790 research outputs found

    The mystery of the brain-culture interface

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    Nature and culture work together to shape who we are. We are embedded in culture and are profoundly influenced by what those around us say and do. The interface between minds occurs at the level of explicit metacognition, which is at the top of our brain's control hierarchy. But how do our brains do this

    Stellar Populations and Star Cluster Formation in Interacting Galaxies with the Advanced Camera for Surveys

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    Pixel-by-pixel colour-magnitude and colour-colour diagrams - based on a subset of the Hubble Space Telescope Advanced Camera for Surveys Early Release Observations - provide a powerful technique to explore and deduce the star and star cluster formation histories of the Mice and the Tadpole interacting galaxies. In each interacting system we find some 40 bright young star clusters (20 <= F606W (mag) <= 25, with a characteristic mass of ~3 x 10^6 Msun), which are spatially coincident with blue regions of active star formation in their tidal tails and spiral arms. We estimate that the main events triggering the formation of these clusters occurred ~(1.5-2.0) x 10^8 yr ago. We show that star cluster formation is a major mode of star formation in galaxy interactions, with >= 35% of the active star formation in encounters occurring in star clusters. This is the first time that young star clusters have been detected along the tidal tails in interacting galaxies. The tidal tail of the Tadpole system is dominated by blue star forming regions, which occupy some 60% of the total area covered by the tail and contribute ~70% of the total flux in the F475W filter (decreasing to ~40% in F814W). The remaining pixels in the tail have colours consistent with those of the main disk. The tidally triggered burst of star formation in the Mice is of similar strength in both interacting galaxies, but it has affected only relatively small, spatially coherent areas.Comment: 23 pages in preprint form, 6 (encapsulated) postscript figures; accepted for publication in New Astronomy; ALL figures (even the grey-scale ones) need to be printed on a colour printer style files included; for full-resolution paper, see http://www.ast.cam.ac.uk/STELLARPOPS/ACSpaper

    Kann die IAB-Beschäftigtenstichprobe benutzt werden, um Erziehungsurlaub verlässlich zu identifizieren? Ein Daten-Report

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    © 2009, Institut für Arbeitsmarkt- und Berufsforschung. The data set that researchers have used most often to study career interruptions due to childbirth in the German context is the German Socio-Economic Panel (GSOEP). An alternative data source is the much larger IAB Employment Sample (IABS). Although this data set does not include direct information on childbirth, mothers on maternity leave can potentially be identified. There are, however, two problems. First, the leave variable in the IABS does not distinguish between maternity leave and other leave taking, such as sick leave. Second, the child's birth month has to be inferred from the month in which the mother goes on maternity leave, which is likely to lead to measurement error in the time that the mother spends at home after childbirth. This paper investigates both problems, using an extended version of the IABS that supplements the social security records with direct information on childbirth from the German Pension Register. I find that for Western West German citizens, at least 90% of leave spells are due to maternity leave. The child's birth month is correctly estimated for at least 70%, and over- or underestimated by one month for about 25% of mothers. I conclude that the most recent scientific use files of the IABS, the IABS 75-01 and IABS 75-04, provide a very valuable alternative data source to the GSOEP to study career interruptions due to childbirth, as long as the focus is on women who are attached to the labour market

    SPECT- and PET-Based Approaches for Noninvasive Diagnosis of Acute Renal Allograft Rejection

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    Molecular imaging techniques such as single photon emission computed tomography (SPECT) or positron emission tomography are promising tools for noninvasive diagnosis of acute allograft rejection (AR). Given the importance of renal transplantation and the limitation of available donors, detailed analysis of factors that affect transplant survival is important. Episodes of acute allograft rejection are a negative prognostic factor for long-term graft survival. Invasive core needle biopsies are still the “goldstandard” in rejection diagnostics. Nevertheless, they are cumbersome to the patient and carry the risk of significant graft injury. Notably, they cannot be performed on patients taking anticoagulant drugs. Therefore, a noninvasive tool assessing the whole organ for specific and fast detection of acute allograft rejection is desirable. We herein review SPECT- and PET-based approaches for noninvasive molecular imaging-based diagnostics of acute transplant rejection

    Regulating craving by anticipating positive and negative outcomes : a multivariate pattern analysis and network connectivity approach

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    During self-control, we may resist short-term temptations in order to reach a favorable future (e.g., resisting cake to stay healthy). The neural basis of self-control is typically attributed to “cold,” unemotional cognitive control mechanisms which inhibit affect-related regions via the prefrontal cortex (PFC). Here, we investigate the neural underpinnings of regulating cravings by mentally evoking the positive consequences of resisting a temptation (e.g., being healthy) as opposed to evoking the negative consequences of giving in to a temptation (e.g., becoming overweight). It is conceivable that when using these types of strategies, regions associated with emotional processing [e.g., striatum, ventromedial prefrontal cortex (vmPFC)] are involved in addition to control-related prefrontal and parietal regions. Thirty-one participants saw pictures of unhealthy snacks in the fMRI scanner and, depending on the trial, regulated their craving by thinking of the positive consequences of resisting, or the negative consequences of not resisting. In a control condition, they anticipated the pleasure of eating and thus, allowed the craving to occur (now-condition). In line with previous studies, we found activation of a cognitive control network during self-regulation. In the negative future thinking condition, the insula was more active than in the positive condition, while there were no activations that were stronger in the positive (> negative) future thinking condition. However, additionally, multivariate pattern analysis showed that during craving regulation, information about the valence of anticipated emotions was present in the vmPFC, the posterior cingulate cortex (PCC) and the insula. Moreover, a network including vmPFC and PCC showed higher connectivity during the positive (> negative) future thinking condition. Since these regions are often associated with affective processing, these findings suggest that “hot,” affective processes may, at least in certain circumstances, play a role in self-control

    Cloud performance variability prediction

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    Cloud computing plays an essential role in our society nowadays. Many important services are highly dependent on the stable performance of the cloud. However, as prior work has shown, clouds exhibit large degrees of performance variability. Next to the stochastic variation induced by noisy neighbors, an important facet of cloud performance variability is given by changepoints—the in- stances where the non-stationary performance metrics exhibit per- sisting changes, which often last until subsequent changepoints occur. Such undesirable artifacts of the unstable application performance lead to problems with application performance evaluation and prediction efforts. Thus, characterization and understanding of performance changepoints become important elements of studying application performance in the cloud. In this paper, we showcase and tune two different changepoint detection methods, as well as demonstrate how the timing of the changepoints they identify can be predicted. We present a gradient-boosting-based prediction method, show that it can achieve good prediction accuracy, and give advice to practitioners on how to use our results.Computer Systems, Imagery and Medi

    Visualizing chiral interactions in carbohydrates adsorbed on Au(111) by high-resolution STM imaging

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    Carbohydrates are the most abundant organic material on Earth and the structural “material of choice” in many living systems. Nevertheless, design and engineering of synthetic carbohydrate materials presently lag behind that for protein and nucleic acids. Bottom-up engineering of carbohydrate materials demands an atomic-level understanding of their molecular structures and interactions in condensed phases. Here, high-resolution scanning tunneling microscopy (STM) is used to visualize at submolecular resolution the three-dimensional structure of cellulose oligomers assembled on Au(1111) and the interactions that drive their assembly. The STM imaging, supported by ab initio calculations, reveals the orientation of all glycosidic bonds and pyranose rings in the oligomers, as well as details of intermolecular interactions between the oligomers. By comparing the assembly of D- and L-oligomers, these interactions are shown to be enantioselective, capable of driving spontaneous enantioseparation of cellulose chains from its unnatural enantiomer and promoting the formation of engineered carbohydrate assemblies in the condensed phases

    Visualizing chiral interactions in carbohydrates adsorbed on Au(111) by high‐resolution STM imaging

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    Carbohydrates are the most abundant organic material on Earth and the structural ‘material of choice’ in many living systems. Nevertheless, design and engineering of synthetic carbohydrate materials presently lag behind that for protein and nucleic acids. Bottom-up engineering of carbohydrate materials demands an atomic-level understanding of their molecular structures and interactions in condensed phases. Here, high-resolution scanning tunneling microscopy (STM) is used to visualize at submolecular resolution the three-dimensional structure of cellulose oligomers assembled on Au(1111) and the interactions that drive their assembly. The STM imaging, supported by ab initio calculations, reveals the orientation of all glycosidic bonds and pyranose rings in the oligomers, as well as details of intermolecular interactions between the oligomers. By comparing the assembly of D- and L-oligomers, these interactions are shown to be enantioselective, capable of driving spontaneous enantioseparation of cellulose chains from its unnatural enantiomer and promoting the formation of engineered carbohydrate assemblies in the condensed phases

    Visualizing Chiral Interactions in Carbohydrates Adsorbed on Au(111) by High‐Resolution STM Imaging

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    Carbohydrates are the most abundant organic material on Earth and the structural “material of choice” in many living systems. Nevertheless, design and engineering of synthetic carbohydrate materials presently lag behind that for protein and nucleic acids. Bottom-up engineering of carbohydrate materials demands an atomic-level understanding of their molecular structures and interactions in condensed phases. Here, high-resolution scanning tunneling microscopy (STM) is used to visualize at submolecular resolution the three-dimensional structure of cellulose oligomers assembled on Au(1111) and the interactions that drive their assembly. The STM imaging, supported by ab initio calculations, reveals the orientation of all glycosidic bonds and pyranose rings in the oligomers, as well as details of intermolecular interactions between the oligomers. By comparing the assembly of D- and L-oligomers, these interactions are shown to be enantioselective, capable of driving spontaneous enantioseparation of cellulose chains from its unnatural enantiomer and promoting the formation of engineered carbohydrate assemblies in the condensed phases
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