564 research outputs found
Understanding in-context interaction: An investigation into on-the-go mobile search
Recent years have seen a profound change in how most users interact with search engines: the majority of search requests now come from mobile devices, which are used in a number of distracting contexts. This use of mobile devices in various situational contexts away from a desk presents a range of novel challenges for users and, consequently, possibilities for interface improvements. However, there is at present a lack of work that evaluates interaction in such contexts to understand what effects context and mobility have on behaviour and errors and, ultimately, users’ search performance.
Through a controlled study, in which we simulate walking conditions on a treadmill and obstacle course, we use a combination of interaction logs and multiple video streams to capture interaction behaviour as participants (n = 24) complete simple search tasks. Using a bespoke tagging tool to analyse these recordings, we investigate how situational context and distractions impact user behaviour and performance, contrasting this with users in a baseline, seated condition. Our findings provide insights into the issues these common contexts cause, how users adapt and how such interfaces could be improved
The exposure of shipping firms’ stock returns to financial risks and oil prices: a global perspective
Shipping is an industry that is highly geared towards international trade and therefore, would seem to be highly susceptible to fluctuations in macroeconomic factors. This article investigates the impact of exchange rates, interest rates and oil prices on stock returns of 143 shipping companies from 16 countries. We also investigate the factors which determine the extent to which firm are sensitive to macroeconomic variables. Our results indicate that the low incidence of significant exposure to exchange rate and interest rates suggests that most shipping firms have utilised reasonably successful hedging strategies to reduce the impact of these macroeconomic risks. Finally, we find that, for the minority of shipping firms significantly affected by oil price increases, the effects have usually been beneficial
Low Mass Group Environments have no Substantial Impact on the Circumgalactic Medium Metallicity
We explore how environment affects the metallicity of the circumgalactic
medium (CGM) using 13 low mass galaxy groups (2-5 galaxies) at identified near background quasars. Using quasar spectra
from HST/COS and from Keck/HIRES or VLT/UVES we measure column densities of, or
determine limits on, CGM absorption lines. We use a Markov chain Monte Carlo
approach with Cloudy to estimate metallicities of cool (K) CGM gas
within groups and compare them to CGM metallicities of 47 isolated galaxies.
Both group and isolated CGM metallicities span a wide range ([Si/H]),
where the mean group () and isolated () CGM
metallicities are similar. Group and isolated environments have similar
distributions of {\HI} column densities as a function of impact parameter.
However, contrary to isolated galaxies, we do not find an anti-correlation
between {\HI} column density and the nearest group galaxy impact parameter. We
additionally divided the groups by member luminosity ratios (i.e.,
galaxy-galaxy and galaxy-dwarf groups). While there was no significant
difference in their mean metallicities, a modest increase in sample size should
allow one to statistically identify a higher CGM metallicity in galaxy-dwarf
groups compared to galaxy-galaxy groups. We conclude that either environmental
effects have not played an important role in the metallicity of the CGM at this
stage and expect that this may only occur when galaxies are strongly
interacting or merging, or that some isolated galaxies have higher CGM
metallicities due to past interactions. Thus, environment does not seem to be
the cause of the CGM metallicity bimodality.Comment: 14 pages, 5 figures, 2 figure sets, 1 machine-readable tabl
Evaluation of the relative sensitivity of carcase swabbing against belly strip excision for TVC, E. coli and Salmonella isolation
The standard US method of swabbmg p1g carcases (3x 100cm2) for determination of E. coli and Salmonella contamination was compared with a belly strip excision method (approx. 120cm2). Swabbing for Salmonella and E. coli detection was found to have a relative sensitivity equal to 1/ 7 and 1/ 2 respecl1vely, of the belly strip technique. Furthermore, swab sampling isolated 2 Salmonella serovars compared with 9 serovars by the belly strip technique. For studies on the effectiveness of carcass decontamination interventions or undertaking abattoir flow-through studies it is recommended that belly strip excision sampling be employed. This study also compared the use of a semisolid culture medium (MSRV) for Salmonella isolation developed for faecal samples with standard media. MSRV gave a result 24 hours faster but was not as sensitive as the standard medium (RV). Therefore, MSRV medium is not recommended for the isolation of Salmonella from carcases for regulatory purposes
Effect of pre-slaughter handling and serology on Salmonella in pigs
This study investigated the combined effect of herd sero-prevalence, time-off-feed prior to slaughter and transport distance to the abattoir on Salmonella spp. infection in slaughter pigs under Australian marketing scenarios. Ten herds situated either \u3c 125 km or \u3e 500 km from the abattoirs were monitored at slaughter over a 12-month period both serologically (Australian Salmonella spp. mix-ELISA) and by caecal culture. On 4 occasions (seasonally) each farm withdrew feed from three groups of slaughter pigs so they were off feed for 12-18 hours, 18-24 hours and \u3e24 hours prior to slaughter, including transport and lairage times. For herds \u3c125 km from the abattoirs, Salmonella spp. infection decreased significantly with an increase in the period between last feed and slaughter. For herds \u3e 500 km from the abattoirs, Salmonella spp. infection increased significantly with an increase in the period between last feed and slaughter, other factors apparently overriding the protective effect of fasting. Herd sero-prevalence was not a significant risk factor for caecal positivity
Cardiac Non-myocyte Cells Show Enhanced Pharmacological Function Suggestive of Contractile Maturity in Stem Cell Derived Cardiomyocyte Microtissues
The immature phenotype of stem cell derived cardiomyocytes is a significant barrier to their use in translational medicine and pre-clinical in vitro drug toxicity and pharmacological analysis. Here we have assessed the contribution of non-myocyte cells on the contractile function of co-cultured human embryonic stem cell derived cardiomyocytes (hESC-CMs) in spheroid microtissue format. Microtissues were formed using a scaffold free 96-well cell suspension method from hESC-CM cultured alone (CM microtissues) or in combination with human primary cardiac microvascular endothelial cells and cardiac fibroblasts (CMEF microtissues). Contractility was characterized with fluorescence and video-based edge detection. CMEF microtissues displayed greater Ca(2+ )transient amplitudes, enhanced spontaneous contraction rate and remarkably enhanced contractile function in response to both positive and negative inotropic drugs, suggesting a more mature contractile phenotype than CM microtissues. In addition, for several drugs the enhanced contractile response was not apparent when endothelial cell or fibroblasts from a non-cardiac tissue were used as the ancillary cells. Further evidence of maturity for CMEF microtissues was shown with increased expression of genes that encode proteins critical in cardiac Ca(2+ )handling (S100A1), sarcomere assembly (telethonin/TCAP) and β-adrenergic receptor signalling. Our data shows that compared with single cell-type cardiomyocyte in vitro models, CMEF microtissues are superior at predicting the inotropic effects of drugs, demonstrating the critical contribution of cardiac non-myocyte cells in mediating functional cardiotoxicity
The Relation Between Galaxy ISM and Circumgalactic OVI Gas Kinematics Derived from Observations and CDM Simulations
We present the first galaxy-OVI absorption kinematic study for 20 absorption
systems (EW>0.1~{\AA}) associated with isolated galaxies (0.150.55) that
have accurate redshifts and rotation curves obtained using Keck/ESI. Our sample
is split into two azimuthal angle bins: major axis () and
minor axis (). OVI absorption along the galaxy major axis is
not correlated with galaxy rotation kinematics, with only 1/10 systems that
could be explained with rotation/accretion models. This is in contrast to
co-rotation commonly observed for MgII absorption. OVI along the minor axis
could be modeled by accelerating outflows but only for small opening angles,
while the majority of the OVI is decelerating. Along both axes, stacked OVI
profiles reside at the galaxy systemic velocity with the absorption kinematics
spanning the entire dynamical range of their galaxies. The OVI found in AMR
cosmological simulations exists within filaments and in halos of ~50 kpc
surrounding galaxies. Simulations show that major axis OVI gas inflows along
filaments and decelerates as it approaches the galaxy while increasing in its
level of co-rotation. Minor axis outflows in the simulations are effective
within 50-75 kpc beyond that they decelerate and fall back onto the galaxy.
Although the simulations show clear OVI kinematic signatures they are not
directly comparable to observations. When we compare kinematic signatures
integrated through the entire simulated galaxy halo we find that these
signatures are washed out due to full velocity distribution of OVI throughout
the halo. We conclude that OVI alone does not serve as a useful kinematic
indicator of gas accretion, outflows or star-formation and likely best probes
the halo virial temperature.Comment: 24 pages, 21 figures, 4 tables. Accepted to ApJ on November 14, 201
'Mindless markers of the nation': The routine flagging of nationhood across the visual environment
The visual environment has increasingly been used as a lens with which to understand wider processes of social and economic change with studies employing in-depth qualitative approaches to focus on, for example, gentrification or trans-national networks. This exploratory paper offers an alternative perspective by using a novel method, quantitative photo mapping, to examine the extent to which a particular socio-cultural marker, the nation, is ‘flagged’ across three contrasting sites in Britain. As a multi-national state with an increasingly diverse population, Britain offers a particularly fruitful case study, drawing in debates around devolution, European integration and Commonwealth migration. In contributing to wider debates around banal nationalism, the paper notes the extent to which nations are increasingly articulated through commerce, consumption and market exchange and the overall significance of everyday markers (signs, objects, infrastructure) in naturalising a national view of the world
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