Occurrence of viruses and Xiphinema spp. in vineyards of the greek islands of Paros and Lemnos

A survey was carried out during 1997–2000 in order to determine the incidence of grapevine viruses and their associated nematode-vectors in Paros and Lemnos, the two main islands of the Aegean sea producing V.Q.P.R.D. wines. Nine viruses, Grapevine fanleaf nepovirus (GFLV), Grapevine leafroll associated closterovirus (GLRaV) 1, 2, 3, 6 and 7, Grapevine vitivirus (GV) A and B, Grapevine fleck virus (GFkV) and three species of Xiphinema, X. index, X. italiae and X. pachtaicum, were recorded. While the three nematode species occurred in both islands, the virological problems of each island were different. In Paros, GFLV and its vector X. index were widespread in selfrooted vineyards, while GVA also occurred in asymptomatic vines. In Lemnos, where vineyards use American rootstocks, the Closteroviruses and GVA were the major problem, explaining the high incidence of leafroll and stem grooving

Energy study of a medieval tower, restored as a museum

Museums are buildings of particular significance due to their function and their status. At the same time they are buildings in which the principles of energy conservation are rarely applied, sometimes without reason. It has been decided by the Hellenic Ministry of Culture to convert a medieval tower, built in the year 1344 as a fortress with 0.8-1.5m thick walls and almost no windows, into a museum. The present paper discusses the difficulties that arise in the attempt to balance between the indoor climate conditions necessary to protect the exhibits and to provide comfortable conditions to the visitors, whilst respecting the aesthetics and the historical significance of the building. Furthermore, one needs to consider the difficult but necessary task of assessing factors such as the building's shell's thermal conductivity and capacity, the ventilation necessary as well as the indoor air movement, in order to determine the cooling loads. Finally, the challenge lies in designing and dimensioning an effective and efficient HVAC system, which should be as discrete as possible. The present paper aims to present the results of the study, to discuss the expected energy behaviour of the building and to comment on the options for introducing energy conservation techniques. © 2003 Elsevier Science B.V. All rights reserved

Production of RNA and artificial top component from parsley carrot leaf virus heated in vitro

The extinction temperature profile of parsley carrot leaf virus in 0.02 M (Na K) phosphate buffer, pH 7.2, containing 0.1 M NaCl, was determined. At the Td (dissociation temperature = 65°C), the point at which E260 begins to increase, the virus particles apparently dissociate to form RNA and empty protein shells (top component). At the Tf (temperature at the inflexion point of the curve = 70°C), corresponding to half the maximum increase in E260, the protein denatures and precipitates. Temperatures below Td have little effect on the virus, whereas temperatures higher than Tf also degrade the RNA. The results of the present work seem to suggest that the increase in E260 of PCLV preparations upon heating is mostly attributable to turbidity caused by coat protein denaturation rather than to effects on RNA