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1.
Pigeons (Columba livia) searched for a hidden target area in images showing a schematic rectangular environment. The absolute position of the goal varied across trials but was constant relative to distinctive featural cues and geometric properties of the environment. Pigeons learned to use both of these properties to locate the goal. Transformation tests showed that pigeons could use either the color or shape of the features, but performance was better with color cues present. Pigeons could also use a single featural cue at an incorrect corner to distinguish between the correct corner and the geometrically equivalent corner; this indicates that they did not simply use the feature at the correct corner as a beacon. Interestingly, pigeons that were trained with features spontaneously encoded geometry. The encoded geometric information withstood vertical translations but not orientation transformations.  相似文献   

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In this paper we expand previous results obtained in [2] about the study of categorical equivalence between the category IRL 0 of integral residuated lattices with bottom, which generalize MV-algebras and a category whose objects are called c-differential residuated lattices. The equivalence is given by a functor ${{\mathsf{K}^\bullet}}$ , motivated by an old construction due to J. Kalman, which was studied by Cignoli in [3] in the context of Heyting and Nelson algebras. These results are then specialized to the case of MV-algebras and the corresponding category ${MV^{\bullet}}$ of monadic MV-algebras induced by “Kalman’s functor” ${\mathsf{K}^\bullet}$ . Moreover, we extend the construction to ?-groups introducing the new category of monadic ?-groups together with a functor ${\Gamma ^\sharp}$ , that is “parallel” to the well known functor ${\Gamma}$ between ? and MV-algebras.  相似文献   

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We report a theoretical investigation on the control of wave-vector filtering (WVF) in a two-dimensional electron gas modulated by realistic magnetic barriers and δ-doping, which can be experimentally realised by depositing a ferromagnetic stripe on the surface of a GaAs/AlxGa1?xAs heterostructure and using atomic layer doping. Theoretical analysis demonstrates that a sizeable WVF effect still exists even if δ-doping is introduced into the device. Numerical calculation reveals that the WVF efficiency is related closely to the δ-doping. Thus, the WVF effect in a magnetic nanostructure can be conveniently manipulated by properly adjusting the weight and/or the position of the δ-doping, giving rise to a tunable momentum filter for nanoelectronics applications.  相似文献   

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Coefficient is generally defined in terms of procedures of computation rather than in terms of a population. Here a population definition is proposed. On this basis, the interpretation of as a measure of diagnostic reliability in characterizing an individual, and the effect of reliability, as measured by, on estimation bias, precision, and test power are examined. Factors influencing the magnitude of are identified. Strategies to improve reliability are proposed, including that of combining multiple unreliable diagnoses.This investigation was supported in part by the National Institute of Mental Health Specialized Research Center Grant # MH-30854.  相似文献   

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Rabbi Akiva Yosef Schlesinger (Pressburg 1838—Jerusalem 1922) is considered by some scholars to be a forerunner of ultra-Orthodoxy, but by others as a forerunner of Zionism. This article unravels this enigmatic personality, demonstrating that he was indeed a forerunner of ultra-Orthodoxy who was motivated by a complete rejection of modernity and promoted religious positions that were more radical than those of the Hatam Sofer. Those who associate Schlesinger with Zionism are misled by the fact that he encountered fierce opposition from his Hungarian colleagues and from the “Yishuv hayashan” in Jerusalem, advocated the use of the Hebrew language and promoted a “settlement” programme in Palestine. The article suggests that Schlesinger's programme was in reality designed to create a sacred utopian society, and was motivated by his desire to isolate the traditional Jewish community from modernity, rather than by a nationalist ideology. Furthermore, the opposition of the Jerusalem rabbis to Schlesinger's ideas was based largely on his unusual religious positions and his suggestion that the youth should be engaged in work. In analysing Schlesinger's legacy, the article also clarifies the distinctions between ultra-Orthodoxy and Zionism, as well as some common elements that they share.  相似文献   

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Philosophical Studies - Is it appropriate to blame people unequally if the only difference between them was a matter of luck? Suppose Alice would drive recklessly if she could, Belen drove...  相似文献   

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Abstract

Numerous studies have demonstrated that planned health education and health promotion interventions are not particularly successful in bringing about behavioural change. It is suggested that the reasons for this are the fallacious theoretical assumptions underlying many intervention strategies and the failure to place sufficient emphasis on the context in which health-related behaviours occur. Studies of self-initiated behavioural change suggest that the antecedents of change are often events or processes which bring a previously routinised and unremarked behaviour into new focus.

This paper describes a preliminary test of a new model of behavioural change in which a group of lay people were recruited to act as paid interviewers on a food survey in their own area. The survey was particularly concerned with the consumption of high fibre foods. he and post-test measures of the interviewers' own food habits as compared with those of a control group indicated modest support for the proposed model. Implications of this study for health education and promotion are discussed.  相似文献   

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Many philosophers and medical scientists assume thatdisease categories or entities used to classify concrete cases ofdisease, are often defined by disease mechanisms or causalprocesses. Others suggest that diseases should always be definedin this manner. This paper discusses these standpoints criticallyand concludes that they are untenable, not only when `diseasemechanism' refers to an objective mechanism, but also when`mechanism' refers to a pragmatically demarcated part of thetotal ``objective' causal structure of diseases. As an alternativeto principles that use the concept of disease mechanism oranalogous concepts, a pragmatic approach is suggested anddescribed. This approach has been suggested before, but inproblematic or inadequate versions. This paper proposes a versioncompiled of two ``pragmatic principles' and shows that they aremuch more adequate than the principle of disease mechanism. Withreference to a case study of a still ongoing internationaldiscussion of various candidates for a classification system formalignant lymphomas, including REAL (Revised European–AmericanClassification of Lymphoid Neoplasms) in which the concept ofdisease mechanism or analogous concepts plays a very small part,it is shown just how pivotal these two pragmatic principles canbe in actual discussions of definitions of diseases. Finally, itis pointed out that with regard to modern philosophy of languageit may, at least in some cases, be problematic to distinguishbetween the two pragmatic principles as they stand.  相似文献   

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The solid–liquid interface of metallic systems of small entropy of fusion is characterized by a rough interface and dendritic morphology. In contrast, systems of high entropy of fusion like semimetals and semiconductors show smooth interfaces and facetted interfaces. The present work demonstrates that, in an undercooled melt of a metal–metalloid alloy Ni2B of intermediate entropy of fusion, a transition from a rough to a smooth interface is induced by forced convection of the melt. Electrostatic levitation is used to container-less undercool droplets in a quiescent state with no convection while electromagnetic levitation (EML) is used to undercool droplets with forced convection. The growth velocity of the solid phase is monitored as a function of undercooling by a high-speed video camera. The data are analysed within dendrite growth theory. In the case of EML, a transition from a rough to a smooth interface is indicated during dendrite growth in the undercooled melt. This is confirmed by facetted microstructures of samples solidified upon undercooling by EML. Hopper-like crystals are formed like in non-metals as bismuth, halite and ice.  相似文献   

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Loss of a child from a multiple birth pregnancy is not uncommon yet the idiographic experience of parents who have lost a single twin from a multiple birth pregnancy is underexplored. This novel study sought to explore the experiences of mothers bereaved after loss of a twin from a multiple birth pregnancy, focusing on the dual challenges of parenting and grieving. Eighteen mothers at least 12 months post loss were recruited from a private UK based Facebook page dedicated to supporting parents after loss from a multiple birth. Eligible mothers completed an independent qualitative open-ended survey to explore maternal experiences of loss. Data were analysed using Thematic Analysis. Findings represented a sense of duality for participants, with mothers experiencing conflict between roles and identities as well as the nature of their loss. Key themes identified include ‘Narrating a story of family and loss’, ‘Finding a place for the twins within the family’ and ‘A changing sense of self’. Findings fit with theoretical conceptualisations of bereavement that acknowledge retaining relationships with the deceased. Practically, suggestions for supporting mothers to identify stock answers to often asked questions about family make up were suggested.  相似文献   

15.
Inhibition of return for the length of a line?   总被引:3,自引:0,他引:3  
Inhibition of return is most often measured using an exogenous spatial cuing method. The experiments presented here follow up on a small number of studies that have examined whether a similar effect occurs for nonspatial stimulus attributes. In Experiments 1 and 2, the task was to identify a target line as either short or long. In this context, targets on valid trials were of the same length as that of a preceding cue, whereas targets on invalid trials were of a different length than that of a preceding cue. The results were similar to those in spatial orienting studies in that responses were slower for valid than for invalid targets only at stimulus onset asynchronies (SOAs) longer than 300 msec. In Experiment 3, the stimuli were the same but the task was to detect the onset of the target line. This task change resulted in slower responses for valid than for invalid targets at all SOAs. A similar result was observed in Experiment 4, in which validity was defined by color rather than line length, and the task was to identify the target color. The discussion centers on an opponent process approach to interpreting cuing effects, and consequent difficulties in distinguishing spatial and nonspatial cuing effects based on their time course.  相似文献   

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This study aimed to explore how a sample of young South African women constructed their perceptions of menstruation. The sample comprised 16 racially/ethnically diverse female university students (blacks = 4, whites = 2, coloured = 8; Christians = 11; Muslims = 5; aged 18 to 23 years). They participated in one of three focus group discussions on their constructions of menstruation. Findings from the discourse analysis indicated that the women perceive social control experiences of their menstruation—even in the context of medical understandings.  相似文献   

17.
The paper examines the “prehistory” in the 18th century of the theory of Bildung. Pedagogical historiography commonly traces the theory back to the influence of Anthony Ashley Cooper, third Earl of Shaftesbury, who is held to be the founder of the concept of “innere Bildung; on the grounds that Shaftesbury’s concept of “inward form” was translated into German as Bildung. The study focuses on the reception of Shaftesbury’s writings in the German-speaking realm in the 17th century in order to discover the contexts of discourse in which this reception took place and to find out what significance the various discourses had for the formulation of a German “theory of Bildung.” What is revealed are varied influences of a religious, literary theory, and aesthetics nature that give indications as to why the construct of Bildung has remained diffuse and excessive in the German tradition up to the very present. It is also shown that the concept, in comparison to other discourses, found its way into the pedagogical discourse relatively late, which may be another reason for the difficulties that the German theory of Bildung continues to present to the science of pedagogy.  相似文献   

18.
Commentators have repeatedly attacked the traditional view that alcoholism is a disease. Their arguments that alcoholism is a central aspect of life, a deviant life style, or a form of learned behavior are examined in the light of the history and philosophy of medicine as well as current bio-behavioral research. Our conclusion is that alcoholism, as a lawful pattern of observable signs and symptoms that deviate significantly from a norm of health, is a bio-psychosocial disease.  相似文献   

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