De la relación inter-individual a la relación inter-organizacional : un análisis de redes multinivel de un mercado de programas de televisión en África subsahariana

Hoy, el encastramiento de las actividades económicas en las relaciones sociales no parece ser un hecho a demostrar en el campo de la sociología económica. Sin embargo, ¿podemos concluir que un contrato comercial entre dos empresas está necesariamente encastrado en las relaciones sociales de sus miembros? Sobre la base de los conceptos de encastramiento y desacoplamiento de White, intentaremos analizar cómo las relaciones inter-individuales pueden convertirse en relaciones inter-organizacionales. El análisis de redes sociales multinivel constituye un marco teórico y metodológico para captar este fenómeno. Describiremos a través del estudio de una red multinivel de un salón de distribución de programas audiovisuales en África, la dinámica entre encastramiento y desacoplamiento que podemos observar en un mercado. Demostramos que en la medida en que los individuos participan más en este salón, más serán los contratos entre las empresas que están encastrados en sus redes.L'encastrement des activités économiques dans les relations sociales ne semble plus aujourd'hui un fait à prouver dans le champ de la sociologie économique. Pourtant, pouvons-nous en conclure qu'un contrat commercial entre deux entreprises est nécessairement encastré dans les relations sociales de leurs membres ? En nous inspirant des concepts d'encastrement et découplage de White, nous chercherons ainsi à analyser comment des relations inter-individuelles peuvent devenir des relations inter-organisationnelles. L'analyse de réseaux sociaux multiniveaux constitue un cadre théorique et méthodologique permettant de saisir ce phénomène. Nous décrirons ainsi à travers une étude de réseau multiniveaux d'un salon de distribution de programmes audiovisuels en Afrique, les dynamiques entre encastrement et découplage observables sur un marché. Nous montrons entre autres que plus les individus participent à ces salons, plus les contrats entre leurs entreprises sont encastrés dans leurs réseaux

A new method for unconstrained measurement of knee joint angle and timing in alpine skiing : Comparison of crossover and crossunder turns

Timing is an important part in the analysis of alpine skiing technique. Key events extracted from dynamics and kinematics of ski were previously proposed, but timing of body segments kinematics is also required to understand the biomechanics and to assess the performance. In this study, we proposed a new method based on inertial sensors to measure timing parameters based on body segments kinematics. To show the efficacy of the method, angle and timing of knee joints during crossover and crossunder techniques were compared. Significant differences were obtained for the timing, but not for the amplitude of the knee angles. The proposed system reported a good repeatability, did not encumber the athletes and allowed the measurement of body movement during the whole run. So it could easily be used to assess performance in training conditions

Large and uniform optical emission shifts in quantum dots externally strained along their growth axis

We introduce a method which enables to directly compare the impact of elastic strain on the optical properties of distinct quantum dots (QDs). Specifically, the QDs are integrated in a cross-section of a semiconductor core wire which is surrounded by an amorphous straining shell. Detailed numerical simulations show that, thanks to the mechanical isotropy of the shell, the strain field in a core section is homogeneous. Furthermore, we use the core material as an in situ strain gauge, yielding reliable values for the emitter energy tuning slope. This calibration technique is applied to self-assembled InAs QDs submitted to incremental tensile strain along their growth axis. In contrast to recent studies conducted on similar QDs stressed perpendicularly to their growth axis, optical spectroscopy reveals 5-10 times larger tuning slopes, with a moderate dispersion. These results highlight the importance of the stress direction to optimise QD response to applied strain, with implications both in static and dynamic regimes. As such, they are in particular relevant for the development of wavelength-tunable single photon sources or hybrid QD opto-mechanical systems

Orientation of body segments in ski jumps using wearable sensors: Analysis of relevant parameters during stable flight phase

Biomechanics analysis of the ski jump is highly required. Some parameters and their interrelations have been reported in previous research studies limited to few athletes. The generalization of these parameters to athletes of various levels and under training conditions should be assessed, since they have the potential to be used for daily evaluation. This study proposed a new 3D approach based on inertial sensors to evaluate relevant kinematic and aerodynamic parameters of stable flight phase. The proposed wearable system can easily be used for daily training. Aerodynamic forces and body segments 3D angles were extracted during the stable flight phase of 86 jumps. Then, their correlations with respect to distance as well as their interrelations were analyzed. Their combination expressed 55% of the total distance variance

Functional Dissection of the Apicomplexan Glideosome Molecular Architecture

SummaryThe glideosome of apicomplexan parasites is an actin- and myosin-based machine located at the pellicle, between the plasma membrane (PM) and inner membrane complex (IMC), that powers parasite motility, migration, and host cell invasion and egress. It is composed of myosin A, its light chain MLC1, and two gliding-associated proteins, GAP50 and GAP45. We identify GAP40, a polytopic protein of the IMC, as an additional glideosome component and show that GAP45 is anchored to the PM and IMC via its N- and C-terminal extremities, respectively. While the C-terminal region of GAP45 recruits MLC1-MyoA to the IMC, the N-terminal acylation and coiled-coil domain preserve pellicle integrity during invasion. GAP45 is essential for gliding, invasion, and egress. The orthologous Plasmodium falciparum GAP45 can fulfill this dual function, as shown by transgenera complementation, whereas the coccidian GAP45 homolog (designated here as) GAP70 specifically recruits the glideosome to the apical cap of the parasite

BCKDH: the missing link in apicomplexan mitochondrial metabolism is required for full virulence of Toxoplasma gondii and Plasmodium berghei

While the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii are thought to primarily depend on glycolysis for ATP synthesis, recent studies have shown that they can fully catabolize glucose in a canonical TCA cycle. However, these parasites lack a mitochondrial isoform of pyruvate dehydrogenase and the identity of the enzyme that catalyses the conversion of pyruvate to acetyl-CoA remains enigmatic. Here we demonstrate that the mitochondrial branched chain ketoacid dehydrogenase (BCKDH) complex is the missing link, functionally replacing mitochondrial PDH in both T. gondii and P. berghei. Deletion of the E1a subunit of T. gondii and P. berghei BCKDH significantly impacted on intracellular growth and virulence of both parasites. Interestingly, disruption of the P. berghei E1a restricted parasite development to reticulocytes only and completely prevented maturation of oocysts during mosquito transmission. Overall this study highlights the importance of the molecular adaptation of BCKDH in this important class of pathogens

Business/IT Alignment in Practice: Lessons Learned From a Requirements Project at P&G

One of the main objectives of the alignment of Business and IT in both small and large organizations is to improve the chances for an IT department to provide services that result in business success. An essential phase for this alignment is the definition of business requirements. In this paper we describe the successful use of a blend of industrial and academic requirements methods for an IT system development at Procter and Gamble, (P&G), UK. We identify two main elements for the success of this phase: (1) the combination of methods from P&G and academia, (2) the focus of P&G’s IT department on providing business solutions. This shift is accompanied by a move from writing specifications of IT systems towards defining business requirements. We dis-cuss how these elements explain the success of this phase and propose research directions that may ease the introduction and use of requirements definition methods in organizations