in 1997 about the recent and last round of redundancies, and were followed up 1 year later in 1998 and again in 2001. Interviews were audiotaped, transcribed and analysed for thematic content. Five themes emerged in relation to nurses' perceived stressors, motivators, and coping options: 'distrust towards the employer', 'concurrent demands and challenges', 'professional ambiguity, 'a wish for collaboration', and 'efforts to gain control'. A common feature was duality and ambiguity in nurses' descriptions of the phenomena studied, meaning that identified themes had underlying sub-themes with both negative and positive dimensions. The concurrence of 'ever-growing job demands' and 'work going unrewarded' contributed to a feeling of being taken advantage of by the employer. The 'waste of human resources' and 'competence drain' that followed redundancies provoked anger. Unfulfilled collaboration with doctors was a major stress producer, which related to both the downsized work organization, and the complex 'deference-dominance' doctor-nurse relationship. The well-being of nurses depends on being an equal/parallel health professional in a comprehensive team that shares knowledge and improves collaborative care of patients. A consciously formulated nursing philosophy emerged as a

  9. 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.

  10. Neural responses to ambiguity involve domain-general and domain-specific emotion processing systems.

    PubMed

    Neta, Maital; Kelley, William M; Whalen, Paul J

    2013-04-01

    Extant research has examined the process of decision making under uncertainty, specifically in situations of ambiguity. However, much of this work has been conducted in the context of semantic and low-level visual processing. An open question is whether ambiguity in social signals (e.g., emotional facial expressions) is processed similarly or whether a unique set of processors come on-line to resolve ambiguity in a social context. Our work has examined ambiguity using surprised facial expressions, as they have predicted both positive and negative outcomes in the past. Specifically, whereas some people tended to interpret surprise as negatively valenced, others tended toward a more positive interpretation. Here, we examined neural responses to social ambiguity using faces (surprise) and nonface emotional scenes (International Affective Picture System). Moreover, we examined whether these effects are specific to ambiguity resolution (i.e., judgments about the ambiguity) or whether similar effects would be demonstrated for incidental judgments (e.g., nonvalence judgments about ambiguously valenced stimuli). We found that a distinct task control (i.e., cingulo-opercular) network was more active when resolving ambiguity. We also found that activity in the ventral amygdala was greater to faces and scenes that were rated explicitly along the dimension of valence, consistent with findings that the ventral amygdala tracks valence. Taken together, there is a complex neural architecture that supports decision making in the presence of ambiguity: (a) a core set of cortical structures engaged for explicit ambiguity processing across stimulus boundaries and (b) other dedicated circuits for biologically relevant learning situations involving faces.

  11. The comprehension of ambiguous idioms in aphasic patients.

    PubMed

    Cacciari, Cristina; Reati, Fabiola; Colombo, Maria Rosa; Padovani, Roberto; Rizzo, Silvia; Papagno, Costanza

    2006-01-01

    The ability to understand ambiguous idioms was assessed in 15 aphasic patients with preserved comprehension at a single word level. A string-to-word matching task was used. Patients were requested to choose one among four alternatives: a word associated with the figurative meaning of the idiom string; a word semantically associate with the last constituent of the idiom string; and two unrelated words. The results showed that patients' performance was impaired with respect to a group of matched controls, with patients showing a frontal and/or temporal lesion being the most impaired. A significant number of semantically associate errors were produced, suggesting an impairment of inhibition mechanisms and/or of recognition/activation of the idiomatic meaning.

  12. Minimizing ambiguities in stream classification of complex drainage structures

    NASA Astrophysics Data System (ADS)

    Sah, Rajesh Kumar; Das, Apurba Kumar

    2017-10-01

    In hydrological studies complex drainage structures in river systems are open to ambiguous subjectivity when conventional classification systems are followed. We suggest rules that compliment both Strahler's and Shreve's methods of stream numbering and their extent consideration to reduce this subjective uncertainty. We delineated three possible complex distributary conditions followed by individual application of Strahler's and Shreve's rationales for stream classifications with concurrent verification in real river situations. As a result, for Strahler's method, we derived the decisive criteria in designating correct stream number in complex stream interconnections by plotting minimum number of segments along with the concept of primary and secondary flow. On the other hand, for Shreve's method, splitting the magnitude of the streams at divides of the distributaries yielded precise results. Final real world verification from both applications substantiated the potential of our proposed methodologies to reduce subjectivity in stream classification.

  13. The spatial-temporal ambiguity in auroral modeling

    NASA Technical Reports Server (NTRS)

    Rees, M. H.; Roble, R. G.; Kopp, J.; Abreu, V. J.; Rusch, D. W.; Brace, L. H.; Brinton, H. C.; Hoffman, R. A.; Heelis, R. A.; Kayser, D. C.

    1980-01-01

    The paper examines the time-dependent models of the aurora which show that various ionospheric parameters respond to the onset of auroral ionization with different time histories. A pass of the Atmosphere Explorer C satellite over Poker Flat, Alaska, and ground based photometric and photographic observations have been used to resolve the time-space ambiguity of a specific auroral event. The density of the O(+), NO(+), O2(+), and N2(+) ions, the electron density, and the electron temperature observed at 280 km altitude in a 50 km wide segment of an auroral arc are predicted by the model if particle precipitation into the region commenced about 11 min prior to the overpass.

  14. Ambiguity and nonidentifiability in the statistical analysis of neural codes.

    PubMed

    Amarasingham, Asohan; Geman, Stuart; Harrison, Matthew T

    2015-05-19

    Many experimental studies of neural coding rely on a statistical interpretation of the theoretical notion of the rate at which a neuron fires spikes. For example, neuroscientists often ask, "Does a population of neurons exhibit more synchronous spiking than one would expect from the covariability of their instantaneous firing rates?" For another example, "How much of a neuron's observed spiking variability is caused by the variability of its instantaneous firing rate, and how much is caused by spike timing variability?" However, a neuron's theoretical firing rate is not necessarily well-defined. Consequently, neuroscientific questions involving the theoretical firing rate do not have a meaning in isolation but can only be interpreted in light of additional statistical modeling choices. Ignoring this ambiguity can lead to inconsistent reasoning or wayward conclusions. We illustrate these issues with examples drawn from the neural-coding literature.

  15. Enduring interest in perceptual ambiguity: alternating views of reversible figures.

    PubMed

    Long, Gerald M; Toppino, Thomas C

    2004-09-01

    Research favoring the so-called bottom-up and top-down classes of explanations for reversible figures that dominated the literature in last half of the 20th century is reviewed. Two conclusions are offered. First, any single-process model is extremely unlikely to be able to accommodate the wide array of empirical findings, suggesting that the "final" explanation will almost certainly involve a hybrid conceptualization of interacting sensory and cognitive processes. Second, the utility of distinguishing between 2 components of the observer's experience with reversible figures is emphasized. This distinction between the observer's ability to access multiple representations from the single stimulus pattern (ambiguity) and the observer's phenomenal experience of oscillation between those representations (reversibility) permits the literature to be segregated into useful categories of research that expose overlapping but distinctive cortical processes.

  16. A practical approach to ambiguous genitalia in the newborn period.

    PubMed

    Lambert, Sarah M; Vilain, Eric J N; Kolon, Thomas F

    2010-05-01

    The evaluation and management of neonates with ambiguous genitalia requires sensitivity, efficiency, and accuracy. The approach to these neonates is facilitated by a multidisciplinary team including urology, endocrinology, genetics, and psychiatry or psychology. Disorders of sex development (DSD) encompass chromosomal DSD, 46,XX DSD, and 46,XY DSD. The 46,XX DSD is the most common DSD and in the majority of these children congenital adrenal hyperplasia is the underlying etiology. The 46,XY DSD is a heterogeneous disorder that often results from a disruption in the production or response to testosterone, dihydrotestosterone, or Mullerian inhibitory substance. Chromosomal DSD includes conditions resulting from abnormal meiosis, including Klinefelter syndrome (47, XXY) and Turner syndrome. The evaluation of children with DSD demands a thorough physical examination, medical history, karyotype, metabolic panel, 17-OH progesterone, testosterone, luteinizing hormone, follicle stimulation hormone, and urinalysis. A radiographic evaluation should begin with an abdominal and pelvic ultrasound but may include magnetic resonance imaging, endoscopy, or laparoscopy.

  17. Quantization of Yang-Mills theory without the Gribov ambiguity

    NASA Astrophysics Data System (ADS)

    Zhou, Gao-Liang; Yan, Zheng-Xin; Zhang, Xin

    2017-03-01

    A gauge fixing condition is presented here for non-Abelian gauge theory on the manifold R ⊗S1 ⊗S1 ⊗S1. It is proved that the new gauge fixing condition is continuous and free from the Gribov ambiguity. While perturbative calculations based on the new gauge condition behave like those based on the axial gauge in ultraviolet region, infrared behaviours of the perturbative series under the new gauge fixing condition are quite nontrivial. The new gauge condition, which reads n ṡ ∂ n ṡ A = 0, may not satisfy the boundary condition Aμ (∞) = 0 as required by conventional perturbative calculations for gauge theories on the manifold S4. However, such contradiction is not harmful for the theory considered here.

  18. Lifting the Gribov ambiguity in Yang-Mills theories

    NASA Astrophysics Data System (ADS)

    Serreau, J.; Tissier, M.

    2012-05-01

    We propose a new one-parameter family of Landau gauges for Yang-Mills theories which can be formulated by means of functional integral methods and are thus well suited for analytic calculations, but which are free of Gribov ambiguities and avoid the Neuberger zero problem of the standard Faddeev-Popov construction. The resulting gauge-fixed theory is perturbatively renormalizable in four dimensions and, for what concerns the calculation of ghost and gauge field correlators, it reduces to a massive extension of the Faddeev-Popov action. We study the renormalization group flow of this theory at one-loop and show that it has no Landau pole in the infrared for some - including physically relevant - range of values of the renormalized parameters.

  19. Covariation bias for ambiguous social stimuli in generalized social phobia.

    PubMed

    Hermann, Christiane; Ofer, Julia; Flor, Herta

    2004-11-01

    The authors investigated whether the negative interpretation bias in generalized social phobia (GSP) reflects and is maintained by illusory correlations. Participants were exposed to descriptions of ambiguous social events, situations involving fear-relevant animals and nature scenes that were randomly paired with negative, positive, or neutral emotional facial expressions. Prior to the experiment, the GSP participants overestimated the contingency social situations-negative outcome, whereas the controls judged negative outcomes as least likely. A posteriori, the GSP participants exhibited an illusory correlation specifically between social cues and negative outcomes. During the experiment, only the controls showed distorted outcome predictions for social situations. Hence, illusory correlations--possibly resulting from acquired associations between social cues and negative consequences--may contribute to a negative interpretation bias in GSP. Copyright 2004 APA.

  20. 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, Andréa 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.

  1. The spatial-temporal ambiguity in auroral modeling

    NASA Technical Reports Server (NTRS)

    Rees, M. H.; Roble, R. G.; Kopp, J.; Abreu, V. J.; Rusch, D. W.; Brace, L. H.; Brinton, H. C.; Hoffman, R. A.; Heelis, R. A.; Kayser, D. C.

    1980-01-01

    The paper examines the time-dependent models of the aurora which show that various ionospheric parameters respond to the onset of auroral ionization with different time histories. A pass of the Atmosphere Explorer C satellite over Poker Flat, Alaska, and ground based photometric and photographic observations have been used to resolve the time-space ambiguity of a specific auroral event. The density of the O(+), NO(+), O2(+), and N2(+) ions, the electron density, and the electron temperature observed at 280 km altitude in a 50 km wide segment of an auroral arc are predicted by the model if particle precipitation into the region commenced about 11 min prior to the overpass.

  2. Abelian gauge theories on compact manifolds and the Gribov ambiguity

    SciTech Connect

    Kelnhofer, Gerald

    2008-05-15

    We study the quantization of Abelian gauge theories of principal torus bundles over compact manifolds with and without boundary. It is shown that these gauge theories suffer from a Gribov ambiguity originating in the nontriviality of the bundle of connections whose geometrical structure will be analyzed in detail. Motivated by the stochastic quantization approach, we propose a modified functional integral measure on the space of connections that takes the Gribov problem into account. This functional integral measure is used to calculate the partition function, Green's functions, and the field strength correlating functions in any dimension by using the fact that the space of inequivalent connections itself admits the structure of a bundle over a finite dimensional torus. Green's functions are shown to be affected by the nontrivial topology, giving rise to nonvanishing vacuum expectation values for the gauge fields.

  3. 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.

  4. Ambiguity and nonidentifiability in the statistical analysis of neural codes

    PubMed Central

    Amarasingham, Asohan; Geman, Stuart; Harrison, Matthew T.

    2015-01-01

    Many experimental studies of neural coding rely on a statistical interpretation of the theoretical notion of the rate at which a neuron fires spikes. For example, neuroscientists often ask, “Does a population of neurons exhibit more synchronous spiking than one would expect from the covariability of their instantaneous firing rates?” For another example, “How much of a neuron’s observed spiking variability is caused by the variability of its instantaneous firing rate, and how much is caused by spike timing variability?” However, a neuron’s theoretical firing rate is not necessarily well-defined. Consequently, neuroscientific questions involving the theoretical firing rate do not have a meaning in isolation but can only be interpreted in light of additional statistical modeling choices. Ignoring this ambiguity can lead to inconsistent reasoning or wayward conclusions. We illustrate these issues with examples drawn from the neural-coding literature. PMID:25934918

  5. Female children with ambiguous genitalia in awareness-poor subregion.

    PubMed

    Osifo, Osarumwense D; Amusan, Taiwo I

    2009-12-01

    Congenital aberrations of female children's external genitalia are common worldwide with varied mode of presentation especially in regions with poor awareness. This prospective experience between July 2004 and June 2008 at two Nigerian healthcare facilities is on the mode of presentation and challenges of management of female children with ambiguous genitalia. Congenital adrenal hyperplasia (CAH) 19 (47.5%), female pseudohermaphroditism 20 (50%) and vaginal atresia 1 (2.5%) manifested as aberrations of external genitalia of 40 female children who presented between the ages of 3 months and 16 years (average 9 years). Cultural influence, lack of awareness, inadequate examination of external genitalia at birth and lack of diagnostic facilities resulted in late presentation and diagnosis with all the cases of CAH and pseudohermaphroditism raised as males. Five cases who developed female secondary sexual characteristics at puberty attempted suicide before presentation. Gender reassignment and feminizing genitoplasty were major challenges, but outcomes were encouraging.

  6. 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.

  7. 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.

  8. Ambiguous genitalia, gender-identity problems, and sex reassignment.

    PubMed

    Dittmann, R W

    1998-01-01

    This article discusses general issues with regard to gender-identity problems, sex reassignment, and clinical management in patients with ambiguous genitalia, based on a detailed case history of a patient with penile agenesis who has been followed more than 20 years. After initial uncertainty, the patient began to grow up as a boy, lived from the fourth year of life as a girl and young woman, and lived from late puberty on as a man. Over his lifetime he experienced extensive corrective surgery plus hormonal substitution therapy. Pre- and perinatal hormonal conditions, phenomenology of the genitalia, sex of rearing, timing of sex reassignment and corrective surgery, for example, appear to be important components for the development of gender-role behavior, gender identity, and sexual orientation of intersex patients. Findings and retrospective considerations for this patient suggest the need for careful differential activities in diagnostic workup, approaches to sex assignment and possible reassignment, and the clinical management of patients and families.

  9. 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.

  10. 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.

  11. N400 to lexical ambiguity and semantic incongruity in schizophrenia.

    PubMed

    Salisbury, Dean

    2010-02-01

    Our previous work showed a semantic bias in interpreting ambiguous words in schizophrenia, with disproportionate misinterpretation of subordinate meanings (toast at a wedding). We proposed pre-selection in schizophrenia of dominant-meaning networks at points of lexical ambiguity, thereby misleading thought. This selection bias may be due to semantic memory hyper-priming causing strong associates to dominate cognition. Alternately, later verbal memory maintenance failure may cause weaker associates to fade more quickly than stronger associates from memory due to less initial activation. To further examine this semantic bias, patients and controls were presented short 4 word long sentences (The toast was buttered). The second word was a homograph or unambiguous noun. The last word disambiguated homographs (dominant or subordinate meaning) or was congruent or incongruent with unambiguous nouns. Previously, we showed increasingly larger N400 from unambiguous associates to dominate associates to subordinate associates to unambiguous non-associates in controls. Pre-selection of dominant meanings predicts that schizophrenia patients would show small N400 to dominant associates and as large N400 to subordinate associates as to incongruous endings. Here, controls again showed graded N400 amplitudes. Patients with schizophrenia showed small N400 to congruent and dominant endings and large N400 to subordinate and incongruous endings. These data suggest early pre-selection of dominant associates in schizophrenia. This effect is unlikely solely due to verbal memory maintenance failure, as patients were able to detect incongruity, albeit with a smaller N400 effect, and displayed generally larger N400 to all stimuli. These results suggest alterations in semantic memory associative networks coupled with verbal working memory maintenance decay in schizophrenia. Copyright 2009 Elsevier B.V. All rights reserved.

  12. The Fungus Candida albicans Tolerates Ambiguity at Multiple Codons.

    PubMed

    Simões, João; Bezerra, Ana R; Moura, Gabriela R; Araújo, Hugo; Gut, Ivo; Bayes, Mónica; Santos, Manuel A S

    2016-01-01

    The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients, and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions, CUG sites incorporate leucine (3% of the times) and serine (97% of the times) on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT) strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations) followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP) and one SNP in the deneddylase (JAB1) gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p) to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans.

  13. The Fungus Candida albicans Tolerates Ambiguity at Multiple Codons

    PubMed Central

    Simões, João; Bezerra, Ana R.; Moura, Gabriela R.; Araújo, Hugo; Gut, Ivo; Bayes, Mónica; Santos, Manuel A. S.

    2016-01-01

    The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients, and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions, CUG sites incorporate leucine (3% of the times) and serine (97% of the times) on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT) strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations) followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP) and one SNP in the deneddylase (JAB1) gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p) to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans. PMID:27065968

  14. Superior ambiguous occasion setting with visual than temporal feature stimuli.

    PubMed

    Delamater, Andrew R; Derman, Rifka C; Harris, Justin A

    2017-01-01

    Three experiments with rats compared the relative ease with which different sets of visual or temporal cues could participate in Pavlovian learning. In Experiment 1, 1 group was trained to discriminate between visual cues (Light vs. Dark), whereas the other group learned to discriminate between temporal cues (early [10 s] vs. late [90 s]). Both groups learned to distinguish food-paired from nonpaired periods equally well. In Experiment 2, 2 groups were trained on an ambiguous occasion setting task. For Group Visual, a 2-min Light period signaled that 1 10-s auditory conditioned stimulus, CS1, was reinforced with 1 unconditioned stimulus, US1, but that CS2 was not reinforced; whereas a 2-min dark period signaled that CS1 was not reinforced, but CS2 was reinforced with US2 (i.e., Light: CS1-US1, CS2-; Dark: CS1-, CS2-US2). For Group Temporal, early (10-s) or late (90-s) temporal cues within each of these Light and Dark periods were diagnostic of these contingencies (i.e., Early: CS1-US1, CS2-; Late: CS1-, CS2-US2). Group Visual learned the task, but Group Temporal did not. In Experiment 3 we demonstrated that animals could not solve a related temporal ambiguous occasion setting task in which 1 visual stimulus signaled that both CSs were reinforced early whereas the other visual stimulus signaled that the CSs were reinforced only late. Contrary to a currently popular information theory approach to timing in Pavlovian learning, these results suggest that overt nontemporal visual stimuli are better incorporated into conditional discrimination learning than are temporal stimuli. (PsycINFO Database Record

  15. Improved ambiguity resolution for URTK with dynamic atmosphere constraints

    NASA Astrophysics Data System (ADS)

    Tang, Weiming; Liu, Wenjian; Zou, Xuan; Li, Zongnan; Chen, Liang; Deng, Chenlong; Shi, Chuang

    2016-12-01

    Raw observation processing method with prior knowledge of ionospheric delay could strengthen the ambiguity resolution (AR), but it does not make full use of the relatively longer wavelength of wide-lane (WL) observation. Furthermore, the accuracy of calculated atmospheric delays from the regional augmentation information has quite different in quality, while the atmospheric constraint used in the current methods is usually set to an empirical value. A proper constraint, which matches the accuracy of calculated atmospheric delays, can most effectively compensate the residual systematic biases caused by large inter-station distances. Therefore, the standard deviation of the residual atmospheric parameters should be fine-tuned. This paper presents an atmosphere-constrained AR method for undifferenced network RTK (URTK) rover, whose ambiguities are sequentially fixed according to their wavelengths. Furthermore, this research systematically analyzes the residual atmospheric error and finds that it mainly varies along the positional relationship between the rover and the chosen reference stations. More importantly, its ionospheric part of certain location will also be cyclically influenced every day. Therefore, the standard deviation of residual ionospheric error can be modeled by a daily repeated cosine or other functions with the help of data one day before, and applied by rovers as pseudo-observation. With the data collected at 29 stations from a continuously operating reference station network in Guangdong Province (GDCORS) in China, the efficiency of the proposed approach is confirmed by improving the success and error rates of AR for 10-20 % compared to that of the WL-L1-IF one, as well as making much better positioning accuracy.

  16. Assimilating ambiguous observations to jointly estimate groundwater recharge and conductivity

    NASA Astrophysics Data System (ADS)

    Erdal, Daniel; Cirpka, Olaf A.

    2016-04-01

    In coupled modelling of catchments, the groundwater compartment can be an important water storage as well as having influence on both rivers and evapotranspirational fluxes. It is therefore important to parameterize the groundwater model as correctly as possible. Primarily important to regional groundwater flow is the spatially variable hydraulic conductivity. However, also the groundwater recharge, in a coupled system coming from the unsaturated zone but in a stand-alone groundwater model a boundary condition, is also of high importance. As with all subsurface systems, groundwater properties are difficult to observe in reality and their estimation is an ongoing topic in groundwater research and practice. Commonly, we have to rely on time series of groundwater head observations as base for any parameter estimation. Heads, however, have the drawback that they can be ambiguous and may not uniquely define the inverse problem, especially if both recharge and conductivity are seen as unknown. In the presented work we use a 2D virtual groundwater test case to investigate how the prior knowledge of recharge and conductivity influence their respective and joint estimation as spatially variable fields using head data. Using the Ensemble Kalman filter, it is shown that the joint estimation is possible if the prior knowledge is good enough. If the prior is erroneous the a-priori sampled fields cannot be corrected by the data. However, it is also shown that if the prior knowledge is directly wrong the estimated recharge field can resemble the true conductivity field, resulting in a model that meets the observations but has very poor predictive power. The study exemplifies the importance of prior knowledge in the joint estimation of parameters from ambiguous measurements.

  17. An ambiguity principle for assigning protein structural domains.

    PubMed

    Postic, Guillaume; Ghouzam, Yassine; Chebrek, Romain; Gelly, Jean-Christophe

    2017-01-01

    Ambiguity is the quality of being open to several interpretations. For an image, it arises when the contained elements can be delimited in two or more distinct ways, which may cause confusion. We postulate that it also applies to the analysis of protein three-dimensional structure, which consists in dividing the molecule into subunits called domains. Because different definitions of what constitutes a domain can be used to partition a given structure, the same protein may have different but equally valid domain annotations. However, knowledge and experience generally displace our ability to accept more than one way to decompose the structure of an object-in this case, a protein. This human bias in structure analysis is particularly harmful because it leads to ignoring potential avenues of research. We present an automated method capable of producing multiple alternative decompositions of protein structure (web server and source code available at www.dsimb.inserm.fr/sword/). Our innovative algorithm assigns structural domains through the hierarchical merging of protein units, which are evolutionarily preserved substructures that describe protein architecture at an intermediate level, between domain and secondary structure. To validate the use of these protein units for decomposing protein structures into domains, we set up an extensive benchmark made of expert annotations of structural domains and including state-of-the-art domain parsing algorithms. The relevance of our "multipartitioning" approach is shown through numerous examples of applications covering protein function, evolution, folding, and structure prediction. Finally, we introduce a measure for the structural ambiguity of protein molecules.

  18. 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 sound’s 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

  19. Erasing Errors due to Alignment Ambiguity When Estimating Positive Selection

    PubMed Central

    Redelings, Benjamin

    2014-01-01

    Current estimates of diversifying positive selection rely on first having an accurate multiple sequence alignment. Simulation studies have shown that under biologically plausible conditions, relying on a single estimate of the alignment from commonly used alignment software can lead to unacceptably high false-positive rates in detecting diversifying positive selection. We present a novel statistical method that eliminates excess false positives resulting from alignment error by jointly estimating the degree of positive selection and the alignment under an evolutionary model. Our model treats both substitutions and insertions/deletions as sequence changes on a tree and allows site heterogeneity in the substitution process. We conduct inference starting from unaligned sequence data by integrating over all alignments. This approach naturally accounts for ambiguous alignments without requiring ambiguously aligned sites to be identified and removed prior to analysis. We take a Bayesian approach and conduct inference using Markov chain Monte Carlo to integrate over all alignments on a fixed evolutionary tree topology. We introduce a Bayesian version of the branch-site test and assess the evidence for positive selection using Bayes factors. We compare two models of differing dimensionality using a simple alternative to reversible-jump methods. We also describe a more accurate method of estimating the Bayes factor using Rao-Blackwellization. We then show using simulated data that jointly estimating the alignment and the presence of positive selection solves the problem with excessive false positives from erroneous alignments and has nearly the same power to detect positive selection as when the true alignment is known. We also show that samples taken from the posterior alignment distribution using the software BAli-Phy have substantially lower alignment error compared with MUSCLE, MAFFT, PRANK, and FSA alignments. PMID:24866534

  20. An ambiguity principle for assigning protein structural domains

    PubMed Central

    Postic, Guillaume; Ghouzam, Yassine; Chebrek, Romain; Gelly, Jean-Christophe

    2017-01-01

    Ambiguity is the quality of being open to several interpretations. For an image, it arises when the contained elements can be delimited in two or more distinct ways, which may cause confusion. We postulate that it also applies to the analysis of protein three-dimensional structure, which consists in dividing the molecule into subunits called domains. Because different definitions of what constitutes a domain can be used to partition a given structure, the same protein may have different but equally valid domain annotations. However, knowledge and experience generally displace our ability to accept more than one way to decompose the structure of an object—in this case, a protein. This human bias in structure analysis is particularly harmful because it leads to ignoring potential avenues of research. We present an automated method capable of producing multiple alternative decompositions of protein structure (web server and source code available at www.dsimb.inserm.fr/sword/). Our innovative algorithm assigns structural domains through the hierarchical merging of protein units, which are evolutionarily preserved substructures that describe protein architecture at an intermediate level, between domain and secondary structure. To validate the use of these protein units for decomposing protein structures into domains, we set up an extensive benchmark made of expert annotations of structural domains and including state-of-the-art domain parsing algorithms. The relevance of our “multipartitioning” approach is shown through numerous examples of applications covering protein function, evolution, folding, and structure prediction. Finally, we introduce a measure for the structural ambiguity of protein molecules. PMID:28097215

  1. 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…

  2. 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…

  3. Comprehension of Ambiguous and Other Polysemous Utterances: Presented in Written Mode.

    ERIC Educational Resources Information Center

    Brause, Rita S.

    Designed to assess comprehension of written ambiguous and polysemous structures, this instrument is a series of written statements that include varying degrees and types of ambiguity. In the first part of the test students are asked to identify (from a choice of three) semantically acceptable paraphrases for an initial sentence. Then students must…

  4. 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…

  5. 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…

  6. 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…

  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. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. Early Morphological Processing Is Sensitive to Morphemic Meanings: Evidence from Processing Ambiguous Morphemes

    ERIC Educational Resources Information Center

    Tsang, Yiu-Kei; Chen, Hsuan-Chih

    2013-01-01

    In three priming experiments, we investigated whether the meanings of ambiguous morphemes were activated during word recognition. Using a meaning generation task, Experiment 1 demonstrated that the dominant meaning of individually presented ambiguous morphemes was reported more often than did other less frequent meanings. Also, participants tended…

  15. 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…

  16. 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…

  17. Role Ambiguity and Self-Efficacy: The Moderating Effects of Goal Orientation and Procedural Justice

    ERIC Educational Resources Information Center

    Li, Andrew; Bagger, Jessica

    2008-01-01

    The present study investigated variables that moderated the relationship between role ambiguity and self-efficacy. Results of a field study found support for the moderating role of learning goal orientation, such that the relationship between role ambiguity and self-efficacy was weaker when learning goal orientation was high. In addition, we found…

  18. 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.

  19. 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…

  20. Role Ambiguity, Role Conflict and Job Satisfaction among Physical Education Teachers in Greece

    ERIC Educational Resources Information Center

    Koustelios, Athanasios; Theodorakis, Nicholas; Goulimaris, Dimitris

    2004-01-01

    This study examines role conflict, role ambiguity, and job satisfaction among Greek physical education teachers, and the extent to which role conflict and role ambiguity predict job satisfaction. All members of the sample of 61 physical education teachers were employed in Greek "Sport for all" programs. The standard multiple regression…

  1. The Ambiguities of Out-of-Home Care: Children with Severe or Profound Disabilities

    ERIC Educational Resources Information Center

    Roper, Susanne Olsen; Jackson, Jeffrey B.

    2007-01-01

    Ambiguous loss and boundary ambiguity experienced by families during the process of placing their child in out-of-home care was described by parents in 20 families raising a child with severe or profound developmental disabilities. In retrospective interviews, parents discussed their experiences before and after placing their child and how they…

  2. Role Conflict and Ambiguity as Predictors of Job Satisfaction in High School Counselors

    ERIC Educational Resources Information Center

    Cervoni, Annemarie; DeLucia-Waack, Janice

    2011-01-01

    The purpose of this study was to examine the relationship between role conflict and role ambiguity, and percentage of time spent on ASCA recommended duties (counseling, coordination, consultation, and large group guidance); and job satisfaction of high school counselors. The Role Conflict and Role Ambiguity Scale and the Job Descriptive Index were…

  3. 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…

  4. A Multiple-Channel Model of Task-Dependent Ambiguity Resolution in Sentence Comprehension

    ERIC Educational Resources Information Center

    Logacev, Pavel; Vasishth, Shravan

    2016-01-01

    Traxler, Pickering, and Clifton (1998) found that ambiguous sentences are read faster than their unambiguous counterparts. This so-called "ambiguity advantage" has presented a major challenge to classical theories of human sentence comprehension (parsing) because its most prominent explanation, in the form of the unrestricted race model…

  5. 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…

  6. 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,…

  7. 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…

  8. In the Face of Uncertainty: A Twin Study of Ambiguous Information, Anxiety and Depression in Children

    ERIC Educational Resources Information Center

    Eley, Thalia C.; Gregory, Alice M.; Lau, Jennifer Y. F.; McGuffin, Peter; Napolitano, Maria; Rijsdijk, Fruhling V.; Clark, David M.

    2008-01-01

    Anxiety and depression share genetic influences, and have been associated with similar cognitive biases. Psychological theories of anxiety and depression highlight threat interpretations of ambiguity. Little is known about whether genes influence cognitive style, or its links to symptoms. We assessed ambiguous word and scenario interpretations,…

  9. Understandings of Environmental Quality: Ambiguities and Values Held by Environmental Professionals

    Treesearch

    R. Bruce Hull; David Richert; Erin Seekamp; David Robertson; Gregory J. Buhyoff

    2003-01-01

    The terms used to describe and negotiate environmental quality are both ambiguous and value-laden. Stakeholders intimately and actively involved in the management of forested lands were interviewed and found to use ambiguous, tautological, and value-laden definitions of terms such as health, biodiversity, sustainability, and naturalness. This confusing language...

  10. 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,…

  11. Improvements in fetal heart rate analysis by the removal of maternal-fetal heart rate ambiguities.

    PubMed

    Pinto, Paula; Costa-Santos, Cristina; Gonçalves, Hernâni; Ayres-De-Campos, Diogo; Bernardes, João

    2015-11-19

    Misinterpretation of the maternal heart rate (MHR) as fetal may lead to significant errors in fetal heart rate (FHR) interpretation. In this study we hypothesized that the removal of these MHR-FHR ambiguities would improve FHR analysis during the final hour of labor. Sixty-one MHR and FHR recordings were simultaneously acquired in the final hour of labor. Removal of MHR-FHR ambiguities was performed by subtracting MHR signals from their FHR counterparts when the absolute difference between the two was less or equal to 5 beats per minute. Major MHR-FHR ambiguities were defined when they exceeded 1% of the tracing. Maternal, fetal and neonatal characteristics were evaluated in cases where major MHR-FHR ambiguities occurred and computer analysis of FHR recordings was compared, before and after removal of the ambiguities. Seventy-two percent of tracings (44/61) exhibited episodes of major MHR-FHR ambiguities, which were not significantly associated with any maternal, fetal or neonatal characteristics, but were associated with MHR accelerations, FHR signal loss and decelerations. Removal of MHR-FHR ambiguities resulted in a significant decrease in FHR decelerations, and improvement in FHR tracing classification. FHR interpretation during the final hour of labor can be significantly improved by the removal of MHR-FHR ambiguities.

  12. Exploring the Relationship between Tolerance of Ambiguity of EFL Learners and Their Vocabulary Knowledge

    ERIC Educational Resources Information Center

    Basöz, Tutku

    2015-01-01

    Learning a new language is akin to exploring an unknown land as ambiguous situations are prevalent in language learning. Ambiguity tolerance, which can hinder or facilitate language learning, is considered as an important learning style. The purpose of the present study was to understand how tolerant/intolerant EFL learners are of foreign language…

  13. 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…

  14. 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…

  15. Perceived Role Conflict, Role Ambiguity, and Burnout among Special Education Teachers.

    ERIC Educational Resources Information Center

    Crane, Stephen J.; Iwanicki, Edward F.

    1986-01-01

    The study examined the relationship of role conflict and role ambiguity to teacher burnout among 443 urban special education teachers. Role conflict and ambiguity explained a significant amount of variance in feelings of emotional exhaustion and depersonalization. While perceived burnout among teachers was moderate, the level varied significantly…

  16. 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…

  17. 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…

  18. A Multiple-Channel Model of Task-Dependent Ambiguity Resolution in Sentence Comprehension

    ERIC Educational Resources Information Center

    Logacev, Pavel; Vasishth, Shravan

    2016-01-01

    Traxler, Pickering, and Clifton (1998) found that ambiguous sentences are read faster than their unambiguous counterparts. This so-called "ambiguity advantage" has presented a major challenge to classical theories of human sentence comprehension (parsing) because its most prominent explanation, in the form of the unrestricted race model…

  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. 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…

  1. 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…

  2. 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.

  3. 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…

  4. 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…

  5. In the Face of Uncertainty: A Twin Study of Ambiguous Information, Anxiety and Depression in Children

    ERIC Educational Resources Information Center

    Eley, Thalia C.; Gregory, Alice M.; Lau, Jennifer Y. F.; McGuffin, Peter; Napolitano, Maria; Rijsdijk, Fruhling V.; Clark, David M.

    2008-01-01

    Anxiety and depression share genetic influences, and have been associated with similar cognitive biases. Psychological theories of anxiety and depression highlight threat interpretations of ambiguity. Little is known about whether genes influence cognitive style, or its links to symptoms. We assessed ambiguous word and scenario interpretations,…

  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. Early Morphological Processing Is Sensitive to Morphemic Meanings: Evidence from Processing Ambiguous Morphemes

    ERIC Educational Resources Information Center

    Tsang, Yiu-Kei; Chen, Hsuan-Chih

    2013-01-01

    In three priming experiments, we investigated whether the meanings of ambiguous morphemes were activated during word recognition. Using a meaning generation task, Experiment 1 demonstrated that the dominant meaning of individually presented ambiguous morphemes was reported more often than did other less frequent meanings. Also, participants tended…

  8. 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

  9. Role conflict, role ambiguity, and burnout in nurses and physicians at a university hospital in Turkey.

    PubMed

    Tunc, Tulin; Kutanis, Rana Ozen

    2009-12-01

    In many countries currently, health-care professionals experience burnout in their professional life. This study explored the relationship between burnout, and role conflict and role ambiguity in nurses and physicians at a university hospital in Turkey. The data were collected by questionnaires that included sociodemographic variables, Maslach's Burnout Inventory (MBI), and Rizzo's Role Conflict and Role Ambiguity Scales. Two hundred and fifty one health-care professionals (170 physicians and 81 nurses) responded to the survey. There was a strong positive correlation between the MBI and Rizzo's Role Conflict and Role Ambiguity Scales. The nurses showed significantly higher levels of role conflict, role ambiguity, and burnout compared to the physicians. A multiple regression analysis showed that role conflict and role ambiguity might help to explain the higher level of burnout experienced by the nurses compared to the physicians. Future research is needed to develop preventive measures for the burnout of health-care professionals.

  10. 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.

  11. More is not always better: coping with ambiguity in natural resources management.

    PubMed

    Brugnach, M; Dewulf, A; Henriksen, H J; van der Keur, P

    2011-01-01

    Coping with ambiguities in natural resources management has become unavoidable. Ambiguity is a distinct type of uncertainty that results from the simultaneous presence of multiple valid, and sometimes conflicting, ways of framing a problem. As such, it reflects discrepancies in meanings and interpretations. Under the presence of ambiguity it is not clear what problem is to be solved, who should be involved in the decision processes or what is an appropriate course of action. Despite the extensive literature about methodologies and tools to deal with uncertainty, not much has been said about how to handle ambiguities. In this paper, we discuss the notions of framing and ambiguity, and we identify five broad strategies to handle it: rational problem solving, persuasion, dialogical learning, negotiation and opposition. We compare these approaches in terms of their assumptions, mechanisms and outcomes and illustrate each approach with a number of concrete methods.

  12. Perinatal loss and parental grief: the challenge of ambiguity and disenfranchised grief.

    PubMed

    Lang, Ariella; Fleiszer, Andrea R; Duhamel, Fabie; Sword, Wendy; Gilbert, Kathleen R; Corsini-Munt, Serena

    2011-01-01

    Following perinatal loss, a type of ambiguous loss, bereaved couples struggle with and experience distress due to various forms of ambiguity. Moreover, the juxtaposition of their grief with society's minimization often disenfranchises them from traditional grieving processes. The purpose of this study was to explore sources of ambiguity and disenfranchised grief related to perinatal loss. Audio-taped interviews with 13 bereaved couples at 2, 6, and 13 months following the death of their fetus or infant were analyzed. Several categories of ambiguity and disenfranchised grief emerged, pertaining to: (a) the viability of the pregnancy; (b) the physical process of pregnancy loss; (c) making arrangements for the remains; and (d) sharing the news. This study uncovers the many sources of ambiguity and disenfranchised grief that bereaved couples face in interactions with family, friends, society, and healthcare professionals. These insights may inform healthcare professionals in their attempts to ease distress related to perinatal loss.

  13. Dealing With Uncertainty: Testing Risk- and Ambiguity-Attitude Across Adolescence.

    PubMed

    Blankenstein, Neeltje E; Crone, Eveline A; van den Bos, Wouter; van Duijvenvoorde, Anna C K

    2016-01-01

    Attitudes to risk (known probabilities) and attitudes to ambiguity (unknown probabilities) are separate constructs that influence decision making, but their development across adolescence remains elusive. We administered a choice task to a wide adolescent age-range (N = 157, 10-25 years) to disentangle risk- and ambiguity-attitudes using a model-based approach. Additionally, this task was played in a social context, presenting choices from a high risk-taking peer. We observed age-related changes in ambiguity-attitude, but not risk-attitude. Also, ambiguity-aversion was negatively related to real-life risk taking. Finally, the social context influenced only risk-attitudes. These results highlight the importance of disentangling risk- and ambiguity-attitudes in adolescent risk taking.

  14. Determinants of translation ambiguity: A within and cross-language comparison.

    PubMed

    Degani, Tamar; Prior, Anat; Eddington, Chelsea M; Arêas da Luz Fontes, Ana B; Tokowicz, Natasha

    2016-01-01

    Ambiguity in translation is highly prevalent, and has consequences for second-language learning and for bilingual lexical processing. To better understand this phenomenon, the current study compared the determinants of translation ambiguity across four sets of translation norms from English to Spanish, Dutch, German and Hebrew. The number of translations an English word received was correlated across these different languages, and was also correlated with the number of senses the word has in English, demonstrating that translation ambiguity is partially determined by within-language semantic ambiguity. For semantically-ambiguous English words, the probability of the different translations in Spanish and Hebrew was predicted by the meaning-dominance structure in English, beyond the influence of other lexical and semantic factors, for bilinguals translating from their L1, and translating from their L2. These findings are consistent with models postulating direct access to meaning from L2 words for moderately-proficient bilinguals.

  15. 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

    2014-12-16

    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.

  16. Evaluation of ambiguous associations in the amygdala by learning the structure of the environment.

    PubMed

    Madarasz, Tamas J; Diaz-Mataix, Lorenzo; Akhand, Omar; Ycu, Edgar A; LeDoux, Joseph E; Johansen, Joshua P

    2016-07-01

    Recognizing predictive relationships is critical for survival, but an understanding of the underlying neural mechanisms remains elusive. In particular, it is unclear how the brain distinguishes predictive relationships from spurious ones when evidence about a relationship is ambiguous, or how it computes predictions given such uncertainty. To better understand this process, we introduced ambiguity into an associative learning task by presenting aversive outcomes both in the presence and in the absence of a predictive cue. Electrophysiological and optogenetic approaches revealed that amygdala neurons directly regulated and tracked the effects of ambiguity on learning. Contrary to established accounts of associative learning, however, interference from competing associations was not required to assess an ambiguous cue-outcome contingency. Instead, animals' behavior was explained by a normative account that evaluates different models of the environment's statistical structure. These findings suggest an alternative view of amygdala circuits in resolving ambiguity during aversive learning.

  17. Ambiguity of non-systematic chemical identifiers within and between small-molecule databases.

    PubMed

    Akhondi, Saber A; Muresan, Sorel; Williams, Antony J; Kors, Jan A

    2015-01-01

    A wide range of chemical compound databases are currently available for pharmaceutical research. To retrieve compound information, including structures, researchers can query these chemical databases using non-systematic identifiers. These are source-dependent identifiers (e.g., brand names, generic names), which are usually assigned to the compound at the point of registration. The correctness of non-systematic identifiers (i.e., whether an identifier matches the associated structure) can only be assessed manually, which is cumbersome, but it is possible to automatically check their ambiguity (i.e., whether an identifier matches more than one structure). In this study we have quantified the ambiguity of non-systematic identifiers within and between eight widely used chemical databases. We also studied the effect of chemical structure standardization on reducing the ambiguity of non-systematic identifiers. The ambiguity of non-systematic identifiers within databases varied from 0.1 to 15.2 % (median 2.5 %). Standardization reduced the ambiguity only to a small extent for most databases. A wide range of ambiguity existed for non-systematic identifiers that are shared between databases (17.7-60.2 %, median of 40.3 %). Removing stereochemistry information provided the largest reduction in ambiguity across databases (median reduction 13.7 percentage points). Ambiguity of non-systematic identifiers within chemical databases is generally low, but ambiguity of non-systematic identifiers that are shared between databases, is high. Chemical structure standardization reduces the ambiguity to a limited extent. Our findings can help to improve database integration, curation, and maintenance.

  18. Phase ambiguity solution with the Pyramid Phasing Sensor

    NASA Astrophysics Data System (ADS)

    Pinna, E.; Esposito, S.; Puglisi, A.; Pieralli, F.; Myers, R. M.; Busoni, L.; Tozzi, A.; Stefanini, P.

    2006-06-01

    In the technological development for the ELTs, one of the key activities is the phasing and alignment of the primary mirror segments. To achieve the phasing accuracy of a small fraction of the wavelength, an optical sensor is required. In 2005 has been demonstrated that the Pyramid Wavefront Sensor can be employed in closed loop to correct simultaneously piston, tip and tilt errors of segmented mirror. The Pyramid Phasing Sensor (PYPS) is based on the sensing of phase step on the segment edges; this kind of phasing sensors have the common limitation of the signal ambiguity induced by the phase periodicity of πδ/λ on the mirror surface step δ, when the wavelength λ is used for the sensing. In this paper we briefly describe three different techniques that allow to solve the phase ambiguity with PYPS. As first we present experimental results on the two wavelengths closed loop procedure proposed by Esposito in 2001; in the laboratory test the multi-wavelength procedure allowed to exceed the sensor capture range of +/-λ/2 and simultaneously retrieve the differential piston of the 32 mirror segments starting from random positions in a 3.2 λ wavefront range, the maximum allowed by the mirror stroke. Then we propose two new techniques based respectively on the segment and wavelength sweep. The Segment Sweep Technique (SST) has been successfully applied during the experimental tests of PYPS at the William Herschel Telescope, when 13 segments of the NAOMI DM has been phased starting from a random position in a 15λ range. The Wavelength Sweep Technique (WST) has been subject of preliminary tests in the Arcetri laboratories in order to prove the concept. Each technique has different capture range, accuracy and operation time, so that each can solve different tasks required to an optical phasing sensor in the ELT application. More in detail the WST and SST could be used combined for the first mirror phasing when the calibration required for the closed loop operations

  19. Ambiguous Capture: Collaborative Capitalism and the Meningitis Vaccine Project

    PubMed Central

    Graham, Janice

    2016-01-01

    ABSTRACT The primary health care approach advanced at Alma Ata to address social determinants of health was replaced by selective health care a year later at Bellagio. Subsequently, immunization was endorsed as a cost-effective technical intervention to combat targeted infectious diseases. Multilateral efforts to collaborate on immunization as a universal public health good ambiguously capture the interests of the world’s governments as well as private, public, and not-for-profit institutions. Global assemblages of scientists, governments, industry and nongovernmental organizations now work in public-private partnerships to develop and make essential vaccines accessible, with vaccines marketed as single fix solutions for global health. Drawing from ethnographic fieldwork in France and Burkina Faso that followed the development, regulation, and implementation of the group A meningococcal conjugate vaccine for sub-Saharan Africa, in this article I describe events during and after the development of MenAfriVac. A technological success narrative steeped in collaborative capitalist rhetoric disguises neglected health care systems. PMID:27027575

  20. 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. © 2013 John Wiley & Sons Ltd.

  1. Expressive intent, ambiguity, and aesthetic experiences of music and poetry

    PubMed Central

    Margulis, Elizabeth Hellmuth; Levine, William H.; Simchy-Gross, Rhimmon; Kroger, Carolyn

    2017-01-01

    A growing number of studies are investigating the way that aesthetic experiences are generated across different media. Empathy with a perceived human artist has been suggested as a common mechanism [1]. In this study, people heard 30 s excerpts of ambiguous music and poetry preceded by neutral, positively valenced, or negatively valenced information about the composer's or author’s intent. The information influenced their perception of the excerpts—excerpts paired with positive intent information were perceived as happier and excerpts paired with negative intent information were perceived as sadder (although across intent conditions, musical excerpts were perceived as happier than poetry excerpts). Moreover, the information modulated the aesthetic experience of the excerpts in different ways for the different excerpt types: positive intent information increased enjoyment and the degree to which people found the musical excerpts to be moving, but negative intent information increased these qualities for poetry. Additionally, positive intent information was judged to better match musical excerpts and negative intent information to better match poetic excerpts. These results suggest that empathy with a perceived human artist is indeed an important shared factor across experiences of music and poetry, but that other mechanisms distinguish the generation of aesthetic appreciation between these two media. PMID:28746376

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

    NASA Astrophysics Data System (ADS)

    Kvasnička, Michal; Heřmánek, Antonín; Kuneš, Michal; Pelant, Martin; Plšek, 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.

  3. Ambiguous Capture: Collaborative Capitalism and the Meningitis Vaccine Project.

    PubMed

    Graham, Janice

    2016-01-01

    The primary health care approach advanced at Alma Ata to address social determinants of health was replaced by selective health care a year later at Bellagio. Subsequently, immunization was endorsed as a cost-effective technical intervention to combat targeted infectious diseases. Multilateral efforts to collaborate on immunization as a universal public health good ambiguously capture the interests of the world's governments as well as private, public, and not-for-profit institutions. Global assemblages of scientists, governments, industry and nongovernmental organizations now work in public-private partnerships to develop and make essential vaccines accessible, with vaccines marketed as single fix solutions for global health. Drawing from ethnographic fieldwork in France and Burkina Faso that followed the development, regulation, and implementation of the group A meningococcal conjugate vaccine for sub-Saharan Africa, in this article I describe events during and after the development of MenAfriVac. A technological success narrative steeped in collaborative capitalist rhetoric disguises neglected health care systems.

  4. Primary care mental health workers: role expectations, conflict and ambiguity.

    PubMed

    Bower, Peter; Jerrim, Sophie; Gask, Linda

    2004-07-01

    A number of professionals are involved in mental health in primary care. The NHS Plan proposed the introduction of a new professional, the primary care mental health worker (PCMHW), to improve care in this setting. The present study was conducted to examine pilot PCMHW-type roles currently in existence, to explore staff expectations concerning the new PCMHW role and to consider the issues relating to roles in primary care mental health that are raised by this new worker. The study used a case study design, and involved qualitative interviews with 46 managers and clinicians from primary care and specialist mental health services, including pilot PCMHW-type roles. The key findings were as follows: The pilot PCMHW-type roles were almost exclusively related to client work, whereas respondents had far wider role expectations of the new PCMHWs, relating to perceived gaps in current service provision. This highlights the potential for role conflict. Secondly, there was disagreement and ambiguity among some respondents as to the nature of the new PCMHW's role in client work, and its relationship with the work undertaken by other mental health professionals such as counsellors, psychologists and nurses. Given that multiple professionals are involved in mental health care in primary care, issues relating to roles are likely to be crucial in the effective implementation of the new PCMHWs.

  5. Ethical assumptions and ambiguities in the Americans With Disabilities Act.

    PubMed

    Kopelman, L M

    1996-04-01

    The Americans With Disabilities Act (ADA) promotes social justice by protecting disabled persons from discrimination and prejudice. It seeks equality of opportunity for them and protects their well being by giving them fair access to goods, services and benefits. These rights are circumscribed in the ADA, however, by constraints of cost, efficiency, utility, and certain social mores. The ADA offers little direction about how to set priorities when these values come into conflict, or about whether equality or opportunity favors equivalent or preferential treatment for disadvantaged people. Until these ambiguities and potential value conflicts are resolved, a central moral and social problem remains unresolved: How can we demonstrate commitment to the rights and welfare of those with severe disabilities while placing fair limits upon their claims? Five special concerns are discussed: (1) eligibility and the allocation of health care; (2) the meaning of 'qualified but disabled' in employing people with mental disabilities; (3) equal opportunity and problems of envy and malingering; (4) ADA accommodation and public protection through testing and licensure; and (5) ADA protection and problems of backlash. Rather than simply wait to see what courts and administrative agencies decide, we should evaluate the moral conflicts, articulate criteria, and help make some difficult choices on morally defensible grounds.

  6. Phrase Length and Prosody in On-Line Ambiguity Resolution.

    PubMed

    Webman-Shafran, Ronit; Fodor, Janet Dean

    2016-06-01

    We investigated the processing of ambiguous double-PP constructions in Hebrew. Selection restrictions forced the first prepositional phrase (PP1) to attach low, but PP2 could attach maximally high to VP or maximally low to the NP inside PP1. A length contrast in PP2 was also examined. This construction affords more potential locations for prosodic boundaries, and has a sharper structural contrast between the two attachment sites, than the single-PP construction which has yielded mixed results in previous work. A combined production-comprehension task showed more productions of pre-PP2 prosodic boundaries for long-PP2 than short-PP2. In comprehension, high PP2-attachment was favored by a prosodic boundary before PP2, regardless of PP2 length. This study provides performance data supporting the interplay of phrase lengths with structure-sensitivity as posited in the linguistics literature on the syntax-prosody interface, and supports the claim that readers are sensitive to the structural implications of the prosody they project onto sentences.

  7. Assumptions and ambiguities in nonplanar acoustic soliton theory

    SciTech Connect

    Verheest, Frank; 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.

  8. 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.

  9. Can false memories prime alternative solutions to ambiguous problems?

    PubMed

    Howe, Mark L; Garner, Sarah R

    2017-05-29

    Research has demonstrated that false memories are capable of priming and facilitating insight-based problem-solving tasks by increasing solution rates and decreasing solution times. The present research extended this finding by investigating whether false memories could be used to bias ambiguous insight-based problem-solving tasks in a similar manner. Compound remote associate task (CRAT) problems with two possible correct answers, a dominant and a non-dominant solution, were created and normed (Experiment 1). In Experiment 2, participants were asked to solve these CRAT problems after they were given Deese/Roediger-McDermott lists whose critical lures were also the non-dominant solution to half of the corresponding CRATs. As predicted, when false memories served as primes, solution rates were higher and solution times were faster for non-dominant than dominant CRAT solutions. This biasing effect was only found when participants falsely recalled the critical lure, and was not found when participants did not falsely recall the critical lure, or when they were not primed. Results are discussed with regard to spreading activation models of solution competition in problem-solving tasks and current theories of false memory priming effects.

  10. Textbook Deficiencies: Ambiguities in Chemical Kinetics Rates and Rate Constants

    NASA Astrophysics Data System (ADS)

    Quisenberry, Keith T.; Tellinghuisen, Joel

    2006-03-01

    Balanced chemical reactions often have at least some stoichiometry coefficients that are not unity. To avoid ambiguity in defining the kinetics rate for a reaction, the IUPAC has established the convention, rate = (1/ν i )/(d[A i ]/d t ) relating the reaction rate to the rate of change of concentration of any reactant or product A i and its stoichiometry number ν i (negative for reactants, positive for products). The rate is a product of the rate constant k and some function of the concentrations of reactants and products that must be determined experimentally. While most general chemistry textbooks correctly state this convention, most also proceed to ignore it in subsequent development, particularly in the use of integrated rate laws and the definition of the reaction half-life. We recommend that in future editions, authors make it clear that (i) the reaction rate and rate constant cannot be defined unambiguously without explicitly stating the reaction for which they apply and therefore (ii) the relation between the half-life, which is a physical property of the reaction system, and the rate constant depends upon how the reaction is written. The errors have arisen in part because most texts simply state the integrated rate expressions for first- and second-order reactions without deriving them. It is both appropriate and easy to include such derivations in texts oriented toward students intending careers in science, engineering, and medicine.

  11. Normalizing biomedical terms by minimizing ambiguity and variability

    PubMed Central

    Tsuruoka, Yoshimasa; McNaught, John; Ananiadou, Sophia

    2008-01-01

    Background One of the difficulties in mapping biomedical named entities, e.g. genes, proteins, chemicals and diseases, to their concept identifiers stems from the potential variability of the terms. Soft string matching is a possible solution to the problem, but its inherent heavy computational cost discourages its use when the dictionaries are large or when real time processing is required. A less computationally demanding approach is to normalize the terms by using heuristic rules, which enables us to look up a dictionary in a constant time regardless of its size. The development of good heuristic rules, however, requires extensive knowledge of the terminology in question and thus is the bottleneck of the normalization approach. Results We present a novel framework for discovering a list of normalization rules from a dictionary in a fully automated manner. The rules are discovered in such a way that they minimize the ambiguity and variability of the terms in the dictionary. We evaluated our algorithm using two large dictionaries: a human gene/protein name dictionary built from BioThesaurus and a disease name dictionary built from UMLS. Conclusions The experimental results showed that automatically discovered rules can perform comparably to carefully crafted heuristic rules in term mapping tasks, and the computational overhead of rule application is small enough that a very fast implementation is possible. This work will help improve the performance of term-concept mapping tasks in biomedical information extraction especially when good normalization heuristics for the target terminology are not fully known. PMID:18426547

  12. Normalizing biomedical terms by minimizing ambiguity and variability.

    PubMed

    Tsuruoka, Yoshimasa; McNaught, John; Ananiadou, Sophia

    2008-04-11

    One of the difficulties in mapping biomedical named entities, e.g. genes, proteins, chemicals and diseases, to their concept identifiers stems from the potential variability of the terms. Soft string matching is a possible solution to the problem, but its inherent heavy computational cost discourages its use when the dictionaries are large or when real time processing is required. A less computationally demanding approach is to normalize the terms by using heuristic rules, which enables us to look up a dictionary in a constant time regardless of its size. The development of good heuristic rules, however, requires extensive knowledge of the terminology in question and thus is the bottleneck of the normalization approach. We present a novel framework for discovering a list of normalization rules from a dictionary in a fully automated manner. The rules are discovered in such a way that they minimize the ambiguity and variability of the terms in the dictionary. We evaluated our algorithm using two large dictionaries: a human gene/protein name dictionary built from BioThesaurus and a disease name dictionary built from UMLS. The experimental results showed that automatically discovered rules can perform comparably to carefully crafted heuristic rules in term mapping tasks, and the computational overhead of rule application is small enough that a very fast implementation is possible. This work will help improve the performance of term-concept mapping tasks in biomedical information extraction especially when good normalization heuristics for the target terminology are not fully known.

  13. Children's use of gesture to resolve lexical ambiguity.

    PubMed

    Kidd, Evan; Holler, Judith

    2009-11-01

    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 that children used during attempts at disambiguation: speech, gesture, or a combination of the two. The results indicated that the 3-year-old children rarely disambiguated the two senses, mainly using deictic pointing gestures during attempts at disambiguation. In contrast, the 4-year-old children attempted to disambiguate the two senses more often, using a larger proportion of iconic gestures than the other children. The 5-year-old children used less iconic gestures than the 4-year-olds, but unlike the 3-year-olds, were able to disambiguate the senses through the verbal channel. The results highlight the value of gesture to the development of children's language and communication skills.

  14. 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.

  15. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements.

    PubMed

    Kreysa, Helene; Kessler, Luise; Schweinberger, Stefan R

    2016-01-01

    A speaker's gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., "sniffer dogs cannot smell the difference between identical twins"). Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted) gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze.

  16. Expressive intent, ambiguity, and aesthetic experiences of music and poetry.

    PubMed

    Margulis, Elizabeth Hellmuth; Levine, William H; Simchy-Gross, Rhimmon; Kroger, Carolyn

    2017-01-01

    A growing number of studies are investigating the way that aesthetic experiences are generated across different media. Empathy with a perceived human artist has been suggested as a common mechanism [1]. In this study, people heard 30 s excerpts of ambiguous music and poetry preceded by neutral, positively valenced, or negatively valenced information about the composer's or author's intent. The information influenced their perception of the excerpts-excerpts paired with positive intent information were perceived as happier and excerpts paired with negative intent information were perceived as sadder (although across intent conditions, musical excerpts were perceived as happier than poetry excerpts). Moreover, the information modulated the aesthetic experience of the excerpts in different ways for the different excerpt types: positive intent information increased enjoyment and the degree to which people found the musical excerpts to be moving, but negative intent information increased these qualities for poetry. Additionally, positive intent information was judged to better match musical excerpts and negative intent information to better match poetic excerpts. These results suggest that empathy with a perceived human artist is indeed an important shared factor across experiences of music and poetry, but that other mechanisms distinguish the generation of aesthetic appreciation between these two media.

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

    NASA Astrophysics Data System (ADS)

    Butkiewicz-Bąk, M.; Kwiatkowski, T.; Bartczak, P.; Dudziński, G.; Marciniak, A.

    2017-09-01

    Among asteroids there exist ambiguities in their rotation period determinations. They are due to incomplete coverage of the rotation, noise and/or aliases resulting from gaps between separate lightcurves. To help to remove such uncertainties, basic characteristic of the lightcurves resulting from constraints imposed by the asteroid shapes and geometries of observations should be identified. We simulated light variations of asteroids whose shapes were modelled as Gaussian random spheres, with random orientations of spin vectors and phase angles changed every 5° from 0° to 65°. This produced 1.4 million lightcurves. For each simulated lightcurve, Fourier analysis has been made and the harmonic of the highest amplitude was recorded. From the statistical point of view, all lightcurves observed at phase angles α < 30°, with peak-to-peak amplitudes A > 0.2 mag, are bimodal. Second most frequently dominating harmonic is the first one, with the 3rd harmonic following right after. For 1 per cent of lightcurves with amplitudes A < 0.1 mag and phase angles α < 40°, 4th harmonic dominates.

  18. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements

    PubMed Central

    Kessler, Luise; Schweinberger, Stefan R.

    2016-01-01

    A speaker’s gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., “sniffer dogs cannot smell the difference between identical twins”). Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted) gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze. PMID:27643789

  19. A method of undifferenced ambiguity resolution for GPS+GLONASS precise point positioning

    PubMed Central

    Yi, Wenting; Song, Weiwei; Lou, Yidong; Shi, Chuang; Yao, Yibin

    2016-01-01

    Integer ambiguity resolution is critical for achieving positions of high precision and for shortening the convergence time of precise point positioning (PPP). However, GLONASS adopts the signal processing technology of frequency division multiple access and results in inter-frequency code biases (IFCBs), which are currently difficult to correct. This bias makes the methods proposed for GPS ambiguity fixing unsuitable for GLONASS. To realize undifferenced GLONASS ambiguity fixing, we propose an undifferenced ambiguity resolution method for GPS+GLONASS PPP, which considers the IFCBs estimation. The experimental result demonstrates that the success rate of GLONASS ambiguity fixing can reach 75% through the proposed method. Compared with the ambiguity float solutions, the positioning accuracies of ambiguity-fixed solutions of GLONASS-only PPP are increased by 12.2%, 20.9%, and 10.3%, and that of the GPS+GLONASS PPP by 13.0%, 35.2%, and 14.1% in the North, East and Up directions, respectively. PMID:27222361

  20. 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