The difficulty with the well-formedness of ontological statements

When Russell argued for his ontological convictions, for instance that there are negative facts or that there are universals, he expressed himself in English. But Wittgenstein must have noticed that from the point of view of Russell's ideal language these ontological statements appear to be pseudo-propositions. He believed therefore that what these statements pretend to say, could not really be said but only shown. Carnap discovered a way out of this mutism: what in the material mode of speech of the object language looks like a pseudo-proposition can be translated into a perfectly meaningful proposition in the formal mode of speech (in the metalinguistic mode of speech of the logical syntax of language). But is this ascent into the metalanguage necessary? Taking advantage of Lésniewski's logical system there exists another way outwe can expand the number of categories of our ideal language. But Le?niewski's formulas raise another profound problem, the problem of “semantical muteness” (cf. W. G. Lycan ‘Semantic Competence and Funny Functors’ Monist 64 (1979), 209–222).     

College Freshmens’ Orientation to Experts’ Personal Characteristics After Failure and the Customary Description of Others in Terms of Dispositions1

A laboratory experiment examined a cognitive response (static thinking) to the stressful experience of a shortcoming. Psychology freshmen performed a memory task that was manipulated in terms of its psychological relevance and difficulty. Additionally, experienced press to succeed was quantified in terms of the specificity of participants’ professional goal in the area of psychology. A control condition performed no task. Dependent measures were personal characteristics ascribed to professional psychologists. The results indicated a strong general tendency to use dispositions to describe others. But in accordance with theoretical predictions by Wicklund (1986a, 1986b), the orientation to traits and external qualities of professional psychologists (i. e., experts) after failure on a psychologically relevant task was correlated with the level of specificity of participants’ professional goal in the area of psychology. These findings suggest that the general orientation to dispositions when describing others is replaced by the process of static thinking after the stressful experience of personal incompetence and when the persons to be described are experts.     

Is it worth generating rules from neural network ensembles?

Although many authors generated comprehensible models from individual networks, much less work has been done in the explanation of ensembles. DIMLP is a special neural network model from which rules are generated at the level of a single network and also at the level of an ensemble of networks. We applied ensembles of 25 DIMLP networks to several datasets of the public domain and a classification problem related to post-translational modifications of proteins. For the classification problems of the public domain, the average predictive accuracy of rulesets extracted from ensembles of neural networks was significantly better than the average predictive accuracy of rulesets generated from ensembles of decision trees. By varying the architectures of DIMLP networks we found that the average predictive accuracy of rules, as well as their complexity were quite stable. The comparison to other rule extraction techniques applied to neural networks showed that rules generated from DIMLP ensembles gave very good results. In the last problem related to bioinformatics, the best result obtained by ensembles of DIMLP networks was also significantly better than the best result obtained by ensembles of decision trees. Thus, although neural networks take much longer to train than decision trees and also rules are generated at a greater computational cost (however, still polynomial), at least for several classification problems it was worth using neural network ensembles, as extracted rules were more accurate, on average. The DIMLP software is available for PC-Linux under http://us.expasy.org/people/Guido.Bologna.html.     

Socratic Proofs and Paraconsistency: A Case Study

This paper develops a new proof method for two propositional paraconsistent logics: the propositional part of Batens' weak paraconsistent logic CLuN and Schütte's maximally paraconsistent logic Φ_v. Proofs are de.ned as certain sequences of questions. The method is grounded in Inferential Erotetic Logic.     

The Differential Contributions of Conceptual Representation Format and Language Structure to Levels of Semantic Abstraction Capacity

This paper reviews some controversies concerning the original and revised versions of the ‘hub-and-spoke’ model of conceptual representations and their implication for abstraction capacity levels. The ‘hub-and-spoke’ model, which is based on data gathered in patients with semantic dementia (SD), is the most authoritative model of conceptual knowledge. Patterson et al.’s (Nature Reviews Neuroscience, 8(12), 976-987, 2007) classical version of this model maintained that conceptual representations are stored in a unitary ‘amodal’ format in the right and left anterior temporal lobes (ATLs), because in SD the semantic disorder cuts across modalities and categories. Several authors questioned the unitary nature of these representations. They showed that the semantic impairment is ‘multi-modal’only in the advanced stages of SD, when atrophy affects the ATLs bilaterally, but that impariments can be modality-specific in lateralised (early) stages of the disease. In these cases, SD mainly affects lexical-semantic knowledge when atrophy predominates on the left side and pictorial representations when atrophy prevails on the right side. Some aspects of the model (i.e. the importance of spokes, the multimodal format of representations and the graded convergence of modalities within the ATLs), which had already been outlined by Rogers et al. (Psychological Review, 111(1), 205–235, 2004) in a computational model of SD, were strengthened by these results. The relevance of these theoretical problems and of empirical data concerning the neural substrate of concrete and abstract words is discussed critically. The conclusion of the review is that the highest levels of abstraction are due more to the structuring influence of language than to the format of representations.     

The costly burden of an inauthentic self: insecure self-esteem predisposes to emotional exhaustion by increasing reactivity to negative events

Background and objectives: A long research tradition has investigated the impact of stress on university students by assuming that individuals have a limited reservoir of resources, and that negative events and circumstances progressively drain resources thereby producing exhaustion. A recent research tradition, instead, has focused on the detrimental consequences of discrepant levels of implicit (ISE) and explicit (ESE) self-esteem on the development of stress-related symptoms. The present research attempted to merge the aforementioned approaches, with the aim of explaining significant predictors of stress.

Design: Within the framework of a Longitudinal Structural Equation Model, we followed a moderated-mediated approach.

Method: A sample of university students (N?=?209; 66% females) completed a questionnaire battery including measures of ISE, ESE, perceptions of negative events, and emotional exhaustion. Participants were assessed once a week for eight consecutive weeks.

Results: ISE significantly moderated the relationship between ESE and negative events; in turn, the latter significantly predicted emotional exhaustion. Monte Carlo method for assessing mediation showed that negative events significantly mediated the relationship between incongruent self-esteem and emotional exhaustion.

Conclusions: The detrimental role of incongruent self-esteem has been corroborated. Practical implications and suggestions for future research dealing with stress in a university setting were provided.     

Positivity: The Dispositional Basis of Happiness

The present study examined in a stringent developmental model whether positivity, conceptualized as a pervasive mode of appraising, viewing, and perceiving life from a positive stance, predicts chronic positive affectivity across time or vice versa. Participants [263 participants (47 % males)], aged 15.5 at the beginning of the study and 23.5 at the end, reported on measures of positivity and dispositional positive affect four times. Longitudinal findings corroborated the posited paths of relations, with positivity significantly predicting positive affectivity across time rather than vice versa.     

A Meta-model of Access Control in a Fibred Security Language

The issue of representing access control requirements continues to demand significant attention. The focus of researchers has traditionally been on developing particular access control models and policy specification languages for particular applications. However, this approach has resulted in an unnecessary surfeit of models and languages. In contrast, we describe a general access control model and a logic-based specification language from which both existing and novel access control models may be derived as particular cases and from which several approaches can be developed for domain-specific applications. We will argue that our general framework has a number of specific attractions and an implication of our work is to encourage a methodological shift from a study of the particulars of access control to its generalities.     

Fibred Security Language

We study access control policies based on the says operator by introducing a logical framework called Fibred Security Language (FSL) which is able to deal with features like joint responsibility between sets of principals and to identify them by means of first-order formulas. FSL is based on a multimodal logic methodology. We first discuss the main contributions from the expressiveness point of view, we give semantics for the language both for classical and intuitionistic fragment), we then prove that in order to express well-known properties like ‘speaks-for’ or ‘hand-off’, defined in terms of says, we do not need second-order logic (unlike previous approaches) but a decidable fragment of first-order logic suffices. We propose a model-driven study of the says axiomatization by constraining the Kripke models in order to respect desirable security properties, we study how existing access control logics can be translated into FSL and we give completeness for the logic.