6,800 research outputs found

    Low cost light traps for coral reef fishery research and sustainable ornamental fisheries

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    ArticleTwo relatively inexpensive light traps to capture pre-settling reef fish and invertebrates are described. A trap made from a plastic bucket (with plastic bottles, a small plastic waste bin and two sheets of plywood) that costs US15appearstobejustaseffectiveasalargealuminiumandplexiglasstrapthatcostsUS15 appears to be just as effective as a large aluminium and plexiglass trap that costs US275

    Ice cliff dynamics in the Everest region of the Central Himalaya

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    The importance of ice cliffs for glacier-scale ablation on debris-covered glaciers is now widely recognised. However, a paucity of data exists to describe the spatio-temporal distribution of ice cliffs. In this study we analysed the position and geometry of 8229 ice cliffs and 5582 supraglacial ponds on 14 glaciers in the Everest region between 2000 and 2015. We observed notable ice cliff and pond spatial coincidence. On average across our study glaciers, 77% of supraglacial pond area was associated with an adjacent ice cliff, and 49% of ice cliffs featured an adjacent supraglacial pond. The spatial density of ice cliffs was not directly related to glacier velocity, but did peak within zones of active ice. Furthermore, we found that ice cliff density was glacier-specific, temporally variable, and was positively correlated with surface lowering and decreasing debris thickness for individual glaciers. Ice cliffs predominantly had a north-facing (commonly north-westerly) aspect, which was independent of glacier flow direction, thereby signifying a strong solar radiation control on cliff evolution. Independent field observations indicated that cliff morphology was related to aspect, local debris thickness, and presence of a supraglacial pond, and highlighted the importance of surface runnel formation, which acts as a preferential pathway for meltwater and debris fluxes. Overall, by coupling remote sensing and in-situ observations it has been possible to capture local and glacier-scale ice cliff dynamics across 14 glaciers, which is necessary if explicit parameterisation of ice cliffs in dynamic glacier models is to be achieved

    Enteric glia mediate neuron death in colitis through purinergic pathways that require connexin-43 and nitric oxide

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    The concept of enteric glia as regulators of intestinal homeostasis is slowly gaining acceptance as a central concept in neurogastroenterology. Yet how glia contribute to intestinal disease is still poorly understood. Purines generated during inflammation drive enteric neuron death by activating neuronal P2X7 purine receptors (P2X7R), triggering ATP release via neuronal pannexin-1 channels that subsequently recruits intracellular calcium ([Ca(2+)]i) responses in the surrounding enteric glia. We tested the hypothesis that the activation of enteric glia contributes to neuron death during inflammation.We studied neuroinflammation in vivo using the 2,4-dinitrobenzenesulfonic acid model of colitis and in situ using whole-mount preparations of human and mouse intestine. Transgenic mice with a targeted deletion of glial connexin-43 (Cx43) [GFAP∷Cre (ERT2+/-)/Cx43(f/f) ] were used to specifically disrupt glial signaling pathways. Mice deficient in inducible nitric oxide (NO) synthase (iNOS (-/-)) were used to study NO production. Protein expression and oxidative stress were measured using immunohistochemistry and in situ Ca(2+) and NO imaging were used to monitor glial [Ca(2+)]i and [NO]i.Purinergic activation of enteric glia drove [Ca(2+)]i responses and enteric neuron death through a Cx43-dependent mechanism. Neurotoxic Cx43 activity, driven by NO production from glial iNOS, was required for neuron death. Glial Cx43 opening liberated ATP and Cx43-dependent ATP release was potentiated by NO.Our results show that the activation of glial cells in the context of neuroinflammation kills enteric neurons. Mediators of inflammation that include ATP and NO activate neurotoxic pathways that converge on glial Cx43 hemichannels. The glial response to inflammatory mediators might contribute to the development of motility disorders

    Nudges and other moral technologies in the context of power: Assigning and accepting responsibility

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    Strawson argues that we should understand moral responsibility in terms of our practices of holding responsible and taking responsibility. The former covers what is commonly referred to as backward-looking responsibility , while the latter covers what is commonly referred to as forward-looking responsibility . We consider new technologies and interventions that facilitate assignment of responsibility. Assigning responsibility is best understood as the second- or third-personal analogue of taking responsibility. It establishes forward-looking responsibility. But unlike taking responsibility, it establishes forward-looking responsibility in someone else. When such assignments are accepted, they function in such a way that those to whom responsibility has been assigned face the same obligations and are susceptible to the same reactive attitudes as someone who takes responsibility. One family of interventions interests us in particular: nudges. We contend that many instances of nudging tacitly assign responsibility to nudgees for actions, values, and relationships that they might not otherwise have taken responsibility for. To the extent that nudgees tacitly accept such assignments, they become responsible for upholding norms that would otherwise have fallen under the purview of other actors. While this may be empowering in some cases, it can also function in such a way that it burdens people with more responsibility that they can (reasonably be expected to) manage

    Socially-mediated arousal and contagion within domestic chick broods

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    Emotional contagion – an underpinning valenced feature of empathy – is made up of simpler, potentially dissociable social processes which can include socially-mediated arousal and behavioural/physiological contagion. Previous studies of emotional contagion have often conflated these processes rather than examining their independent contribution to empathic response. We measured socially-mediated arousal and contagion in 9-week old domestic chicks (n = 19 broods), who were unrelated but raised together from hatching. Pairs of observer chicks were exposed to two conditions in a counterbalanced order: air puff to conspecifics (AP) (during which an air puff was applied to three conspecifics at 30 s intervals) and control with noise of air puff (C) (during which the air puff was directed away from the apparatus at 30 s intervals). Behaviour and surface eye temperature of subjects and observers were measured throughout a 10-min pre-treatment and 10-min treatment period. Subjects and observers responded to AP with increased freezing, and reduced preening and ground pecking. Subjects and observers also showed reduced surface eye temperature - indicative of stress-induced hyperthermia. Subject-Observer behaviour was highly correlated within broods during both C and AP conditions, but with higher overall synchrony during AP. We demonstrate the co-occurrence of socially-mediated behavioural and physiological arousal and contagion; component features of emotional contagion

    To achieve a sustainable blue future, progress assessments must include interdependencies between the sustainable development goals

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    The Sustainable Development Goals (SDGs) focus on providing society with a sustainable future. Progress toward the goals is being tracked by a series of indicators. These indicators show progress toward individual goals and targets but do not show how success or failure in relation to one goal might affect success or failure in another area. We show how interactions between the oceans and human poverty, hunger, and gender equity are hidden by indicator assessments and how this undermines the capacity of governments and organizations to maximize long-term moves toward sustainability. These findings are important for decision makers who work in the public and private sectors and wish to avoid unforeseen outcomes when implementing sustainability initiatives. Here, we suggest extensions to the current assessment framework to help counteract the identified issues, providing a research agenda for scientists working in all fields of sustainability science

    Faster subsequence recognition in compressed strings

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    Computation on compressed strings is one of the key approaches to processing massive data sets. We consider local subsequence recognition problems on strings compressed by straight-line programs (SLP), which is closely related to Lempel--Ziv compression. For an SLP-compressed text of length mˉ\bar m, and an uncompressed pattern of length nn, C{\'e}gielski et al. gave an algorithm for local subsequence recognition running in time O(mˉn2logn)O(\bar mn^2 \log n). We improve the running time to O(mˉn1.5)O(\bar mn^{1.5}). Our algorithm can also be used to compute the longest common subsequence between a compressed text and an uncompressed pattern in time O(mˉn1.5)O(\bar mn^{1.5}); the same problem with a compressed pattern is known to be NP-hard

    Predicting Visibility of Aircraft

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    Visual detection of aircraft by human observers is an important element of aviation safety. To assess and ensure safety, it would be useful to be able to be able to predict the visibility, to a human observer, of an aircraft of specified size, shape, distance, and coloration. Examples include assuring safe separation among aircraft and between aircraft and unmanned vehicles, design of airport control towers, and efforts to enhance or suppress the visibility of military and rescue vehicles. We have recently developed a simple metric of pattern visibility, the Spatial Standard Observer (SSO). In this report we examine whether the SSO can predict visibility of simulated aircraft images. We constructed a set of aircraft images from three-dimensional computer graphic models, and measured the luminance contrast threshold for each image from three human observers. The data were well predicted by the SSO. Finally, we show how to use the SSO to predict visibility range for aircraft of arbitrary size, shape, distance, and coloration

    Correlation Functions in 2-Dimensional Integrable Quantum Field Theories

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    In this talk I discuss the form factor approach used to compute correlation functions of integrable models in two dimensions. The Sinh-Gordon model is our basic example. Using Watson's and the recursive equations satisfied by matrix elements of local operators, I present the computation of the form factors of the elementary field ϕ(x)\phi(x) and the stress-energy tensor Tμν(x)T_{\mu\nu}(x) of the theory.Comment: 19pp, LATEX version, (talk at Como Conference on ``Integrable Quantum Field Theories''
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