Encourager et accompagner les producteurs de mangues de la région de Ziguinchor dans l'adoption de méthodes de lutte intégrée contre les mouches des fruits

The main objective of APPRI Workshop was to analyse conditions for implementing alternative action-research practices in partnership for development, taking into account the difficulties of "official" research and of the rural world, faced with the major challenges of sustainable development in the South. One originality of APPRI was to compare experiences from rural zones of Africa, with those of the UNICAMPO Peasants' University set up 10 years ago in the Brazilian Nordeste, a semi-arid region where small holders' farms exhibit some major similarities with those in Drylands Africa. The "Peasants' University" concept was unanimously chosen as a place to unify partnership initiatives bringing together research, rural development officers, farmer's organizations and rural communities. These Peasants' Universities will be places of learning where a common vision is shared for implementing development and environmental improvement activities. The APPRI group unanimously accepted that technical and institutional innovation in partnership is paramount. It needs to be co-constructed from local know-how and scientific and technical knowledge. Information and communication between all those involved in development needs to be revised and strengthened for ore interactivity and efficiency in order to contribute to cultural recognition and social economic transformation of rural communities. L'objectif de l'atelier APPRI était principalement d'analyser les conditions de mise en œuvre de pratiques alternatives de recherche-action en partenariat pour le développement, prenant en compte les difficultés de la recherche «officielle» et du monde rural face aux grands enjeux du développement durable au Sud. Une originalité d'APPRI était de confronter les expériences des zones rurales africaines à celles de l'Université Paysanne UNICAMPO mise en place depuis 10 ans dans le Nordeste brésilien, région semi-aride où les petites exploitations familiales présentent de grandes similitudes avec celles des zones sèches d'Afrique. Le concept d' «Université Paysanne» a été retenu à l'unanimité comme lieu de fédération d'initiatives en partenariat regroupant la recherche, les agents du développement rural, les organisations et groupements de producteurs et les communautés rurales. Ces universités paysannes seront des lieux d'apprentissage où se partage une vision commune pour la mise en œuvre d'actions de développement et de valorisation du milieu destinées. De façon unanime, le groupe APPRI2008 admet que l'innovation technique et institutionnelle en partenariat est centrale. Elle doit être co-construite à partir des savoirs locaux et de la connaissance scientifique et technique. L'information et la communication entre tous les acteurs du développement doivent être repensées et renforcées pour être plus interactives et plus efficaces afin de participer à la reconnaissance culturelle et la transformation sociale et économique des communautés rurales

Sensor potency of the moonlighting enzyme-decorated cytoskeleton

Background: There is extensive evidence for the interaction of metabolic enzymes with the eukaryotic cytoskeleton. The significance of these interactions is far from clear. Presentation of the hypothesis: In the cytoskeletal integrative sensor hypothesis presented here, the cytoskeleton senses and integrates the general metabolic activity of the cell. This activity depends on the binding to the cytoskeleton of enzymes and, depending on the nature of the enzyme, this binding may occur if the enzyme is either active or inactive but not both. This enzyme-binding is further proposed to stabilize microtubules and microfilaments and to alter rates of GTP and ATP hydrolysis and their levels. Testing the hypothesis: Evidence consistent with the cytoskeletal integrative sensor hypothesis is presented in the case of glycolysis. Several testable predictions are made. There should be a relationship between post-translational modifications of tubulin and of actin and their interaction with metabolic enzymes. Different conditions of cytoskeletal dynamics and enzyme-cytoskeleton binding should reveal significant differences in local and perhaps global levels and ratios of ATP and GTP. The different functions of moonlighting enzymes should depend on cytoskeletal binding. Implications of the hypothesis: The physical and chemical effects arising from metabolic sensing by the cytoskeleton would have major consequences on cell shape, dynamics and cell cycle progression. The hypothesis provides a framework that helps the significance of the enzyme-decorated cytoskeleton be determined

Multi-objective optimization of a building envelope for thermal performance using genetic algorithms and artificial neural network

International audienceThe objective of this paper is to present a method to optimize the equivalent thermophysical properties of the external walls (thermal conductivity k wall and volumetric specific heat (c) wall) of a dwelling in order to improve its thermal efficiency. Classical optimization involves several dynamic yearly thermal simulations, which are commonly quite time consuming. To reduce the computational requirements, we have adopted a methodology that couples an artificial neural network and the genetic algorithm NSGA-II. This optimization technique has been applied to a dwelling for two French climates, Nancy (continental) and Nice (Mediterranean). We have chosen to characterize the energy performance of the dwelling with two criteria, which are the optimization targets: the annual energy consumption Q TOT and the summer comfort degree I sum. First, using a design of experiments, we have quantified and analyzed the impact of the variables k wall and (c) wall on the objectives Q TOT and I sum , depending on the climate. Then, the optimal Pareto fronts obtained from the optimization are presented and analyzed. The optimal solutions are compared to those from mono-objective optimization by using an aggregative method and a constraint problem in GenOpt. The comparison clearly shows the importance of performing multi-objective optimization

Impact of occupant's actions on energy building performance and thermal sensation

International audienceIn this study, the impact of behavioral actions of a building occupant on energy performance and thermal sensation are investigated. The study focuses on the six following actions: use of blinds, lighting system, windows, fan, thermostat and clothing adjustments. Eight types of buildings, classified among three criteria (air-conditioning, thermal inertia and climate), are studied. Simulation of the occupant's actions, building performance and thermal sensation have been carried out by using TRNSYS 17. Impact on energy demand and thermal sensation of each action has been investigated with a design of experiments methodology coupled with the use of Yate's algorithm. This study shows that for a given building, the occupant's actions have a significant impact on energy demand. Building simulation in literature typically does not model human activity in energy consumption, yet our study demonstrate a strong correlation. Results from the design of experiments methodology are compared to conventional French design strategy. It appears that conventional French design strategy, which does not take into account occupants' actions, tends to strongly underestimate building energy demand

Inverse radiative design in human thermal environment

International audienceThis work investigates inverse boundary design for radiative heat transfer applied to human thermal environment. The problem consists in finding the temperatures of certain surfaces in a complex configuration around the human being that satisfy both the temperature and the heat flux prescribed on his body. Such a mathematical procedure is called inverse modeling which is described by an ill-conditioned system of linear equations based on the absorption factors method. The solution is obtained by regularizing the system of equations by the Tikhonov method. As a result we obtain optimized conditions for a complex human thermal system

Sans occupant, les bâtiments ne consomment pas d'énergie !

International audienc

Understanding non-ideal paleointensity recording in igneous rocks: Insights from aging experiments on lava samples and the causes and consequences of ‘fragile’ curvature in Arai plots

The theory for recording of thermally blocked remanences predicts a quasilinear relationship between low fields like the Earth's in which rocks cool and acquire a magnetization. This serves as the foundation for estimating ancient magnetic field strengths. Addressing long-standing questions concerning Earth's magnetic field requires a global paleointensity data set, but recovering the ancient field strength is complicated because the theory only pertains to uniformly magnetized particles. A key requirement of a paleointensity experiment is that a magnetization blocked at a given temperature should be unblocked by zero-field reheating to the same temperature. However, failure of this requirement occurs frequently and the causes and consequences of failure are understood incompletely. Recent experiments demonstrate that the remanence in many samples typical of those used in paleointensity experiments is unstable, exhibiting an “aging” effect in which the (un)blocking temperature spectra can change over only a few years resulting in nonideal experimental behavior. While a fresh remanence may conform to the requirement of equality of blocking and unblocking temperatures, aged remanences may not. Blocking temperature spectra can be unstable (fragile), which precludes reproduction of the conditions under which the original magnetization was acquired. This limits our ability to acquire accurate and precise ancient magnetic field strength estimates because differences between known and estimated fields can be significant for individual specimens, with a low field bias. Fragility of unblocking temperature spectra may be related to grain sizes with lower energy barriers and may be detected by features observed in first-order reversal curves

Chemical and mineralogical effects of saline water movement through a soil during evaporation

Cet article illustre les résultats d'une expérience menée dans le but d'étudier les effets de l'évaporation dans un sol homogène reconstitué. Les conditions expérimentales sont celles qui caractérisent les zones de polders du lac Tchad. Les données obtenues montrent que les phénomènes de capillarité déterminent un transfert des ions en solution vers la surface du sol. Puisque l'évaporation se réalise dans cette zone, les concentrations ioniques des solutions deviennent très élevées. Les simulations et les calculs théoriques montrent que dans ce milieu et sous ces conditions des argiles magnésiennes précipitent : ceci est confirmé par leurs observations au microscope électronique à transmissio