Mostrando recursos 1 - 20 de 5.211

  1. Modelling and control of an elastically joint-actuated cart-pole underactuated system

    Liu, Pengcheng; Yu, Hongnian; Cang, Shuang
    This paper investigates the modelling and closedloop tracking control issues of a novel elastic underactuated multibody system. A torsional inverted pendulum cart-pole system with a single rotary actuator at the pivot of the cart is proposed. The system dynamics which incorporates with motion planning is firstly described. An optimization procedure is then discussed to plan the feasible trajectories that not just meet the performance requirements but also obtain optimality with respect to the cart displacement and average velocity. A closed-loop tracking controller is designed under collocated partial feedback linearization (CPFL). Subsequent presentation of simulation demonstrates that the proposed system is...

  2. Golf Science: optimum performance from tee to green [2nd Edition]

    Smith, Mark F.
    Golf is perhaps the most complicated simple game ever invented. Watching the professionals gives you only a glimpse of the complexity of what is happening, with each shot involving biomechanics, aerodynamics, ballistics, materials science, probability, even meteorology. Golf Science takes a timely new look at the game by investigating the scientific wonders that transfer the ball from tee to hole. Each chapter investigates a different area of the game and is organized around a series of Q&As. What is the optimum length for a driver? How does backspin work? The answers and the data are presented through illuminating info-graphics. The...

  3. Psicometria aplicada à neuropsicologia

    Menezes, Igor; Alchieri, João Carlos
    This chapter addresses the application of psychometrics into neuropsychology

  4. Amara West and the shrinking Nile

    Woodward, Jamie; Macklin, Mark
    A series of well-preserved old river channels is a distinctive feature of the landscape around Amara West. One of the palaeochannels lies immediately north of the town: it may have been much like the small channel beside Ernetta Island today (below). The dried-up channel at Amara West raises key questions, fundamental to our understanding of life here. When did flow in this channel cease to be permanent? Was the town founded on an island? Was the abandonment of the town linked to the failure of this channel and resulting changes to living conditions?

  5. “The weakest ink is stronger than the sharpest memory”: testing the effects of witness note taking and retention interval on eyewitness memory

    Onwuegbusi, Tochukwu; Bull, Ray; ,; ,; ,
    Objectives: The subject of eyewitness memory has been in the mainstream of empirical and theoretical activities in the discipline of forensic psychology with scholars devoting their time on devising a technique, tool, or approach for improving eyewitness memory. The present study examines the effects of note taking and retention interval on eyewitness memory. Design: A 2 (witness note: note v no note) x 2 (retention interval: two days v one week) between group MANOVA factorial design was used in this study. The dependent variables are (a) eyewitness memory (verbal recall) measured in three categories: (i) correct (ii) incorrect (error) and...

  6. Spatial attention can bias the accuracy of eyewitness identification

    Onwuegbusi, Tochukwu; Flowe, Heather; Barrett, Douglas; ,; ,
    Visual working memory (VWM) is a limited-capacity resource for the temporary storage of visual information (Cowan, 2001). Selective visual attention can protect VWM capacity by filtering relevant from irrelevant information during encoding or maintenance (Griffin & Nobre, 2003).The aim of the current study was to investigate changes in the accuracy of face recognition memory when attention was reflexively oriented to the location of a face before (pre-cue) or after (retro-cue) it was disappeared. The results indicate that VWM capacity for unfamiliar faces is poor and declines as a function of the number of faces in the display (load). When attention...

  7. Target distinctiveness modulates resource allocation in visual working memory for faces: implications for eyewitness face identification

    Onwuegbusi, Tochukwu; Flowe, Heather; Barrett, Douglas; ,; ,
    Visual working memory (VWM) is a limited-capacity resource for the temporary storage of visual information (Cowan, 2001). Selective visual attention can protect VWM capacity by filtering relevant from irrelevant information during encoding or maintenance (Griffin & Nobre, 2003).The aim of the current study was to investigate whether target distinctiveness bias the allocation of visual working memory (VWM) resources during the encoding of unfamiliar faces. The results indicate that VWM capacity for unfamiliar faces is poor and declines as a function of the number of faces in the display (load). When one of the faces in the display was made distinct...

  8. Fallen

    Westerside, Andrew; Lawrence, Conan; Wilde, Mark; Baynton, Rachel
    Part of the Performance-as-Commemoration project, this practice-as-research performance took place on the 100th anniversary of the Battle of the Somme (1 July, 2016) at the Judge's Lodgings in Lincoln, and was later broadcast on BBC Radio Lincolnshire and BBC iPlayer. The performance is a response to the following research questions: How can live performance 'commemorate' rather than 'memorialise' or 're-enact' significant historical events? How can music and the musical archive commemorate loss? Are there any unperformed compositions/arrangements of music from composers who fought and fell at the Somme?

  9. H. N. Werkman

    Vassilakis, Nico; Tullett, Barrie; Reed, Brian; Bury, Louis; Tierney, Orchid; Earl, Amanda; Baeten, Anneke; Saroyan, Aram; bisset, bill; Dimichelle, Bill; Mavreas, Billy; Downing, Brandon; Stetser, Carol; Padin, Clemente; Tettenborn, Connie; Hill, Crag; Agrafiotis, Demosthenes; Smith, Denis; Beaulieu, Derek; Kulemin, Edward; Aprile, Francesco; Huth, Geof; Gatza, Geoffrey; Kolomiets, Gleb; Johnson, Jeff T.; Glass, Jesse; Chace, Joel; Kempton, Karl; Ernst, K. S.; Upton, Lawrence; Fierens, Luc; Young, Mark; Koppány, Márton; Peters, Michael; Winkler, Michael; Jimenez, Miguel; Borkent, Mike; Collier, Patrick; Helmes, Scott; Isin, Serkan; Nelson, Stephen; Staelens, Sven; Gaze, Tim; Restrepo, Tulio; Baroni, Vittore; Sutherland, W. Mark; Bohn, Willard
    A piece commissioned for COLDFRONT – Singular Vispo :: First Encounters. Artists were asked to talk about their introduction to Visual Poetry and the piece of work that changed the way they saw language.

  10. Implementing integrating technologies: developing managerial integration for CAD/CAM

    Twigg, David; Voss, Christopher A.; Winch, Graham M.
    Companies are increasingly adopting technologies that can promote integration between functions and tasks. The implementation of these technologies has largely concerned the tasks of installation and the technical integration of the system. However, insufficient attention appears to have been directed towards organisational and managerial integration issues. Argues, based on empirical data from 15 UK engineering companies, that effective implementation of integrating technology requires a better understanding of issues concerning the integration of functions/tasks involved. Focuses on the issues and problems concerning managers involved with improving engineering/production integration, and proposes alternative organisational and technical mechanisms for implementing such integration. Reviews these...

  11. Operations and production management on the Internet

    Twigg, David
    Contends, contrary to some media portrayals of the Internet as a surfer’s playground without signposts, that the Internet does offer some direction to serious researchers seeking operations and production management information. Attempts to decipher the Internet as a medium for information gathering and to explain how it may be used as a resource for those in the operations management field. Aims to assist the Internet novice to find his or her point of embarkation and to introduce the more experienced user to new sources of useful data. Considers how the Internet may be used to promote the operations and production...

  12. Asymmetry in antennal contacts during trophallaxis in ants

    Frasnelli, Elisa; Iakovlev, Ivan; Reznikova, Zhanna
    Behavioural and brain left–right asymmetries are a common feature among the animal kingdom. Lateralization often manifests itself at the population-level with most individuals showing the same direction of lateral bias. Theoretical model based on evolutionary stable strategy predicts that lateralization at the population-level is more likely to characterize social rather than solitary species. Empirical data supporting this hypothesis has been recently obtained in Hymenoptera showing that eusocial honeybees present an asymmetrical use of the antennae: the right antenna is involved in olfactory learning and present more olfactory receptors. However, no evidences about the role of antennal asymmetries in social interactions have been provided so far. Highly social...

  13. Searching for anatomical correlates of olfactory lateralization in the honeybee antennal lobes: a morphological and behavioural study

    Rigosi, Elisa; Frasnelli, Elisa; Vinegoni, Claudio; Antolini, Renzo; Anfora, Gianfranco; Vallortigara, Giorgio; Haase, Albrecht
    The honeybee, Apis mellifera L. (Hymenoptera: Apidae), has recently become a model for studying brain asymmetry among invertebrates. A strong lateralization favouring the right antenna was discovered in odour learning and short-term memory recall experiments, and a lateral shift favouring the left antenna for long-term memory recall. Corresponding morphological asymmetries have been found in the distribution of olfactory sensilla between the antennae and confirmed by electrophysiological odour response measurements in isolated right and left antennae. The aim of this study was to investigate whether a morphological asymmetry can be observed in the volume of the primary olfactory centres of the central nervous system, the antennal lobes (ALs)....

  14. Origins of brain asymmetry: Lateralization of odour memory recall in primitive Australian stingless bees

    Frasnelli, Elisa; Vallortigara, Giorgio; Rogers, Lesley J.
    Left–right antennal asymmetry has been reported in honeybees. We studied primitive social bees to investigate the evolutionary origins of the asymmetry. Three species of Australian native, stingless bees (Trigona carbonaria, Trigona hockingsi and Austroplebeia australis) were trained to discriminate two odours, lemon (+)/vanilla (−), using the Proboscis Extension Reflex (PER). Recall of the olfactory memory at 1 h after training was better when the odour was presented on the right than on the left side of the bee. In contrast, recall at 5 h after training was better when the odour was presented on the left than on the right side of the bee. An additional...

  15. Morpho-functional asymmetry of the olfactory receptors of the honeybee (Apis mellifera)

    Frasnelli, Elisa; Anfora, Gianfranco; Trona, Federica; Tessarolo, Francesco; Vallortigara, Giorgio
    Lateralization, i.e., the different functional specialisation of the left and right side of the brain, has been documented in many vertebrate species and, recently, in invertebrate species as well. In the Honeybee, Apis mellifera L. (Hymenoptera Apidae), it has been shown that short-term (<1 h) recall of olfactory memories would be possible mainly from the right rather than from the left antenna. Here we confirmed this finding showing that recall of the olfactory memory 1 h after training to associate (−)-linalool, a floral volatile compound, with a sugar reward, as revealed by the bee extending its proboscis when presented with the trained odour, was better when...

  16. Response competition associated with right–left antennal asymmetries of new and old olfactory memory traces in honeybees

    Frasnelli, Elisa; Vallortigara, Giorgio; Rogers, Lesley J.
    Lateralized recall of olfactory memory in honeybees was tested, following conditioning of the proboscis extension reflex (PER), at 1 or 6 h after training. After training with lemon (+)/vanilla (−) or cineol (+)/eugenol (−) recall at 1 h was better when the odour was presented to the right side of the bee than when it was presented to the left side. In contrast, recall at 6 h was better when the odour was presented to the left than to the right side. This confirmed previous evidence of shorter-term recall via the right antenna and long-term memory recall via the left antenna. However, when trained with...

  17. Behavioural and electrophysiological lateralization in a social (Apis mellifera) but not in a non-social (Osmia cornuta) species of bee

    Anfora, Gianfranco; Frasnelli, Elisa; Maccagnani, Bettina; Rogers, Lesley J.; Vallortigara, Giorgio
    Recent evidence suggests that asymmetry between the left and right sides of the brain is not limited to vertebrates but extends to invertebrates as well. We compared olfactory lateralization in two species of Hymenoptera Apoidea, the honeybee (Apis mellifera), a social species, and the mason bee (Osmia cornuta), a solitary species. Recall of the olfactory memory 1 h after training to associate an odour with a sugar reward, as revealed by the bee extending its proboscis when presented with the trained odour, was better in honeybees trained with their right than with their left antenna. No such asymmetry was observed in mason bees. Similarly, electroantennographic responses...

  18. Characterization and polyanion-binding properties of purified recombinant prion protein

    Brimacombe, Debbie B.; Bennett, Alan D.; Wusteman, Fred S.; Gill, Andrew C.; Dann, Janine C.; Bostock, Christopher J.
    Certain polysulphated polyanions have been shown to have prophylactic effects on the progression of transmissible spongiform encephalopathy disease, presumably because they bind to prion protein (PrP). Until now, the difficulty of obtaining large quantities of native PrP has precluded detailed studies of these interactions. We have over-expressed murine recombinant PrP (recPrP), lacking its glycophosphoinositol membrane anchor, in modified mammalian cells. Milligram quantities of secreted, soluble and partially glycosylated protein were purified under non-denaturing conditions and the identities of mature-length aglycosyl recPrP and two cleavage fragments were determined by electrospray MS. Binding was assessed by surface plasmon resonance techniques using both...

  19. Stability and conformational properties of doppel, a prion-like protein, and its single-disulphide mutant

    Whyte, Sheena M.; Sylvester, Ian D.; Martin, Stephen R.; Gill, Andrew C.; Wopfner, Franziska; Schatzl, Hermann M.; Dodson, Guy G.; Bayley, Peter M.
    Both prion protein and the structurally homologous protein doppel are associated with neurodegenerative disease by mechanisms which remain elusive. We have prepared murine doppel, and a mutant with one of the two disulphide bonds removed, in the expectation of increasing the similarity of doppel to prion protein in terms of conformation and stability. Unfolding studies of doppel and the mutant have been performed using far-UV CD over a range of solution conditions known to favour the alpha --> beta transformation of recombinant prion protein. Only partial unfolding of doppel or the mutant occurs at elevated temperature, but both exhibit full...

  20. Characterization of 2′-fluoro-RNA aptamers that bind preferentially to disease-associated conformations of prion protein and inhibit conversion

    Rhie, Alexandre; Kirby, Louise; Sayer, Natalie; Wellesley, Rosanna; Disterer, Petra; Sylvester, Ian; Gill, Andrew C.; Hope, James; James, William; Tahiri-Alaoui, Abdessamad
    We have isolated artificial ligands or aptamers for infectious prions in order to investigate conformational aspects of prion pathogenesis. The aptamers are 2'-fluoro-modified RNA produced by in vitro selection from a large, randomized library. One of these ligands (aptamer SAF-93) had more than 10-fold higher affinity for PrPSc than for recombinant PrPC and inhibited the accumulation of PrPres in near physiological cell-free conversion assay. To understand the molecular basis of these properties and to distinguish specific from nonspecific aptamer-PrP interactions, we studied deletion mutants of bovine PrP in denatured, alpha-helix-rich and beta-sheet-rich forms. We provide evidence that, like scrapie-associated fibrils...

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