119 research outputs found
Estimation of the control parameter from symbolic sequences: Unimodal maps with variable critical point
The work described in this paper can be interpreted as an application of the
order patterns of symbolic dynamics when dealing with unimodal maps.
Specifically, it is shown how Gray codes can be used to estimate the
probability distribution functions (PDFs) of the order patterns of parametric
unimodal maps. Furthermore, these PDFs depend on the value of the parameter,
what eventually provides a handle to estimate the parameter value from symbolic
sequences (in form of Gray codes), even when the critical point depends on the
parameter.Comment: 10 pages, 14 figure
Geography, private costs and uptake of screening for abdominal aortic aneurysm in a remote rural area
BACKGROUND: The relationship between geographical location, private costs, health provider costs and uptake of health screening is unclear. This paper examines these relationships in a screening programme for abdominal aortic aneurysm in the Highlands and Western Isles of Scotland, a rural and remote area of over 10,000 square miles. METHODS: Men aged 65–74 (n = 9323) were invited to attend screening at 51 locations in 50 settlements. Effects of geography, deprivation and age on uptake were examined. Among 8,355 attendees, 8,292 completed a questionnaire detailing mode of travel and costs incurred, time travelled, whether accompanied, whether dependants were cared for, and what they would have been doing if not attending screening, thus allowing private costs to be calculated. Health provider (NHS) costs were also determined. Data were analysed by deprivation categories, using the Scottish Indices of Deprivation (2003), and by settlement type ranging from urban to very remote rural. RESULTS: Uptake of screening was high in all settlement types (mean 89.6%, range 87.4 – 92.6%). Non-attendees were more deprived in terms of income, employment, education and health but there was no significant difference between non-attendees and attendees in terms of geographical access to services. Age was similar in both groups. The highest private costs (median £7.29 per man) and NHS screening costs (£18.27 per man invited) were observed in very remote rural areas. Corresponding values for all subjects were: private cost £4.34 and NHS cost £15.72 per man invited. CONCLUSION: Uptake of screening for abdominal aortic aneurysm in this remote and rural setting was high in comparison with previous studies, and this applied across all settlement types. Geographical location did not affect uptake, most likely due to the outreach approach adopted. Private and NHS costs were highest in very remote settings but still compared favourably with other published studies
A model of visual-olfactory integration for odour localisation in free-flying fruit flies
Flying fruit flies (Drosophila melanogaster) locate a concealed appetitive odour source most accurately in environments containing vertical visual contrasts. To investigate how visuomotor and olfactory responses may be integrated, we examine the free-flight behaviour of flies in three visual conditions, with and without food odour present. While odour localisation is facilitated by uniformly distributed vertical contrast as compared with purely horizontal contrast, localised vertical contrast also facilitates odour localisation, but only if the odour source is situated close to it. We implement a model of visuomotor control consisting of three parallel subsystems: an optomotor response stabilising the model fly\u27s yaw orientation; a collision avoidance system to saccade away from looming obstacles; and a speed regulation system. This model reproduces many of the behaviours we observe in flies, including visually mediated ‘rebound’ turns following saccades. Using recordings of real odour plumes, we simulate the presence of an odorant in the arena, and investigate ways in which the olfactory input could modulate visuomotor control. We reproduce the experimental results by using the change in odour intensity to regulate the sensitivity of collision avoidance, resulting in visually mediated chemokinesis. Additionally, it is necessary to amplify the optomotor response whenever odour is present, increasing the model fly\u27s tendency to steer towards features of the visual environment. We conclude that visual and olfactory responses of Drosophila are not independent, but that relatively simple interaction between these modalities can account for the observed visual dependence of odour source localisation
Towards a Muon Collider
A muon collider would enable the big jump ahead in energy reach that is
needed for a fruitful exploration of fundamental interactions. The challenges
of producing muon collisions at high luminosity and 10 TeV centre of mass
energy are being investigated by the recently-formed International Muon
Collider Collaboration. This Review summarises the status and the recent
advances on muon colliders design, physics and detector studies. The aim is to
provide a global perspective of the field and to outline directions for future
work.Comment: 118 pages, 103 figure
Towards a muon collider
A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work
Towards a muon collider
A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by the recently-formed International Muon Collider Collaboration. This Review summarises the status and the recent advances on muon colliders design, physics and detector studies. The aim is to provide a global perspective of the field and to outline directions for future work
Erratum: Towards a muon collider
The original online version of this article was revised: The additional reference [139] has been added. Tao Han’s ORICD ID has been incorrectly assigned to Chengcheng Han and Chengcheng Han’s ORCID ID to Tao Han. Yang Ma’s ORCID ID has been incorrectly assigned to Lianliang Ma, and Lianliang Ma’s ORCID ID to Yang Ma. The original article has been corrected
Synthesis and characterization of new through-space TADF (macro)molecular materials
International audienceThis presentation deals with the synthesis and the study of new through-space TADF-based π-conjugated molecules and polymers [1] designed for OLEDs applications. Indeed, TADF emitters are the third generation of organic building blocks which are currently investigated for organic lightening.[2]On the one hand, novel TADF isomers using a dithia[3.3]-paracyclophane building block as a versatile 3D platform to promote through-space interactions are presented.[3] Such a 3D platform allows to bring together the donor D and acceptor A units into close proximity and to probe the effect of their orientation, contact site and distance on their TADF emission properties. We evidenced that such platform is promising to control intramolecular through-space interactions and obtain an efficient TADF emission with short RISC lifetimes.On the other hand, several macromolecular architectures based on through space D-A interactions have been designed and investigated. Thus, after describing their synthesis, their photophysical properties such as photoluminescence quantum yield (PLQY) and fluorescence lifetime in both solution and solid state will be presented to evidence their TADF activity. The electroluminescence properties of these materials in OLED configuration have been measured as well recently, and preliminary EQE results will be presented.[4
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