A reversible random sequence arising in the metric theory of the continued fraction expansion

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INTERNALIZING A REFLEXIVE IDENTITY – A CHALLENGE FOR SCHOOL MANAGEMENT

For thirty years, learning is an intense concept studied by organizations, the specialists thinking that “the time of strategic planning is rapidly changing into the era of organizational learning” (Schon, 1994), as man is considered not only a resource for the school organization, but a valuable source in heart of the strategic development process of the organization. Relatively recent research (Senge, 1991; Schon, 1994) shows that innovation is becoming easier and more sustainable in “learning organizations”. Our article aims to feed the theoretical reflection on the school as a “learning organization”, on its ambivalence and paradoxes, and to make further clarification about its management directions. We base our analysis on the principles of postmodernism in education, on an interpretative posture, humanistic essence, building a transversal and multi-level “reading grid” of the school organization focused on such a learning approach. The concept has much to offer to the reforming and restructuring thinking about the organization. Although the theoretical analysis exerts a great attraction, the learning organization remains a philosophy rather than a program. This raises many questions. Let’s not forget that the school is (still) quite strong perceived as the place “of teaching”, of transmitting knowledge. But the learner, the learning organization, are built on something else

Reduced Hedonic Capacity in Major Depressive Disorder: Evidence from a Probabilistic Reward Task

Objective: Anhedonia, the lack of reactivity to pleasurable stimuli, is a cardinal feature of depression that has received renewed interest as a potential endophenotype of this debilitating disease. The goal of the present study was to test the hypothesis that individuals with major depression are characterized by blunted reward responsiveness, particularly when anhedonic symptoms are prominent. Methods: A probabilistic reward task rooted within signal-detection theory was utilized to objectively assess hedonic capacity in 23 unmedicated subjects meeting DSM-IV criteria for major depressive disorder (MDD) and 25 matched control subjects recruited from the community. Hedonic capacity was defined as reward responsiveness – i.e., the participants’ propensity to modulate behavior as a function of reward. Results: Compared to controls, MDD subjects showed significantly reduced reward responsiveness. Trial-by-trial probability analyses revealed that MDD subjects, while responsive to delivery of single rewards, were impaired at integrating reinforcement history over time and expressing a response bias toward a more frequently rewarded cue in the absence of immediate reward. This selective impairment correlated with self-reported anhedonic symptoms, even after considering anxiety symptoms and general distress. Conclusions: These findings indicate that MDD is characterized by an impaired tendency to modulate behavior as a function of prior reinforcements, and provides initial clues about which aspects of hedonic processing might be dysfunctional in depression.Psycholog

A decade of geoinformation sharing at ETH Zurich

Paper presented at the 27th International Cartographic Conference: Spatial data infrastructures, standards, open source and open data for geospatial (SDI-Open 2015) 20-21 August 2015, Brazilian Institute of Geography and Statistics (IBGE), Rio de Janeiro, Brazil.http://sdistandards.icaci.org/2015/09/sdi-open-2015-proceedingsam201

Euthymic Patients with Bipolar Disorder Show Decreased Reward Learning in a Probabilistic Reward Task

Background: Bipolar disorder (BPD) features cycling mood states ranging from depression to mania with intermittent phases of euthymia. Bipolar disorder subjects often show excessive goal-directed and pleasure-seeking behavior during manic episodes and reduced hedonic capacity during depressive episodes, indicating that BPD might involve altered reward processing. Our goal was to test the hypothesis that BPD is characterized by impairments in adjusting behavior as a function of prior reinforcement history, particularly in the presence of residual anhedonic symptoms. Methods: Eighteen medicated BPD subjects and 25 demographically matched comparison subjects performed a probabilistic reward task. To identify putative dysfunctions in reward processing irrespective of mood state, primary analyses focused on euthymic BPD subjects (n = 13). With signal-detection methodologies, response bias toward a more frequently rewarded stimulus was used to objectively assess the participants' propensity to modulate behavior as a function of reinforcement history. Results: Relative to comparison subjects, euthymic BPD subjects showed a reduced and delayed acquisition of response bias toward the more frequently rewarded stimulus, which was partially due to increased sensitivity to single rewards of the disadvantageous stimulus. Analyses considering the entire BPD sample revealed that reduced reward learning correlated with self-reported anhedonic symptoms, even after adjusting for residual manic and anxious symptoms and general distress. Conclusions: The present study provides preliminary evidence indicating that BPD, even during euthymic states, is characterized by dysfunctional reward learning in situations requiring integration of reinforcement information over time and thus offers initial insights about the potential source of dysfunctional reward processing in this disorder.Psycholog

Two Modes of Magnetization Switching in a Simulated Iron Nanopillar in an Obliquely Oriented Field

Finite-temperature micromagnetics simulations are employed to study the magnetization-switching dynamics driven by a field applied at an angle to the long axis of an iron nanopillar. A bi-modal distribution in the switching times is observed, and evidence for two competing modes of magnetization-switching dynamics is presented. For the conditions studied here, temperature $T = 20$ K and the reversal field 3160 Oe at an angle of 75$^\circ$ to the long axis, approximately 70% of the switches involve unstable decay (no free-energy barrier) and 30% involve metastable decay (a free-energy barrier is crossed). The latter are indistinguishable from switches which are constrained to start at a metastable free-energy minimum. Competition between unstable and metastable decay could greatly complicate applications involving magnetization switches near the coercive field.Comment: 19 pages, 7 figure