5,905 research outputs found

    Broadening access to earth science information for education in the UK

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    The presentation describes strategies for enhancing earth science teaching through inspiring role-play and long-term experiments. Over the past decade there has been a growing concern that earth sciences are often poorly served in UK schools. In parallel with this there has been a general decline in the number of students choosing science. The government's response has been a number of initiatives designed to stimulate interest in scientific careers and enhance the learning experience. Over the same period, UK and European government alongside popular campaigns have encouraged the release of national datasets for educational purposes. The British Geological Survey (BGS) has an international reputation in the delivery of data for professional geologists and is now building a portfolio of projects based on free, convenient access to digital data alongside face-to-face contact with inspirational role models with the aim of introducing exciting, relevant science to schools. The UK-wide School Seismology Project provides a specially designed instrument records earthquakes from anywhere on the globe and the data may be shared through a web portal. Schools receive training, sponsorship and practical support. Students benefit from the experience of collecting unique data and opportunities to report their findings via local press and TV. Sister projects are running in Ireland and Africa. STEM Ambassadors provide a wide range of in-school support, from simple experiments to careers advice and mentoring. Our most requested activities include 'Seconds from Catastrophe?' and 'Quarry or Not?'. In these, students take on the roles of scientists, government officials and residents and vigorously debate, respectively, the issues involved in planning an emergency response to a volcanic eruption and the environmental impacts of the extractive industry. Real data are analysed and an important feature is that the facilitators have genuine experience of the scenarios

    Do agonistic behaviours bias baited remote underwater video surveys of fish?

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    Marine environments require monitoring to determine the effects of impacts such as climate change, coastal development and pollution and also to assess the effectiveness of conservation measures. Marine protected areas (MPAs) are being established globally and require periodic monitoring to determine whether their objectives are being met. Baited underwater video systems are becoming a popular method for monitoring change within protected fish populations, because they are less damaging to habitats than bottom trawling and allow for more statistical powerful comparisons to determine spatial and temporal patterns in the relative abundances, lengths and biomass of demersal and pelagic fishes. However, much remains uncertain about how interactions between the fish and bait and between the fish themselves affect the results obtained. Agonistic behaviours are frequently observed around the bait of the camera and potentially bias fish density estimates by altering the number and size classes seen at cameras. Here we counted the number of agonistic behaviours between pink snappers (Pagrus auratus), the size of fish involved and whether the fish left the field of view following such behaviours. The study consisted of 20 baited underwater video deployments inside a New Zealand marine reserve and 20 in adjacent open areas. We observed a significant relationship between the peak number of fish observed at the camera and the total number of agonistic behaviours, as well as the number of both aggressor and subordinate fish leaving the camera field of view following interactions. The slope of the latter relationship and thus the absolute numbers of fish leaving were higher for subordinate fish. As subordinates were significantly smaller than aggressors, the apparent size frequency distribution is likely skewed away from smaller size classes. The staying time of the fish and thus the maximum number of fish present at the camera will be reduced by agonistic behaviours and the absolute magnitude of this effect appears to be greater at high fish densities. Our results suggest that an overall effect of these phenomena is to underestimate the differences in abundance between MPAs and open areas, but also to overestimate differences in average size

    Bipartite Dot Product Graphs

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    Given a bipartite graph G = (X, Y, E), the bipartite dot product representation of G is a function f : X ∪Y → ℝk and a positive threshold t such that for any x ∈ X and y ∈ Y , xy ∈ E if and only if f(x) · f(y) ≥ t. The minimum k such that a bipartite dot product representation exists for G is the bipartite dot product dimension of G, denoted bdp(G). We will show that such representations exist for all bipartite graphs as well as give an upper bound for the bipartite dot product dimension of any graph. We will also characterize the bipartite graphs of bipartite dot product dimension 1 by their forbidden subgraphs

    Generalized Integer Partitions, Tilings of Zonotopes and Lattices

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    In this paper, we study two kinds of combinatorial objects, generalized integer partitions and tilings of two dimensional zonotopes, using dynamical systems and order theory. We show that the sets of partitions ordered with a simple dynamics, have the distributive lattice structure. Likewise, we show that the set of tilings of zonotopes, ordered with a simple and classical dynamics, is the disjoint union of distributive lattices which we describe. We also discuss the special case of linear integer partitions, for which other dynamical systems exist. These results give a better understanding of the behaviour of tilings of zonotopes with flips and dynamical systems involving partitions.Comment: See http://www.liafa.jussieu.fr/~latapy

    The Role of PPARs in the Endothelium: Implications for Cancer Therapy

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    The growth and metastasis of cancers intimately involve the vasculature and in particular the endothelial cell layer. Tumours require new blood vessel formation via angiogenesis to support growth. In addition, inflammation, coagulation, and platelet activation are common signals in the growth and metastasis of tumour cells. The endothelium plays a central role in the homeostatic control of inflammatory cell recruitment, regulating platelet activation and coagulation pathways. PPARα, -β/δ, and -γ are all expressed in endothelial cells. This review will discuss the roles of PPARs in endothelial cells in relation to angiogenesis, inflammation, coagulation, and platelet control pathways. In particular, we will discuss the recent evidence that supports the hypothesis that PPARα and PPARγ are antiangiogenic receptors, while PPARβ/δ is proangiogenic

    Mitral valve infective endocarditis following device occlusion of a coronary artery fistula

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    A three year old girl, with a right coronary artery fistula and signs of a hyperdynamic circulation, underwent uncomplicated closure of the fistula using an occluding device introduced via the femoral arterial route and covered with appropriate antibiotics. Two months later she presented with a persistent fever, signs of infective endocarditis (IE) and embolic phenomena in the left lower limb. Mitral valve endocarditis was confirmed immediately and treated effectively. However, initial ultrasound and doppler did not show the femoral artery thrombo-occlusion that was only confirmed on magnetic resonance angiography (MRA) one month later. This case highlights the usefulness of MRA in diagnosing suspected vessel occlusion in young children, and is in keeping with the latest NICE guidelines that suggest that prophylactic antibiotics do not always prevent IE. Parent and patient education on ‘what to look out for’, combined with careful clinical vigilance is paramount in the early detection of IE with a consequent reduction in morbidity and mortality.peer-reviewe

    Combinatorially Orthogonal Paths

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    Vectors x=(x1,x2,...,xn)T and y=(y1,y2,...,yn)T are combinatorially orthogonal if |{i:xiyi≠0}|≠1. An undirected graph G=(V,E) is a combinatorially orthogonal graph if there exists f:V→ℝn such that for any u,v∈V, uv∉E iff f(u) and f(v) are combinatorially orthogonal. We will show that every graph has a combinatorially orthogonal representation. We will show the bounds for the combinatorially orthogonal dimension of any path Pn

    Binary Colloidal Alloy Test-5: Compete

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    The Binary Colloidal Alloy Test - 5: Compete (BCAT-5-Compete) investigation will photograph andomized colloidal samples onboard the International Space Station (ISS) to determine their resulting structure over time. The use of EarthKAM software and hardware will allow the scientists to capture the kinetics (evolution) of their samples, as well as the final equilibrium state of each sample. BCAT-5-Compete will utilize samples 6 - 8 in the BCAT-5 hardware to study the competition between phase separation and crystallization, which is important in the manufacture of plastics and other materials
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