Search results for "Tipa"
showing 10 items of 596 documents
Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles
2009
[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…
Precision measurement of the mass difference between light nuclei and anti-nuclei
2015
The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons and anti-deuterons, and $^{3}{\rm He}$ and $^3\overline{\rm He}…
Melatonin levels in Parkinson's disease: Drug therapy versus electrical stimulation of the internal globus pallidus
1997
The objective of our work was to measure plasma melatonin levels in patients with Parkinson's Disease (PD) following electrical stimulation of the internal globus pallidus (GPi), and to compare these levels with groups of PD patients under drug therapy and healthy controls. The levels of melatonin were measured twice daily at 1000 and 1200. The GPi stimulation at 130 Hz lowered melatonin levels, while no changes were observed in the absence of stimulation. The melatonin levels from healthy subjects were lower than those observed in PD patients. The melatonin levels from PD patients under drug therapy were also measured during the night (2000-2400-0400) and at 0800 in order to observe their …
Salmon lice in the Pacific Ocean show evidence of evolved resistance to parasiticide treatment
2022
AbstractParasitic salmon lice (Lepeophtheirus salmonis) threaten the economic and ecological sustainability of salmon farming, and their evolved resistance to treatment with emamectin benzoate (EMB) has been a major problem for salmon farming in the Atlantic Ocean. In contrast, the Pacific Ocean, where wild salmon are far more abundant, has not seen widespread evolution of EMB-resistant lice. Here, we use EMB bioassays and counts of lice on farms from the Broughton Archipelago, Canada—a core region of salmon farming in the Pacific—to show that EMB sensitivity has dramatically decreased since 2010, concurrent with marked decrease in the field efficacy of EMB treatments. Notably, these bioass…
Memory for time intervals is impaired in left hemi-Parkinson patients.
2004
The basal ganglia have been proposed as one of the neural correlates of timekeeping functions. Both encoding and memory retrieval components for time perception are impaired in Parkinson's disease (PD). The aim of our study was to investigate in hemi-Parkinsonian patients the existence of a specific alteration in memory for time depending on the affected side, to better understand the contribution of the left or right basal ganglia circuits in different components of time perception. Right and left hemi-PD patients performed a time reproduction task in which they were required to reproduce in the same session short (5 s) and long (15 s) time intervals, in off- and on-therapy condition. Whil…
Estudio epidemiológico de las parasitosis intestinales en población infantil del departamento de Managua (Nicaragua)
2012
La presente tesis doctoral se enmarca en un macroproyecto que tiene por objeto conocer el estado coproparasitologico, y su correlación con diferentes factores intrínsecos y estrínsecos, de la población infantil nicaragüense. En esta primera contribución se estudia un total de 1936 sujetos (914 niños y 1022 niñas) de edades comprendidas entre 0 y 15 años del Departamento de Managua (Nicaragua), procedentes de diferentes escuelas y barrios, diferenciando la población objeto de estudio según su procedencia (zonas urbanas centro y periférica y zona rural). El estudio coproparasitológico sobre una muestra fecal por sujeto ha permitido detectar un espectro parasitario constituido por 20 especies …
Muistisairaan ihmisen kokemukset teknologiasta osana arkea - turvaa vai tunkeilevuutta
2018
Tässä tutkimuksessa selvitettiin muistisairaiden ihmisten arkea tukevan teknologian käyttöönottoa ja heidän sekä heidän läheistensä kokemuksia teknologian käytöstä. Tutkimuksen viitekehyksenä toimi Lawtonin ekologinen malli. Tutkimuksessa käytettiin etnografista näkökulmaa haastattelemalla ja havainnoimalla muistisairaita ihmisiä teknologian käyttötilanteissa. Ensimmäinen vaihe toteutettiin vuosina 2004-2007. Ensimmäisessä vaiheessa kohderyhmänä olivat 25 muistisairautta sairastavaa kotona yksin tai omaishoitajansa kanssa asuvaa henkilöä sekä heidän läheistään ja viisi vastaajaa kuntien kotihoidosta. Koteihin vietiin yhteensä 29 erilaista laitetta. Toinen keruuvaihe toteutettiin vuosina 201…
FLUMO: FLexible Underwater MOdem
2019
The last years have seen a growing interest in underwater acoustic communications because of its applications in marine research, oceanography, marine commercial operations, the offshore oil industry and defense. High-speed communication in the underwater acoustic channel has been challenging because of limited bandwidth, extended multipath, refractive properties of the medium, severe fading, rapid time variation and large Doppler shifts. In this paper, we show an implementation of a flexible Software-Defined Acoustic (SDA) underwater modem, where modulation parameters are completely tunable to optimize performance. In particular, we develop the system architecture following two key ideas. …
A Synopsis of the Genus Stipa (Poaceae) in Middle Asia, Including a Key to Species Identification, an Annotated Checklist, and Phytogeographic Analys…
2020
The genus Stipa L. comprises over 150 species, all native to the Old World, where they grow in warm temperate regions throughout Europe, Asia, and North Africa. It is one of the largest genera in the family Poaceae in Middle Asia, where one of its diversity hotspots is located. However, identification of Middle Asian Stipa species is difficult because of the lack of new, comprehensive taxonomic studies including all of the species recorded in the region. We present a critical review of the Mid-Asian representatives of Stipa, together with an identification key and taxonomic listing. We relied on both published and unpublished information for the taxa involved, many of which are poorly known…
Multiparameter quantum critical metrology
2022
Single parameter estimation is known to benefit from extreme sensitivity to parameter changes in quantum critical systems. However, the simultaneous estimation of multiple parameters is generally limited due to the incompatibility arising from the quantum nature of the underlying system. A key question is whether quantum criticality may also play a positive role in reducing the incompatibility in the simultaneous estimation of multiple parameters. We argue that this is generally the case and verify this prediction in paradigmatic quantum many-body systems close to first and second order phase transitions. The antiferromagnetic and ferromagnetic 1-D Ising chain with both transverse and longi…