Identification of planar defects in D019 phases using high-resolution transmission electron microscopy

An analysis based on crystal symmetry and high-resolution transmission electron microscopy (HRTEM) is presented as a general methodology to identify planar defects on the basal planes of D0₁₉ compounds. As a starting point, the possible (close-packing preserving) planar defects are classified in accordance with their visibility, and the magnitude of the displacement vector on prismatic projections. Analysis of experimental HRTEM images, obtained under two different viewing conditions, followed by matching with simulated images, enables unambiguous identification to be made. The methodology is applied to planar defects observed in D0₁₉ Co₃     

The Secret of My Success

In an information state where various agents have both factual knowledge and knowledge about each other, announcements can be made that change the state of information. Such informative announcements can have the curious property that they become false because they are announced. The most typical example of that is ‘fact p is true and you don’t know that’, after which you know that p, which entails the negation of the announcement formula. The announcement of such a formula in a given information state is called an unsuccessful update. A successful formula is a formula that always becomes common knowledge after being announced. Analysis of information systems and ‘philosophical puzzles’ reveals a growing number of dynamic phenomena that can be described or explained by unsuccessful updates. This increases our understanding of such philosophical problems. We also investigate the syntactic characterization of the successful formulas. An erratum to this article is available at .     

Trying to Resolve the Two-Envelope Problem

After explaining the well-known two-envelope paradox by indicating the fallacy involved, we consider the two-envelope problem of evaluating the factual information provided to us in the form of the value contained by the envelope chosen first. We try to provide a synthesis of contributions from economy, psychology, logic, probability theory (in the form of Bayesian statistics), mathematical statistics (in the form of a decision-theoretic approach) and game theory. We conclude that the two-envelope problem does not allow a satisfactory solution. An interpretation is made for statistical science at large.     

Changes in personality pathology after pharmacotherapy and combined therapy for depressed patients

The central question addressed by this article is whether courses of treatment consisting of pharmacotherapy or pharmacotherapy combined with psychotherapy (combined therapy) produce different changes in personality pathology at follow-up after 40 weeks. We also examined whether recovery from depression has an influence on outcome. The study population consisted of 128 outpatients in whom personality pathology and severity of depression were determined at the start of the study. For 72 patients, personality pathology and severity of depression were determined again after 40 weeks. Of the group of 72 patients, 25 patients received only pharmacotherapy for 6 months, and 47 patients received combined treatment (pharmacotherapy and psychodynamic supportive psychotherapy). The antidepressant protocol provides for three successive steps in case of intolerance or inefficacy: fluoxetine, amitriptyline, and moclobemide. The combined therapy condition consisted of 16 sessions of Short Psychodynamic Supportive Psychotherapy in addition to pharmacotherapy. In the combined therapy condition there was a significant reduction in personality pathology in patients who recovered from depression but also in patients who had not. In the pharmacotherapy condition the significant decrease was restricted to patients who recovered from depression. The results were most striking for Cluster C psychopatology. Patients with cluster B pathology changed the least. Depressed patients with comorbid personality pathology appear to benefit most from a combination of pharmacotherapy and a form of short, psychodynamic, supportive psychotherapy.     

Moral Conflicts between Groups of Agents

Two groups of agents, and , face a moral conflict if has a moral obligation and has a moral obligation, such that these obligations cannot both be fulfilled. We study moral conflicts using a multi-agent deontic logic devised to represent reasoning about sentences like ‘In the interest of group of agents, group of agents ought to see to it that .’ We provide a formal language and a consequentialist semantics. An illustration of our semantics with an analysis of the Prisoner’s Dilemma follows. Next, necessary and sufficient conditions are given for (1) the possibility that a single group of agents faces a moral conflict, for (2) the possibility that two groups of agents face a moral conflict within a single moral code, and for (3) the possibility that two groups of agents face a moral conflict.     

Properties of the recombination of one-dimensional motion signals into a pattern motion signal

We have examined the human ability to determine the direction of movement of a variety of plaid patterns. The plaids were composed of two orthogonal sine-wave gratings. When the plaid components are of unequal spatial frequency or sometimes of unequal contrast, observers judge the direction of movement incorrectly. In terms of the two-stage model of Adelson and Movshon (1982), these errors may result from either a misjudgment in the perceived speeds of each of the components or a failure in the combination of one-dimensional-component movements into a coherent direction of motion of the two-dimensional plaid pattern, or both. A comparison of the perceived direction of motion of plaids with the relative perceived-speeds of the plaid component gratings suggests that both failures occur, but in different circumstances The relative perceived speed of the plaid components was measured with a spatial and a temporal forced-choice technique, the former leading to larger differences. Our results support the notion that the visual system decomposes a moving plaid into oriented components and subsequently recombines the component motions.     

Properties of the recombination of one-dimensional motion signals into a pattern motion signal.

We have examined the human ability to determine the direction of movement of a variety of plaid patterns. The plaids were composed of two orthogonal sine-wave gratings. When the plaid components are of unequal spatial frequency or sometimes of unequal contrast, observers judge the direction of movement incorrectly. In terms of the two-stage model of Adelson and Movshon (1982), these errors may result from either a misjudgment in the perceived speeds of each of the components or a failure in the combination of one-dimensional component movements into a coherent direction of motion of the two-dimensional plaid pattern, or both. A comparison of the perceived direction of motion of plaids with the relative perceived speeds of the plaid component gratings suggest that both failures occur, but in different circumstances. The relative perceived speed of the plaid components was measured with a spatial and a temporal forced-choice technique, the former leading to larger differences. Our results support the notion that the visual system decomposes a moving plaid into oriented components and subsequently recombines the component motions.     

Dynamic Update with Probabilities

Current dynamic-epistemic logics model different types of information change in multi-agent scenarios. We generalize these logics to a probabilistic setting, obtaining a calculus for multi-agent update with three natural slots: prior probability on states, occurrence probabilities in the relevant process taking place, and observation probabilities of events. To match this update mechanism, we present a complete dynamic logic of information change with a probabilistic character. The completeness proof follows a compositional methodology that applies to a much larger class of dynamic-probabilistic logics as well. Finally, we discuss how our basic update rule can be parameterized for different update policies, or learning methods.     

Calvin's Theology of Creation and Providence: God's Care and Human Fragility

This article describes some of the basic elements of John Calvin's theology of creation and providence by situating them within a trinitarian framework. By using metaphors such as mirror, theatre and garment, Calvin pictured the earth as a generous gift of the Creator within which God shows his goodness, power and fatherly care. Calvin understands God not to be far away, but rather to be near and to sustain all life on earth by the power of the Holy Spirit. The visibility and tangibility of God's care as shown in the order of the universe and the reality of the world as a habitable place is of particular significance for Calvin. I argue that although contemporary science has changed our ideas regarding the universe in significant ways, there is an important aspect of Calvin's thinking that may be recognizable for the modern mind: the fragility of life on earth.