Leibniz-linked Pairs of Deductive Systems

A pair of deductive systems (S,S??) is Leibniz-linked when S?? is an extension of S and on every algebra there is a map sending each filter of S to a filter of S?? with the same Leibniz congruence. We study this generalization to arbitrary deductive systems of the notion of the strong version of a protoalgebraic deductive system, studied in earlier papers, and of some results recently found for particular non-protoalgebraic deductive systems. The necessary examples and counterexamples found in the literature are described.     

Neural correlates of skill acquisition with a cortical brain-machine interface

Research into the development of brain-machine interfaces (BMIs) has led to demonstrations of rodents, nonhuman primates, and humans controlling prosthetic devices in real time through modulation of neural signals. In particular, cortical BMI studies have shown that improvements in performance require learning and are associated with changes in neuronal tuning properties. These studies have further shown evidence of long-term improvements in performance with practice. The authors conducted experiments to understand long-term skill acquisition with BMIs and to characterize the neural correlates of improvements in task performance. They specifically assessed long-term acquisition of neuroprosthetic skill (i.e., accurate task performance readily recalled across days). In 2 monkeys performing a center-out task using a brain-controlled (BC) computer cursor, they closely monitored daily performance trends and the neural correlates under different conditions. Importantly, they assessed BC performance using a continuous-control multistep task. The authors first conducted experiments that mimicked experimental conditions commonly used. Specifically, a large set of neurons was incorporated with daily recalibration of the transform of neural activity to BC. Under such conditions, they found evidence of variable daily performance. In contrast, when a fixed transform was applied to stable recordings from an ensemble of neurons across days, there was consistent evidence of long-term skill acquisition. Such skill acquisition was associated with the crystallization of a cortical map for prosthetic control. Taken together, the results suggest that the primate motor cortex can achieve skilled control of a neuroprosthetic device through consolidation of a cortical representation.     

An exploratory study of the relationship between diverse life events and specific personality disorders in a sample of suicide attempters

Personality disorder (PD) increases risk for suicidal behavior. Certain life events (LE) can precipitate suicidal behaviors in patients with PD. A fundamental question is whether specific combinations of LE and PD increase suicidal risk. Four hundred forty-six suicide attempters (SA) were recruited from emergency rooms. We used a healthy control group (n = 515) to identify the best cut-off point for the instrument used to diagnose PD. We used the DSM-IV version of the International Personality Disorder Questionnaire-Screening Questionnaire, the Mini International Neuropsychiatric Interview, and the Social Adjustment Scale to assess PD, Axis I disorders, and LE, respectively. After controlling for Axis I disorders, we found that "Death of spouse" preceded suicidal acts in those with antisocial PD (FET p = 0.024) and patients with narcissistic PD attempted suicide after being Fired at work (FET p = 0.002), among others. Our data suggest the presence of particular LE-PD associations in suicide attempters. Some LE-PD relationships appear independent of Axis I disorders in suicide attempters. This may offer a basis for specific targeted therapies or prevention programs aimed at decreasing suicidal risk.     

Adult attachment styles and cognitive vulnerability to depression in a sample of undergraduate students: the mediational roles of sociotropy and autonomy

We analysed the mediational role of the personality dimensions of sociotropy and autonomy in the relationship between certain styles of attachment and depressive symptoms. In order for us to do so, a group of university students filled out the Beck Depression Inventory (BDI), the Revised Personal Style Inventory (PSI-II) and the Relationship Questionnaire (RQ). Individuals having attachment styles with a negative model of self (preoccupied and fearful) obtained significantly higher scores in the BDI than those having attachment styles with a positive model of self (secure and dismissing), which coincides with previous research. We followed the standard procedure of Baron and Kenny of linear regression in order to perform the mediational analyses. The preoccupied attachment style-depressive symptoms relationship was mediated by sociotropy. It was also found that autonomy exerted a significant mediational effect on the relationship between the fearful attachment style and depressive symptoms. These results are consistent with the notion that insecure attachment predisposes individuals to the development of depressogenic personality styles. Thus, the findings of the present study contribute to improving the understanding of the factors involved in the development of vulnerability to depression. Furthermore, the results point out the importance of evaluating both attachment style and sociotropy/autonomy personality dimensions for the treatment of depressive patients.     

Consumer attitudes towards the future and some purchase patterns

The research detailed in this paper had two objectives. First, to carry out an exploratory analysis and a measurement of consumer attitudes towards the future (CATF). Secondly, to check whether a stronger or weaker attitude permits the detection of differences in some purchase patterns. After a review of the literature, an empirical study, representative of the Spanish population, is presented. A two‐dimensional structure of CATF and its acceptable goodness‐of‐fit with the statistical Weibull function were found. Hypotheses related to the adoption of purchasing patterns were also contrasted. The results disclose that a higher CATF is found when consumers have a clear idea of what they want to buy, are loyal to their usual outlets, prefer to pay cash and are not spendthrift. Finally, several future research directions are proposed. Copyright © 2005 John Wiley & Sons, Ltd.     

On the Closure Properties of the Class of Full G-models of a Deductive System

In this paper we consider the structure of the class FGModS of full generalized models of a deductive system S from a universal-algebraic point of view, and the structure of the set of all the full generalized models of S on a fixed algebra A from the lattice-theoretical point of view; this set is represented by the lattice FACS_s A of all algebraic closed-set systems C on A such that (A, C) ε FGModS. We relate some properties of these structures with tipically logical properties of the sentential logic S. The main algebraic properties we consider are the closure of FGModS under substructures and under reduced products, and the property that for any A the lattice FACS_s A is a complete sublattice of the lattice of all algebraic closed-set systems over A. The logical properties are the existence of a fully adequate Gentzen system for S, the Local Deduction Theorem and the Deduction Theorem for S. Some of the results are established for arbitrary deductive systems, while some are found to hold only for deductive systems in more restricted classes like the protoalgebraic or the weakly algebraizable ones. The paper ends with a section on examples and counterexamples. Dedicated to the memory of Willem Johannes Blok     

Selfextensional Logics with a Conjunction

A logic is selfextensional if its interderivability (or mutual consequence) relation is a congruence relation on the algebra of formulas. In the paper we characterize the selfextensional logics with a conjunction as the logics that can be defined using the semilattice order induced by the interpretation of the conjunction in the algebras of their algebraic counterpart. Using the charactrization we provide simpler proofs of several results on selfextensional logics with a conjunction obtained in [13] using Gentzen systems. We also obtain some results on Fregean logics with conjunction.This paper is a version of the invited talk at the conference Trends in Logic III, dedicated to the memory of A. MOSTOWSKI, H. RASIOWA and C. RRAUSZER, and held in Warsaw and Ruciane-Nida from 23rd to 25th September 2005.     

Sport participation,body satisfaction and depressive symptoms in adolescence: a moderated-mediation analysis of gender differences

This research aimed to analyse the partial mediating role of body satisfaction in the relationship between sport participation and depressive symptoms, as well as to examine the moderating role of gender in these associations. A cross-sectional study was conducted with a sample of 1810 adolescents aged 13–18 years old who completed self-report measures regarding sport participation, body satisfaction and depressive symptoms. The results indicated that a higher frequency of sport participation was associated with a lower presence of depressive symptoms, both directly and through greater body satisfaction, although gender differences were found in this partial mediation model. It was detected that sport participation had a greater effect on positive body satisfaction among boys, whereas body dissatisfaction indicated a greater presence of depressive symptoms among girls. The results emphasize the need to implement gender-specific programmes to improve psychological adjustment in adolescents by promoting sport practice and body acceptance.     

Assessing cognitive load using oculometrics to identify deceit during interviews

Lying requires a long‐term memory search and is a cognitive load task. Telling a spontaneous lie is associated with a higher cognitive load compared with the truth, although when memories are planned before telling a lie, the cognitive load can be less compared with the truth; therefore, telling a spontaneous lie could be associated with a higher cognitive load compared with a planned lie. In this study, we examined cognitive load, as measured through oculometrics, to identify deceit in interviews. Twenty‐four subjects were questioned, and their answers classified as spontaneous lies, planned lies, and truths. Results show that saccades and fixations were associated with a higher cognitive load when telling spontaneous lies compared with telling truths. Blinks and pupillometry show that subjects require greater cognitive load when telling truths compared with planned lies. Finally, telling spontaneous lies required higher cognitive load compared with planned lies, as assessed by blinks.