The ideal free distribution theory (Fretwell & Lucas, 1970) predicts that the ratio of foragers at two patches will equal the ratio of food resources obtained at the two patches. The theory assumes that foragers have "perfect knowledge" of patch profitability and that patch choice maximizes fitness. How foragers assess patch profitability has been debated extensively. One assessment strategy may be the use of past experience with a patch. Under stable environmental conditions, this strategy enhances fitness. However, in a highly unpredictable environment, past experience may provide inaccurate information about current conditions. Thus, in a nonstable environment, a strategy that allows rapid adjustment to present circumstances may be more beneficial. Evidence for this type of strategy has been found in individual choice. In the present experiments, a flock of pigeons foraged at two patches for food items and demonstrated results similar to those found in individual choice. Experiment 1 utilized predictable and unpredictable sequences of resource ratios presented across days or within a single session. Current foraging decisions depended on past experience, but that dependence diminished when the current foraging environment became more unpredictable. Experiment 2 repeated Experiment I with a different flock of pigeons under more controlled circumstances in an indoor coop and produced similar results. 相似文献
The term active imagination is sometimes applied rather uncritically to describe all forms of creative activity that take place in depth psychology. Whilst there are many forms of expression that evoke or are evoked by active imagination, they cannot automatically be classed as active imagination. In this article investigation of visualized mental imagery, dreams and art reveals three distinct forms of image-based psychological activity. Integrated and mediated within the transference and countertransference dynamic, it is proposed that the engagement in active imagination reflects and is influenced by the transference. Distinctions between sign and symbol, simple and big dreams as well as diagrammatic and embodied imagery clarify the differences. Examples from clinical practice demonstrate each mode in action within the analytic frame. 相似文献
The fixed point combinator (Y) is an important non-proper combinator, which is defhable from a combinatorially complete base. This combinator guarantees
that recursive equations have a solution. Structurally free logics (LC) turn combinators into formulas and replace structural rules by combinatory ones. This paper introduces the fixed point and
the dual fixed point combinator into structurally free logics. The admissibility of (multiple) cut in the resulting calculus is not provable by a simple adaptation of the similar proof for LC with proper combinators. The novelty of our proof—beyond proving the cut for a newly extended calculus–is that we add a fourth induction to the by-and-large Gentzen-style proof.
Presented by Robert Goldblatt相似文献
This article argues that there is no sound basis for thinking that we have a general and strong duty to rectify disparities of wealth around the world, apart from the special case where some become wealthy by theft or fraud. The nearest thing we have to a rational morality for all has to be built on the interests of all, and they include substantial freedoms, but not substantial entitlements to others assistance. It is also pointed out that the situation of the worlds poor is not that of victims of disasters, but simply of less-developed technology, which can be repaired by full and free trade relations with others. The true savior of the worlds poor is the businessman, not the missionary. What we do need to do is strike down barriers to commerce, rather than requisition aid. 相似文献
Hoop residuation algebras are the {, 1}-subreducts of hoops; they include Hilbert algebras and the {, 1}-reducts of MV-algebras (also known as Wajsberg algebras). The paper investigates the structure and cardinality of finitely generated free algebras in varieties of k-potent hoop residuation algebras. The assumption of k-potency guarantees local finiteness of the varieties considered. It is shown that the free algebra on n generators in any of these varieties can be represented as a union of n subalgebras, each of which is a copy of the {, 1}-reduct of the same finite MV-algebra, i.e., of the same finite product of linearly ordered (simple) algebras. The cardinality of the product can be determined in principle, and an inclusion-exclusion type argument yields the cardinality of the free algebra. The methods are illustrated by applying them to various cases, both known (varieties generated by a finite linearly ordered Hilbert algebra) and new (residuation reducts of MV-algebras and of hoops). 相似文献
Nonparametric tests for testing the validity of polytomous ISOP-models (unidimensional ordinal probabilistic polytomous IRT-models) are presented. Since the ISOP-model is a very general nonparametric unidimensional rating scale model the test statistics apply to a great multitude of latent trait models. A test for the comonotonicity of item sets of two or more items is suggested. Procedures for testing the comonotonicity of two item sets and for item selection are developed. The tests are based on Goodman-Kruskal's gamma index of ordinal association and are generalizations thereof. It is an essential advantage of polytomous ISOP-models within probabilistic IRT-models that the tests of validity of the model can be performed before and without the model being fitted to the data. The new test statistics have the further advantage that no prior order of items or subjects needs to be known. 相似文献
Karl Schmitz-Moormann's thought as expressed in his last book exemplifies Catholic theology based on realism, flow, evolution, and free will. Categories of creation are reviewed: from nothing, continuous, called forth, informed, and free. 相似文献
In his classic paper, The Principle of Alternate Possibilities, Harry Frankfurt presented counterexamples to the principle named in his title: A person is morally responsible for what he has done only if he could have done otherwise. He went on to argue that the falsity of the Principle of Alternate Possibilities (PAP) implied that the debate between the compatibilists and the incompatibilists (as regards determinism and the ability to do otherwise) did not have the significance that both parties had attributed to it -- since moral responsibility could exist even if no one was able to do otherwise. I have argued that even if PAP is false, there are other principles that imply that moral responsibility entails the ability to do otherwise, and that these principles are immune to Frankfurt-style counterexamples. Frankfurt has attempted to show that my arguments for this conclusion fail. This paper is a rejoinder to that reply; I argue that he has failed to show this. 相似文献
Two experiments were conducted to examine bidirectional semantic associations between power and weight using a priming paradigm. Bidirectionality in the relationship between power and weight was demonstrated, utilising tasks that were identical except that the orders in which the stimuli were presented were reversed. In Experiment 1, an empty scale leaning either leftward or rightward was used as a priming stimulus, and a scale that appeared in equilibrium with a pair of power words was used as a target stimulus. In Experiment 2, a scale with a pair of words that appeared in equilibrium was used as a priming stimulus, and an empty scale leaning either leftward or rightward was used as a target stimulus. We identified interaction effects between power and weight in both experiments. Associations between power and weight provide evidence for both conceptual metaphor views and evolutionary theory. The bidirectionality of metaphorical effects is in line with the strong version of metaphoric structuring. Both language and experiential correlations play important roles in the development of the mapping between power and weight. 相似文献
Objective: The feelings and emotions individuals associate with health-related behaviours influence engagement in those behaviours. However, the structure and the content of these affective associations have not been examined. The studies reported here examined competing hypotheses about the structure (unidimensional or bidimensional) and content (generalised affect or specific emotions) of affective associations with two health-related behaviours: physical activity and fruit/vegetable consumption.
Design: For each behaviour, participants (fruit and vegetable consumption n = 149; physical activity n = 199) completed an assessment of the association of 40 positive and 51 negative affect concepts with the behaviour.
Main outcome measures: Ratings of affective associations with each behaviour.
Results: Confirmatory factor analyses comparing unidimensional and bidimensional affect structure models showed that the structure of individuals’ affective associations was bidimensional for both behaviours – positive and negative affective associations were shown to be separate and distinct constructs. Exploratory factor analyses supported a model of affective associations as generalised affect for both behaviours.
Conclusion: Affective associations with both physical activity and with fruit/vegetable consumption consist of separate positive and negative dimensions of generalised affect. These findings lead to recommendations for research and intervention development based on the implications for how affective associations might operate to influence behavioural decision-making. 相似文献