Synchronous Behavior of Two Coupled Electronic Neurons

We report on experimental studies of synchronization phenomena in a pair of analog electronic neurons (ENs). The ENs were designed to reproduce the observed membrane voltage oscillations of isolated biological neurons from the stomatogastric ganglion of the California spiny lobster Panulirus interruptus. The ENs are simple analog circuits which integrate four dimensional differential equations representing fast and slow subcellular mechanisms that produce the characteristic regular/chaotic spiking-bursting behavior of these cells. In this paper we study their dynamical behavior as we couple them in the same configurations as we have done for their counterpart biological neurons. The interconnections we use for these neural oscillators are both direct electrical connections and excitatory and inhibitory chemical connections: each realized by analog circuitry and suggested by biological examples. We provide here quantitative evidence that the ENs and the biological neurons behave similarly when coupled in the same manner. They each display well defined bifurcations in their mutual synchronization and regularization. We report briefly on an experiment on coupled biological neurons and four dimensional ENs which provides further ground for testing the validity of our numerical and electronic models of individual neural behavior. Our experiments as a whole present interesting new examples of regularization and synchronization in coupled nonlinear oscillators.Comment: 26 pages, 10 figure

Disaster scenario simulation of the 2010 cloudburst in Leh, Ladakh, India

Leh district in the Ladakh region of north-western India experienced a disaster when a cloudburst generated debris flows, killed hundreds of people, destroyed houses, and damaged the hospital, communication infrastructure, the bus station, and vital roads. A simulation of the Leh cloudburst disaster analysed the disaster itself, disaster risk reduction plans in the region, gaps in existing response mechanisms and reducing hazard impacts in the future. The participant group comprised academic researchers and industry experts in natural hazards, social vulnerability, engineering, historical and social sciences, education, journalism, disaster management and disaster risk reduction. Many of the participants had extensive local knowledge of Ladakh or comparable neighbouring Himalayan regions. Following the disaster, Leh Autonomous Hill Development Council (LAHDC), produced a District Disaster Management Plan (DDMP), which addressed many of the gaps identified in the simulation. Most importantly, the document outlined a civil protection mechanism to respond to future hazardous events. This was utilised to assess future disaster response in the simulation scenario. From analysis of the scenario simulation, the role of the army was found to be key in minimizing the impact of the 2010 disaster, although in the future, the army may coordinate with the civil protection body as set out in the DDMP. Participants identified the lack of a local formalized civil protection plan as a major vulnerability, and the most vulnerable populations as the migrant communities. The group also discussed evidence of resilience among the population such as the role of monasteries and spirituality in psychological recovery and the impact of the initial local response. From broader discussion of the simulation scenario, it was possible to identify aspects of resilience for further study in a wider research project, such as identifying hazardous slopes from satellite mapping, informing the fieldwork program, designing social questionnaires to understand risk perception and formulating questions to guide focus-group discussions on community resilience

Scaling Behaviour and Complexity of the Portevin-Le Chatelier Effect

The plastic deformation of dilute alloys is often accompanied by plastic instabilities due to dynamic strain aging and dislocation interaction. The repeated breakaway of dislocations from and their recapture by solute atoms leads to stress serrations and localized strain in the strain controlled tensile tests, known as the Portevin-Le Chatelier (PLC) effect. In this present work, we analyse the stress time series data of the observed PLC effect in the constant strain rate tensile tests on Al-2.5%Mg alloy for a wide range of strain rates at room temperature. The scaling behaviour of the PLC effect was studied using two complementary scaling analysis methods: the finite variance scaling method and the diffusion entropy analysis. From these analyses we could establish that in the entire span of strain rates, PLC effect showed Levy walk property. Moreover, the multiscale entropy analysis is carried out on the stress time series data observed during the PLC effect to quantify the complexity of the distinct spatiotemporal dynamical regimes. It is shown that for the static type C band, the entropy is very low for all the scales compared to the hopping type B and the propagating type A bands. The results are interpreted considering the time and length scales relevant to the effect.Comment: 35 pages, 6 figure

10 Years of C-K Theory: A Survey on the Academic and Industrial Impacts of a Design Theory.

The goal of our research1 was to understand what is expected today from a design theory and what types of impact such type of scientific proposition may reach. To answer these questions with a grounded approach we chosed to study the developement of C-K theory as phenomenon per se that can inform our research work. C-K theory is clearly recognized as a design theory and it is a good representative of the level of generality and abstraction of contemporary design theory. Indeed, the validity of the theory as such has already been documented (e.g. Hatchuel & Weil 2002, 2003, 2008, 2009; Kazakçi 2009; Reich et al 2010; Le Masson et al 2010; Ullah et al 2012). Instead the current work sets out to understand the dissemination and the impact of the theory in both academic and industrial fields. The data collection overlooks the literature on C-K theory in English and in French, and includes interviews and feedbacks of students and industrial partners who applied C-K methodologies and tools. This research confirms the rapid diffusion and multiples impact of C-K theory. Beyond, such study signals that there are important expectations and potential impacts of a Design Theory within the field of knowledge at large. However there are strong conditions to meet these expectations: generality, generativity, and relatedness to contemporary sciences. A similar research could be done on Nam Suh's axiomatic approach to further test these conditions. It is impossible to say what will be the next generations of Design theory but it is sure that they should progress on these directions

Turbo décodage de code produit haut débit utilisant un code BCH étendu (128,106,8) t=3

- Cet article propose une nouvelle architecture de turbo décodage de codes BCH (128,106,8) à entrées et sorties pondérées corrigeant 3 erreurs. En utilisant le concept de parallélisme et les propriétés de la matrice générée par un code produit, cet article présente la conception et la complexité de trois décodeurs capables de traiter 2, 4 et 8 données en même temps pour obtenir le haut débit dans le décodage. Pour comparer les performances et la complexité entre les différents décodeurs, le langage C a été utilisé pour les simulations, le langage VHDL pour les simulations fonctionnelles et Synopsys Design Compiler pour la synthèse. Les résultats ainsi obtenus ouvrent la possibilité d'intégration sur le silicium de turbo décodeurs à fort pouvoir de correction (distance de 64, rendement de 0,8) et à haut débit (6,4Gbits/s)

System aspects of the FDMA PON conceived within the FABULOUS European project (Invited)

International audienc

Generalizations of Yang-Mills Theory with Nonlinear Constitutive Equations

We generalize classical Yang-Mills theory by extending nonlinear constitutive equations for Maxwell fields to non-Abelian gauge groups. Such theories may or may not be Lagrangian. We obtain conditions on the constitutive equations specifying the Lagrangian case, of which recently-discussed non-Abelian Born-Infeld theories are particular examples. Some models in our class possess nontrivial Galilean (c goes to infinity) limits; we determine when such limits exist, and obtain them explicitly.Comment: Submitted to the Proceedings of the 3rd Symposium on Quantum Theory and Symmetries (QTS3) 10-14 September 2003. Preprint 9 pages including reference

Engaging pictograms! A methodology for graphic design in enhancing player engagement as applied to the design of a serious game for nepalese women with low literacy

In the graphic design of serious games, player engagement is an important consideration. We propose a new approach towards aiding the graphic designer to consider the major factors relevant to player engagement. This article describes a method for creating effective graphical content for serious games that takes into account the impact of complex pictograms on player engagement and on the learning process. We show how we applied our method to the design of a serious game for mobile phones aimed at Nepalese women in rural areas with low literacy skills. Initial results from case study suggest that our method helps designers to improve the design and the logic behind their use of imagery to the extent where the need to use text in the game’s user interface was removed

Non-Hermitian matrix description of the PT symmetric anharmonic oscillators

Schroedinger equation H \psi=E \psi with PT - symmetric differential operator H=H(x) = p^2 + a x^4 + i \beta x^3 +c x^2+i \delta x = H^*(-x) on L_2(-\infty,\infty) is re-arranged as a linear algebraic diagonalization at a>0. The proof of this non-variational construction is given. Our Taylor series form of \psi complements and completes the recent terminating solutions as obtained for certain couplings \delta at the less common negative a.Comment: 18 pages, latex, no figures, thoroughly revised (incl. title), J. Phys. A: Math. Gen., to appea

New PRSS1 and common CFTR mutations in a child with acute recurrent pancreatitis, could be considered an "Hereditary" form of pancreatitis ?

<p>Abstract</p> <p>Background</p> <p>acute recurrent pancreatitis is a complex multigenic disease, the diagnosis is even more difficult when this disease develops in a child.</p> <p>Case Presentation</p> <p>a 6-years old boy, hospitalized with epigastric pain radiating to the back showed high serum levels of serum amylase, lipase, CRP and erythrosedimentation rate. Several similar milder episodes of pain, followed by quick recovery and complete disappearance of symptoms were reported during the previous 13 months. The child was medically treated and after 7 days with normal clinic and laboratory tests was discharged with a hypolipidic diet. All the known aetiologic hypotheses were excluded by anamnestic investigation, clinical observation and biochemical evaluation, whereas, anatomic abnormality were excluded by a secretin stimulated magnetic resonance (MRI). At the last follow-up visit, (11 months later), the child showed a normal body weight and anthropometric profile, without further abdominal pain. Mutation screening for coding regions of <it>PRSS1, SPINK1, CFTR </it>and the new hereditary pancreatitis-associated chymotrypsin C (<it>CTRC</it>) genes showed a novel variation, c.541A > G (p.S181G), in the exon 4 of PRSS1 gene and the classical CF p.F508del mutation in the <it>CFTR. </it>Both mutations were present in his clinically normal mother and absent in the patient's father.</p> <p>Conclusions</p> <p>this report extend the spectrum of PRSS1 mutations, however, the absence of family history of pancreatitis leaves the present case without the hallmark of the hereditary origin of pancreatitis. At the present knowledge it can be only stated that the combined genotype CFTR (F508del)/PRSS1 (S181G) is associated to a mild phenotype of acute recurrent pancreatitis in this child without any further conclusion on its pathogenetic role or prediction on the course of the disease.</p