Fisher-information condition for enhanced signal detection via stochastic resonance

Various situations where a signal is enhanced by noise through stochastic resonance are now known. This paper contributes to determining general conditions under which improvement by noise can be a priori decided as feasible or not. We focus on the detection of a known signal in additive white noise. Under the assumptions of a weak signal and a sufficiently large sample size, it is proved, with an inequality based on the Fisher information, that improvement by adding noise is never possible, generically, in these conditions. However, under less restrictive conditions, an example of signal detection is shown with favorable action of adding noise.Fabing Duan, François Chapeau-Blondeau, Derek Abbot

Fine and ultrafine particle number and size measurements from industrial combustion processes : primary emissions field data

This study is to our knowledge the first to present the results of on-line measurements of residual nanoparticle numbers downstream of the flue gas treatment systems of a wide variety of medium- and large-scale industrial installations. Where available, a semi-quantitative elemental composition of the sampled particles is carried out using a Scanning Electron Microscope coupled with an Energy Dispersive Spectrometer (SEM-EDS). The semi-quantitative elemental composition as a function of the particle size is presented. EU's Best Available Technology documents (BAT) show removal efficiencies of Electrostatic Precipitator (ESP) and bag filter dedusting systems exceeding 99% when expressed in terms of weight. Their efficiency decreases slightly for particles smaller than 1 mu m but when expressed in terms of weight, still exceeds 99% for bag filters and 96% for ESP. This study reveals that in terms of particle numbers, residual nanoparticles (NP) leaving the dedusting systems dominate by several orders of magnitude. In terms of weight, all installations respect their emission limit values and the contribution of NP to weight concentrations is negligible, despite their dominance in terms of numbers. Current World Health Organisation regulations are expressed in terms of PM2.5 wt concentrations and therefore do not reflect the presence or absence of a high number of NP. This study suggests that research is needed on possible additional guidelines related to NP given their possible toxicity and high potential to easily enter the blood stream when inhaled by humans

Span morphing using the GNATSpar wing

Rigid wings usually fly at sub-optimal conditions generating unnecessary aerodynamic loses represented in flight time, fuel consumption, and unfavourable operational characteristics. High aspect ratio wings have good range and fuel efficiency, but lack manoeuvrability. On the other hand, low aspect ratio wings fly faster and are more manoeuvrable, but have poor aerodynamic performance. Span morphing technology allows integrating both features in a single wing design and allows continuously adjusting the wingspan to match the instantaneous flight conditions and mission objectives. This paper develops, a novel span morphing concept, the Gear driveN Autonomous Twin Spar (GNATSpar) for a mini-UAV. The GNATSpar can be used to achieve span extensions up to 100% but for demonstration purposes it is used here to achieve span extensions up to 20% to reduce induced drag and increase flight endurance. The GNATSpar is superior to conventional telescopic and articulated structures as it uses the space available in the opposite sides of the wing instead of relying on overlapping structures and bearings. In addition, it has a self-locking actuation mechanism due to the low lead angle of the driving worm gear. Following the preliminary aero-structural sizing of the concept, a physical prototype is developed and tested in the 7?×5? wind-tunnel at the University of Southampton. Finally, benefits and drawbacks of the design are highlighted and analysed

Modeling Epac1 interactions with the allosteric inhibitor AM-001 by co-solvent molecular dynamics

The exchange proteins activated by cAMP (EPAC) are implicated in a large variety of physiological processes and they are considered as promising targets for a wide range of therapeutic applications. Several recent reports provided evidence for the therapeutic effectiveness of the inhibiting EPAC1 activity cardiac diseases. In that context, we recently characterized a selective EPAC1 antagonist named AM-001. This compound was featured by a non-competitive mechanism of action but the localization of its allosteric site to EPAC1 structure has yet to be investigated. Therefore, we performed cosolvent molecular dynamics with the aim to identify a suitable allosteric binding site. Then, the docking and molecular dynamics were used to determine the binding of the AM-001 to the regions highlighted by cosolvent molecular dynamics for EPAC1. These analyses led us to the identification of a suitable allosteric AM-001 binding pocket at EPAC1. As a model validation, we also evaluated the binding poses of the available AM-001 analogues, with a different biological potency. Finally, the complex EPAC1 with AM-001 bound at the putative allosteric site was further refined by molecular dynamics. The principal component analysis led us to identify the protein motion that resulted in an inactive like conformation upon the allosteric inhibitor binding

Computer-Assisted Generation of Patterns and Virtual Reality Techniques for Fashion Design

We present a methodology for the design of aesthetic patterns and their visualization on virtual clothes. Generated patterns are directly mapped on the dress of a virtual mannequin. Furthermore, patterns sets may be interactively mapped on the virtual dress using a specific 3D interaction technique called Back-and-Forth. Pattern generation involves different mathematical approaches such as iterated function systems (IFS) and nonlinear trajectory models. Both model parameters and color space exploration is performed through a simple user interface. This work contributes to promote both computer assistance in the context of mass customization for fashion design

Noise suppression by noise

We have analyzed the interplay between an externally added noise and the intrinsic noise of systems that relax fast towards a stationary state, and found that increasing the intensity of the external noise can reduce the total noise of the system. We have established a general criterion for the appearance of this phenomenon and discussed two examples in detail.Comment: 4 pages, 4 figure

Exposure in utero to maternal diabetes leads to glucose intolerance and high blood pressure with no major effects on lipid metabolism

AIM: Recent evidence shows that adult metabolic disease may originate from an adverse fetal environment that can alter organ development and function in postnatal life. This study aimed to analyze the effect of exposure in utero to maternal diabetes on the development of the metabolic syndrome in the offspring. METHODS: Pregnant rats were made diabetic (blood glucose was 20mM) with a single streptozotocin injection on day 0 of gestation. Offspring from diabetic mothers (DMO) and control mothers (CMO) were followed from birth to 12 months of age. In these animals, metabolic parameters, such as glucose tolerance, insulin sensitivity and plasma lipid levels, as well as pancreatic insulin and morphology were studied. RESULTS: Compared with controls, DMO offspring had normal birth weights, but impaired postnatal growth that persisted throughout life. Metabolic tests revealed that DMO offspring also showed impaired glucose tolerance at six months associated with decreased insulin sensitivity and low insulin secretion. In older animals (12 months old), this phenotype persisted, but to a lesser extent. The DMO offspring also presented with high blood pressure and decreased levels of fasting plasma triglycerides, but normal plasma NEFA, and HDL and total cholesterol. CONCLUSION: Altogether, these results show that our model of exposure in utero to maternal diabetes led to normal birth weights, and induced transient glucose intolerance and increased blood pressure with no major effects on lipid metabolism. It also suggests that a hyperglycaemic fetal environment may be able to \u27programme\u27 hypertension and glucose intolerance, but not alter lipid metabolism