4,916 research outputs found
Robust degradation and enhancement of robot mission behaviour in unpredictable environments
© 2015 ACM.Temporal logic based approaches that automatically generate controllers have been shown to be useful for mission level planning of motion, surveillance and navigation, among others. These approaches critically rely on the validity of the environment models used for synthesis. Yet simplifying assumptions are inevitable to reduce complexity and provide mission-level guarantees; no plan can guarantee results in a model of a world in which everything can go wrong. In this paper, we show how our approach, which reduces reliance on a single model by introducing a stack of models, can endow systems with incremental guarantees based on increasingly strengthened assumptions, supporting graceful degradation when the environment does not behave as expected, and progressive enhancement when it does
Fair game: exploring the dynamics, perception and environmental impact of ‘surplus’ wild foods in England 10kya-present
This paper brings together zooarchaeological data from Neolithic to Post-medieval sites in England to explore the plasticity of cultural attitudes to the consumption of wild animals. It shows how, through time, game has been considered variously as ‘tabooed’ and ‘edible’, each having implications for patterns of biodiversity and wildlife management. The essential points being made are that deeper-time studies can reveal how human perceptions of ‘surplus foods’ have the potential to both create and remedy problems of environmental sustainability and food security. Perhaps more significantly, this paper argues that understanding the bio-cultural past of edible wild animal species has the potential to transform human attitudes to game in the present. This is important at a time when food security and the production of surplus are pressing national and global concerns
Camouflage during movement in the European cuttlefish (Sepia officinalis)
A moving object is considered conspicuous because of the movement itself. When moving from one background to another, even dynamic camouflage experts such as cephalopods should sacrifice their extraordinary camouflage. Therefore, minimizing detection at this stage is crucial and highly beneficial. In this study, we describe a background-matching mechanism during movement, which aids the cuttlefish to downplay its presence throughout movement. In situ behavioural experiments using video and image analysis, revealed a delayed, sigmoidal, colour-changing mechanism during movement of Sepia officinalis across uniform black and grey backgrounds. This is a first important step in understanding dynamic camouflage during movement, and this new behavioural mechanism may be incorporated and applied to any dynamic camouflaging animal or man-made system on the move.info:eu-repo/semantics/publishedVersio
Rabbits and the Specious Origins of Domestication
Rabbits are commonly thought to have been domesticated in ∼AD600 by French monks. Using historical and archaeological records, and genetic methods, we demonstrate that this is a misconception and the general inability to date domestication stems from both methodological biases and the lack of appreciation of domestication as a continuum
Using community development to build critical health literacy
Critical health literacy is a domain of health literacy that has been presented as existing at both individual and community level with a potential to contribute to improved health outcomes and reduced inequalities. However, it remains the least well explored and researched domain of health literacy and there are few examples of initiatives designed specifically to build critical health literacy. This study explores how community development processes can be used to develop the key attributes of critical health literacy
False Positive Rate of Rapid Oral Fluid HIV Tests Increases as Kits Near Expiration Date
Background: Because a recent cluster of false positive results on the OraQuick ADVANCEH Rapid HIV-1/2 Antibody Test occurred in San Francisco on test kits close to their expiration date, we decided to assess the relationship between time to expiration and rate of false positive results from tests used with oral fluid. Methodology/Principal Findings: We analyzed results of 20,904 tests with either an initial HIV-negative result (n = 20,828) or a preliminary positive result that was then negative on confirmatory tests (n = 76). We computed specificity for kits with time to expiration from #1 to$6 months, with exact binomial confidence intervals, then used logistic regression to estimate the independent association of time to expiration with false positive results, adjusting for site and technician effects. For 1,108 kits used in the last month before expiration, specificity was 98.83 % (95 % exact binomial confidence interval (CI) 98.00%–99.37%); the upper bound is below the claimed specificity of 99.60%. After adjustment using regression standardization for the effects of site, test lot, and technician factors, adjusted specificity in the last month before expiration was 99.18 % (95 % bootstrap confidence interval 98.60–99.57%). Conclusions/Significance: We found that specificity of the OraQuick ADVANCEH with oral fluid declined significantly wit
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