24,652 research outputs found

    Selection for cognitive control: a functional magnetic resonance imaging study on the selection of task-relevant information

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    The complex environment we live in makes it necessary to distinguish relevant from irrelevant information constantly and reliably. The aim of the present study was to investigate the neural substrate underlying the selection of task-relevant information. We devised a new paradigm in which participants had to switch between two different tasks that were instructed by task cues. The task cues had a relevant and an irrelevant cue dimension. In congruent trials, both cue dimensions indicated the same task; in incongruent trials, they indicated different tasks; and in neutral trials, only the relevant dimension indicated a task. By comparing trials in which both cue dimensions were informative (congruent and incongruent trials) with trials in which only the relevant dimension was informative (neutral trials), we were able to show that the lateral prefrontal cortex and a region in the intraparietal sulcus are involved in the selection of task-relevant information. Furthermore, the present paradigm allows the influence of the selected task and stimulus dimension to be investigated. No significant influence was found in the prefrontal cortex, indicating that this region serves a very abstract role in the selection of task-relevant information

    Very Singular Similarity Solutions and Hermitian Spectral Theory for Semilinear Odd-Order PDEs

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    Very singular self-similar solutions of semilinear odd-order PDEs are studied on the basis of a Hermitian-type spectral theory for linear rescaled odd-order operators.Comment: 49 pages, 12 Figure

    Quantifying the behavior of stock correlations under market stress

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    Understanding correlations in complex systems is crucial in the face of turbulence, such as the ongoing financial crisis. However, in complex systems, such as financial systems, correlations are not constant but instead vary in time. Here we address the question of quantifying state-dependent correlations in stock markets. Reliable estimates of correlations are absolutely necessary to protect a portfolio. We analyze 72 years of daily closing prices of the 30 stocks forming the Dow Jones Industrial Average (DJIA). We find the striking result that the average correlation among these stocks scales linearly with market stress reflected by normalized DJIA index returns on various time scales. Consequently, the diversification effect which should protect a portfolio melts away in times of market losses, just when it would most urgently be needed. Our empirical analysis is consistent with the interesting possibility that one could anticipate diversification breakdowns, guiding the design of protected portfolios

    Spiritual connections made through music making: sharing faith and music in an Australian setting

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    The musical involvement of people over the centuries is fundamentally interwoven with spiritual experiences (Seifert 2011). This paper discusses the connection between music and spirituality in an inter-denominational group in the southeastern suburbs of Melbourne. With ethical clearance, through semi-structured interviews with two church leaders and the music worship team, subsequently employing Interpretative Phenomenological Analysis (IPA), I analysed and codified the data gathered. Two overarching themes are discussed: insights into music and spirituality; and connecting music to worship with self and others. The findings show that music in worship may provide a rich pathway for people to explore, experience, and express their spirituality, and to connect to the wider multicultural society. It also adds to the current debates on whether music has spiritual significance for some people apart from community expressions of spirituality through music. Limitations of the current study are knowledged and generalizations cannot be made regarding connections to music and spirituality. However, the findings do indicate that music in worship can enrich one’s spiritual experience and connection with God and others

    Interactive volumetric segmentation for textile micro-tomography data using wavelets and nonlocal means

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    This work addresses segmentation of volumetric images of woven carbon fiber textiles from micro-tomography data. We propose a semi-supervised algorithm to classify carbon fibers that requires sparse input as opposed to completely labeled images. The main contributions are: (a) design of effective discriminative classifiers, for three-dimensional textile samples, trained on wavelet features for segmentation; (b) coupling of previous step with nonlocal means as simple, efficient alternative to the Potts model; and (c) demonstration of reuse of classifier to diverse samples containing similar content. We evaluate our work by curating test sets of voxels in the absence of a complete ground truth mask. The algorithm obtains an average 0.95 F1 score on test sets and average F1 score of 0.93 on new samples. We conclude with discussion of failure cases and propose future directions toward analysis of spatiotemporal high-resolution micro-tomography images

    Bilateral Accessory Breast: A Case Report

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    Accessory breast is a relatively rare conduction, which is commoner in females than males. Most of them do not cause any discomforting symptoms but cosmetic embarrassment especially to a woman in the presence of her partner.Case Summary: A 23-year-old postpartum woman is presented who was managed for bilateral accessory breast at a district hospital. The accessory breasts were excised under ketamine anaesthesia.Conclusion: The treatment of accessory breast is excision because all disease conditions that affect normal breast can also affect accessory breast including malignant transformation
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