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- Chen, S., et al.
(författare)
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SEMarbeta: Mobile sketch-gesture-video remote support for car drivers
- 2013
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Ingår i: ACM International Conference Proceeding Series. - New York, NY, USA : ACM. - 9781450319041 ; , s. 69-76
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Konferensbidrag (refereegranskat)abstract
- Uneven knowledge distribution is often an issue in remote support systems, creating the occasional need for additional information layers that extend beyond plain videoconference and shared workspaces. This paper introduces SEMarbeta, a remote support system designed for car drivers in need of help from an officebound professional expert. We introduce a design concept and its technical implementation using low-cost hardware and techniques inspired by augmented reality research. In this setup, the driver uses a portable Android tablet PC while the expert mechanic uses a stationary computer equipped with a video camera capturing his gestures and sketches. Hence, verbal instructions can be combined with supportive gestures and sketches added by the expert mechanic to the car's video display. To validate this concept, we carried out a user study involving two typical automotive repair tasks: checking engine oil and examining fuses. Based on these tasks and following a between-group (drivers and expert mechanics) design, we compared voice-only with additional sketch- and gesture-overlay on video screenshots measuring objective and perceived quality of help. Results indicate that sketch- and gesture-overlay can benefit remote car support in typical breakdown situations.
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- Aronsen, T., et al.
(författare)
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The operational sex ratio and density influence spatial relationships between breeding pipefish
- 2013
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Ingår i: Behavioral Ecology. - : Oxford University Press (OUP). - 1045-2249 .- 1465-7279. ; 24:4, s. 888-897
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Tidskriftsartikel (refereegranskat)abstract
- The operational sex ratio (ratio of sexually receptive males to females) has been extensively studied in behavioral ecology, whereas other demographic factors such as the effect of density on mating behavior have received less empirical attention. We manipulated mating competition by establishing breeding populations of the sex-role reversed broad-nosed pipefish (Syngnathus typhle) at 2 sex ratios (male biased or female biased) and 2 densities. We used mean crowding (m*) and the index of association (X) to measure spatial distributions within and between the sexes, respectively, and investigated how these measures reflect the predicted strength of mating competition. In general, female m* increased as fewer males were available for mating, which suggests increased intrasexual competition in the most competitive sex. However, male m* also increased as the operational sex ratio became more female biased, suggesting that m* did not reflect mating competition for males. Association between the sexes (X) was higher under male bias than female bias, probably because males were still available for mating under male bias. In addition, X decreased in the female-biased treatment as the operational sex ratio became even more female biased. Higher density increased m* in both sex ratios and sexes, although for both sexes in the female-biased high-density treatment the operational sex ratio did not influence m*, probably because femalefemale competition inhibits further crowding in this treatment. In this study, we show that the use of m* and X can be a useful tool in behavioral studies but their interpretation requires detailed information about the mating system. Therefore, we recommend caution with their broadscale application.
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- Davis, Rohan A., et al.
(författare)
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Solving the supply of resveratrol tetramers from Papua New Guinean rainforest anisoptera species that inhibit bacterial type Ill secretion systems
- 2014
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Ingår i: Journal of natural products (Print). - Washington : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 77:12, s. 2633-2640
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: The supply of (−)-hopeaphenol (1) was achieved via enzymatic biotransformation in order to provide material for preclinical investigation. High-throughput screen- ing of a prefractionated natural product library aimed to identify compounds that inhibit the bacterial virulence type III secretion system (T3SS) identified several fractions derived from two Papua New Guinean Anisoptera species, showing activity against Yersinia pseudotuberculosis outer proteins E and H (YopE and YopH). Bioassay-directed isolation from the leaves of A. thurifera, and similarly A. polyandra, resulted in three known resveratrol tetramers, (−)-hopeaphenol (1), vatalbinoside A (2), and vaticanol B (3). Compounds 1−3 displayed IC50 values of 8.8, 12.5, and 9.9 μM in a luminescent reporter-gene assay (YopE) and IC50 values of 2.9, 4.5, and 3.3 μM in an enzyme-based YopH assay, respectively, which suggested that they could potentially act against the T3SS in Yersinia. The structures of 1−3 were confirmed through a combination of spectrometric, chemical methods, and single-crystal X-ray structure determinations of the natural product 1 and the permethyl ether analogue of 3. The enzymatic hydrolysis of the β-glycoside 2 to the aglycone 1 was achieved through biotransformation using the endogenous leaf enzymes. This significantly enhanced the yield of the target bioactive natural product from 0.08% to 1.3% and facilitates ADMET studies of (−)-hopeaphenol (1).
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