1,720,984 research outputs found
On the Axiomatization of Finite K-Frames
No full textWe find a short way to construct a formula which axiomatizes a given finite frame of the modal logic K, in the sense that for each finite frame A, we construct a formula ωA which holds in those and only those frames in which every formula true in A holds. To obtain this result we find, for each finite model {Mathematical expression} and each natural number n, a formula ω {Mathematical expression} which holds in those and only those models in which every formula true in {Mathematical expression}, and involving the first n propositional letters, holds. © 1983 Polish Academy of Sciences
Acceptance, and not its interaction with attention monitoring, increases psychological well-being: testing the monitor and acceptance theory of mindfulness
No full textObjectives: According to the influential Monitor and Acceptance Theory (MAT), mindfulness includes the two components of attention monitoring and acceptance, which, in conjunction, can explain its benefits on psychological well-being: monitoring alone would increase affective reactivity (MAT tenet 1b), but when combined with acceptance, it would lead to increased psycho-physical well-being (MAT tenet 2b). However, the studies cited in support to MAT are not completely consistent with the theory, Thus, we conducted a cross-sectional study to further test it. Methods: In a pool of 154 participants, we measured the two mindfulness components with the Five Facets Mindfulness Questionnaire, while also assessing ill-being or psychological distress in terms of depression, anxiety, stress, and sleep disturbances, and psychological well-being in terms of life satisfaction and happiness. We then conducted hierarchical regression analysis on these data for assessing the role of monitoring, acceptance, and their interaction on the other psychological variables. Results: Our results show that monitoring alone marginally predicted few ill-being variables, whereas acceptance strongly predicted both reductions in psychological symptoms and increases in well-being. Moreover, no significant interaction between monitoring and acceptance was found for any of the tested variables. Conclusions: The present study provides very little support for the two tested MAT tenets. On the contrary, in line with most of the available literature, our results strongly support the alternative view according to which the beneficial effects of mindfulness on psychological outcomes depend mostly on acceptance
Stress as the missing link between mindfulness, sleep quality, and well-being: a cross-sectional study
No full textObjectives: There is ample evidence that mindfulness contributes to psychological well-being. There is also evidence that mindfulness can improve sleep, and previous research has suggested that the positive effects of mindfulness on well-being may depend on its capacity to decrease sleep disturbances. However, it is possible that a third factor that is affected by mindfulness may in turn affect both sleep quality and well-being. Given the well-known protective effects of mindfulness on stress and the influence of stress on both sleep disturbance and well-being, stress represents a strong candidate for such a mediational role. Methods: We collected cross-sectional data on mindfulness, stress, sleep disturbance, and well-being in a sample of adults taken from the general population, and then we applied structural equation modeling to analyze the relationships between a set of latent variables. Results: Our results confirm that mindfulness is negatively related to stress and this effect fully mediates the positive relationship between mindfulness and both sleep quality and well-being. Furthermore, our results show that if the effect of stress is taken into account, sleep quality does not mediate the influence of mindfulness on well-being and in fact does not relate to well-being at all. Conclusions: Our study points to the central role of stress reduction in explaining the beneficial effects of mindfulness on both behavioral and psychological variables
Accept anxiety to improve sleep: The impact of the covid-19 lockdown on the relationships between mindfulness, distress and sleep quality
Full text linkIt has been recently proposed that mindfulness can improve sleep quality through the mediating role on psychological distress and that acceptance may play a pivotal role in mindfulness beneficial effects. The aim of the present work was to understand the effects of the COVID-19 lockdown on dispositional mindfulness, sleep, and distress, and on their relationships. In particular, we wanted to test the hypothesis that the detrimental effects of lockdown on sleep depended on mindfulness and distress (including anxiety and depression) and that the acceptance facet of mindfulness played the leading role. A longitudinal study based on self-report questionnaires was conducted on 39 Italian adults (M age = 35.03, SD = 14.02; 21 men) assessing mindfulness, distress, and sleep quality before (23 December 2019–8 March 2020) and during (27 April 2020–10 May 2020) the first Italian COVID-19 lockdown. Lockdown decreased mindfulness while increasing distress and sleep problems. Path analysis showed that the effects of lockdown on sleep were fully mediated by mindfulness and distress. Furthermore, a more detailed analysis showed that these effects were mainly dependent on the acceptance component of mindfulness working through anxiety. The present study confirms, in the context of the COVID-19 lockdown, a model according to which mindfulness, and specifically acceptance, influences sleep through the mediating role of distress
Mathematical analysis of submicroscopical sperm alterations as a tool for the evaluation of defective spermatogenesis
No full textPAC learning of probability distributions over a discrete domain
No full textWe investigate learning of classes of distributions over a discrete domain in a PAC context. We introduce two paradigms of PAC learning, namely absolute PAC learning, which is independent of the representation of the class of hypotheses, and PAC learning wrt the indexes, which heavily depends on such representations. We characterize non-computable learnability in both contexts. Then we investigate efficient learning strategies which are simulated by a polynomial-time Turing machine. One strategy is the frequentist one. According to this strategy, the learner conjectures a hypothesis which is as close as possible to the distribution given by the frequency relative to the examples. We characterize the classes of distributions which are absolutely PAC learnable by means of this strategy, and we relate frequentist learning wrt the indexes to the NP = RP problem. Finally, we present another strategy for learning wrt the indexes, namely learning by tests
Automatic Design of Boolean Networks for Modelling Cell Differentiation
No full textA mathematical model based on Random Boolean Networks has been recently proposed to describe the main features of cell differentiation. The model captures in a unique framework all the main phenomena involved in cell differentiation and can be subject to experimental testing. A prominent role in the model is played by cellular noise, which somehow controls the cell ontogenetic process from the stem, totipotent state to the mature, completely differentiated one. Noise is high in stem cells and it decreases while the cell undergoes the differentiation process. A limitation of the current mathematical model is that Random Boolean Networks, as an ensemble, are not endowed with the property of showing a smooth relation between noise level and the differentiation stages of cells. In this work, we show that it is possible to generate an ensemble of Boolean networks that can accomplish such requirement, while keeping the other main relevant statistical features of classical Random Boolean Networks. This ensemble is designed by means of an optimisation process, in which a stochastic local search optimises an objective function which accounts for the requirements the network ensemble has to fulfil
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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