2,125 research outputs found
Twitter and Disasters: A Social Resilience Fingerprint
Understanding the resilience of a community facing a crisis event is critical to improving its adaptive capacity. Community resilience has been conceptualized as a function of the resilience of components of a community such as ecological, infrastructure, economic, and social systems, etc. In this paper, we introduce the concept of a âresilience fingerprintâ and propose a multi-dimensional method for analyzing components of community resilience by leveraging existing definitions of community resilience with data from the social network Twitter. Twitter data from 14 events are analyzed and their resulting resilience fingerprints computed. We compare the fingerprints between events and show that major disasters such as hurricanes and earthquakes have a unique resilience fingerprint which is consistent between different events of the same type. Specifically, hurricanes have a distinct fingerprint which differentiates them from other major events. We analyze the components underlying the similarity among hurricanes and find that ecological, infrastructure and economic components of community resilience are the primary drivers of the difference between the community resilience of hurricanes and other major events
A Closed-Form Expression for the Gravitational Radiation Rate from Cosmic Strings
We present a new formula for the rate at which cosmic strings lose energy
into gravitational radiation, valid for all piecewise-linear cosmic string
loops. At any time, such a loop is composed of straight segments, each of
which has constant velocity. Any cosmic string loop can be arbitrarily-well
approximated by a piecewise-linear loop with sufficiently large. The
formula is a sum of polynomial and log terms, and is exact when the
effects of gravitational back-reaction are neglected. For a given loop, the
large number of terms makes evaluation ``by hand" impractical, but a computer
or symbolic manipulator yields accurate results. The formula is more accurate
and convenient than previous methods for finding the gravitational radiation
rate, which require numerical evaluation of a four-dimensional integral for
each term in an infinite sum. It also avoids the need to estimate the
contribution from the tail of the infinite sum. The formula has been tested
against all previously published radiation rates for different loop
configurations. In the cases where discrepancies were found, they were due to
errors in the published work. We have isolated and corrected both the analytic
and numerical errors in these cases. To assist future work in this area, a
small catalog of results for some simple loop shapes is provided.Comment: 29 pages TeX, 16 figures and computer C-code available via anonymous
ftp from directory pub/pcasper at alpha1.csd.uwm.edu, WISC-MILW-94-TH-10,
(section 7 has been expanded, two figures added, and minor grammatical
changes made.
Exploring the spread and scale of a web-based clinical decision support portal in Sydney, Australia, during COVID-19: a case study
Purpose HealthPathways is an online decision support portal, primarily aimed at General Practitioners (GPs), that provides easy to access and up to date clinical, referral and resource pathways. It is free to access, with the intent of providing the right care, at the right place, at the right time. This case study focuses on the experience and learnings of a HealthPathways program in metropolitan Sydney during the COVID-19 pandemic. It reviews the team's program management responses and looks at key factors that have facilitated the spread and scale of HealthPathways. Design/methodology/approach Available data and experiences of two HealthPathways program managers were used to recount events and aspects influencing spread and scale. Findings The key factors for successful spread and scale are a coordinated response, the maturity of the HealthPathways program, having a single source of truth, high level governance, leadership, collaboration, flexible funding and ability to make local changes where required. Originality/value There are limited published articles on HealthPathways. The focus of spread and scale of HealthPathways during COVID-19 is unique
Regulation of CD44 binding to hyaluronan by glycosylation of variably spliced exons
The hyaluronan (HA)-binding function (lectin function) of the leukocyte homing receptor, CD44, is tightly regulated. Herein we address possible mechanisms that regulate CD44 isoform-specific HA binding. Binding studies with melanoma transfectants expressing CD44H, CD44E, or with soluble immunoglobulin fusions of CD44H and CD44E (CD44H-Rg, CD44E-Rg) showed that although both CD44 isoforms can bind HA, CD44H binds HA more efficiently than CD44E. Using CD44-Rg fusion proteins we show that the variably spliced exons in CD44E, V8-V10, specifically reduce the lectin function of CD44, while replacement of V8-V10 by an ICAM-1 immunoglobulin domain restores binding to a level comparable to that of CD44H. Conversely, CD44 bound HA very weakly when exons V8-V10 were replaced with a CD34 mucin domain, which is heavily modified by O-linked glycans. Production of CD44E-Rg or incubation of CD44E-expressing transfectants in the presence of an O-linked glycosylation inhibitor restored HA binding to CD44H-Rg and to cell surface CD44H levels, respectively. We conclude that differential splicing provides a regulatory mechanism for CD44 lectin function and that this effect is due in part to O-linked carbohydrate moieties which are added to the Ser/Thr rich regions encoded by the variably spliced CD44 exons. Alternative splicing resulting in changes in protein glycosylation provide a novel mechanism for the regulation of lectin activit
The Human Fertilisation and Embryology Act 2008
This paper provides an overview of the regulatory developments in the UK which impact on the use of in vitro fertilization (IVF) and embryo screening techniques for the creation of âsaviour siblings.â Prior to the changes implemented under the Human Fertilisation and Embryology Act 2008, this specific use of IVF was not addressed by the legislative framework and regulated only by way of policy issued by the Human Fertilisation and Embryology Authority (HFEA). Following the implementation of the statutory reforms, a number of restrictive conditions are now imposed on the face of the legislation. This paper considers whether there is any justification for restricting access to IVF and pre-implantation tissue typing for the creation of âsaviour siblings.â The analysis is undertaken by examining the normative factors that have guided the development of the UK regulatory approach prior to the 2008 legislative reforms. The approach adopted in relation to the âsaviour siblingâ issue is compared to more general HFEA policy, which has prioritized the notion of reproductive choice and determined that restrictions on access are only justified on the basis of harm considerations
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Food geographies I: relational foodscapes and the busy-ness of being more-than-food
The study of foodscapes has spread throughout geography at the same time as food scholarship has spearheaded post-disciplinary research. This report argues that geographers have taken to post-disciplinarity to explore the ways that food is âmore-than-foodâ through analyses of the visceral nature of eating and politics and the vital (re)materializations of foodâs cultural geographies. Visceral food geographies illuminate what I call the âcontingent relationalitiesâ of food in the critical evaluation of the indeterminate, situated politics of âfeeling foodâ and those of the embodied collectivities of obesity. Questions remain, however, about how a visceral framework might be deployed for broader critiques within foodscapes and the study of human geography. The study of foodâs vital materialisms opens up investigation into the practices of the âmakingsâ of meat, food waste and eating networks. Analysis of affect, embodiment and cultural practices is central to these theorizations and suggests consideration of the multiple materialisms of food, space and eating. There is, I contend, in the more radical, âpost-relationalâ approaches to food, the need for a note of caution. Exuberant claims for the ontological, vital agency of food should be tempered by, or at least run parallel to, critical questions of the real politik of political and practical agency in light of recent struggles over austerity, food poverty and food justice
The incidence and make up of ability grouped sets in the UK primary school
The adoption of setting in the primary school (pupils ability grouped across classes for particular subjects) emerged during the 1990s as a means to raise standards. Recent research based on 8875 children in the Millennium Cohort Study showed that 25.8% of children in Year 2 were set for literacy and mathematics and a further 11.2% of children were set for mathematics or literacy alone. Logistic regression analysis showed that the best predictors of being in the top set for literacy or mathematics were whether the child was born in the Autumn or Winter and cognitive ability scores. Boys were significantly more likely than girls to be in the bottom literacy set. Family circumstances held less importance for setting placement compared with the childâs own characteristics, although they were more important in relation to bottom set placement. Children in bottom sets were significantly more likely to be part of a long-term single parent household, have experienced poverty, and not to have a mother with qualifications at NVQ3 or higher levels. The findings are discussed in relation to earlier research and the implications for schools are set out
Radio Interferometric Planet Search II: Constraints on sub-Jupiter-Mass Companions to GJ 896A
We present results from the Radio Interferometric Planet (RIPL) search for
compan- ions to the nearby star GJ 896A. We present 11 observations over 4.9
years. Fitting astrometric parameters to the data reveals a residual with
peak-to-peak amplitude of ~ 3 mas in right ascension. This residual is well-fit
by an acceleration term of 0.458 \pm 0.032 mas/y^2. The parallax is fit to an
accuracy of 0.2 mas and the proper motion terms are fit to accuracies of 0.01
mas/y. After fitting astrometric and acceleration terms residuals are 0.26 mas
in each coordinate, demonstrating that stellar jitter does not limit the
ability to carry out radio astrometric planet detection and characterization.
The acceleration term originates in part from the companion GJ 896B but the
amplitude of the acceleration in declination is not accurately predicted by the
orbital model. The acceleration sets a mass upper limit of 0.15 MJ at a
semi-major axis of 2 AU for a planetary companion to GJ 896A. For semi-major
axes between 0.3 and 2 AU upper limits are determined by the maximum angular
separation; the upper limits scale from the minimum value in proportion to the
inverse of the radius. Upper limits at larger radii are set by the acceleration
and scale as the radius squared. An improved solution for the stellar binary
system could improve the exoplanet mass sensitivity by an order of magnitude.Comment: Accepted for publication in Ap
Why, what, and how? case study on law, risk, and decision making as necessary themes in built environment teaching
The paper considers (and defends) the necessity of including legal studies as a core part of built environment undergraduate and postgraduate curricula. The writer reflects upon his own experience as a lawyer working alongside and advising built environment professionals in complex land remediation and site safety management situations in the United Kingdom and explains how themes of liability, risk, and decision making can be integrated into a practical simulation in order to underpin more traditional lecture-based law teaching. Through reflection upon the writer's experiments with simulation-based teaching, the paper suggests some innovations that may better orientate law teaching to engage these themes and, thereby, enhance the relevance of law studies to the future needs of built environment professionals in practice.</p
Notes on Recent Approaches Concerning the Kirchhoff-Law-Johnson-Noise-based Secure Key Exchange
We critically analyze the results and claims in [Physics Letters A 373 (2009)
901-904].
We show that the strong security leak appeared in the simulations is only an
artifact and not caused by "multiple reflections". Since no wave modes exist at
cable length of 5% of the shortest wavelength of the signal, no wave is present
to reflect it.
In the high wave impedance limit, the conditions used in the simulations are
heavily unphysical (requiring cable diameters up to 28000 times greater than
the measured size of the known universe) and the results are modeling artifacts
due to the unphysical values.
At the low cable impedance limit, the observed artifacts are due to violating
the recommended (and tested) conditions by neglecting the cable capacitance
restrictions and using about 100 times longer cable than recommended without
cable capacitance compensation arrangement.
We implement and analyze the general circuitry of Liu's circulator and
confirm that they are conceptually secure against passive attacks. We introduce
an asymmetric, more robust version without feedback loop. Then we crack all
these systems by an active attack: a circulator-based man-in-the middle attack.
Finally, we analyze the proposed method to increase security by dropping only
high-risk bits. We point out the differences between different types of
high-risk bits and show the shortage of this strategy for some simple key
exchange protocols.Comment: Accepted for publication in Physics Letters A on May 29, 2009. In the
present version, DOI and acceptance info is added in the pdf file, to
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