895 research outputs found

    MACiE: a database of enzyme reaction mechanisms.

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    SUMMARY: MACiE (mechanism, annotation and classification in enzymes) is a publicly available web-based database, held in CMLReact (an XML application), that aims to help our understanding of the evolution of enzyme catalytic mechanisms and also to create a classification system which reflects the actual chemical mechanism (catalytic steps) of an enzyme reaction, not only the overall reaction. AVAILABILITY: http://www-mitchell.ch.cam.ac.uk/macie/.EPSRC (G.L.H. and J.B.O.M.), the BBSRC (G.J.B. and J.M.T.—CASE studentship in association with Roche Products Ltd; N.M.O.B. and J.B.O.M.—grant BB/C51320X/1), the Chilean Government’s Ministerio de Planificacio´n y Cooperacio´n and Cambridge Overseas Trust (D.E.A.) for funding and Unilever for supporting the Centre for Molecular Science Informatics.application note restricted to 2 printed pages web site: http://www-mitchell.ch.cam.ac.uk/macie

    Ami - The Chemist's Amanuensis

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    RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract The Ami project was a six month Rapid Innovation project sponsored by JISC to explore the Virtual Research Environment space. The project brainstormed with chemists and decided to investigate ways to facilitate monitoring and collection of experimental data. A frequently encountered use-case was identified of how the chemist reaches the end of an experiment, but finds an unexpected result. The ability to replay events can significantly help make sense of how things progressed. The project therefore concentrated on collecting a variety of dimensions of ancillary data - data that would not normally be collected due to practicality constraints. There were three main areas of investigation: 1) Development of a monitoring tool using infrared and ultrasonic sensors; 2) Time-lapse motion video capture (for example, videoing 5 seconds in every 60); and 3) Activity-driven video monitoring of the fume cupboard environs. The Ami client application was developed to control these separate logging functions. The application builds up a timeline of the events in the experiment and around the fume cupboard. The videos and data logs can then be reviewed after the experiment in order to help the chemist determine the exact timings and conditions used. The project experimented with ways in which a Microsoft Kinect could be used in a laboratory setting. Investigations suggest that it would not be an ideal device for controlling a mouse, but it shows promise for usages such as manipulating virtual molecules.Peer Reviewe

    The influence of stereotypes about old age on the perception of elderly employees’ labor activity

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    In this article the problem of increasing retirement age in terms of age discrimination and creating conditions encouraging elderly people to continue to work is discussed. This paper presents a study of stereotypes that affect students of management specialties in Russian institutions of higher education between the ages of 20 to 25 years old. The stereotype is investigated in the context of emotionally colored image of reality simplifying the process of perceiving it. The correlation between the students’ existing stereotypes about elderly people and their perception of older employees has been conducted. As a result, 5 stereotypes that exist in young people have been defined. An analysis of the words chosen by students to describe the elderly shows little diversity in young people’s perception of them. Lexical analysis shows that in the Russian language there are practically no concepts which allow creating a positive image of the elderly. The influence of the stereotypes on the perception of elderly people in terms of employment shows that older specialists are perceived as people with experience and knowledge but these experience and knowledge are irrelevant to the present

    The Evolution of Sunspot Magnetic Fields Associated with a Solar Flare

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    Solar flares occur due to the sudden release of energy stored in active-region magnetic fields. To date, the pre-cursors to flaring are still not fully understood, although there is evidence that flaring is related to changes in the topology or complexity of an active region's magnetic field. Here, the evolution of the magnetic field in active region NOAA 10953 was examined using Hinode/SOT-SP data, over a period of 12 hours leading up to and after a GOES B1.0 flare. A number of magnetic-field properties and low-order aspects of magnetic-field topology were extracted from two flux regions that exhibited increased Ca II H emission during the flare. Pre-flare increases in vertical field strength, vertical current density, and inclination angle of ~ 8degrees towards the vertical were observed in flux elements surrounding the primary sunspot. The vertical field strength and current density subsequently decreased in the post-flare state, with the inclination becoming more horizontal by ~7degrees. This behaviour of the field vector may provide a physical basis for future flare forecasting efforts.Comment: Accepted for Publication in Solar Physics. 16 pages, 4 figure

    Oncogenic RET Kinase domain mutations perturb the autophosphorylation trajectory by enhancing substrate presentation in trans

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    To decipher the molecular basis for RET kinase activation and oncogenic deregulation, we defined the temporal sequence of RET autophosphorylation by label-free quantitative mass spectrometry. Early autophosphorylation sites map to regions flanking the kinase domain core, while sites within the activation loop only form at later time points. Comparison with oncogenic RET kinase revealed that late autophosphorylation sites become phosphorylated much earlier than wild-type RET, which is due to a combination of an enhanced enzymatic activity, increased ATP affinity, and surprisingly, by providing a better intermolecular substrate. Structural analysis of oncogenic M918T and wild-type RET kinase domains reveal a cis-inhibitory mechanism involving tethering contacts between the glycine-rich loop, activation loop, and αC-helix. Tether mutations only affected substrate presentation but perturbed the autophosphorylation trajectory similar to oncogenic mutations. This study reveals an unappreciated role for oncogenic RET kinase mutations in promoting intermolecular autophosphorylation by enhancing substrate presentation

    Acts of interfacing in an entangled life

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    Digital interfaces are becoming increasingly simple and intuitive. However, beneath the surface, the technological infrastructures underlying these interfaces are growing more complex and elusive. This paper draws on theories from human-com- puter interaction, software studies, and social practice to revisit the notion of the in- terface as a site of representation and control. By briefly tracing the historical devel- opment of digital interfaces, we propose to shift from ideas of representation and con- trol towards a notion of co-performance and negotiation. Through this lens, we recon- ceptualize the interface as acts of interfacing—a new concept that captures the con- tested, constructive, and performative character of interaction within large-scale digi- tal systems

    The early childhood generalized trust belief scale

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    The study was designed to develop and evaluate the Early Childhood Generalized Trust Belief Scale (ECGTBS) as a method of assessing 5-to-8-year-olds’ generalized trust. Two hundred and eleven (103 male and 108 female) children (mean age 6 years and 2 months at Time 1) completed the ECGTBS twice over a year. A subsample of participants completed the ECGTBS after two weeks to assess the scale’s test-retest reliability. Exploratory and confirmatory factor analyses confirmed that the ECGTBS assessed the expected three factors: reliability, emotional trust, and honesty with item-pairs loading most strongly on their corresponding factor. However, the ECGTBS demonstrated low to modest internal consistency and test-retest reliability which indicates a need for further development of this instrument. As evidence for the convergent validity of the ECGTBS, the reliability and emotional trust items were associated with the children’s trust in classmates at Time 2. Concurrent asymmetric quadratic relationships indicated the importance of midrange generalized trust. Specifically, children with very high generalized trust experienced greater loneliness and children with very low generalized trust had fewer friendships than children with midrange trust

    O- vs. N-protonation of 1-dimethylaminonaphthalene-8-ketones: formation of a peri N–C bond or a hydrogen bond to the pi-electron density of a carbonyl group

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    X-ray crystallography and solid-state NMR measurements show that protonation of a series of 1-dimethylaminonaphthalene-8-ketones leads either to O protonation with formation of a long N–C bond (1.637–1.669 Å) between peri groups, or to N protonation and formation of a hydrogen bond to the π surface of the carbonyl group, the latter occurring for the larger ketone groups (C(O)R, R = t-butyl and phenyl). Solid state 15N MAS NMR studies clearly differentiate the two series, with the former yielding significantly more deshielded resonances. This is accurately corroborated by DFT calculation of the relevant chemical shift parameters. In the parent ketones X-ray crystallography shows that the nitrogen lone pair is directed towards the carbonyl group in all cases

    Parametric study of EEG sensitivity to phase noise during face processing

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    <b>Background: </b> The present paper examines the visual processing speed of complex objects, here faces, by mapping the relationship between object physical properties and single-trial brain responses. Measuring visual processing speed is challenging because uncontrolled physical differences that co-vary with object categories might affect brain measurements, thus biasing our speed estimates. Recently, we demonstrated that early event-related potential (ERP) differences between faces and objects are preserved even when images differ only in phase information, and amplitude spectra are equated across image categories. Here, we use a parametric design to study how early ERP to faces are shaped by phase information. Subjects performed a two-alternative force choice discrimination between two faces (Experiment 1) or textures (two control experiments). All stimuli had the same amplitude spectrum and were presented at 11 phase noise levels, varying from 0% to 100% in 10% increments, using a linear phase interpolation technique. Single-trial ERP data from each subject were analysed using a multiple linear regression model. <b>Results: </b> Our results show that sensitivity to phase noise in faces emerges progressively in a short time window between the P1 and the N170 ERP visual components. The sensitivity to phase noise starts at about 120–130 ms after stimulus onset and continues for another 25–40 ms. This result was robust both within and across subjects. A control experiment using pink noise textures, which had the same second-order statistics as the faces used in Experiment 1, demonstrated that the sensitivity to phase noise observed for faces cannot be explained by the presence of global image structure alone. A second control experiment used wavelet textures that were matched to the face stimuli in terms of second- and higher-order image statistics. Results from this experiment suggest that higher-order statistics of faces are necessary but not sufficient to obtain the sensitivity to phase noise function observed in response to faces. <b>Conclusion: </b> Our results constitute the first quantitative assessment of the time course of phase information processing by the human visual brain. We interpret our results in a framework that focuses on image statistics and single-trial analyses
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