4,440 research outputs found

    Run-Time Selection of Coordination Mechanisms in Multi-Agent Systems

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    This paper presents a framework that enables autonomous agents to dynamically select the mechanism they employ in order to coordinate their inter-related activities. Adopting this framework means coordination mechanisms move from the realm of being imposed upon the system at design time, to something that the agents select at run-time in order to fit their prevailing circumstances and their current coordination needs. Empirical analysis is used to evaluate the effect of various design alternatives for the agent's decision making mechanisms and for the coordination mechanisms themselves

    Playas of inland Australia

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    [Abstract] Playas, mostly in the form of salinas, are characteristic of the Australian arid zone. Many are associated with lunettes in sebkha complexes or assemblages and can be attributed to the deflation of bare alluvial flats. Many playas are structurally controlled. Lake Eyre, for example, occupies a downfaulted segment of the crust, and many other playas large and small are associated with faults. Lakes Frome, Callabonna, Blanche, and Gregory each displays a linear shoreline, but also and arguably, all are located on a regional structural arc. Lake Gairdner occupies a valley probably blocked by faulting. Others may be caused by preferential weathering along fracture zones, some linear but others arcuate. Many salinas are developed in dismembered rivers channels, the position and pattern of which are structurally determined. But many owe their existence to the interaction of several of these factors. The various salts precipitated in playas constitute a significant resource, regional and local, past, present and future

    Desarrollo de formas multietapa en varias situaciones geomorfolĂłgicas y a diferentes escalas

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    [Abstract] That many landforms have their origins in the distant past is highlighted by the multistage concept, whereby the structural properties of bedrock which have been exploited by shallow groundwaters are taken fully into account. Fractures of various types are par- ticularly vulnerable to weathering and hence to erosion. Examples are discussed from various lithological and environmental settings - plutonic, volcanic and sedimentary rocks, and different climates

    Amino acid sequence of retinal transducin at the site ADP-ribosylated by cholera toxin

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    Transducin was [32P]ADP-ribosylated by cholera toxin in bovine retinal rod outer segments and then partially purified on ω-amino octyl agarose to remove other ADP-ribosylated proteins. Trypsin digestion of the ADP-ribosylated transducin and further purification using boronate-polyacrylamide beads and high performance liquid chromatography yielded a single radiolabeled tetrapeptide, Ser-Arg-Val-Lys. The ADP-ribose is linked to the guanidinium group of arginine

    Comparison between SELEX and single-step selection for the identification of bivalent aptamers for thrombin

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    The identification of bivalent aptamers for thrombin by SELEX and single-step selection are compared using next generation (massively parallel) sequencing and motif finding informatics. Results show that similar aptamers are identified by both methods

    A Comparison of Reach-to-Grasp and Transport-to-Place Performance in Participants With Age-Related Macular Degeneration and Glaucoma

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    PURPOSE: To compare visually guided manual prehension in participants with primarily central field loss (CFL) due to age-related macular degeneration and peripheral visual field loss (PFL) due to glaucoma. This study extends current literature by comparing directly "reach-to-grasp" performance, and presents a new task of "transport-to-place" the object accurately to a new location. Data were compared to age-matched controls. METHODS: Three-dimensional motion data were collected from 17 glaucoma participants with PFL, 17 participants with age-related macular degeneration CFL and 10 age-matched control participants. Participants reached toward and grasped a cylindrical object (reach-to-grasp), and then transported and placed (transport-to-place) it at a different (predefined) peripheral location. Various kinematic indices were measured. Correlation analyses explored relationships between visual function and kinematic data. RESULTS: In the reach-to-grasp phase, CFL patients exhibited significantly longer movement and reaction times when compared to PFL participants and controls. Central field loss participants also took longer to complete the movement and made more online movements in the latter part of the reach. During the transport-to-place phase, CFL participants showed increased deceleration times, longer movement trajectory, and increased vertical wrist displacement. Central field loss also showed higher errors in placing the object at a predefined location. A number of kinematic indices correlated significantly to central visual function indices (P < 0.05). CONCLUSIONS: Significant differences in performance exist between CFL and PFL participants. Various indices correlated significantly with loss in acuity and contrast sensitivity (CS), suggesting that performance is more dependent on central visual function irrespective of underlying pathology

    PROTECTED-UK – Clinical pharmacist interventions in the UK critical care unit: exploration of relationship between intervention, service characteristics and experience level

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    PURPOSE: Clinical pharmacist (CP) interventions from the PROTECTED-UK cohort, a multi-site critical care interventions study, were further analysed to assess effects of: time on critical care, number of interventions, CP expertise and days of week, on impact of intervention and ultimately contribution to patient care. METHODS: Intervention data were collected from 21 adult critical care units over 14 days. Interventions could be error, optimisation or consults, and were blind-coded to ensure consistency, prior to bivariate analysis. Pharmacy service demographics were further collated by investigator survey. KEY FINDINGS: Of the 20 758 prescriptions reviewed, 3375 interventions were made (intervention rate 16.1%). CPs spent 3.5 h per day (mean, ±SD 1.7) on direct patient care, reviewed 10.3 patients per day (±SD 4.2) and required 22.5 min (±SD 9.5) per review. Intervention rate had a moderate inverse correlation with the time the pharmacist spent on critical care (P = 0.05; r = 0.4). Optimisation rate had a strong inverse association with total number of prescriptions reviewed per day (P = 0.001; r = 0.7). A consultant CP had a moderate inverse correlation with number of errors identified (P = 0.008; r = 0.6). No correlation existed between the presence of electronic prescribing in critical care and any intervention rate. Few centres provided weekend services, although the intervention rate was significantly higher on weekends than weekdays. CONCLUSIONS: A CP is essential for safe and optimised patient medication therapy; an extended and developed pharmacy service is expected to reduce errors. CP services should be adequately staffed to enable adequate time for prescription review and maximal therapy optimisation
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