Introducing Performativity to Crisis Management Theory: An Illustration from the 2003 French Heat Wave Crisis Response

While current crisis management literature focuses on the necessity of consistent data and shared interpretation to coordinate effectively, contrastingly, this paper highlights the predominating influence of crisis responders' performances on information transmission. Based on an exploratory interpretive analysis of the 2003 French heat wave crisis response, our findings reveal that performances can support immediate reaction and involvement, but can also generate conflicts or misunderstandings that may burden coordination. This work's contribution to the crisis management literature is in threefold. First, we enrich the crisis management literature by proposing performativity as a potential analytical lens for collective action during crisis response. Second, we propose some practical recommendations to improve crisis management training through the application of the concept of performativity. Finally, we propose a critical perspective on tacitly held assumptions in crisis management.     

Modelling of hydrogen production in batch cultures of the photosynthetic bacterium Rhodobacter capsulatus

The photosynthetic bacterium, Rhodobacter capsulatus, produces hydrogen under nitrogen-limited, anaerobic, photosynthetic culture conditions, using various carbon substrates. In the present study, the relationship between light intensity and hydrogen production has been modelled in order to predict both the rate of hydrogen production and the amount of hydrogen produced at a given time during batch cultures of R. capsulatus. The experimental data were obtained by investigating the effect of different light intensities (6000–50,000 lux) on hydrogen-producing cultures of R. capsulatus grown in a batch photobioreactor, using lactate as carbon and hydrogen source. The rate of hydrogen production increased with increasing light intensity in a manner that was described by a static Baly model, modified to include the square of the light intensity. In agreement with previous studies, the kinetics of substrate utilization and growth of R. capsulatus was represented by the classical Monod or Michaelis–Menten model. When combined with a dynamic Leudekong–Piret model, the amount of hydrogen produced as a function of time was effectively predicted. These results will be useful for the automatization and control of bioprocesses for the photoproduction of hydrogen.     

State estimation of a batch hydrogen production process using the photosynthetic bacteria Rhodobacter capsulatus

This paper addresses the problem of estimating the states of an anaerobic photosynthetic process used for biohydrogen production by the photosynthetic bacterium Rhodobacter capsulatus. The process is described by a non-linear, time-discrete model and the state estimation is solved using an observer based on the Moving-Horizon State Estimation Method (MHSE). This approach is based on the minimization of a criterion (a non-linear function), in this case, the difference between the estimated output and the measured output of the system over a considered time horizon, where the solution is computed by using a numerical interval method. The observer was successfully applied to hydrogen production by R. capsulatus strain B10 in a batch process.     

Formation control of multiple vehicles using dynamic surface control and hybrid systems

This paper deals with the formation control of multiple vehicles, using a combination of dynamic surface sliding control and hybrid systems. Each vehicle must perform several manoeuvres, either independently, or in a coordinated fashion as part of a vehicle formation. A dynamic surface controller is designed for each manoeuvre. Switches between manoeuvres and communication protocols between vehicles are represented using hybrid systems formalisms. Here, we present the design of both independent and coordinated dynamic positioning (DP) controllers for ocean vehicles using dynamic surface control. Independent and coordinated dynamic positioning are manoeuvres that the modules forming a floating runway at sea must perform. Experimental results using scaled modules are shown.     

Proteomic serum biomarkers and their potential application in cancer screening programs

Early diagnosis of cancer is of pivotal importance to reduce disease-related mortality. There is great need for non-invasive screening methods, yet current screening protocols have limited sensitivity and specificity. The use of serum biomarkers to discriminate cancer patients from healthy persons might be a tool to improve screening programs. Mass spectrometry based proteomics is widely applied as a technology for mapping and identifying peptides and proteins in body fluids. One commonly used approach in proteomics is peptide and protein profiling. Here, we present an overview of profiling methods that have the potential for implementation in a clinical setting and in national screening programs.     

Data reconciliation with uncertain models

Data reconciliation has proven to be an effective technique for providing frequent, accurate and consistent "best estimates" of plant operation data. However, in almost all the proposed techniques until today, the mathematical model of the process has been considered as exact. In point of fact, this hypothesis is uncommon and frequently the models used are uncertain. This paper proposes a new technique of data reconciliation which is able to exploit the knowledge about the uncertainties of the model with regard to which the reconciliation is done. It leads to the solution of a classical quadratic optimisation problem subject to constraints. The originality of the proposed technique is to use penalty functions for solving this problem and to weight each constraint with regard to their uncertainties.     

Parity relations for linear uncertain dynamic systems

A new approach for the design of parity relations for linear dynamic systems with additive and multiplicative uncertainties is presented. Instead of cancelling uncertainties following the example of the so-called robust approaches, uncertain parity relations take uncertainties into account as bounded variables. The method is based on the analysis of zonotopes representing the uncertainties. It leads both to Boolean detection results and to an indicator representing the distance to the opposite decision.