Experimental archeology and serious games: challenges of inhabiting virtual heritage

Experimental archaeology has long yielded valuable insights into the tools and techniques that featured in past peoples’ relationship with the material world around them. However, experimental archaeology has, hitherto, confined itself to rigid, empirical and quantitative questions. This paper applies principles of experimental archaeology and serious gaming tools in the reconstructions of a British Iron Age Roundhouse. The paper explains a number of experiments conducted to look for quantitative differences in movement in virtual vs material environments using both “virtual” studio reconstruction as well as material reconstruction. The data from these experiments was then analysed to look for differences in movement which could be attributed to artefacts and/or environments. The paper explains the structure of the experiments, how the data was generated, what theories may make sense of the data, what conclusions have been drawn and how serious gaming tools can support the creation of new experimental heritage environments

Intravital Multiphoton Microscopy with Fluorescent Bile Salts in Rats as an In Vivo Biomarker for Hepatobiliary Transport Inhibition

The bile salt export pump (BSEP) is expressed at the canalicular domain of hepatocytes, where it mediates the elimination of monovalent bile salts into the bile. Inhibition of BSEP is considered a susceptibility factor for drug-induced liver injury that often goes undetected during nonclinical testing. Although in vitro assays exist for screening BSEP inhibition, a reliable and specific method for confirming Bsep inhibition in vivo would be a valuable follow up to a BSEP screening strategy, helping to put a translatable context around in vitro inhibition data, incorporating processes such as metabolism, protein binding, and other exposure properties that are lacking in most in vitro BSEP models. Here, we describe studies in which methods of quantitative intravital microscopy were used to identify dose-dependent effects of two known BSEP/Bsep inhibitors, 2-[4-[4-(butylcarbamoyl)-2-[(2,4-dichlorophenyl)sulfonylamino]phenoxy]-3-methoxyphenyl]acetic acid (AMG-009) and bosentan, on hepatocellular transport of the fluorescent bile salts cholylglycyl amidofluorescein and cholyl-lysyl-fluorescein in rats. Results of these studies demonstrate that the intravital microscopy approach is capable of detecting Bsep inhibition at drug doses well below those found to increase serum bile acid levels, and also indicate that basolateral efflux transporters play a significant role in preventing cytosolic accumulation of bile acids under conditions of Bsep inhibition in rats. Studies of this kind can both improve our understanding of exposures needed to inhibit Bsep in vivo and provide unique insights into drug effects in ways that can improve our ability interpret animal studies for the prediction of human drug hepatotoxicity

Studies of atmospheric refraction effects on laser data

The refraction effect from three perspectives was considered. An analysis of the axioms on which the accepted correction algorithms were based was the first priority. The integrity of the meteorological measurements on which the correction model is based was also considered and a large quantity of laser observations was processed in an effort to detect any serious anomalies in them. The effect of refraction errors on geodetic parameters estimated from laser data using the most recent analysis procedures was the focus of the third element of study. The results concentrate on refraction errors which were found to be critical in the eventual use of the data for measurements of crustal dynamics

An exploration of the accentuation effect: errors in memory for voice fundamental frequency (F0) and speech rate

The accentuation effect demonstrates how memory often reflects category typical representations rather than the specific features of learned items. The present study investigated the impact of manipulating fundamental frequency (F0) and speech rate (syllables per second) on immediate target matching performance (selecting a voice from a pair to match a previously heard target voice) for a range of synthesised voices. It was predicted that when participants were presented with high or low frequency target voices, voices even higher or lower in frequency would be selected. The same pattern was also predicted for speech rate. Inconsistent with the accentuation account, the results showed a general bias to select voices higher in frequency for high, moderate, and low frequency target voices. For speech rate, listeners selected voices faster in rate for slow rate target voices. Overall it seems doubtful that listeners rely solely on categorical information about voices during recognition

Integrated processes in person perception: matching novel faces and voices [oral presentation]

A series of studies investigated whether people can match novel faces and voices of the same age (20-30) and sex at a level significantly above chance. The studies also tested whether accuracy is affected by facial stimuli type: static or moving, and the order of stimuli presentation: face first or voice first. In Experiment 1 participants saw a face and heard a voice one after the other. They had to decide whether the stimuli were matching or not matching. When the correct matching stimulus was present participants consistently performed above chance level, regardless of facial stimuli type or stimuli order. When the correct matching stimulus was not present participants were either just guessing (voice first) or significantly below chance (face first). In Experiment 2 and 3 participants had to select the correct matching stimuli in a two-alternative forced choice task. The correct matching stimuli was always present in Experiment 2. It was never present in Experiment 3. Experiments 2 and 3 replicated the results of Experiment 1. Participants in Experiment 2 were more accurate when the correct matching stimulus was present in position 1. Experiment 3 showed that a response bias was operating; participants selected stimulus 1 more often than stimulus 2. However, the bias did not wholly explain the overall above-chance accuracy levels in Experiment 2. This set of results show that people can accurately match novel faces and voices, indicating that faces and voices offer concordant information. Face and voice perception appears to be an integrated process

Earwitness memory: factors that influence voice recognition accuracy across the lifespan [poster presentation]

We aimed to explore the effect of change in frequency (F0 in Hz) and speech rate (syllables per second - SPS) on voice recognition accuracy. In part one of our experiment, participants (M=36; F=36; aged 18-30 years) were given a 2AFC voice matching task which involved hearing (binaural headphone presentation) synthesised (using NaturalReader 12) voices (uttering the phrase “spring is the season where flowers appear, summer is the warmest season of the year”). Participants had to identify whether the two voices were the ‘same’ or ‘different’ (using a key press, left/right). There were six target voices (six different identities, three male and three female) in total. In each trial the to be matched voices comprised the original voice or a modulated version (increased/decreased F0 or increased/decreased SPS) of the original voice presented in a random order. In part two of our experiment, the same participants heard the original voice and the modulated versions in a random order. After presenting each voice, participants had to decide whether the voice they heard was ‘male’ or ‘female’ (using a key press, left/right). Results from part one indicated that participants could discriminate a more subtle pitch shift than they could for speech rate. Results from part two indicated that participants correctly identified the sex of the speaker when SPS was modulated for both male and female voices, and when F0 was modulated for male voices. However, participants incorrectly identified a female voice as ‘male’ when F0 decreased. This suggests that both pitch and speech rate variations are important for accurate speaker identification and voice discrimination

Distance to Multiple Kinematic Components of Quasar Outflows: VLT Observations of QSO 2359-1241 and SDSS J0318-0600

Using high resolution VLT spectra, we study the multi-component outflow systems of two quasars exhibiting intrinsic Fe II absorption (QSO 2359-1241 and SDSS J0318-0600). From the extracted ionic column densities and using photoionization modeling we determine the gas density, total column density, and ionization parameter for several of the components. For each object the largest column density component is also the densest, and all other components have densities of roughly 1/4 of that of the main component. We demonstrate that all the absorbers lie roughly at the same distance from the source. Further, we calculate the total kinetic luminosities and mass outflow rates of all components and show that these quantities are dominated by the main absorption component.Comment: 27 pages, 5 figure

Studying the X-ray hysteresis in GX 339-4: the disc and iron line over one decade

We report on a comprehensive and consistent investigation into the X-ray emission from GX 339-4. All public observations in the 11 year RXTE archive were analysed. Three different types of model - single powerlaw, broken powerlaw and a disc + powerlaw - were fitted to investigate the evolution of the disc, along with a fixed gaussian component at 6.4 keV to investigate any iron line in the spectrum. We show that the relative variation in flux and X-ray colour between the two best sampled outbursts are very similar. The decay of the disc temperature during the outburst is clearly seen in the soft state. The expected decay is S_Disc \propto T^4; we measure T^4.75\pm0.23. This implies that the inner disc radius is approximately constant in the soft state. We also show a significant anti-correlation between the iron line significant width and the X-ray flux in the soft state while in the hard state the EW is independent of the flux. This results in hysteresis in the relation between X-ray flux and both line flux and EW. To compare the X-ray binary outburst to the behaviour seen in AGN, we construct a Disc Fraction Luminosity Diagram for GX 339-4, the first for an X-ray binary. The shape qualitatively matches that produced for AGN. Linking this with the radio emission from GX 339-4 the change in radio spectrum between the disc and power-law dominated states is clearly visible.Comment: Accepted for publication in MNRAS, 20 pages, 17 figures. For high-res version see http://www.astro.soton.ac.uk/~r.j.dunn/publications.htm