Search results for "Servo"
showing 10 items of 283 documents
Phylogeography and genetic divergence of some lymnaeid snails, intermediate hosts of human and animal fascioliasis with special reference to lymnaeid…
1997
Abstract A population genetic study using starch gel electrophoresis was performed on populations of several species of lymnaeid snails acting as intermediate hosts for Fasciola hepatica (Trematoda, Plathyhelminth). Lymnaea viatrix was collected in 16 sites from the Bolivian Northern Altiplano. L. cubensis were obtained in one site from Venezuela, one site from Guadeloupe, three sites from Cuba and one site from the Dominican Republic. L. truncatula were collected in one site from France, one from Portugal and one from Morocco. Multilocus enzyme electrophoresis (MEE) were determined for 282 snails at 18 loci. A complete monomorphism was encountered at each geographic site. However, among th…
Sheep and Cattle Reservoirs in the Highest Human Fascioliasis Hyperendemic Area: Experimental Transmission Capacity, Field Epidemiology, and Control …
2020
The Northern Bolivian Altiplano is the human fascioliasis hyperendemic area where the highest prevalences and intensities of infection by Fasciola hepatica in humans have been reported. Four animal species are the reservoir species for F. hepatica in this area, namely, sheep, cattle, pigs, and donkeys. Livestock for the Aymara inhabitants is crucial because vegetable cultures are not viable due to the inhospitality of the very high altitude of 3,820–4,100 m. A One Health initiative has been implemented in this area in recent years, as the first such control action in a human endemic area ever. Among the different control axes included, special focus is devoted to the two main reservoirs she…
Burial dissolution of micrite in Middle East carbonate reservoirs (Jurassic–Cretaceous): keys for recognition and timing.
2006
14 pages; International audience; This paper discusses burial diagenesis and especially a burial dissolution phase and its effects on micrite microtexture in reservoirs in the Middle East. Three microporous reservoirs were selected: the Cenomanian Mishrif Formation in Iraq; the Kimmeridgian–Tithonian Arab D and the Barremian Kharaib Formations, both in Abu Dhabi. Staining, cathodoluminescence and scanning electron microscopy were used for petrographic observations. In the selected reservoirs, three typical micrite microtextures are distinguished: micro-rhombic, compact anhedral, and rounded. The chronology of diagenesis, based on petrographic observations, shows that mineralogical stabilisa…
Driven Brownian particle as a paradigm for a nonequilibrium heat bath: Effective temperature and cyclic work extraction
2017
We apply the concept of a frequency-dependent effective temperature based on the fluctuation-dissipation ratio to a driven Brownian particle in a nonequilibrium steady state. Using this system as a thermostat for a weakly coupled harmonic oscillator, the oscillator thermalizes according to a canonical distribution at the respective effective temperature across the entire frequency spectrum. By turning the oscillator from a passive "thermometer" into a heat engine, we realize the cyclic extraction of work from a single thermal reservoir, which is feasible only due to its nonequilibrium nature.
Dracunculiasis: water-borne anthroponosis vs. food-borne zoonosis.
2019
Abstract Dracunculiasis is the first parasitic disease set for eradication. However, recent events related to the Dracunculus medinensis epidemiology in certain African countries are apparently posing new challenges to its eradication. Two novel facts have emerged: the existence of animal reservoirs (mainly dogs but also cats and baboons), and possibly a new food-borne route of transmission by the ingestion of paratenic (frogs) or transport (fish) hosts. Therefore, instead of being exclusively a water-borne anthroponosis, dracunculiasis would also be a food-borne zoonosis. The existence of a large number of infected dogs, mainly in Chad, and the low number of infected humans, have given ris…
Combination of linear and nonlinear multivariate approaches effectively uncover responses of phytoplankton communities to environmental changes at re…
2022
The response of a community to environmental changes is either linear or non-linear, so that they can be investigated approximately by linear or nonlinear models. At community level, redundancy analysis (RDA) and canonical correspondence analysis (CCA), and Mantel test and Generalized Dissimilarity Modelling (GDM) are two pairs of fundamental multivariate approaches. Thus, it is necessary to determine how they are used for a given group of communities or a metacommunity. In the present study, we explored the applications of the two pairs of commonly used multivariate methods for the analysis of tropical phytoplankton communities. Phytoplankton were collected from 60 tropical reservoirs in s…
The use of zooplankton metrics to determine the trophic status and ecological potential: An approach in a large Mediterranean watershed.
2021
In the European Water Framework Directive, zooplankton was not included as a Biological Quality Element despite its important place in the aquatic trophic web. In the present study on zooplankton abundances and biomasses, we used several metrics to test their ability to detect differences among trophic statuses and ecological potential levels, and collected a large sum of data in more than 60 reservoirs at Ebro watershed, on more than 300 sampling occasions over 10 years. Our results indicate that most zooplankton metrics are correlated to environmental variables that determine reservoirs’ trophic states, especially chlorophyll a and total phosphorus. The metrics with better sensitivity to …
Robust Finite-Time Control of Switched Linear Systems and Application to a Class of Servomechanism Systems
2015
This paper investigates finite-time (FT) stability and stabilization problems for a class of switched linear systems with polytopic uncertainties. Both stable and unstable subsystems are considered to coexist in the system, and a new concept of extended FT stability is proposed as the first attempt. A stability criterion is first established, where the admissible maximum switching number is obtained while ensuring extended FT stability of switched linear systems with time-varying delays under a given maximum ratio between the running time of unstable subsystems and the running time of stable subsystems. Sufficient conditions on the existence of desired memory state-feedback controllers are …
Phytoplankton equilibrium phases during thermal stratification in a deep subtropical reservoir
2008
SUMMARY 1. Equilibrium and non-equilibrium hypotheses have often been used to explain observations in community ecology. Published case studies have demonstrated that steady state phytoplankton assemblages are more likely to occur in deep lakes than in shallow mixed ones. 2. Phytoplankton seasonal succession was studied by weekly sampling in Faxinal Reservoir (S Brazil), a subtropical deep, clear, warm monomictic and slightly eutrophic reservoir. This study demonstrated an alternation of steady and non-steady state phases of phytoplankton assemblages with different dominant species during the steady states. 3. During the studied period, three steady states were identified with different dom…
The promise of spintronics for unconventional computing
2021
Novel computational paradigms may provide the blueprint to help solving the time and energy limitations that we face with our modern computers, and provide solutions to complex problems more efficiently (with reduced time, power consumption and/or less device footprint) than is currently possible with standard approaches. Spintronics offers a promising basis for the development of efficient devices and unconventional operations for at least three main reasons: (i) the low-power requirements of spin-based devices, i.e., requiring no standby power for operation and the possibility to write information with small dynamic energy dissipation, (ii) the strong nonlinearity, time nonlocality, and/o…