392 resultados para Darkness
Resumo:
People all over the world are regularly hit by floods, cyclones, and other natural disasters. Many use smart phones and social media to stay connected, seek help, improvise, and cope with crises or challenging situations. This column discusses these practices after dark or during disasters to unveil challenges and opportunities for innovative designs that increase resilience and safety.
Resumo:
Australian law teachers are increasingly recognising that psychological distress is an issue for our students. This article describes how the Queensland University of Technology Law School is reforming its curriculum to promote student psychological well-being. Part I of the article examines the literature on law student psychological distress in Australia. It is suggested that cross-sectional and longitudinal studies undertaken in Australia provide us with different, but equally important, information with respect to law student psychological well-being. Part II describes a subject in the QUT Law School - Lawyering and Dispute Resolution – which has been specifically designed as one response to declines in law student psychological well-being. Part III then considers two key elements of the design of the subject: introducing students to the idea of a positive professional identity, and introducing students to non-adversarial lawyering and the positive role of lawyers in society as dispute resolvers. These two areas of focus specifically promote law student psychological well-being by encouraging students to engage with elements of positive psychology – in particular, hope and optimism.
Resumo:
Spatial navigation requires the processing of complex, disparate and often ambiguous sensory data. The neurocomputations underpinning this vital ability remain poorly understood. Controversy remains as to whether multimodal sensory information must be combined into a unified representation, consistent with Tolman's "cognitive map", or whether differential activation of independent navigation modules suffice to explain observed navigation behaviour. Here we demonstrate that key neural correlates of spatial navigation in darkness cannot be explained if the path integration system acted independently of boundary (landmark) information. In vivo recordings demonstrate that the rodent head direction (HD) system becomes unstable within three minutes without vision. In contrast, rodents maintain stable place fields and grid fields for over half an hour without vision. Using a simple HD error model, we show analytically that idiothetic path integration (iPI) alone cannot be used to maintain any stable place representation beyond two to three minutes. We then use a measure of place stability based on information theoretic principles to prove that featureless boundaries alone cannot be used to improve localization above chance level. Having shown that neither iPI nor boundaries alone are sufficient, we then address the question of whether their combination is sufficient and - we conjecture - necessary to maintain place stability for prolonged periods without vision. We addressed this question in simulations and robot experiments using a navigation model comprising of a particle filter and boundary map. The model replicates published experimental results on place field and grid field stability without vision, and makes testable predictions including place field splitting and grid field rescaling if the true arena geometry differs from the acquired boundary map. We discuss our findings in light of current theories of animal navigation and neuronal computation, and elaborate on their implications and significance for the design, analysis and interpretation of experiments.
Resumo:
In this paper we demonstrate passive vision-based localization in environments more than two orders of magnitude darker than the current benchmark using a 100 webcam and a 500 camera. Our approach uses the camera’s maximum exposure duration and sensor gain to achieve appropriately exposed images even in unlit night-time environments, albeit with extreme levels of motion blur. Using the SeqSLAM algorithm, we first evaluate the effect of variable motion blur caused by simulated exposures of 132 ms to 10000 ms duration on localization performance. We then use actual long exposure camera datasets to demonstrate day-night localization in two different environments. Finally we perform a statistical analysis that compares the baseline performance of matching unprocessed greyscale images to using patch normalization and local neighbourhood normalization – the two key SeqSLAM components. Our results and analysis show for the first time why the SeqSLAM algorithm is effective, and demonstrate the potential for cheap camera-based localization systems that function across extreme perceptual change.
Resumo:
Purpose The purpose of this chapter is to analyse the deviant behaviour of individuals in organisations. Deviants are those who depart from organisational norms. A typology of perceived deviant behaviour is developed from the deviance literature, and subsequently tested. Methodology/approach Star Trek: Into Darkness text is qualitatively analysed as a data source. Three different character arcs are analysed in relation to organisational deviance. Starfleet is the specific, fictional, organisational context. Findings We found that the typology of deviance is conceptually robust, and facilitates categorisation of different types of deviant behaviour, over time. Research limitations/implications Deviance is socially ascribed; so better categorisation of such behaviour improves our understanding of how specific behaviour might deviate from organisational norms, and how different behaviours can mean individuals can be viewed positively or negatively over time. Further research might determine management responses to the different forms of deviance, and unpack the processes where individuals eschew ‘averageness’ and become deviants. Practical implications The typology advanced has descriptive validity to describe deviant behaviour. Social implications Social institutions such as organisations ascribe individual deviants, both negatively and positively. Originality/value This chapter extends our understanding of positive and negative deviance in organisations by developing a new typology of deviant behaviour. This typology has descriptive validity in understanding deviant behaviour. Our understanding of both positive and negative deviance in organisational contexts is enhanced, as well as the utility of science fiction literature in ethical analysis.
Resumo:
Humic lakes are abundant in the temperate and cold regions of the Boreal Zone. High levels of water colour and strong thermal stratification of humic lakes limit the potential fish habitats and give a special role to the intraspecific and interspecific interactions. Water colour has different effects on species depending on species-specific life-history traits and trophic interactions. Fish species whose success in predation is based on visual cues are more susceptible to suffer in competition. The main aim of the thesis was to demonstrate the effects of water colour on European perch (Perca fluviatilis) in humic lakes. The contribution of water colour to diet, feeding, growth and competitive interactions of fish was studied both in laboratory and in small humic lakes with varying levels of water colour. The main findings of the thesis were that water colour has different effects on species, depending on species-specific life-history traits and trophic interactions. Water colour affected visually-oriented perch feeding and growth negatively, and the prolonged benthic feeding phase of perch resulting from the increased water colour could increase intraspecific competition in perch populations and may result in a partial bottleneck in growth for perch. Moreover, water colour may act as a proximate factor behind the population dependency of sexual growth dimorphism in perch.
Resumo:
Background: In the violaxanthin (V) cycle, V is de-epoxidized to zeaxanthin (Z) when strong light or light combined with other stressors lead to an overexcitation of photosystems. However, plants can also suffer stress in darkness and recent reports have shown that dehydration triggers V-de-epoxidation in the absence of light. In this study, we used the highly stress-tolerant brown alga Pelvetia canaliculata as a model organism, due to its lack of lutein and its non-photochemical quenching independent of the transthylakoidal-ΔpH, to study the triggering of the V-cycle in darkness induced by abiotic stressors. Results: We have shown that besides desiccation, other factors such as immersion, anoxia and high temperature also induced V-de-epoxidation in darkness. This process was reversible once the treatments had ceased (with the exception of heat, which caused lethal damage). Irrespective of the stressor applied, the resulting de-epoxidised xanthophylls correlated with a decrease in Fv/Fm, suggesting a common function in the down-regulation of photosynthetical efficiency. The implication of the redox-state of the plastoquinone-pool and of the differential activity of V-cycle enzymes on V-de-epoxidation in darkness was also examined. Current results suggest that both violaxanthin de-epoxidase (VDE) and zeaxanthin-epoxidase (ZE) have a basal constitutive activity even in darkness, being ZE inhibited under stress. This inhibition leads to Z accumulation. Conclusion: This study demonstrates that V-cycle activity is triggered by several abiotic stressors even when they occur in an absolute absence of light, leading to a decrease in Fv/Fm. This finding provides new insights into an understanding of the regulation mechanism of the V-cycle and of its ecophysiological roles.
Resumo:
The dynamics of planktonic cyanobacteria in eutrophicated freshwaters play an important role in formation of annual summer blooms, yet overwintering mechanisms of these water bloom forming cyanobacteria remain unknown. The responses to darkness and low temperature of three strains (unicellular Microcystis aeruginosa FACHB-905, colonial M. aeruginosa FACHB-938, and a green alga Scenedesmus quadricauda FACHB-45) were investigated in the present study. After a 30-day incubation under darkness and low temperature, cell morphology, cell numbers, chlorophyll a, photosynthetic activity (ETRmax and I-k), and malodialdehyde (MDA) content exhibited significant changes in Scenedesmus. In contrast, Microcystis aeruginosa cells did not change markedly in morphology, chlorophyll a, photosynthetic activity, and MDA content. The stress caused by low temperature and darkness resulted in an increase of the antioxidative enzyme-catalase (CAT) in all three strains. When the three strains re-grew under routine cultivated condition subjected to darkness and low temperature, specific growth rate of Scenedesmus was lower than that of Microcystis. Flow cytometry (FCM) examination indicated that two distinct types of metabolic response to darkness and low temperature existed in the three strains. The results from the present study reveal that the cyanobacterium Microcystis, especially colonial Microcystis, has greater endurance and adaptation ability to the stress of darkness and low temperature than the green alga Scenedesmus.
Resumo:
Field-collected tetrasporophytes of Palmaria palmata were tumbled in 300-L outdoor tanks from January to August at ambient daylength or in a constant short-day (SD) regime (8 h light per day), both at 10 or 15 degrees C. Tetrasporangia were massively induced after 2.5 months under SD conditions at 10 degrees C and completely lacking at 15 degrees C, both under SD or ambient daylength conditions, with a few tetrasporangia present at 10 degrees C and ambient daylength. Elongation rates of tagged tetrasporophytic thalli peaked from March to April in all four conditions, when the biomass densities in the outdoor tanks were close to 2.5 kg fresh weight m(-2). Under all four conditions, juvenile proliferations started to appear in June from the margins of the old fronds, and attained approximately 1 cm in length by the end of July. Approximately 80% of the tetraspores were released during the first three dark phases in a light/dark regime, and the remaining 20% during the light phases. A minimum of 10 min darkness was observed to trigger spore release. White light inhibited tetraspore release, while a similar number of spores were released in continuous red light or in the light/dark regime, although with no significant differences of spore release during subjective days and nights. Sporelings were successfully derived from the released tetraspores for mass propagation of the male gametophyte in 2000-L outdoor tanks in a greenhouse. Mass production of male gametophytic sporelings of P. palmata was completed two times by SD induction of tetrasporangia at 10 degrees C, release of spores in darkness and culturing the sporelings until they were ready to be propagated vegetatively in greenhouse tanks. One experiment lasted from January to October 2001, with spore release in June, and the second from September to April 2003, with spore release in January. These results may support the development of sustainable, year-round Palmaria farming. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
http://www.archive.org/details/daughtersofdarkn00harbuoft
Resumo:
Over the past decade or more there has been a growing concern at the levels of educational underachievement within loyalist working-class areas of Northern Ireland. The inability of both educational and social policy initiatives over the past decade to improve the situation in any meaningful way has raised important questions concerning how the problem can be tackled more effectively. Placing the issue within the theoretical framework of Gramsci’s hegemony, this paper argues that there is a need to better understand the historical nature of the problem and to recognise the political and social forces that have shaped its existence. It argues that there is a need to move away from explaining Protestant underachievement simply by the availability of jobs in Ulster’s industrial past and to place its roots in the complex battle for social, political, and economic power since the 1801 Act of Union.
Resumo:
This is an essay including annotated critical editions documenting the history of reception of this song since 1848. Published in the Liederlexikon for the AHRC and DFG funded project 'The History of Reception of the Songs of the 1848 Revolution' (2009-2013).
Resumo:
In Le Guin's Earthsea Quartet, knowledge of the name of a thing or person guarantees control over their destiny. In a world where light and darkness co-exist and where dragons are an extension of humans, a name is the means with which one can achieve one's vision of the world. If utopia is the individual projection of a supposedly collective ideal, then knowledge of names is the vehicle for the realization of one's own utopia, which may well come into conflict with the utopias of others. However, Earthsea is not simply a series of battles between individual utopists. Earthsea itself constitutes a precarious and non-traditional utopia, where antithetical sides co-exist and neither prevails forever. As its name denotes, “earth” and “sea,” darkness and light, tombs and open seas, tiny islands and eternal journeys operate together to produce the setting for the novels and enable the chase of an ever-elusive knowledge. For as the utopists in Earthsea find out, knowledge can only be complete if it also comprises its Jungian opposite, namely ignorance. In an attempt to explore the relation between utopia, knowledge, and ignorance, this article employs psychology and linguistics, and constructs a description of a “just” world which remains necessarily utopian.