On the scaling of the damping time for resonantly damped oscillations in coronal loops

There is not as yet full agreement on the mechanism that causes the rapid damping of the oscillations observed by TRACE in coronal loops. It has been suggested that the variation of the observed values of the damping time as function of the corresponding observed values of the period contains information on the possible damping mechanism. The aim of this Letter is to show that, for resonant absorption, this is definitely not the case unless detailed a priori information on the individual loops is available

Del manuscrito al primitivo impreso: la labor editora de Francesc Argilagues (fl. Ca. 1470-1508) en el Renacimiento médico italiano

Se presenta a un protagonista destacado del proceso de transición del manuscrito médico al primitivo impreso (aunque practicamente desconocido). Se trata de Francesc Argilagues (fl. C. 1470-1508), médico valenciano que tras cursar sus estudios en Italia, se estableció profesionalmente allí, donde fue uno de los más tempranos editores de obras médicas para la imprenta, entre ellas dos de primer orden en la medicina universitaria bajomedieval y renacentista: Conciliator differentiarum philosophorum et praecipue medicorum de Pietro d'Abano (en 1483, 1490 y 1496). Se aborda la personalidad y la obra de Francesc Argilagues a partir de diferentes fuentes básicas de información. Dado el indudable interés de los prólogos y de la nota introductoria que dirigió a los lectores de las dos obras por el editadas, se ofrece tambien su edición y traducción castellanaPeer reviewe

Survival of two strains of Phthorimaea operculella (Lepidoptera: Gelechiidae) reared on transgenic potatoes expressing a Bacillus thuringiensis crystal protein

[Otros] Survie de deux souches de Phthorimaea operculella (Lepidoptera : Gelechiidae) élevées sur des pommes de terre transgéniques exprimant la protéine CrylAb de Bacillus thuringiensis. Deux populations de Phthorimaea operculella (Zeller), l'une supposée résistante au DipelTM (une préparation commerciale de delta-endotoxines de Bacillus thuringiensis) et l'autre sensible, ont été cultivées sur quatre cultivars de pomme de terre, deux transgéniques de première génération, exprimant la protéine CrylAb de Bacillus thuringiensis, et deux non transformés. La population de papillons considérée comme résistante a présenté une mortalité inférieure à celle de l'autre population, mais n'était pas vraiment résistante à CrylAb. Les pommes de terre transgéniques étaient en partie protégées d'une attaque de l'insecte. La survie au stade adulte des deux souches de Phthorimaea élevées sur les plantes transgéniques était au moins deux fois inférieure à celle constatée sur les plantes non transformées. Il en résulte que les pommes de terre exprimant le gène cry1Ab sont partiellement protégées des attaques du papillon. (© Inra/Elsevier, Paris.)[EN] Two populations of Phthorimaea operculella (Zeller), one of them presumed to be resistant to Dipel (a commercial preparation of Bacillus thuringiensis delta-endotoxins), and the other susceptible, were grown on four cultivars of potatoes, two of them a first generation of transgenic plants, expressing the Bacillus thuringiensis Cry1Ab delta endotoxin protein, and the other two untransformed. The moth population which was reported to be resistant, proved to have less mortality than the susceptible one, but it was not really resistant to Cry1Ab. The transgenic potatoes were partially protected against the attack of the moth. The adult survival of the two strains of Phthorimaea operculella reared on transgenic potatoes was less than half their survival on untransformed potatoes, so that Cry1Ab expressing potato tubers proved to protect partially against attack of the moth. ((C) Inra/Elsevier, Paris.).We thank Juan Ferre for helpful discussion and suggestions. We thank also Eric Bonnel, from Germicopa (France), who provided us the two transgenic and one of the untransformed tubers; Marnix Peferoen, from Plant Genetic System, who provided ust he two populations of Phthorimaea operculella. This research was funded by the European Comunity through AGRE 0003(GDF).Rico Inglada, E.; Ballester, V.; Ménsua, JL. (1998). Survival of two strains of Phthorimaea operculella (Lepidoptera: Gelechiidae) reared on transgenic potatoes expressing a Bacillus thuringiensis crystal protein. Agronomie. 18(2):151-155. https://doi.org/10.1051/agro:19980205S15115518

Magnetic Rossby waves in the solar tachocline and Rieger-type periodicities

Apart from the 11-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive and enigmatic character, since it usually appears only near the maxima of solar cycles, and seems to be related with a periodic emergence of strong magnetic flux at the solar surface. Therefore, it is probably connected with the tachocline, a thin layer located near the base of the solar convection zone, where strong dynamo magnetic field is stored. We study the dynamics of Rossby waves in the tachocline in the presence of a toroidal magnetic field and latitudinal differential rotation. Our analysis shows that the magnetic Rossby waves are generally unstable and that the growth rates are sensitive to the magnetic field strength and to the latitudinal differential rotation parameters. Variation of the differential rotation and the magnetic field strength throughout the solar cycle enhance the growth rate of a particular harmonic in the upper part of the tachocline around the maximum of the solar cycle. This harmonic is symmetric with respect to the equator and has a period of 155-160 days. A rapid increase of the wave amplitude could give place to a magnetic flux emergence leading to observed periodicities in solar activity indicators related with magnetic flux.Comment: 34 pages, 5 figures, accepted in Ap

La salud ambiental a través de los indicadores relacionados en la Salud para Todos en el año 2000

[email protected] [email protected]

Detection of a Tristeza-Seedling Yellows Strain in Spain

In late 1984, some growers were found to be using budwood of a very early maturing satsuma mandarin of uncertain origin, for topworking citrus orchards near Valencia. Indexing of this material showed that it was infected with a very severe strain of citrus tristeza virus (CTV). It induced severe stunting, stem pitting, vein clearing and vein corking in Mexican lime and C. macrophylla; conspicuous stunting and seedling-yellows on Eureka lemon and Duncan grapefruit and stem pitting on sweet orange, grapefruit arid rough lemon. None of the common CTV strains previously studied in Spain induces these severe symptoms. There is some evidence indicating that the original satsuma was illegally introduced from Japan. A program has been established for the eradication of this CTV strain

La obra de Andrés Alcázar sobre la trepanación

Entre las muchas y valiosas contribuciones originales que los cirujanos españoles del Renacimiento aportaron a la técnica y al saber quirúrgicos de su tiempo, ocupa un lugar destacado la obra sobre cirugía craneal de Andrés Alcázar. El siglo XVI es en este terreno un momento crucial en el que se asume la tradición anterior, se la depura y se la enriquece con multitud de novedades. Uno de los escritos en los que culmina tal esfuerzo es el primero de los Seis Libros dé Cirugía que Alcázar, entonces ya venerable titular de la cátedra quirúrgica de la Universidad de Salamanca, publicó en dicha ciudad el año 1575. Para dar noticia de la importancia de su labor es necesario primero que tengamos en cuenta la tradición anterior sobre la materia, así corno las grandes líneas de la forma en la que los cirujanos renacentistas se enfrentaron con ella.// Entre les moltes i valuoses contribucions originals que els cirurgians espanyols del Renaixement van aportar a la tècnica i saber quirúrgics del seu temps, ocupa un lloc destacat l'obra sobre cirurgia cranial d'Andrés Alcázar. El segle XVI és en aquest terreny un moment crucial on s'assumeix la tradició anterior, se la depura i se l'enriqueix amb multitud de novetats. Un dels escrits en què culmina aquest esforç és el primer dels Sis Llibres de Cirurgia que Alcázar, llavors ja venerable titular de la càtedra quirúrgica de la Universitat de Salamanca, va publicar en aquesta ciutat l'any 1575. Per donar notícia de la importància de la seua tasca cal primer que tinguem en compte la tradició anterior sobre la matèria, així com les grans línies de la manera com els cirurgians renaixentistes es van enfrontar amb ella

Damping of Fast Magnetohydrodynamic Oscillations in Quiescent Filament Threads

High-resolution observations provide evidence about the existence of small-amplitude transverse oscillations in solar filament fine structures. These oscillations are believed to represent fast magnetohydrodynamic (MHD) waves and the disturbances are seen to be damped in short timescales of the order of 1 to 4 periods. In this Letter we propose that, due to the highly inhomogeneous nature of the filament plasma at the fine structure spatial scale, the phenomenon of resonant absorption is likely to operate in the temporal attenuation of fast MHD oscillations. By considering transverse inhomogeneity in a straight flux tube model we find that, for density inhomogeneities typical of filament threads, the decay times are of a few oscillatory periods only.Comment: 11 pages, 2 figures, ApJL accepte

The Citrus Quarantine Station in Spain

A Citrus Quarantine Station has been recently established in Spain. It is based in a tissue culture procedure developed for safe budwood introduction, consisting of the following steps: a) preliminary budwood inspection; b) budwood disinfestation; c) budwood culture in vitro at 32 C for flushing; d) disinfestation of flushes obtained; e) isolation of 0.1-0.2 mm long shoot tips; f) grafting shoot tips in vitro; g) transplanting micrografted plants to a quarantine greenhouse; h) indexing of micrografted plants; i) release of budwood. Any abnormal or contaminated tissue or plant found during the process and all introduced plant material except the shoot tips are destroyed. Pests, fungi, bacteria and even virus and virus-like diseases introduced with the original material can be easily eliminated by this procedure. The estimated time from budwood introduction until budwood release is 24-30 months, including 18-24 months for xyloporosis indexing