1,197 research outputs found
Merging Environments for Shared Spaces in Mixed Reality
In virtual reality a real walking interface limits the extent of a virtual environment to our local walkable space. As local spaces are specific to each user, sharing a virtual environment with others for collaborative work or games becomes complicated. It is not clear which user's walkable space to prefer, or whether that space will be navigable for both users.
This paper presents a technique which allows users to interact in virtual reality while each has a different walkable space. With this method mappings are created between pairs of environments. Remote users are then placed in the local environment as determined by the corresponding mapping.
A user study was conducted with 38 participants. Pairs of participants were invited to collaborate on a virtual reality puzzle-solving task while in two different virtual rooms. An avatar representing the remote user was mapped into the local user's space. The results suggest that collaborative systems can be based on local representations that are actually quite different
Constraining the dark energy equation of state with double source plane strong lenses
We investigate the possibility of constraining the dark energy equation of
state by measuring the ratio of Einstein radii in a strong gravitational lens
system with two source planes. This quantity is independent of the Hubble
parameter and directly measures the growth of angular diameter distances as a
function of redshift. We investigate the prospects for a single double source
plane system and for a forecast population of systems discovered by
re-observing a population of single source lenses already known from a
photometrically selected catalogue such as CASSOWARY or from a
spectroscopically selected catalogue such as SLACS. We find that constraints
comparable to current data-sets (15% uncertainty on the dark equation of state
at 68%CL) are possible with a handful of double source plane systems. We also
find that the method's degeneracy between Omega_M and w is almost orthogonal to
that of CMB and BAO measurements, making this method highly complimentary to
current probes.Comment: 13 Page
Diversity and structure of Bettongia tropica: using population genetics to guide reintroduction and help prevent the extinction of an endangered Australian marsupial
Conservation translocations can restore populations and prevent extinction of threatened species. Sourcing adequate genetic diversity is an essential consideration when planning reintroductions, because it influences individual fitness and long-term persistence of populations, yet available populations of threatened species may lack diversity. We estimated population genetic parameters for one of Australiaâs most threatened mammals, the northern bettong, Bettongia tropica, to select source populations for reintroduction. Individuals from sites across the speciesâ extant range in the Wet Tropics of north Queensland were genotyped, using 6,133 informative SNPs. We found that samples clustered into four populations: an isolated northern population at Mt Spurgeon and three connected southern populations in the Lamb Range. Most of the speciesâ genetic diversity was dispersed across the Lamb Range populations in approximately equal proportions. Populations showed an isolation-by-distance effect, even over short distances within continuous habitat. Admixture of populations was high at distances 11Â km, and there was asymmetrical gene flow between the two closest neighboring populations. All populations had small effective sizes and experienced drift, but connectivity appears to have mitigated drift and stabilized population sizes within the Lamb Range. The Mt Spurgeon population had a very small effective population size and low genetic diversity. We use our findings to weigh up the risks and benefits of mixing sources for reintroduction, and we recommend a mixed source approach. We do not currently recommend sourcing individuals from Mt Spurgeon and conservation efforts to preserve this population are urgently required
Self-refraction, ready-made glasses and quality of life among rural myopic Chinese children: a non-inferiority randomized trial.
PURPOSE: To study, for the first time, the effect of wearing ready-made glasses and glasses with power determined by self-refraction on children's quality of life. METHODS: This is a randomized, double-masked non-inferiority trial. Children in grades 7 and 8 (age 12-15 years) in nine Chinese secondary schools, with presenting visual acuity (VA) â€6/12 improved with refraction to â„6/7.5 bilaterally, refractive error â€-1.0 D and <2.0 D of anisometropia and astigmatism bilaterally, were randomized to receive ready-made spectacles (RM) or identical-appearing spectacles with power determined by: subjective cycloplegic retinoscopy by a university optometrist (U), a rural refractionist (R) or non-cycloplegic self-refraction (SR). Main study outcome was global score on the National Eye Institute Refractive Error Quality of Life-42 (NEI-RQL-42) after 2 months of wearing study glasses, comparing other groups with the U group, adjusting for baseline score. RESULTS: Only one child (0.18%) was excluded for anisometropia or astigmatism. A total of 426 eligible subjects (mean age 14.2 years, 84.5% without glasses at baseline) were allocated to U [103 (24.2%)], RM [113 (26.5%)], R [108 (25.4%)] and SR [102 (23.9%)] groups, respectively. Baseline and endline score data were available for 398 (93.4%) of subjects. In multiple regression models adjusting for baseline score, older age (p = 0.003) and baseline spectacle wear (p = 0.016), but not study group assignment, were significantly associated with lower final score. CONCLUSION: Quality of life wearing ready-mades or glasses based on self-refraction did not differ from that with cycloplegic refraction by an experienced optometrist in this non-inferiority trial
Tracking serendipitous interactions: How individual cultures shape the office
In many work environments, serendipitous interactions between members of
different groups may lead to enhanced productivity, collaboration and knowledge
dissemination. Two factors that may have an influence on such interactions are
cultural differences between individuals in highly multicultural workplaces,
and the layout and physical spaces of the workplace itself. In this work, we
investigate how these two factors may facilitate or hinder inter-group
interactions in the workplace. We analyze traces collected using wearable
electronic badges to capture face-to-face interactions and mobility patterns of
employees in a research laboratory in the UK. We observe that those who
interact with people of different roles tend to come from collectivist cultures
that value relationships and where people tend to be comfortable with social
hierarchies, and that some locations in particular are more likely to host
serendipitous interactions, knowledge that could be used by organizations to
enhance communication and productivity.This work was supported by the Google Europe Fellowship in Mobile Computing.This is the author accepted manuscript. The final version is published in the Proceedings of the ACM Conference on Computer Supported Cooperative Work and Social Computing and can be found in the ACM digital library here: http://dl.acm.org/citation.cfm?doid=2531602.2531641
Predicting risky choices from brain activity patterns
Previous research has implicated a large network of brain regions in the processing of risk during decision making. However, it has not yet been determined if activity in these regions is predictive of choices on future risky decisions. Here, we examined functional MRI data from a large sample of healthy subjects performing a naturalistic risk-taking task and used a classification analysis approach to predict whether individuals would choose risky or safe options on upcoming trials. We were able to predict choice category successfully in 71.8% of cases. Searchlight analysis revealed a network of brain regions where activity patterns were reliably predictive of subsequent risk-taking behavior, including a number of regions known to play a role in control processes. Searchlights with significant predictive accuracy were primarily located in regions more active when preparing to avoid a risk than when preparing to engage in one, suggesting that risk taking may be due, in part, to a failure of the control systems necessary to initiate a safe choice. Additional analyses revealed that subject choice can be successfully predicted with minimal decrements in accuracy using highly condensed data, suggesting that information relevant for risky choice behavior is encoded in coarse global patterns of activation as well as within highly local activation within searchlights
Memory systems in schizophrenia: Modularity is preserved but deficits are generalized
OBJECTIVE: Schizophrenia patients exhibit impaired working and episodic memory, but this may represent generalized impairment across memory modalities or performance deficits restricted to particular memory systems in subgroups of patients. Furthermore, it is unclear whether deficits are unique from those associated with other disorders. METHOD: Healthy controls (n=1101) and patients with schizophrenia (n=58), bipolar disorder (n=49) and attention-deficit-hyperactivity-disorder (n=46) performed 18 tasks addressing primarily verbal and spatial episodic and working memory. Effect sizes for group contrasts were compared across tasks and the consistency of subjects\u27 distributional positions across memory domains was measured. RESULTS: Schizophrenia patients performed poorly relative to the other groups on every test. While low to moderate correlation was found between memory domains (r=.320), supporting modularity of these systems, there was limited agreement between measures regarding each individual\u27s task performance (ICC=.292) and in identifying those individuals falling into the lowest quintile (kappa=0.259). A general ability factor accounted for nearly all of the group differences in performance and agreement across measures in classifying low performers. CONCLUSIONS: Pathophysiological processes involved in schizophrenia appear to act primarily on general abilities required in all tasks rather than on specific abilities within different memory domains and modalities. These effects represent a general shift in the overall distribution of general ability (i.e., each case functioning at a lower level than they would have if not for the illness), rather than presence of a generally low-performing subgroup of patients. There is little evidence that memory impairments in schizophrenia are shared with bipolar disorder and ADHD
High-throughput tertiary amine deoxygenated photopolymerizations for synthesizing polymer libraries
The huge chemical space potential of synthetic polymers means that in many studies only a small parameter range can be realistically synthesized in a short time and hence the âbestâ formulations may not be optimum. Throughput is traditionally limited by the need for deoxygenation in radical polymerizations, but advances in photopolymerization now provide opportunities for âin-airâ polymerizations. Here, we have developed a protocol using liquid handling robots (or multichannel pipettes) with blue light photolysis of reversible addition fragmentation chain transfer agents and tertiary amine deoxygenation to enable the synthesis of polymer libraries in industry-standard 96-well plates with no specialized infrastructure and no degassing step. The roles of solvents and amine deoxygenators are explored to optimize the polymerization, particularly to look at alternatives to dimethyl sulfoxide (DMSO) for hydrophobic monomer (co)polymerization. DMSO is shown to aid the degassing process but is not easy to remove and hence prevents isolation of pure polymers. In contrast, using dioxane in-plate evaporation or precipitation of the tertiary amine allowed isolation of polymers in-plate. This removed all reaction components yielding pure polymers, which is not easily achieved with systems using metal catalysts and secondary reductants, such as ascorbic acid. As an example of the throughput, in just under 40 h, 392 polymers were synthesized and subsequently analyzed direct from plates by a 96-well plate sampling size exclusion chromatography system to demonstrate reproducibility. Due to less efficient degassing in dioxane (compared to DMSO), the molecular weight and dispersity control were limited in some cases (with acrylates giving the lowest dispersities), but the key aim of this system is to access hundreds of polymers quickly and in a format needed to enable testing. This method enables easy exploration of chemical space and development of screening libraries to identify hits for further study using precision polymerization methods
The iron law of democratic socialism: British and Austrian influences on the young Karl Polanyi
This article has been made available through the Brunel Open Access Publishing Fund.A central thesis of Karl Polanyi's The great transformation concerns the tensions between capitalism and democracy: the former embodies the principle of inequality, while democracy represents that of equality. This paper explores the intellectual heritage of this thesis, in the âfunctional theoryâ of G.D.H. Cole and Otto Bauer and in the writings of Eduard Bernstein. It scrutinizes Polanyi's relationship with Bernstein's âevolutionary socialismâ and charts his âdouble movementâ vis-Ă -vis Marxist philosophy: in the 1910s he reacted sharply against Marxism's deterministic excesses, but he then, in the 1920s, engaged in sympathetic dialogue with Austro-Marxist thinkers. The latter, like Bernstein, disavowed economic determinism and insisted upon the importance and autonomy of ethics. Yet they simultaneously predicted a law-like expansion of democracy from the political to the economic arena. Analysis of this contradiction provides the basis for a concluding discussion that reconsiders the deterministic threads in Polanyi's oeuvre. Whereas for some Polanyi scholars these attest to his residual attraction to Marxism, I argue that matters are more complex. While Polanyi did repudiate the more rigidly deterministic of currents in Marxist philosophy, those to which he was attracted, notably Bernstein's ârevisionâ and Austro-Marxism, incorporated a deterministic fatalism of their own, in respect of democratization. Herein lies a more convincing explanation of Polanyi's incomplete escape from a deterministic philosophy of history, as exemplified in his masterwork, The great transformation
The Failure of Northern Rock: A multi-dimensional Case Study
In August 2007 the United Kingdom experienced its first bank run in over 140 years. Although Northern Rock was not a particularly large bank (it was at the time ranked 7th in terms of assets) it was nevertheless a significant retail bank and a substantial mortgage lender. In fact, ten years earlier it had converted from a mutual building society whose activities were limited by regulation largely to retail deposits and mortgages. Graphic television news pictures showed very long queues outside the bank as depositors rushed to withdraw their deposits. There was always a fear that this could spark a systemic run on bank deposits. After failed attempts to secure a buyer in the private sector, the government nationalised the bank and, for the first time, in effect socialised the credit risk of the bank. It is now a fully state-owned bank..
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