Development of SMEs and heterogeneity of trajectories: the case of biotechnology in France

Biotechnology is an emergent sector based on the creation of research-intensive Small and Medium Enterprises (SMEs). While some SMEs are growing, most of them remain small, even those set-up several years ago. What is the pattern of development of the biotech sector? What are the patterns of development of firms? Studies on the development of high-tech SMEs have focused on a business model, in which entrepreneurs rely on growth forecasts to persuade capital investors (business angels and venture capitalists) to invest in a radical innovation project. Firms aim for a world market to industrialise their innovation, and initial public offering (IPO) enables initial investors to make profits that offset risky initial investment. While this model is appealing, it is simply one of the possible models of biotechnology development. Some firms are not designed to experience exponential growth, and choose to target local markets. Moreover, not all firms have the ambition of being listed on the stock exchange. Based on an in-depth analysis of the business and development of 60 French biotech SMEs, this article identifies two business models. By defining the development trajectories of each of these models, it highlights the temporary nature of the emergent model.     

Finite Memory Observers for linear time-varying systems. Part II: Observer and residual sensitivity

Fault detection and diagnosis are important issues in process engineering. Hence, considerable interest is growing in this field from industrial practitioners as well as academic researchers, as opposed to 30 years ago. This paper focusses on a model-based approach for fault detection. This approach is based on Finite Memory Observers (FMO), properties of this observer are presented in the first part of our work (Graton et al., 2014 [1]), the main results of this paper are recalled at the beginning of this paper and constitute the basis of this second part. Properties of the Finite Memory Observer (FMO) are studied from a global point of view for the class of linear time-varying (LTV) systems with stochastic noises. FMO performances take their framework from the study of their properties, and from the study of their influences on diagnosis results. Fundamentally, the generation of residuals is essential in a diagnosis procedure. In Graton et al. (2014) [1], the design for the finite memory observer is shown, the determination of its optimal window length is solved, and the generation of residuals for diagnosis is completed. This paper is the second part of this work and is devoted to the study of the observer and residual sensitivity towards model parameter variations and noises.     

Tour de France,Giro, Vuelta,and classic European races show a unique progression of road cycling speed in the last 20 years

Abstract

Road cycling ranks among the most intense endurance exercises. Previous studies and mathematical models describing road cycling have not analysed performances per se. We describe the evolution of road cycling performance over the past 116 years. We studied the top ten cyclists' mean speeds in eight famous classic races and three European Grand Tours, using a previously published multi-exponential model that highlights the different progression periods of an event during the century. In addition, we measured an indicator of difficulty for the Tour de France by calculating the climbing index (i.e. the total altitude climbed over total distance). The eleven races' mean speed increased progressively from 23.13 km · h^?1 in 1892 to 41.19 ± 2.03 km · h^?1 in 2008. Road cycling development, like other quantifiable disciplines, fits a piecewise progression pattern that follows three periods: before, between, and after the two World Wars. However, a fourth period begins after 1993, providing a speed progression of 6.38% from the third one. The Tour de France's climbing index also provided insight into a recent paradoxical relationship with speeds: when the climbing index increased, the winner's speed also increased. Our results show a major improvement (6.38%) in road cycling performance in the last 20 years and question the role of extra-physiological parameters in this recent progression.     

Muscle oxygenation and EMG activity during isometric exercise in children

Abstract

The aim of this study was to examine the time-course of and the relationships between muscle oxygenation, blood volume and myoelectrical manifestations during isometric exercise in children. Twelve healthy children aged 12.5 ± 1.2 years (mean ± s) performed an isometric knee extension at 50% of their maximal voluntary contraction (MVC) until exhaustion to assess endurance time (limit time, T _lim). Changes in muscle oxygenation and blood volume were assessed by near infrared spectroscopy (NIRS). The root mean square (RMS) amplitude and the mean power frequency (MPF) from electromyogram (EMG) signals were obtained, as NIRS parameters, from the vastus lateralis. Mean T _lim was 117 ± 34 s. The muscle oxygenation and blood volume curves decreased immediately at the beginning of exercise. Maximal deoxygenation occurred at 50% T _lim, and fell by 76.9% from the resting value. Similarly, minimal blood volume was observed at 50% T _lim; it reached a plateau that lasted until the end of exercise. The kinetics of the MPF and RMS curves were inversely related to time. At the last set of exercises (after 75% T _lim), a steeper RMS curve and an abrupt decrease in the MPF curve were observed. Significant correlations (r) between muscle oxygenation, blood volume, root mean square amplitude and mean power frequency were observed, which ranged from 0.72 to 0.99. These findings suggest that the fatigue resulting from sustained isometric exercise is related to a decrease in oxygenation and blood volume.     

A comparison of lactate indices during ramp exercise using modelling techniques and conventional methods

Abstract

The aim of this study was to compare the lactate indices provided by single- and double-breakpoint models with lactate thresholds obtained with conventional methods. Arterial samples for the determination of lactate concentrations were drawn from eight participants at rest and every minute during a ramp test (15 W · min^?1) on a cycle ergometer. Lactate thresholds were determined from a blood lactate concentration equal to 4 mM (LT₄), from an increase of 1 mM above the resting level (Δ1 mM), and from indirect methods using ventilatory parameters. Other indices were computed from the modelling of the lactate curve using an exponential function (LSI), a polynomial function (Dmax), a semi-log model (SLog), a parabola plus delay model (Mod P), and a two-breakpoint model (Mod M). Mod P and Mod M showed poor agreement with the other methods. LT₄, Dmax, LSI, and respiratory exchange ratio equal to 1 were correlated with each other (0.81 ≤ R ≤ 0.92) and their mean differences ranged from 2.8 to 15 W, with limits of agreement within the range ± 24.6 to ± 42.4 W. These results question the interest in breakpoints models to detect lactate thresholds, knowing that LT₄, LSI, Dmax, and respiratory exchange ratio equal to 1 provide indices that occur at similar power outputs.     

Examining perceived control level and instability as predictors of first-year college students’ academic achievement

The aim of the present study was to examine the intraindividual level and instability of perceived academic control (PC) among first-year college students, and their predictive effects on academic achievement. Two studies were conducted measuring situational (state) PC on different schedules: Study 1 (N = 242) five times over a 6-month period and Study 2 (N = 80) daily over a 2-week period. Consistent across both studies were confirmatory factor analyses and structural equation models demonstrating significant PC instability, as well as negative correlations between intraindividual PC levels (average across measurements) and instability (standard deviation across measurements). Also, in both studies PC level positively predicted subsequent academic achievement, although no significant PC instability first-order effects were found. Both studies revealed a PC level by instability interaction, as students with high-unstable PC typically received poorer grades than high-stable PC students. Study findings highlight the importance of considering both PC level and instability, and identify a previously unknown group of first-year college students at-risk of under-achieving academically – students with high-unstable perceived control.     

Predicting intraindividual changes in teacher burnout: The role of perceived school environment and motivational factors

Based on self-determination theory, this study proposes and tests a motivational model of intraindividual changes in teacher burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment). Participants were 806 French-Canadian teachers in public elementary and high schools. Results show that changes in teachers’ perceptions of classroom overload and students’ disruptive behavior are negatively related to changes in autonomous motivation, which in turn negatively predict changes in emotional exhaustion. Results also indicate that changes in teachers’ perceptions of students’ disruptive behaviors and school principal’s leadership behaviors are related to changes in self-efficacy, which in turn negatively predict changes in three burnout components.