D. Navarro-reyes - Academia.edu (original) (raw)

Papers by D. Navarro-reyes

Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence, 2017

To represent the meaning of a word, most models use external language resources, such as text cor... more To represent the meaning of a word, most models use external language resources, such as text corpora, to derive the distributional properties of word usage. In this study, we propose that internal language models, that are more closely aligned to the mental representations of words, can be used to derive new theoretical questions regarding the structure of the mental lexicon. A comparison with internal models also puts into perspective a number of assumptions underlying recently proposed distributional text-based models could provide important insights into cognitive science, including linguistics and artificial intelligence. We focus on word-embedding models which have been proposed to learn aspects of word meaning in a manner similar to humans and contrast them with internal language models derived from a new extensive data set of word associations. An evaluation using relatedness judgments shows that internal language models consistently outperform current state-of-the art text-...

Network: Computation in Neural Systems, 2020

Many researchers have tried to model how environmental knowledge is learned by the brain and used... more Many researchers have tried to model how environmental knowledge is learned by the brain and used in the form of cognitive maps. However, previous work was limited in various important ways: there was little consensus on how these cognitive maps were formed and represented, the planning mechanism was inherently limited to performing relatively simple tasks, and there was little consideration of how these mechanisms would scale up. This paper makes several significant advances. Firstly, the planning mechanism used by the majority of previous work propagates a decaying signal through the network to create a gradient that points towards the goal. However, this decaying signal limited the scale and complexity of tasks that can be solved in this manner. Here we propose several ways in which a network can can self-organize a novel planning mechanism that does not require decaying activity. We also extend this model with a hierarchical planning mechanism: a layer of cells that identify frequently-used sequences of actions and reuse them to significantly increase the efficiency of planning. We speculate that our results may explain the apparent ability of humans and animals to perform model-based planning on both small and large scales without a noticeable loss of efficiency.

Frontiers in Neural Circuits, 2020

Journal of Doctoral Nursing Practice, 2019

BackgroundOnce a person is diagnosed with diabetes, aggressive management is imperative to minimi... more BackgroundOnce a person is diagnosed with diabetes, aggressive management is imperative to minimize poor glycemic control devastating outcomes. However, for some patients reaching optimum blood glucose levels is challenging due to the complexity of diabetes care. To achieve good blood glucose control, patients affected by diabetes must engage in self-care activities that include routine blood glucose check, dietary control, physical activity, medication regimen, and routine medical provider visits. Diabetes-associated self-care activities aimed to reach good blood glucose control can be hindered by multiple factors including shift work.ObjectiveTo evaluate self-management activities of individuals affected by diabetes who are employed as shift workers. This study also informs primary care nurse practitioners of the challenges shift workers face in managing their disease.MethodsThis was a cross-sectional descriptive study. Participants were individuals affected by type II diabetes fr...

PLOS ONE, 2018

We study a self-organising neural network model of how visual representations in the primate dors... more We study a self-organising neural network model of how visual representations in the primate dorsal visual pathway are transformed from an eye-centred to head-centred frame of reference. The model has previously been shown to robustly develop head-centred output neurons with a standard trace learning rule, but only under limited conditions. Specifically it fails when incorporating visual input neurons with monotonic gain modulation by eye-position. Since eye-centred neurons with monotonic gain modulation are so common in the dorsal visual pathway, it is an important challenge to show how efferent synaptic connections from these neurons may self-organise to produce head-centred responses in a subpopulation of postsynaptic neurons. We show for the first time how a variety of modified, yet still biologically plausible, versions of the standard trace learning rule enable the model to perform a coordinate transformation from eye-centred to head-centred reference frames when the visual input neurons have monotonic gain modulation by eye-position.

Nuclear Physics B, 2001

We study the near-horizon AdS 2 ×S 2 geometry of evaporating near-extremal Reissner-Nordström bla... more We study the near-horizon AdS 2 ×S 2 geometry of evaporating near-extremal Reissner-Nordström black holes interacting with null matter. The non-local (boundary) terms t ± , coming from the effective theory corrected with the quantum Polyakov-Liouville action, are treated as dynamical variables. We describe analytically the evaporation process which turns out to be compatible with the third law of thermodynamics, i.e., an infinite amount of time is required for the black hole to decay to extremality. Finally we comment briefly on the implications of our results for the information loss problem.

Journal of experimental psychology. General, Sep 1, 2016

Similarity plays an important role in organizing the semantic system. However, given that similar... more Similarity plays an important role in organizing the semantic system. However, given that similarity cannot be defined on purely logical grounds, it is important to understand how people perceive similarities between different entities. Despite this, the vast majority of studies focus on measuring similarity between very closely related items. When considering concepts that are very weakly related, little is known. In this article, we present 4 experiments showing that there are reliable and systematic patterns in how people evaluate the similarities between very dissimilar entities. We present a semantic network account of these similarities showing that a spreading activation mechanism defined over a word association network naturally makes correct predictions about weak similarities, whereas, though simpler, models based on direct neighbors between word pairs derived using the same network cannot. (PsycINFO Database Record

We investigate the canonical equivalence of a matter-coupled 2D dilaton gravity theory defined by... more We investigate the canonical equivalence of a matter-coupled 2D dilaton gravity theory defined by the action functional S = d 2 x √ −g (Rφ + V (φ) − 1 2 H (φ) (∇f) 2 , and a free field theory. When the scalar field f is minimally coupled to the metric field (H(φ) = 1) the theory is equivalent, up to a boundary contribution, to a theory of three free scalar fields with indefinite kinetic terms, irrespective of the particular form of the potential V (φ). If the potential is an exponential function of the dilaton one recovers a generalized form of the classical canonical transformation of Liouville theory. When f is a dilaton coupled scalar (H(φ) = φ) and the potential is an arbitrary power of the dilaton the theory is also canonically equivalent to a theory of three free fields with a Minkowskian target space. In the simplest case (V (φ) = 0) we provide an explicit free field realization of the Einstein-Rosen midisuperspace. The Virasoro anomaly and the consistence of the Dirac operator quantization play a central role in our approach.

Cognitive psychology, Jan 21, 2015

A robust finding in category-based induction tasks is for positive observations to raise the will... more A robust finding in category-based induction tasks is for positive observations to raise the willingness to generalize to other categories while negative observations lower the willingness to generalize. This pattern is referred to as monotonic generalization. Across three experiments we find systematic non-monotonicity effects, in which negative observations raise the willingness to generalize. Experiments 1 and 2 show that this effect emerges in hierarchically structured domains when a negative observation from a different category is added to a positive observation. They also demonstrate that this is related to a specific kind of shift in the reasoner's hypothesis space. Experiment 3 shows that the effect depends on the assumptions that the reasoner makes about how inductive arguments are constructed. Non-monotonic reasoning occurs when people believe the facts were put together by a helpful communicator, but monotonicity is restored when they believe the observations were sa...

Proceedings of the 9th Conference of the Australasian Society for Cognitive Science, 2010

Category-based feature generalisations are affected by similarity relationships between objects a... more Category-based feature generalisations are affected by similarity relationships between objects and by knowledge of causal relationships between features. However, there is disagreement between recent studies about whether people will simultaneously consider both relationships. To help resolve this discrepancy, the current study addresses an important difference between past experimental designs: the strength of causal relationships between features. Participants were trained on a set of four different kinds of artificial alien animals (with a known perceptual similarity structure), and were taught about three novel features. Participants were taught that either: 1) there were no relationships between the three features; 2) the features shared weak causal relationships; or 3) the features shared strong causal relationships. After training, all participants then made predictions about the features of the four kinds of animals. As expected, it was found that the strength of the causal relationships influenced the degree to which participants' feature predictions were affected by causal and similarity considerations. Three probabilistic graphical models were fit to the participants' predictions, in a preliminary effort to predict participant responses.

Proceedings of the 9th Conference of the Australasian Society for Cognitive Science, 2010

We present a new experimental method for studying the illusion of control in a gambling context, ... more We present a new experimental method for studying the illusion of control in a gambling context, along with a new multi-item measure of the degree of perceived control. Responses to the measure were found to reflect a distinction between primary and secondary control-a distinction not recognised by traditional single-item measures. Furthermore, responses to the new measure were, in contrast to ratings on a concurrently administered traditional measure, found to be completely independent of the experienced reinforcement frequency. This finding highlights the purity of the newlydeveloped measure and calls into question the status of reinforcement frequency as a fundamental determinant of the degree of illusorily perceived control.

2014 IEEE 10th International Conference on e-Science, 2014

Historical data provide valuable information for the understanding of human interactions through ... more Historical data provide valuable information for the understanding of human interactions through time. However, mining this data is challenging as the available records are generally noise digitized handwritten, typewritten or press printed documents. In this research proposal, we plan to develop tools and techniques for pre-processing and extracting information from documents of the military dictatorship period that ruled Brazil from 1964 to 1985. The data to be analyzed consists of digitized images of records from DEOPS/SP (São Paulo State Department of Political and Social Order), an emblematic police agency which have monitored (and in some cases, harassed and tortured) hundreds of thousands Brazilian citizens during that period. The idea is to use state-of-the-art powerful artificial intelligence algorithms in conjunction with crowdsourcing techniques to preprocess and extract information from this important period of the Brazilian History.

Theory & Psychology, 2009

Causal reasoning has been studied extensively in experimental cognitive psychology. Generally, th... more Causal reasoning has been studied extensively in experimental cognitive psychology. Generally, the focus is on how individuals learn causal relationships in their environment through observation or interventions. Although it seems self-evident that causal beliefs about some phenomena are learnt largely through linguistic channels, to our knowledge no empirical studies have addressed this issue. In this paper we investigate causal reasoning that is embedded in naturally occurring language. We focus on genetic counselling for cancer, in which complex relationships between genes, medical interventions, and cancer are communicated by health professionals to clients. We borrow the idea of graphical causal maps from previous experimental studies and show that they can be applied to the study of causal reasoning in naturally occurring talk. We see this study as complementing existing experimental research, while maintaining that the study of causal structures embedded in naturalistic langu...

Psychonomic Bulletin & Review, 2002

Physical Review Letters, 2000

The formation of near-extremal Reissner-Nordström black holes in the S-wave approximation can be ... more The formation of near-extremal Reissner-Nordström black holes in the S-wave approximation can be described, near the event horizon, by an effective solvable model. The corresponding one-loop quantum theory remains solvable and allows to follow analytically the evaporation process which is shown to require an infinite amount of time.

Kidney International, 2003

Impact of surgeon and surgical center characteristics on choice of permanent vascular access. Bac... more Impact of surgeon and surgical center characteristics on choice of permanent vascular access. Background. The impact of the surgeon and surgical center characteristics on choice of autogenous arteriovenous (AV) fistula versus artificial AV graft as permanent vascular access for hemodialysis has not been studied. Methods. We used national data from the Department of Veterans Affairs Veterans Health Administration to measure the association of surgeon and surgical center characteristics with choice of initial permanent vascular access among patients undergoing their first vascular access placement procedure between October 1, 2000 and September 30, 2001 (fiscal year 2001). Data were analyzed using a hierarchical logistic regression model clustered for surgical center and surgeon. Results. The study population included 1114 patients, 74 Veterans Administration Medical Centers, and 182 surgeons. Seventy-two percent of patients received an AV fistula as their initial form of permanent vascular access. After adjusting for differences in patient, center, and surgeon characteristics, odds of AV fistula placement at high volume centers (Ͼ30 procedures per year) were more than three times greater than at low volume centers [odds ratio (OR) 3.26, 95% confidence interval (95% CI) 1.37 to 7.75, P ϭ 0.008]. In addition, a strong clustering effect was present at the level of the surgeon (OR 1.55, 95% CI 1.19 to 2.03, P ϭ 0.001) but not at the level of the surgical center, indicating an association with surgeon practice pattern. Conclusion. Barriers to AV fistula placement can exist at the levels of the surgeon and surgical center, respectively. Future strategies to improve AV fistula placement rates should target surgeons and surgical centers in addition to patients, nephrologists, and primary care providers.

Journal of Mathematical Psychology, 2006

After the embargo period  via non-commercial hosting platforms such as their institutional repos... more After the embargo period  via non-commercial hosting platforms such as their institutional repository  via commercial sites with which Elsevier has an agreement In all cases accepted manuscripts should:  link to the formal publication via its DOI  bear a CC-BY-NC-ND license-this is easy to do, click here to find out how  if aggregated with other manuscripts, for example in a repository or other site, be

Journal of Gambling Studies, 2013

Different classification systems for erroneous beliefs about gambling have been proposed, consist... more Different classification systems for erroneous beliefs about gambling have been proposed, consistently alluding to 'illusion of control' and 'gambler's fallacy' categories. None of these classification systems have, however, considered the how the illusion of control and the gambler's fallacy might be interrelated. In this paper, we report the findings of a confirmatory factor analysis that examines the proposal that most erroneous gambling-related beliefs can be defined in terms of Rothbaum et al.'s (1982) distinction between 'primary' and 'secondary' illusory control, with the former being driven to a large extent by the well-known gambler's fallacy and the latter being driven by a complex of beliefs about supernatural forces such as God and luck. A survey consisting of 100 items derived from existing instruments was administered to 329 participants. The analysis confirmed the existence of two latent structures (beliefs in primary and secondary control), while also offering support to the idea that gambler's fallacy-style reasoning may underlie both perceived primary control and beliefs about the cyclical nature of luck, a form of perceived secondary control. The results suggest the need for a greater focus on the role of underlying processes or belief structures as factors that foster susceptibility to specific beliefs in gambling situations. Addressing and recognising the importance of these underlying factors may also have implications for cognitive therapy treatments for problem gambling.

Journal of Allergy and Clinical Immunology, 2006

Background: The prostanoid DP receptor (PTGDR) gene on chromosome 14q22.1 has been identified as ... more Background: The prostanoid DP receptor (PTGDR) gene on chromosome 14q22.1 has been identified as an asthma susceptibility gene. A haplotype with decreased transcription factor binding and transcription efficiency was associated with decreased asthma susceptibility in African American and white subjects. The significance of PTGDR gene variants in asthma has yet to be determined in Latinos, the largest US minority population, nor has the association been replicated in other populations. Objective: To determine the role of PTGDR gene variants in asthma susceptibility and asthma-related traits among the Mexican, Puerto Rican, and African American populations. Methods: We determined whether single nucleotide polymorphisms (SNPs) and haplotypes in PTGDR were associated with asthma and asthma-related traits by familybased and cross-sectional cohort analyses in 336 Puerto Rican and 273 Mexican asthmatic trios and by case-control analysis among African American subjects with asthma and healthy controls (n 5 352). Results: We identified 13 SNPs in the PTGDR gene, and 6 were further analyzed. There was no significant association between PTGDR variants and asthma by family-based or case-control analyses. SNPs-441C and-197C and haplotype TTT showed marginal association with asthma-related traits in Mexican subjects. SNP-441 genotype TT (P 5 .05) and haplotype TTT (P 5 .02) were associated with increased IgE levels in African Americans. Conclusion: We conclude that the PTGDR gene is not a significant risk factor for asthma among Puerto Ricans, Mexicans, or African Americans. Clinical implications: Asthma candidate genes provide insights to pathophysiology and potentially new therapeutic targets, although the PTGDR gene was not found to be a significant risk factor for asthma in 3 populations.

Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence, 2017

To represent the meaning of a word, most models use external language resources, such as text cor... more To represent the meaning of a word, most models use external language resources, such as text corpora, to derive the distributional properties of word usage. In this study, we propose that internal language models, that are more closely aligned to the mental representations of words, can be used to derive new theoretical questions regarding the structure of the mental lexicon. A comparison with internal models also puts into perspective a number of assumptions underlying recently proposed distributional text-based models could provide important insights into cognitive science, including linguistics and artificial intelligence. We focus on word-embedding models which have been proposed to learn aspects of word meaning in a manner similar to humans and contrast them with internal language models derived from a new extensive data set of word associations. An evaluation using relatedness judgments shows that internal language models consistently outperform current state-of-the art text-...

Network: Computation in Neural Systems, 2020

Many researchers have tried to model how environmental knowledge is learned by the brain and used... more Many researchers have tried to model how environmental knowledge is learned by the brain and used in the form of cognitive maps. However, previous work was limited in various important ways: there was little consensus on how these cognitive maps were formed and represented, the planning mechanism was inherently limited to performing relatively simple tasks, and there was little consideration of how these mechanisms would scale up. This paper makes several significant advances. Firstly, the planning mechanism used by the majority of previous work propagates a decaying signal through the network to create a gradient that points towards the goal. However, this decaying signal limited the scale and complexity of tasks that can be solved in this manner. Here we propose several ways in which a network can can self-organize a novel planning mechanism that does not require decaying activity. We also extend this model with a hierarchical planning mechanism: a layer of cells that identify frequently-used sequences of actions and reuse them to significantly increase the efficiency of planning. We speculate that our results may explain the apparent ability of humans and animals to perform model-based planning on both small and large scales without a noticeable loss of efficiency.

Frontiers in Neural Circuits, 2020

Journal of Doctoral Nursing Practice, 2019

BackgroundOnce a person is diagnosed with diabetes, aggressive management is imperative to minimi... more BackgroundOnce a person is diagnosed with diabetes, aggressive management is imperative to minimize poor glycemic control devastating outcomes. However, for some patients reaching optimum blood glucose levels is challenging due to the complexity of diabetes care. To achieve good blood glucose control, patients affected by diabetes must engage in self-care activities that include routine blood glucose check, dietary control, physical activity, medication regimen, and routine medical provider visits. Diabetes-associated self-care activities aimed to reach good blood glucose control can be hindered by multiple factors including shift work.ObjectiveTo evaluate self-management activities of individuals affected by diabetes who are employed as shift workers. This study also informs primary care nurse practitioners of the challenges shift workers face in managing their disease.MethodsThis was a cross-sectional descriptive study. Participants were individuals affected by type II diabetes fr...

PLOS ONE, 2018

We study a self-organising neural network model of how visual representations in the primate dors... more We study a self-organising neural network model of how visual representations in the primate dorsal visual pathway are transformed from an eye-centred to head-centred frame of reference. The model has previously been shown to robustly develop head-centred output neurons with a standard trace learning rule, but only under limited conditions. Specifically it fails when incorporating visual input neurons with monotonic gain modulation by eye-position. Since eye-centred neurons with monotonic gain modulation are so common in the dorsal visual pathway, it is an important challenge to show how efferent synaptic connections from these neurons may self-organise to produce head-centred responses in a subpopulation of postsynaptic neurons. We show for the first time how a variety of modified, yet still biologically plausible, versions of the standard trace learning rule enable the model to perform a coordinate transformation from eye-centred to head-centred reference frames when the visual input neurons have monotonic gain modulation by eye-position.

Nuclear Physics B, 2001

We study the near-horizon AdS 2 ×S 2 geometry of evaporating near-extremal Reissner-Nordström bla... more We study the near-horizon AdS 2 ×S 2 geometry of evaporating near-extremal Reissner-Nordström black holes interacting with null matter. The non-local (boundary) terms t ± , coming from the effective theory corrected with the quantum Polyakov-Liouville action, are treated as dynamical variables. We describe analytically the evaporation process which turns out to be compatible with the third law of thermodynamics, i.e., an infinite amount of time is required for the black hole to decay to extremality. Finally we comment briefly on the implications of our results for the information loss problem.

Journal of experimental psychology. General, Sep 1, 2016

Similarity plays an important role in organizing the semantic system. However, given that similar... more Similarity plays an important role in organizing the semantic system. However, given that similarity cannot be defined on purely logical grounds, it is important to understand how people perceive similarities between different entities. Despite this, the vast majority of studies focus on measuring similarity between very closely related items. When considering concepts that are very weakly related, little is known. In this article, we present 4 experiments showing that there are reliable and systematic patterns in how people evaluate the similarities between very dissimilar entities. We present a semantic network account of these similarities showing that a spreading activation mechanism defined over a word association network naturally makes correct predictions about weak similarities, whereas, though simpler, models based on direct neighbors between word pairs derived using the same network cannot. (PsycINFO Database Record

We investigate the canonical equivalence of a matter-coupled 2D dilaton gravity theory defined by... more We investigate the canonical equivalence of a matter-coupled 2D dilaton gravity theory defined by the action functional S = d 2 x √ −g (Rφ + V (φ) − 1 2 H (φ) (∇f) 2 , and a free field theory. When the scalar field f is minimally coupled to the metric field (H(φ) = 1) the theory is equivalent, up to a boundary contribution, to a theory of three free scalar fields with indefinite kinetic terms, irrespective of the particular form of the potential V (φ). If the potential is an exponential function of the dilaton one recovers a generalized form of the classical canonical transformation of Liouville theory. When f is a dilaton coupled scalar (H(φ) = φ) and the potential is an arbitrary power of the dilaton the theory is also canonically equivalent to a theory of three free fields with a Minkowskian target space. In the simplest case (V (φ) = 0) we provide an explicit free field realization of the Einstein-Rosen midisuperspace. The Virasoro anomaly and the consistence of the Dirac operator quantization play a central role in our approach.

Cognitive psychology, Jan 21, 2015

A robust finding in category-based induction tasks is for positive observations to raise the will... more A robust finding in category-based induction tasks is for positive observations to raise the willingness to generalize to other categories while negative observations lower the willingness to generalize. This pattern is referred to as monotonic generalization. Across three experiments we find systematic non-monotonicity effects, in which negative observations raise the willingness to generalize. Experiments 1 and 2 show that this effect emerges in hierarchically structured domains when a negative observation from a different category is added to a positive observation. They also demonstrate that this is related to a specific kind of shift in the reasoner's hypothesis space. Experiment 3 shows that the effect depends on the assumptions that the reasoner makes about how inductive arguments are constructed. Non-monotonic reasoning occurs when people believe the facts were put together by a helpful communicator, but monotonicity is restored when they believe the observations were sa...

Proceedings of the 9th Conference of the Australasian Society for Cognitive Science, 2010

Category-based feature generalisations are affected by similarity relationships between objects a... more Category-based feature generalisations are affected by similarity relationships between objects and by knowledge of causal relationships between features. However, there is disagreement between recent studies about whether people will simultaneously consider both relationships. To help resolve this discrepancy, the current study addresses an important difference between past experimental designs: the strength of causal relationships between features. Participants were trained on a set of four different kinds of artificial alien animals (with a known perceptual similarity structure), and were taught about three novel features. Participants were taught that either: 1) there were no relationships between the three features; 2) the features shared weak causal relationships; or 3) the features shared strong causal relationships. After training, all participants then made predictions about the features of the four kinds of animals. As expected, it was found that the strength of the causal relationships influenced the degree to which participants' feature predictions were affected by causal and similarity considerations. Three probabilistic graphical models were fit to the participants' predictions, in a preliminary effort to predict participant responses.

Proceedings of the 9th Conference of the Australasian Society for Cognitive Science, 2010

We present a new experimental method for studying the illusion of control in a gambling context, ... more We present a new experimental method for studying the illusion of control in a gambling context, along with a new multi-item measure of the degree of perceived control. Responses to the measure were found to reflect a distinction between primary and secondary control-a distinction not recognised by traditional single-item measures. Furthermore, responses to the new measure were, in contrast to ratings on a concurrently administered traditional measure, found to be completely independent of the experienced reinforcement frequency. This finding highlights the purity of the newlydeveloped measure and calls into question the status of reinforcement frequency as a fundamental determinant of the degree of illusorily perceived control.

2014 IEEE 10th International Conference on e-Science, 2014

Historical data provide valuable information for the understanding of human interactions through ... more Historical data provide valuable information for the understanding of human interactions through time. However, mining this data is challenging as the available records are generally noise digitized handwritten, typewritten or press printed documents. In this research proposal, we plan to develop tools and techniques for pre-processing and extracting information from documents of the military dictatorship period that ruled Brazil from 1964 to 1985. The data to be analyzed consists of digitized images of records from DEOPS/SP (São Paulo State Department of Political and Social Order), an emblematic police agency which have monitored (and in some cases, harassed and tortured) hundreds of thousands Brazilian citizens during that period. The idea is to use state-of-the-art powerful artificial intelligence algorithms in conjunction with crowdsourcing techniques to preprocess and extract information from this important period of the Brazilian History.

Theory & Psychology, 2009

Causal reasoning has been studied extensively in experimental cognitive psychology. Generally, th... more Causal reasoning has been studied extensively in experimental cognitive psychology. Generally, the focus is on how individuals learn causal relationships in their environment through observation or interventions. Although it seems self-evident that causal beliefs about some phenomena are learnt largely through linguistic channels, to our knowledge no empirical studies have addressed this issue. In this paper we investigate causal reasoning that is embedded in naturally occurring language. We focus on genetic counselling for cancer, in which complex relationships between genes, medical interventions, and cancer are communicated by health professionals to clients. We borrow the idea of graphical causal maps from previous experimental studies and show that they can be applied to the study of causal reasoning in naturally occurring talk. We see this study as complementing existing experimental research, while maintaining that the study of causal structures embedded in naturalistic langu...

Psychonomic Bulletin & Review, 2002

Physical Review Letters, 2000

The formation of near-extremal Reissner-Nordström black holes in the S-wave approximation can be ... more The formation of near-extremal Reissner-Nordström black holes in the S-wave approximation can be described, near the event horizon, by an effective solvable model. The corresponding one-loop quantum theory remains solvable and allows to follow analytically the evaporation process which is shown to require an infinite amount of time.

Kidney International, 2003

Impact of surgeon and surgical center characteristics on choice of permanent vascular access. Bac... more Impact of surgeon and surgical center characteristics on choice of permanent vascular access. Background. The impact of the surgeon and surgical center characteristics on choice of autogenous arteriovenous (AV) fistula versus artificial AV graft as permanent vascular access for hemodialysis has not been studied. Methods. We used national data from the Department of Veterans Affairs Veterans Health Administration to measure the association of surgeon and surgical center characteristics with choice of initial permanent vascular access among patients undergoing their first vascular access placement procedure between October 1, 2000 and September 30, 2001 (fiscal year 2001). Data were analyzed using a hierarchical logistic regression model clustered for surgical center and surgeon. Results. The study population included 1114 patients, 74 Veterans Administration Medical Centers, and 182 surgeons. Seventy-two percent of patients received an AV fistula as their initial form of permanent vascular access. After adjusting for differences in patient, center, and surgeon characteristics, odds of AV fistula placement at high volume centers (Ͼ30 procedures per year) were more than three times greater than at low volume centers [odds ratio (OR) 3.26, 95% confidence interval (95% CI) 1.37 to 7.75, P ϭ 0.008]. In addition, a strong clustering effect was present at the level of the surgeon (OR 1.55, 95% CI 1.19 to 2.03, P ϭ 0.001) but not at the level of the surgical center, indicating an association with surgeon practice pattern. Conclusion. Barriers to AV fistula placement can exist at the levels of the surgeon and surgical center, respectively. Future strategies to improve AV fistula placement rates should target surgeons and surgical centers in addition to patients, nephrologists, and primary care providers.

Journal of Mathematical Psychology, 2006

After the embargo period  via non-commercial hosting platforms such as their institutional repos... more After the embargo period  via non-commercial hosting platforms such as their institutional repository  via commercial sites with which Elsevier has an agreement In all cases accepted manuscripts should:  link to the formal publication via its DOI  bear a CC-BY-NC-ND license-this is easy to do, click here to find out how  if aggregated with other manuscripts, for example in a repository or other site, be

Journal of Gambling Studies, 2013

Different classification systems for erroneous beliefs about gambling have been proposed, consist... more Different classification systems for erroneous beliefs about gambling have been proposed, consistently alluding to 'illusion of control' and 'gambler's fallacy' categories. None of these classification systems have, however, considered the how the illusion of control and the gambler's fallacy might be interrelated. In this paper, we report the findings of a confirmatory factor analysis that examines the proposal that most erroneous gambling-related beliefs can be defined in terms of Rothbaum et al.'s (1982) distinction between 'primary' and 'secondary' illusory control, with the former being driven to a large extent by the well-known gambler's fallacy and the latter being driven by a complex of beliefs about supernatural forces such as God and luck. A survey consisting of 100 items derived from existing instruments was administered to 329 participants. The analysis confirmed the existence of two latent structures (beliefs in primary and secondary control), while also offering support to the idea that gambler's fallacy-style reasoning may underlie both perceived primary control and beliefs about the cyclical nature of luck, a form of perceived secondary control. The results suggest the need for a greater focus on the role of underlying processes or belief structures as factors that foster susceptibility to specific beliefs in gambling situations. Addressing and recognising the importance of these underlying factors may also have implications for cognitive therapy treatments for problem gambling.

Journal of Allergy and Clinical Immunology, 2006

Background: The prostanoid DP receptor (PTGDR) gene on chromosome 14q22.1 has been identified as ... more Background: The prostanoid DP receptor (PTGDR) gene on chromosome 14q22.1 has been identified as an asthma susceptibility gene. A haplotype with decreased transcription factor binding and transcription efficiency was associated with decreased asthma susceptibility in African American and white subjects. The significance of PTGDR gene variants in asthma has yet to be determined in Latinos, the largest US minority population, nor has the association been replicated in other populations. Objective: To determine the role of PTGDR gene variants in asthma susceptibility and asthma-related traits among the Mexican, Puerto Rican, and African American populations. Methods: We determined whether single nucleotide polymorphisms (SNPs) and haplotypes in PTGDR were associated with asthma and asthma-related traits by familybased and cross-sectional cohort analyses in 336 Puerto Rican and 273 Mexican asthmatic trios and by case-control analysis among African American subjects with asthma and healthy controls (n 5 352). Results: We identified 13 SNPs in the PTGDR gene, and 6 were further analyzed. There was no significant association between PTGDR variants and asthma by family-based or case-control analyses. SNPs-441C and-197C and haplotype TTT showed marginal association with asthma-related traits in Mexican subjects. SNP-441 genotype TT (P 5 .05) and haplotype TTT (P 5 .02) were associated with increased IgE levels in African Americans. Conclusion: We conclude that the PTGDR gene is not a significant risk factor for asthma among Puerto Ricans, Mexicans, or African Americans. Clinical implications: Asthma candidate genes provide insights to pathophysiology and potentially new therapeutic targets, although the PTGDR gene was not found to be a significant risk factor for asthma in 3 populations.