1,492 research outputs found
Langevin analysis for time-nonlocal Brownian motion with algebraic memories and delay interactions
Starting from a Langevin equation with memory describing the attraction of a particle to
a center, we investigate its transport and response properties corresponding to two
special forms of the memory: one is algebraic, i.e., power-law, and the other involves a
delay. We examine the properties of the Green function of the Langevin equation and
encounter Mittag-Leffler and Lambert W-functions well-known in the literature. In the
presence of white noise, we study two experimental situations, one involving the motional
narrowing of spectral lines and the other the steady-state size of the particle under
consideration. By comparing the results to counterparts for a simple exponential memory,
we uncover instructive similarities and differences. Perhaps surprisingly, we find that
the Balescu-Swenson theorem that states that non-Markoffian equations do not add anything
new to the description of steady-state or equilibrium
observables is violated for our system in that the saturation size of the
particle in the steady-state depends on the memory function utilized. A natural
generalization of the Smoluchowski equation for the time-local case is examined and found
to satisfy the Balescu-Swenson theorem and describe accurately the first moment but not
the second and higher moments. We also calculate two-time correlation functions for all
three cases of the memory, and show how they differ from (tend to) their Markoffian
counterparts at small (large) values of the difference between the two times
Langevin analysis for time-nonlocal Brownian motion with algebraic memories and delay interactions
Starting from a Langevin equation with memory describing the attraction of a particle to
a center, we investigate its transport and response properties corresponding to two
special forms of the memory: one is algebraic, i.e., power-law, and the other involves a
delay. We examine the properties of the Green function of the Langevin equation and
encounter Mittag-Leffler and Lambert W-functions well-known in the literature. In the
presence of white noise, we study two experimental situations, one involving the motional
narrowing of spectral lines and the other the steady-state size of the particle under
consideration. By comparing the results to counterparts for a simple exponential memory,
we uncover instructive similarities and differences. Perhaps surprisingly, we find that
the Balescu-Swenson theorem that states that non-Markoffian equations do not add anything
new to the description of steady-state or equilibrium
observables is violated for our system in that the saturation size of the
particle in the steady-state depends on the memory function utilized. A natural
generalization of the Smoluchowski equation for the time-local case is examined and found
to satisfy the Balescu-Swenson theorem and describe accurately the first moment but not
the second and higher moments. We also calculate two-time correlation functions for all
three cases of the memory, and show how they differ from (tend to) their Markoffian
counterparts at small (large) values of the difference between the two times
Testing the relationship between lateralization on sequence-based motor tasks and language laterality using an online battery
Studies have highlighted an association between motor laterality and speech production laterality. It is thought that common demands for sequential processing may underlie this association. However, most studies in this area have relied on relatively small samples and have infrequently explored the reliability of the tools used to assess lateralization. We, therefore, established the validity and reliability of an online battery measuring sequence-based motor laterality and language laterality before exploring the associations between laterality indices on language and motor tasks. The online battery was completed by 621 participants, 52 of whom returned to complete the battery a second time. The three motor tasks included in the battery showed good between-session reliability (r ≥ .78) and were lateralized in concordance with hand preference. The novel measure of speech production laterality was left lateralized at population level as predicted, but reliability was less satisfactory (r = .62). We found no evidence of an association between sequence-based motor laterality and language laterality. Those with a left-hand preference were more strongly lateralized on motor tasks requiring midline crossing; this effect was not observed in right-handers. We conclude that there is little evidence of the co-lateralization of language and sequence-based motor skill on this battery
Mtss1 promotes cell-cell junction assembly and stability through the small GTPase Rac1
Cell-cell junctions are an integral part of epithelia and are often disrupted in cancer cells during epithelial-to-mesenchymal transition (EMT), which is a main driver of metastatic spread. We show here that Metastasis suppressor-1 (Mtss1; Missing in Metastasis, MIM), a member of the IMD-family of proteins, inhibits cell-cell junction disassembly in wound healing or HGF-induced scatter assays by enhancing cell-cell junction strength. Mtss1 not only makes cells more resistant to cell-cell junction disassembly, but also accelerates the kinetics of adherens junction assembly. Mtss1 drives enhanced junction formation specifically by elevating Rac-GTP. Lastly, we show that Mtss1 depletion reduces recruitment of F-actin at cell-cell junctions. We thus propose that Mtss1 promotes Rac1 activation and actin recruitment driving junction maintenance. We suggest that the observed loss of Mtss1 in cancers may compromise junction stability and thus promote EMT and metastasis
Illness perceptions and explanatory models of viral hepatitis B & C among immigrants and refugees: a narrative systematic review.
© 2015 Owiti et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.BACKGROUND: Hepatitis B and C (HBV, HCV) infections are associated with high morbidity and mortality. Many countries with traditionally low prevalence (such as UK) are now planning interventions (screening, vaccination, and treatment) of high-risk immigrants from countries with high prevalence. This review aimed to synthesise the evidence on immigrants' knowledge of HBV and HCV that might influence the uptake of clinical interventions. The review was also used to inform the design and successful delivery of a randomised controlled trial of targeted screening and treatment. METHODS: Five databases (PubMed, CINHAL, SOCIOFILE, PsycINFO & Web of Science) were systematically searched, supplemented by reference tracking, searches of selected journals, and of relevant websites. We aimed to identify qualitative and quantitative studies that investigated knowledge of HBV and HCV among immigrants from high endemic areas to low endemic areas. Evidence, extracted according to a conceptual framework of Kleinman's explanatory model, was subjected to narrative synthesis. We adapted the PEN-3 model to categorise and analyse themes, and recommend strategies for interventions to influence help-seeking behaviour. RESULTS: We identified 51 publications including quantitative (n = 39), qualitative (n = 11), and mixed methods (n = 1) designs. Most of the quantitative studies included small samples and had heterogeneous methods and outcomes. The studies mainly concentrated on hepatitis B and ethnic groups of South East Asian immigrants residing in USA, Canada, and Australia. Many immigrants lacked adequate knowledge of aetiology, symptoms, transmission risk factors, prevention strategies, and treatment, of hepatitis HBV and HCV. Ethnicity, gender, better education, higher income, and English proficiency influenced variations in levels and forms of knowledge. CONCLUSION: Immigrants are vulnerable to HBV and HCV, and risk life-threatening complications from these infections because of poor knowledge and help-seeking behaviour. Primary studies in this area are extremely diverse and of variable quality precluding meta-analysis. Further research is needed outside North America and Australia
A Fast Track towards the `Higgs' Spin and Parity
The LHC experiments ATLAS and CMS have discovered a new boson that resembles
the long-sought Higgs boson: it cannot have spin one, and has couplings to
other particles that increase with their masses, but the spin and parity remain
to be determined. We show here that the `Higgs' + gauge boson invariant-mass
distribution in `Higgs'-strahlung events at the Tevatron or the LHC would be
very different under the J^P = 0+, 0- and 2+ hypotheses, and could provide a
fast-track indicator of the `Higgs' spin and parity. Our analysis is based on
simulations of the experimental event selections and cuts using PYTHIA and
Delphes, and incorporates statistical samples of `toy' experiments.Comment: 18 pages, 9 pdf figure
Completeness and Incompleteness of Synchronous Kleene Algebra
Synchronous Kleene algebra (SKA), an extension of Kleene algebra (KA), was
proposed by Prisacariu as a tool for reasoning about programs that may execute
synchronously, i.e., in lock-step. We provide a countermodel witnessing that
the axioms of SKA are incomplete w.r.t. its language semantics, by exploiting a
lack of interaction between the synchronous product operator and the Kleene
star. We then propose an alternative set of axioms for SKA, based on Salomaa's
axiomatisation of regular languages, and show that these provide a sound and
complete characterisation w.r.t. the original language semantics.Comment: Accepted at MPC 201
Casting Light on Dark Matter
The prospects for detecting a candidate supersymmetric dark matter particle
at the LHC are reviewed, and compared with the prospects for direct and
indirect searches for astrophysical dark matter. The discussion is based on a
frequentist analysis of the preferred regions of the Minimal supersymmetric
extension of the Standard Model with universal soft supersymmetry breaking (the
CMSSM). LHC searches may have good chances to observe supersymmetry in the near
future - and so may direct searches for astrophysical dark matter particles,
whereas indirect searches may require greater sensitivity, at least within the
CMSSM.Comment: 16 pages, 13 figures, contribution to the proceedings of the LEAP
2011 Conferenc
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