83,097 research outputs found
Dynamical linke cluster expansions: Algorithmic aspects and applications
Dynamical linked cluster expansions are linked cluster expansions with
hopping parameter terms endowed with their own dynamics. They amount to a
generalization of series expansions from 2-point to point-link-point
interactions. We outline an associated multiple-line graph theory involving
extended notions of connectivity and indicate an algorithmic implementation of
graphs. Fields of applications are SU(N) gauge Higgs systems within variational
estimates, spin glasses and partially annealed neural networks. We present
results for the critical line in an SU(2) gauge Higgs model for the electroweak
phase transition. The results agree well with corresponding high precision
Monte Carlo results.Comment: LATTICE98(algorithms
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My Home Life: promoting quality of life in care homes
A new report from JRF outlines the findings from the My Home Life project. My Home Life is a collaborative initiative between Age UK, City University, the Joseph Rowntree Foundation and Dementia UK promoting quality of life in care homes.
This study found:
- positive relationships in care homes enable staff to listen to older people, gain insights into individual needs and facilitate greater voice, choice and control;
- relationship-centred care is at the heart of many examples of best practice;
- care home managers play a pivotal role in promoting relationships between older people, staff and relatives;
- care home providers and statutory agencies should consider how their attitudes, practices and policies can create pressure and unnecessary paperwork which ultimately reduce the capacity of care homes to respond to the needs of older people; and
- negative stereotypes of care homes have an impact on the confidence of staff and managers
Coordinated oscillations in cortical actin and Ca2+ correlate with cycles of vesicle secretion.
The actin cortex both facilitates and hinders the exocytosis of secretory granules. How cells consolidate these two opposing roles was not well understood. Here we show that antigen activation of mast cells induces oscillations in Ca(2+) and PtdIns(4,5)P(2) lipid levels that in turn drive cyclic recruitment of N-WASP and cortical actin level oscillations. Experimental and computational analysis argues that vesicle fusion correlates with the observed actin and Ca(2+) level oscillations. A vesicle secretion cycle starts with the capture of vesicles by actin when cortical F-actin levels are high, followed by vesicle passage through the cortex when F-actin levels are low, and vesicle fusion with the plasma membrane when Ca(2+) levels subsequently increase. Thus, cells employ oscillating levels of Ca(2+), PtdIns(4,5)P(2) and cortical F-actin to increase secretion efficiency, explaining how the actin cortex can function as a carrier as well as barrier for vesicle secretion
Untangling the Web of E-Research: Towards a Sociology of Online Knowledge
e-Research is a rapidly growing research area, both in terms of publications
and in terms of funding. In this article we argue that it is necessary to
reconceptualize the ways in which we seek to measure and understand e-Research
by developing a sociology of knowledge based on our understanding of how
science has been transformed historically and shifted into online forms. Next,
we report data which allows the examination of e-Research through a variety of
traces in order to begin to understand how the knowledge in the realm of
e-Research has been and is being constructed. These data indicate that
e-Research has had a variable impact in different fields of research. We argue
that only an overall account of the scale and scope of e-Research within and
between different fields makes it possible to identify the organizational
coherence and diffuseness of e-Research in terms of its socio-technical
networks, and thus to identify the contributions of e-Research to various
research fronts in the online production of knowledge
Non-empirical pairing energy density functional. First order in the nuclear plus Coulomb two-body interaction
We perform systematic calculations of pairing gaps in semi-magic nuclei
across the nuclear chart using the Energy Density Functional method and a {\it
non-empirical} pairing functional derived, without further approximation, at
lowest order in the two-nucleon vacuum interaction, including the Coulomb
force. The correlated single-particle motion is accounted for by the SLy4
semi-empirical functional. Rather unexpectedly, both neutron and proton pairing
gaps thus generated are systematically close to experimental data. Such a
result further suggests that missing effects, i.e. higher partial-waves of the
NN interaction, the NNN interaction and the coupling to collective
fluctuations, provide an overall contribution that is sub-leading as for
generating pairing gaps in nuclei. We find that including the Coulomb
interaction is essential as it reduces proton pairing gaps by up to 40%.Comment: 6 pages, 1 figure, accepted for publication in EPJ
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