Linear matrix inequalities control driven for non-ideal power source energy harvesting

The dynamic model of a linear energy harvester excited by a non-ideal power source is coupled to a controller to maximum vibration adjustment. Numerical analysis is taken toevaluate the energy harvested keeping the vibration optimized for the maximum interaction to the energy source using linear matrix inequalities for control driven. The dimensionless power output, actuation power and net output power is determined. As a result, it is possible to verify that the total energy harvested via exogenous vibration using the proposed controller is increased up to 65 times when in comparison to the open loop system

Towards mistake-aware systems

The complexity of today’s enterprise computer systems poses a major challenge to system administrators, with a multitude of inter-related software components distributed in non-obvious ways across multiple computers. Not surprisingly, several studies have shown that human mistakes are an important source of outages and incorrect system behavior. To make matters worse, as computers permeate all aspects of our lives, higher demands are placed on the availability and correct operation of many computer systems. Given this state-of-affairs, we envisioned that systems must gracefully tolerate human mistakes made during system administration and operation. To realize our vision, we first studied human operator behavior and mistakes by means of live experiments with volunteers and a survey with database administrators. The results of this study led us to investigate a few techniques for dealing with mistakes, namely, validation of operator actions and model-based validation. Our research efforts culminate in a radically different approach, which we call mistake-aware systems management. We evaluate the effectiveness of validation of operator actions applied to databases, model-based validation, and mistake-aware systems management through a combination of live operator experiments, operator-emulation experiments, and mistake-injection experiments in a realistic prototype three-tier Internet service.Ph.D.Includes bibliographical referencesIncludes vitaby F´abio Abreu Dias de Oliveir

Could shading reduce the negative impacts of drought on coffee? A morphophysiological analysis

Based on indirect evidence, it was previously suggested that shading could attenuate the negative impacts of drought on coffee (Coffea arabica), a tropical crop species native to shady environments. A variety (47) of morphological and physiological traits were examined in plants grown in 30‐l pots in either full sunlight or 85% shade for 8 months, after which a 4‐month water shortage was implemented. Overall, the traits showed weak or negligible responses to the light × water interaction, explaining less than 10% of the total data variation. Only slight variations in biomass allocation were observed in the combined shade and drought treatment. Differences in relative growth rates were mainly associated with physiological and not with morphological adjustments. In high light, drought constrained the photosynthetic rate through stomatal limitations with no sign of apparent photoinhibition; in low light, such constraints were apparently linked to biochemical factors. Sun‐grown plants displayed osmotic adjustments, decreased tissue elasticities and improved long‐term water use efficiencies, especially under drought. Regardless of the water availability, higher concentrations of lipids, total phenols, total soluble sugars and lignin were found in high light compared to shade conditions, in contrast to the effects on cellulose and hemicellulose concentrations. Proline concentrations increased in water‐deprived plants, particularly those grown under full sun. Phenotypic plasticity was much higher in response to the light than to the water supply. Overall, shading did not alleviate the negative impacts of drought on the coffee tree

Genetic and pharmacological regulation of the endocannabinoid CB1 receptor in Duchenne muscular dystrophy

The endocannabinoid system refers to a widespread signaling system and its alteration is implicated in a growing number of human diseases. However, the potential role of endocannabinoids in skeletal muscle disorders remains unknown. Here we report the role of the endocannabinoid CB1 receptors in Duchenne's muscular dystrophy. In murine and human models, CB1 transcripts show the highest degree of expression at disease onset, and then decline overtime. Similar changes are observed for PAX7, a key regulator of muscle stem cells. Bioinformatics and biochemical analysis reveal that PAX7 binds and upregulates the CB1 gene in dystrophic more than in healthy muscles. Rimonabant, an antagonist of CB1, promotes human satellite cell differentiation in vitro, increases the number of regenerated myofibers, and prevents locomotor impairment in dystrophic mice. In conclusion, our study uncovers a PAX7-CB1 cross talk potentially exacerbating DMD and highlights the role of CB1 receptors as target for potential therapies

The intergenerational impact of long-term care financing alternatives in Spain

This paper examines the financial sustainability of long-term care funding options in Spain. We employ the generational accounting ("GA") methodology to evaluate the intertemporal impact of funding policies for long-term care services in the face of demographic change. Our findings suggest first that, although at present the system seems actuarially fair, the resources currently employed will be clearly insufficient to fund future needs, due to the demographic dependency of expenditures; second, that the specific tax instrument used to fund long-term care plays a less significant role. Conversely, the role of co-payment turns out to be key in offsetting the adverse effect of demography on the finances of the system