492 research outputs found
Implementation of mean-timing and subsequent logic functions on an FPGA
This article describes the implementation of a mean-timer and coincidence
logic on a Virtex-5 FPGA for trigger purposes in a particle physics experiment.
The novel feature is that the mean-timing and the coincidence logic are not
synchronized with a clock which allows for a higher resolution of approximately
400 ps, not limited by a clock frequency.Comment: 15 pages, 11 figure
Noncommutative waves have infinite propagation speed
We prove the existence of global solutions to the Cauchy problem for
noncommutative nonlinear wave equations in arbitrary even spatial dimensions
where the noncommutativity is only in the spatial directions. We find that for
existence there are no conditions on the degree of the nonlinearity provided
the potential is positive. We furthermore prove that nonlinear noncommutative
waves have infinite propagation speed, i.e., if the initial conditions at time
0 have a compact support then for any positive time the support of the solution
can be arbitrarily large.Comment: 15 pages, references adde
Conceptualisations of landscape differ across European languages
Acknowledgments: Thanks to Peter Sercombe for assistance with English data collection and to Maximilian Hartmann for assisting in the creation of the network visualisations. Funding: This work was funded by a Bank of Sweden Tercentenary Foundation Jubilee Initiative Grant (https://www.rj.se/en), grant ref. NHS14-1665:1. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Scattering of Noncommutative Waves and Solitons in a Supersymmetric Chiral Model in 2+1 Dimensions
Interactions of noncommutative waves and solitons in 2+1 dimensions can be
analyzed exactly for a supersymmetric and integrable U(n) chiral model
extending the Ward model. Using the Moyal-deformed dressing method in an
antichiral superspace, we construct explicit time-dependent solutions of its
noncommutative field equations by iteratively solving linear equations. The
approach is illustrated by presenting scattering configurations for two
noncommutative U(2) plane waves and for two noncommutative U(2) solitons as
well as by producing a noncommutative U(1) two-soliton bound state.Comment: 1+13 pages; v2: reference added, version published in JHE
The effects of financialisation and financial development on investment: Evidence from firm-level data in Europe
In this paper we estimate the effects of financialization on physical investment in selected western European countries using panel data based on the balance-sheets of publicly listed non-financial companies (NFCs) supplied by Worldscope for the period 1995-2015. We find robust evidence of an adverse effect of both financial payments
(interests and dividends) and financial incomes on investment in fixed assets by the NFCs. This finding is robust for both the pool of all Western European firms and single country estimations. The negative impacts of financial incomes are non-linear with respect to the companies’ size: financial incomes crowd-out investment in large companies, and have a positive effect on the investment of only small, relatively more credit-constrained companies. Moreover, we find that a higher degree of financial development is associated with a stronger negative effect of financial incomes on companies’ investment. This finding challenges the common wisdom on ‘finance-growth nexus’. Our findings support the ‘financialization thesis’ that the increasing orientation of the non-financial sector towards financial activities is ultimately leading to lower physical investment, hence to stagnant or fragile growth, as well as long term stagnation in productivity
Dispersionless limit of the noncommutative potential KP hierarchy and solutions of the pseudodual chiral model in 2+1 dimensions
The usual dispersionless limit of the KP hierarchy does not work in the case
where the dependent variable has values in a noncommutative (e.g. matrix)
algebra. Passing over to the potential KP hierarchy, there is a corresponding
scaling limit in the noncommutative case, which turns out to be the hierarchy
of a `pseudodual chiral model' in 2+1 dimensions (`pseudodual' to a hierarchy
extending Ward's (modified) integrable chiral model). Applying the scaling
procedure to a method generating exact solutions of a matrix (potential) KP
hierarchy from solutions of a matrix linear heat hierarchy, leads to a
corresponding method that generates exact solutions of the matrix
dispersionless potential KP hierarchy, i.e. the pseudodual chiral model
hierarchy. We use this result to construct classes of exact solutions of the
su(m) pseudodual chiral model in 2+1 dimensions, including various multiple
lump configurations.Comment: 37 pages, 10 figures, 2nd version: some extensions (Fig 3, Appendix
A, additional references), 3rd version: some minor changes, additional
reference
Kank Is an EB1 Interacting Protein that Localises to Muscle-Tendon Attachment Sites in Drosophila
Little is known about how microtubules are regulated in different cell types during development. EB1 plays a central role in the regulation of microtubule plus ends. It directly binds to microtubule plus ends and recruits proteins which regulate microtubule dynamics and behaviour. We report the identification of Kank, the sole Drosophila orthologue of human Kank proteins, as an EB1 interactor that predominantly localises to embryonic attachment sites between muscle and tendon cells. Human Kank1 was identified as a tumour suppressor and has documented roles in actin regulation and cell polarity in cultured mammalian cells. We found that Drosophila Kank binds EB1 directly and this interaction is essential for Kank localisation to microtubule plus ends in cultured cells. Kank protein is expressed throughout fly development and increases during embryogenesis. In late embryos, it accumulates to sites of attachment between muscle and epidermal cells. A kank deletion mutant was generated. We found that the mutant is viable and fertile without noticeable defects. Further analysis showed that Kank is dispensable for muscle function in larvae. This is in sharp contrast to C. elegans in which the Kank orthologue VAB-19 is required for development by stabilising attachment structures between muscle and epidermal cells
Noncommutative Burgers Equation
We present a noncommutative version of the Burgers equation which possesses
the Lax representation and discuss the integrability in detail. We find a
noncommutative version of the Cole-Hopf transformation and succeed in the
linearization of it. The linearized equation is the (noncommutative) diffusion
equation and exactly solved. We also discuss the properties of some exact
solutions. The result shows that the noncommutative Burgers equation is
completely integrable even though it contains infinite number of time
derivatives. Furthermore, we derive the noncommutative Burgers equation from
the noncommutative (anti-)self-dual Yang-Mills equation by reduction, which is
an evidence for the noncommutative Ward conjecture. Finally, we present a
noncommutative version of the Burgers hierarchy by both the Lax-pair generating
technique and the Sato's approach.Comment: 24 pages, LaTeX, 1 figure; v2: discussions on Ward conjecture, Sato
theory and the integrability added, references added, version to appear in J.
Phys.
Kebab: Kinetochore and EB1 Associated Basic Protein That Dynamically Changes Its Localisation during Drosophila Mitosis
Microtubule plus ends are dynamic ends that interact with other cellular structures. Microtubule plus end tracking proteins are considered to play important roles in the regulation of microtubule plus ends. Recent studies revealed that EB1 is the central regulator for microtubule plus end tracking proteins by recruiting them to microtubule plus ends through direct interaction. Here we report the identification of a novel Drosophila protein, which we call Kebab (kinetochore and EB1 associated basic protein), through in vitro expression screening for EB1-interacting proteins. Kebab fused to GFP shows a novel pattern of dynamic localisation in mitosis. It localises to kinetochores weakly in metaphase and accumulates progressively during anaphase. In telophase, it associates with microtubules in central-spindle and centrosomal regions. The localisation to kinetochores depends on microtubules. The protein has a domain most similar to the atypical CH domain of Ndc80, and a coiled-coil domain. The interaction with EB1 is mediated by two SxIP motifs but is not required for the localisation. Depletion of Kebab in cultured cells by RNA interference did not show obvious defects in mitotic progression or microtubule organisation. Generation of mutants lacking the kebab gene indicated that Kebab is dispensable for viability and fertility
Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton
Measurements of the Collins and Sivers asymmetries for charged pions and
charged and neutral kaons produced in semi-inclusive deep-inelastic scattering
of high energy muons off transversely polarised protons are presented. The
results were obtained using all the available COMPASS proton data, which were
taken in the years 2007 and 2010. The Collins asymmetries exhibit in the
valence region a non-zero signal for pions and there are hints of non-zero
signal also for kaons. The Sivers asymmetries are found to be positive for
positive pions and kaons and compatible with zero otherwise.Comment: 15 pages, 13 figures and 1 tabl
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