361 research outputs found
A cautionary tale of topography and tilt from KÄ«lauea Caldera
We conduct finite element analysis to investigate the effect of sharp topography on surface ground deformation caused by pressure changes in a magma reservoir. Tilt data expresses the horizontal gradient of vertical deformation and therefore can emphasise small variations in deformation that go unnoticed using other methods. We find that the vertical displacement profile at a surface with a cliff can be thought of as the superposition of the deformation from shallow and deeper sources. This combination can create a small peak in vertical displacement that acts as a pseudoâsource, creating a reversal of the deformation gradient and therefore anomalous tilt magnitude and a rotation of up to 180° . We apply these models to KÄ«lauea Caldera and find that surface geometry creates a tilt rotation of âŒ10°, partially explaining anomalous tilt that has been observed. Our analysis highlights the importance of considering topography when assessing tilt measurements at active volcanoes
A Logical Framework for Behaviour Reasoning and Assistance in a Smart Home
Abstract- Smart Homes (SH) have emerged as a realistic intelligent assistive environment capable of providing assistive living for the elderly and the disabled. Nevertheless, it still remains a challenge to assist the inhabitants of a SH in performing the ârightâ action(s) at the âright â time in the âright â place. To address this challenge, this paper introduces a novel logical framework for cognitive behavioural modelling, reasoning and assistance based on a highly developed logical theory of actions- the Event Calculus. Cognitive models go beyond data-centric behavioural models in that they govern an inhabitantâs behaviour by reasoning about its knowledge, actions and environmental events. In our work we outline the theoretical foundation of such an approach and describe cognitive modelling of SH. We discuss the reasoning capabilities and algorithms of the cognitive SH model and present the details of the various tasks it can support. A system architecture is proposed to illustrate the use of the framework in facilitating assistive living. We demonstrate the perceived effectiveness of the approach through presentation of its operation in the context of a real world daily activity scenario. Index Terms â Event calculus, cognitive modelling
Master equation approach to DNA-breathing in heteropolymer DNA
After crossing an initial barrier to break the first base-pair (bp) in
double-stranded DNA, the disruption of further bps is characterized by free
energies between less than one to a few kT. This causes the opening of
intermittent single-stranded bubbles. Their unzipping and zipping dynamics can
be monitored by single molecule fluorescence or NMR methods. We here establish
a dynamic description of this DNA-breathing in a heteropolymer DNA in terms of
a master equation that governs the time evolution of the joint probability
distribution for the bubble size and position along the sequence. The transfer
coefficients are based on the Poland-Scheraga free energy model. We derive the
autocorrelation function for the bubble dynamics and the associated relaxation
time spectrum. In particular, we show how one can obtain the probability
densities of individual bubble lifetimes and of the waiting times between
successive bubble events from the master equation. A comparison to results of a
stochastic Gillespie simulation shows excellent agreement.Comment: 12 pages, 8 figure
Space-Based Imaging Radar Studies of U.S. Volcanoes
The arrival of space-based imaging radar as a revolutionary land-surface mapping and monitoring tool little more than a quarter century ago enabled a spate of innovative volcano research worldwide. Soon after launch of European Space Agencyâs ERS-1 spacecraft in 1991, the U.S. Geological Survey began SAR and InSAR studies of volcanoes in the Aleutian and Cascades arcs, in Hawaiâi, and elsewhere in the western U.S. including the Yellowstone and Long Valley calderas. This paper summarizes results of that effort and presents new findings concerning: (1) prevalence of volcano deformation in the Aleutian and Cascade arcs; (2) surface-change detection and hazard assessment during eruptions at Aleutian and Hawaiian volcanoes; (3) geodetic imaging of magma storage and transport systems in Hawaiâi; and (4) deformation sources and processes at the Yellowstone and Long Valley calderas. Surface deformation caused by a variety of processes is common in arc settings and could easily escape detection without systematic InSAR surveillance. Space-based SAR imaging of active lava flows and domes in remote or heavily vegetated settings, including during periods of bad weather and darkness, extends land-based monitoring capabilities and improves hazards assessments. At KÄ«lauea Volcano, comprehensive SAR and InSAR observations identify multiple magma storage zones beneath the summit area and along the East Rift Zone, and illuminate magma transport pathways. The same approach at Yellowstone tracks the ascent of magmatic volatiles from a mid-crustal intrusion to shallow depth and relates that process to increased hydrothermal activity at the surface. Together with recent and planned launches of highly capable imaging-radar satellites, these findings support an optimistic outlook for near-real time surveillance of volcanoes at global scale in the coming decade
Exploring disconnected discourses about patient and public involvement and volunteer involvement in English health and social care
Background: Patient and public involvement (PPI) in health and social care policy, service decision-making and research are presented as good practice in England. Yet the explicit rationale for PPI and how it is positioned within the literature, policy and practice remain confused, in particular, in relation to Volunteer Involvement (VI). In health and social care, PPI and VI are managed and valued as conceptually distinct, yet the discourses in their policy and practice documents treat them as closely related in fundamental ways. Objective: Compare and critically evaluate discourses framing PPI and VI within English health and social care. Design: A critical discourse approach was used to explore the accounts of PPI and VI in policy. These accounts were then compared and contrasted with personal accounts of volunteering in health and social care settings. Results: Twenty documents from key national health and social care bodies were discursively examined in terms of their framing PPI and VI. A narrative disconnect between the two was repeatedly confirmed. This finding contrasted with an analysis of personal accounts of VI which displayed VI as a form of PPI. Conclusion: There is a disconnect between language, narratives and practice in PPI and in VI which may have direct consequences for policy and practice. Recognising and managing it can offer innovative ways of enabling volunteers to be involved across health and social care settings, ensuring the experiential value added by volunteersâ service contributions, to be recognised so that their democratic participation may be seen to shape services
Analysis and Functional Annotation of Expressed Sequence Tags from the Asian Longhorned Beetle, Anoplophora glabripennis
The Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), is one of the most economically and ecologically devastating forest insects to invade North America in recent years. Despite its substantial impact, limited effort has been expended to define the genetic and molecular make-up of this species. Considering the significant role played by late-stadia larvae in host tree decimation, a small-scale EST sequencing project was done using a cDNA library constructed from 5th -instar A. glabripennis. The resultant dataset consisted of 599 high quality ESTs that, upon assembly, yielded 381 potentially unique transcripts. Each of these transcripts was catalogued as to putative molecular function, biological process, and associated cellular component according to the Gene Ontology classification system. Using this annotated dataset, a subset of assembled sequences was identified that are putatively associated with A. glabnpennis development and metamorphosis. This work will contribute to understanding of the diverse molecular mechanisms that underlie coleopteran morphogenesis and enable the future development of novel control strategies for management of this insect pest
Evolution of dike opening during the March 2011 Kamoamoa fissure eruption, KÄ«lauea Volcano, Hawai\u27i
The 5â9 March 2011 Kamoamoa fissure eruption along the east rift zone of KÄ«lauea Volcano, Hawai`i, followed months of pronounced inflation at KÄ«lauea summit. We examine dike opening during and after the eruption using a comprehensive interferometric synthetic aperture radar (InSAR) data set in combination with continuous GPS data. We solve for distributed dike displacements using a whole KÄ«lauea model with dilating rift zones and possibly a deep dĂ©collement. Modeled surface dike opening increased from nearly 1.5 m to over 2.8 m from the first day to the end of the eruption, in agreement with field observations of surface fracturing. Surface dike opening ceased following the eruption, but subsurface opening in the dike continued into May 2011. Dike volumes increased from 15, to 16, to 21 million cubic meters (MCM) after the first day, eruption end, and 2 months following, respectively. Dike shape is distinctive, with a main limb plunging from the surface to 2â3 km depth in the up-rift direction toward KÄ«laueaâs summit, and a lesser projection extending in the down-rift direction toward Pu`u `Ć`Ć at 2 km depth. Volume losses beneath KÄ«lauea summit (1.7 MCM) and Pu`u `Ć`Ć (5.6 MCM) crater, relative to dike plus erupted volume (18.3 MCM), yield a dike to source volume ratio of 2.5 that is in the range expected for compressible magma without requiring additional sources. Inflation of KÄ«laueaâs summit in the months before the March 2011 eruption suggests that the Kamoamoa eruption resulted from overpressure of the volcanoâs magmatic system
The use of live attenuated influenza vaccine (LAIV) in healthcare personnel (HCP): Guidance from the society for healthcare epidemiology of America (SHEA)
Because of the live viral backbone of live attenuated influenza vaccine (LAIV), questions have arisen regarding infection control precautions and restrictions surrounding its use in healthcare personnel (HCP). This document provides guidance from the Society for Healthcare Epidemiology of America regarding use of LAIV in HCP and the infection control precautions that are recommended with its use in this population. Infect Control Hosp Epidemiol 2012;33(10):981-98
Geostrategies of the European neighbourhood policy
The debate about the European Neighbourhood Policy (ENP) has, in essence, been about borders and bordering. Such departures could contribute â and often do so â to a rather fixed geopolitical vision of what the EU is about and how it aims to run and to organize the broader European space. However, this article aims to retain space for viewing the ENP as a developmental and somewhat fluid process. A conceptual framework, based on outlining three geopolitical models and a series of different geopolitical strategies employed by the EU in regard to its borders, is hence employed in order to be able to tell a more dynamic story regarding the developing nature of the ENP and the EU's evolving nature more generally. The complexity traced informs us that various geostrategies may be held at the same time at the external border. Moreover, the dominance of one geostrategy may be replaced by another or a different combination of them with regard to the same neighbourhood. It is, more generally, argued that if anything it is precisely this dynamism that should be championed as a valuable resource, avoiding the tendency to close off options through the reification of particular visions of the nature of the EU and its borders
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