1,409 research outputs found
Hopf Bifurcations of Twisted States in Phase Oscillators Rings with Nonpairwise Higher-Order Interactions
Synchronization is an essential collective phenomenon in networks of
interacting oscillators. Twisted states are rotating wave solutions in ring
networks where the oscillator phases wrap around the circle in a linear
fashion. Here, we analyze Hopf bifurcations of twisted states in ring networks
of phase oscillators with nonpairwise higher-order interactions. Hopf
bifurcations give rise to quasiperiodic solutions that move along the
oscillator ring at nontrivial speed. Because of the higher-order interactions,
these emerging solutions may be stable. Using the Ott--Antonsen approach, we
continue the emergent solution branches which approach anti-phase type
solutions (where oscillators form two clusters whose phase is apart) as
well as twisted states with a different winding number.Comment: 24 pages, 8 figure
Using a Logic Programming Framework to Control Database Query Dialogues in Natural Language
We present a natural language question/answering system to interface the University of Évora databases that uses clarification dialogs in order to clarify user questions. It was developed in an integrated logic programming framework, based on constraint logic programming using the GnuProlog(-cx) language [2,11] and the ISCO framework [1]. The use of this LP framework allows the integration of Prolog-like inference mechanisms with classes and inheritance, constraint solving algorithms and provides the connection with relational databases, such as PostgreSQL. This system focus on the questions’ pragmatic analysis, to handle ambiguity, and on an efficient dialogue mechanism, which is able to place relevant questions to clarify the user intentions in a straightforward manner. Proper Nouns resolution and the pp-attachment problem are also handled.
This paper briefly presents this innovative system focusing on its ability to correctly determine the user intention through its dialogue capability
Metabolic Versatility in Melainabacteria, a Close Relative of Cyanobacteria
A New Member of Melainabacteria, the Closest Relatives of Cyanobacteria
Melainabacteria are the recently discovered, closest non-photosynthetic relatives of cyanobacteria, the organisms responsible for the oxygenation of Earth\u27s atmosphere. Previous work has shown that Melainabacteria live in a wide range of environments, including deep groundwater, anoxic sediments, and the digestive tracts of termites and mammals. These bacteria have been suggested to play a significant role in the latter environments and may contribute to neurodegenerative and gastrointestinal disease in human populations. However, our knowledge of Melainabacteria diversity and metabolism is still very limited, principally because no member of this group has been successfully cultured in the laboratory.
Recently, DNA sequencing has revealed that a member of the Melainabacteria is growing in co-culture with an established diatom strain at the University of Montana’s Miller lab. In this study, we obtained a nearly complete Melainabacteria genome from metagenomic sequencing data. We then compared this genome to other previously sequenced Melainabacteria genomes to better understand genome architecture and the metabolic capacity of this bacterium. These data will guide further culturing efforts and future experiments. Together, our work will help clarify the functional role(s) of Melainabacteria in its environment and how it “makes a living” energetically. It will also provide new insights regarding the metabolic capabilities of the cyanobacterial ancestor and the origin of oxygenic photosynthesis
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The Topic of Cancer: new perspectives on the emotional experience of cancer
Jury deliberation: An observation study.
In this article, the way that the jury works is considered from a
group-analytic perspective. Observational fieldwork of simulated
jury deliberations is presented. The data was gathered from a joint
funded Home Office and Law Commission project at the Socio-
Legal Studies Centre, Oxford in 1995. Inferences are drawn from the
observations and the unconscious group processes are considered.
The efficacy of the jury process is discussed
The Lorentzian distance formula in noncommutative geometry
For almost twenty years, a search for a Lorentzian version of the well-known
Connes' distance formula has been undertaken. Several authors have contributed
to this search, providing important milestones, and the time has now come to
put those elements together in order to get a valid and functional formula.
This paper presents a historical review of the construction and the proof of a
Lorentzian distance formula suitable for noncommutative geometry.Comment: 16 pages, final form, few references adde
Neuronal oscillations on evolving networks: dynamics, damage, degradation, decline, dementia, and death
This is the final version. Available from the American Physical Society via the DOI in this recordNeurodegenerative diseases, such as Alzheimer’s or Parkinson’s disease, show characteristic degradation of structural brain networks. This degradation eventually leads to changes in the network dynamics and degradation of cognitive functions. Here, we model the progression in terms of coupled physical processes: The accumulation of toxic proteins, given by a nonlinear reaction-diffusion transport process, yields an evolving brain connectome characterized by weighted edges on which a neuronal-mass model evolves. The progression of the brain functions can be tested by simulating the resting-state activity on the evolving brain network. We show that while the evolution of edge weights plays a minor role in the overall progression of the disease, dynamic biomarkers predict a transition over a period of 10 years associated with strong cognitive decline
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