124 research outputs found
Scheduling access to shared space in multi-robot systems
Through this study, we introduce the idea of applying scheduling techniques to allocate spatial resources that are shared among multiple robots moving in a static environment and having temporal constraints on the arrival time to destinations. To illustrate this idea, we present an exemplified algorithm that plans and assigns a motion path to each robot. The considered problem is particularly challenging because: (i) the robots share the same environment and thus the planner must take into account overlapping paths which cannot happen at the same time; (ii) there are time deadlines thus the planner must deal with temporal constraints; (iii) new requests arrive without a priori knowledge thus the planner must be able to add new paths online and adjust old plans; (iv) the robot motion is subject to noise thus the planner must be reactive to adapt to online changes. We showcase the functioning of the proposed algorithm through a set of agent-based simulations
Autocatalytic amplification of Alzheimer-associated Aβ42 peptide aggregation in human cerebrospinal fluid
Alzheimer’s disease is linked to amyloid β (Aβ) peptide aggregation in the brain, and a
detailed understanding of the molecular mechanism of Aβ aggregation may lead to improved
diagnostics and therapeutics. While previous studies have been performed in pure buffer, we
approach the mechanism in vivo using cerebrospinal fluid (CSF). We investigated the
aggregation mechanism of Aβ42 in human CSF through kinetic experiments at several Aβ42
monomer concentrations (0.8–10 µM). The data were subjected to global kinetic analysis and
found consistent with an aggregation mechanism involving secondary nucleation of monomers on the fibril surface. A mechanism only including primary nucleation was ruled out. We
find that the aggregation process is composed of the same microscopic steps in CSF as in
pure buffer, but the rate constant of secondary nucleation is decreased. Most importantly, the
autocatalytic amplification of aggregate number through catalysis on the fibril surface is
prevalent also in CSF
Mechanism of Pion Production in p Scattering at 1 GeV/nucleon
The one-pion and two-pion production in the p(alpha, alpha prime)X reaction
at an energy of E{alpha} = 4.2 GeV has been studied by simultaneous
registration of the scattered alpha particles and the secondary pion or proton.
The obtained results demonstrate that the inelastic alpha-particle scattering
on the proton at the energy of the experiment proceeds either through
excitation and decay of Delta resonance in the projectile or through excitation
in the target proton of the Roper resonance, which decays mainly on a nucleon
and a pion or a nucleon and a sigma meson - system of two pions in the isospin
I = 0, S-wave.Comment: 16 pages, 10 figures. Submitted to Proceedings of the XX
International Baldin Seminar on High - Energy Physics Problems, Dubna,
October 4 - 9, 201
Increasing the power of the poor? NGO-led social accountability initiatives and political capabilities in rural Uganda
Social accountability has become an important new buzzword among development actors seeking to understand the forms of state-society synergy that may be supportive of better public services. Advocates suggest demand-side initiatives are key to increasing the power of the poor in service provision, while sceptics question the application of technical fixes to complex political challenges. This article reports findings from qualitative research into the political capabilities outcomes achieved among local health and education stakeholders through the social accountability interventions of a non-governmental organisation (NGO) in Western Uganda. It argues that NGOs are unlikely to generate substantive advances for social accountability in agrarian contexts characterised by patronage politics without organising marginalised groups themselves to tackle the causes of their disadvantage
Borel reductibility and classification of von neumann algebras
We announce some new results regarding the classification problem for separable von Neumann algebras. Our results are obtained by applying the notion of Borel reducibility and Hjorth's theory of turbulence to the isomorphism relation for separable von Neumann algebras.Fil: Sasyk, Roman. Universidad Nacional de General Sarmiento. Instituto de Ciencias; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; ArgentinaFil: Törnquist, Asger. Universidad de Viena; Austri
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