Stochastic approximations and differential inclusions II: applications

We apply the theoretical results on "stochastic approximations and differential inclusions" developed in Benaim, Hofbauer and Sorin (2005) to several adaptive processes used in game theory including: classical and generalized approachability, no-regret potential procedures (Hart and Mas-Colell), smooth fictitious play (Fudenberg and Levine

Generalized Urn Models of Evolutionary Processes

Generalized Polya urn models can describe the dynamics of finite populations of interacting genotypes. Three basic questions these models can address are: Under what conditions does a population exhibit growth? On the event of growth, at what rate does the population increase? What is the long-term behavior of the distribution of genotypes? To address these questions, we associate a mean limit ordinary differential equation (ODE) with the urn model. Previously, it has been shown that on the event of population growth, the limiting distribution of genotypes is a connected internally chain recurrent set for the mean limit ODE. To determine when growth and convergence occurs with positive probability, we prove two results. First, if the mean limit ODE has an ``attainable'' attractor at which growth is expected, then growth and convergence toward this attractor occurs with positive probability. Second, the population distribution almost surely does not converge to sets where growth is not expecte

Implied volatility of basket options at extreme strikes

In the paper, we characterize the asymptotic behavior of the implied volatility of a basket call option at large and small strikes in a variety of settings with increasing generality. First, we obtain an asymptotic formula with an error bound for the left wing of the implied volatility, under the assumption that the dynamics of asset prices are described by the multidimensional Black-Scholes model. Next, we find the leading term of asymptotics of the implied volatility in the case where the asset prices follow the multidimensional Black-Scholes model with time change by an independent increasing stochastic process. Finally, we deal with a general situation in which the dependence between the assets is described by a given copula function. In this setting, we obtain a model-free tail-wing formula that links the implied volatility to a special characteristic of the copula called the weak lower tail dependence function

Are patients with hypermobile Ehlers-Danlos syndrome or hypermobility spectrum disorder so different?

Diagnosing hypermobile Ehlers-Danlos syndrome (hEDS) remains challenging, despite new 2017 criteria. Patients not fulfilling these criteria are considered to have hypermobile spectrum disorder (HSD). Our first aim was to evaluate whether patients hEDS were more severely affected and had higher prevalence of extra-articular manifestations than HSD. Second aim was to compare their outcome after coordinated physical therapy. Patients fulfilling hEDS/HSD criteria were included in this real-life prospective cohort (November 2017/April 2019). They completed a 16-item Clinical Severity Score (CSS-16). We recorded bone involvement, neuropathic pain (DN4) and symptoms of mast cell disorders (MCAS) as extra-articular manifestations. After a standardized initial evaluation (T0), all patients were offered the same coordinated physical therapy, were followed-up at 6 months (T1) and at least 1 year later (T2), and were asked whether or not their condition had subjectively improved at T2. We included 97 patients (61 hEDS, 36 HSD). Median age was 40 (range 18-73); 92.7% were females. Three items from CSS-16 (pain, motricity problems, and bleeding) were significantly more severe with hEDS than HSD. Bone fragility, neuropathic pain and MCAS were equally prevalent. At T2 (20 months [range 18-26]) 54% of patients reported improvement (no difference between groups). On multivariable analysis, only family history of hypermobility predicted (favorable) outcome (p = 0.01). hEDS and HDS patients showed similar disease severity score except for pain, motricity problems and bleeding, and similar spectrum of extra-articular manifestations. Long-term improvement was observed in > 50% of patients in both groups. These results add weight to a clinical pragmatic proposition to consider hEDS/HSD as a single entity that requires the same treatments

Activity of the antiarrhythmic drug amiodarone against Leishmania (L.) infantum: an in vitro and in vivo approach

<div><p>Abstract Background: Considering the high toxicity and limited therapies available for treating visceral leishmaniasis (VL), the drug repositioning approach represents a faster way to deliver new therapies to the market. Methods: In this study, we described for the first time the activity of a potent antiarrhythmic, amiodarone (AMD), against L. (L.)infantum and its in vitro and in vivo activity. Results: The evaluation against promastigotes has shown that amiodarone presents leishmanicidal effect against the extracellular form, with an IC50 value of 10 μM. The activity was even greater against amastigotes in comparison with promastigotes with an IC50 value of 0.5 μM. The selectivity index in relation to the intracellular form demonstrated that the antiparasitic activity was approximately 56 times higher than its toxicity to mammalian cells. Investigation of the in vivo AMD activity in the L. infantum-infected hamster model showed that 51 days after the initial infection, amiodarone was unable to reduce the parasite burden in the spleen and liver when treated for 10 consecutive days, intraperitoneally, at 50 mg/kg/day, as determined by qPCR. Although not statistically significant, AMD was able to reduce the parasite burden by 20% in the liver when treated for 10 consecutive days, orally, at 100 mg/kg/day; no reduction in the spleen was found by qPCR. Conclusions: Our findings may help further drug design studies seeking new AMD derivatives that may provide new candidates with an in vitro selectivity close to or even greater than that observed in the prototype delivering effectiveness in the experimental model of VL.</p></div

Transcultural adaptation and validation of a French version of the Prosthetic Limb Users Survey of Mobility 12-item Short-Form (PLUS-M/FC-12) in active amputees.

The PLUS-M 12-item Short-Form is a self-questionnaire that assesses the perceived capacity of lower limb amputees (LLAs) to perform a number of daily-life activities. Its psychometric properties are excellent (intraclass correlation coefficient [ICC]&gt;0.9, fast administration and scoring, normative data available), and it can be used in clinical practice or for research purposes. We aimed to develop a French version of this questionnaire and to assess its psychometric properties. We followed international recommendations for translation and cross-cultural validation of questionnaires. In total, 52 LLAs (age 53±16, 40 males, 28/12/12 transtibial/Gritti-Stokes/transfemoral, 20/28/4 ischemic/traumatic/other) participated. Criterion and construct validities were assessed with the Pearson correlation coefficient (PCC) between the PLUS-M 12-item Short-Form and other constructs (Prosthetic-Profile-of-the-Amputee-Locomotor Capabilities Index, Activities-specific Balance Confidence scale, 2-min walking test and Timed Up and Go test), internal consistency with the Cronbach α and reliability with the ICC in 46 individuals who completed the questionnaire twice in a 7-day interval. The mean (SD) PLUS-M 12-item Short-Form T-score was 56.1 (7.8; range 40.3 to 71.4). Construct and criterion validity, internal consistency and reliability ranged from low to excellent (r=0.43 to 0.84, P&lt;10 &lt;sup&gt;-2&lt;/sup&gt; to 0.002; Cronbach α=0.90, ICC=0.89 [0.81-0.94]). We found no floor or ceiling effect. The French version of the PLUS-M 12-item Short-Form has good to excellent psychometric properties, comparable to those of the original version. Its use could definitely be proposed for both clinical and research purposes, once its validation is completed by assessing other psychometric qualities, especially sensitivity to change

Crafting the Composite Garment: The role of hand weaving in digital creation

There is a growing body of practice-led textile research, focused on how digital technologies can inform new design and production strategies that challenge and extend the field. To date, this research has emphasized a traditional linear transition between hand and digital production; with hand production preceding digital as a means of acquiring the material and process knowledge required to negotiate technologies and conceptualize designs. This paper focuses on current Doctoral research into the design and prototyping of 3D woven or 'composite' garments and how the re-learning, or reinterpreting, of hand weaving techniques in a digital Jacquard format relies heavily on experiential knowledge of craft weaving skills. Drawing parallels between hand weaving and computer programming, that extend beyond their shared binary (pixel-based) language, the paper discusses how the machine-mediated experience of hand weaving can prime the weaver to ‘think digitally’ and make the transition to digital production. In a process where the weaver acts simultaneously as designer, constructor and programmer, the research explores the inspiring, but often indefinable space between craft and digital technology by challenging the notion that 'the relationship between hand, eye and material’ naturally precedes the use of computing (Harris 2012: 93). This is achieved through the development of an iterative working methodology that encompasses a cycle of transitional development, where hand weaving and digital processes take place in tandem, and techniques and skills are reinterpreted to exploit the advantages and constraints of each construction method. It is argued that the approach challenges the codes and conventions of computer programming, weaving and fashion design to offer a more sustainable clothing solution

Mean-Field Limits Beyond Ordinary Differential Equations

16th International School on Formal Methods for the Design of Computer, Communication, and Software Systems, SFM 2016, Bertinoro, Italy, June 20-24, 2016, Advanced LecturesInternational audienceWe study the limiting behaviour of stochastic models of populations of interacting agents, as the number of agents goes to infinity. Classical mean-field results have established that this limiting behaviour is described by an ordinary differential equation (ODE) under two conditions: (1) that the dynamics is smooth; and (2) that the population is composed of a finite number of homogeneous sub-populations, each containing a large number of agents. This paper reviews recent work showing what happens if these conditions do not hold. In these cases, it is still possible to exhibit a limiting regime at the price of replacing the ODE by a more complex dynamical system. In the case of non-smooth or uncertain dynamics, the limiting regime is given by a differential inclusion. In the case of multiple population scales, the ODE is replaced by a stochastic hybrid automaton