-Eucalyptus globulus is widely used in productive exotic plantations but the expansion of these plantations is limited by low temperatures, as its cold hardening capacity is limited (0.5 to 3.0 • C). It is not well understood how nursery fertilisation affects the field performance of plants. This led us to study the effect of three mineral nutrients (N, P and K) on both plant quality and frost tolerance. The experiment comprised eight growth treatments in which a high dose (H-) or a low dose (L-) of each nutrient was applied. Nitrogen was the nutrient that determined shoot growth, new root growth after transplanting (root egress), frost tolerance and field performance. Performance was better with treatment H-N than with treatment L-N, leaf nitrogen contents being 1.53 and 0.89% respectively. The effects of phosphorus and potassium were not significant between treatments for any parameter. The exception was P which, when interacting with N, favoured root egress for the H-N treatment. It was concluded that nursery fertilisation offers a management tool for eucalyptus growers concerned with plant stock quality.field performance / frost tolerance / mineral nutrients / non-structural carbohydrates / root egress Résumé -La fertilisation en pépinière affecte la tolérance au froid et la qualité des plants bouturés d'Eucalyptus globulus Labill. Eucalyptus globulus est largement utilisé dans des plantations exotiques productives, mais l'expansion de ces plantations est limitée par les basses températures, étant donné que l'endurcissement potentiel au froid de cette espèce est limité (0,5 à 3,0 • C). On ne comprenait pas bien comment la fertilisation en pépinière pouvait affecter la performance en plantation des plants. Ceci nous a amené à étudier l'effet de trois nutriments minéraux (N, P et K) sur la qualité des plants et la résistance au froid. L'expérimentation a comporté huit traitements pour l'étude de la croissance pour lesquels une forte dose (H-) ou une faible dose (L-) de chaque nutriment a été apportée. L'azote a été le nutriment qui a déterminé la croissance de la pousse, la croissance de nouvelles racines après transplantation (émission de racines), la résistance au froid et la performance en plantation. Les performances étaient meilleures avec le traitement H-N que avec le traitement L-N, la teneur en azote des feuilles atteignant respectivement 1,53 et 0,89 %. Les effets du phosphore et du potassium n'ont été significatifs pour aucun des paramètres. L'exception a concerné le phosphore qui lorsqu'il était en interaction avec l'azote a favorisé l'émission de racines dans le traitement H-N. On conclut de cette étude que la fertilisation en pépinière offre un outil de gestion pour les producteurs d'eucalyptus confrontés au problème de la qualité des plants.performance en plantation / tolérance au froid / nutriments minéraux / hydrates de carbones non structuraux / émission de racines

Changes in sap pH seemed to be a response to changes in atmospheric conditions rather than soil water in the species. Stomata closed after a considerable amount of hydraulic conductance was lost, although intraspecific differences in leaf-specific hydraulic conductance suggest the possibility of selection for improved productivity under water-limiting conditions combined with high temperatures in the early stages of growth.

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Public transportation systems in many cities of Latin America must employ physical architectures of intelligent transportation systems for the operation and control of passenger transportation vehicles. However, the high cost of specialized computational systems for this physical architectures in one of the higher impediments to the integration of this systems in the vehicle network. For the purpose of this work, is necessary to ask what are the currently low-cost computational systems used in vehicular applications. In this paper we made a documentary research to analyse the current computational systems associated with the physical architecture for public transportation in intermediate cities. We analysed collected information following the three points of methodological development for a documentary researches. Results shows that the use of low-cost computational systems for data capture in vehicles, the use of millimetre waves in the electromagnetic spectrum for data transmission by means of mobile communication networks, and the adoption of international standards, are viable alternatives for the integration of technologies into physical architectures of vehicle networks, in order to improve the operation of public passenger transportation systems in intermediate cities in Latin America.

The effect of initial planting density on the growth and wood density of Eucalyptus globulus was examined in a trial established in the southeast of Buenos Aires Province, Argentina. A modified Nelder design was used to generate 9 planting densities ranging from 582 to 2.083 trees/ha. The effect of planting density on diameter at breast height, total tree height, basal area, relative bark thickness and wood density was studied over a 10-year period. By reducing the initial density of planting to 761 trees/ha, an increase on individual tree growth was observed, principally on diameter and to a lesser extent on tree height. However, basal area (m2/ha) was greatest at intermediate densities. Initial planting density affected wood basic density at 6 years of age but not relative bark thickness. In conclusion, 1,095 trees/ha was found to be the best initial density to optimize individual and stand growth.