The Contribution of Imperfections in Nursery Stock to the Decline of Young Vines in California

‘Petri disease’, as defined at the 2nd International Workshop on Grapevine Trunk Diseases (Esca and Grapevine Declines, September 14–15 2001, Lisbon, Portugal), is a condition associated worldwide with the decline of young vines contaminated by Phaeoacremonium and/or Phaeomoniella pathogens. Vines exhibit stunted development with vascular tissues characteristically exuding darkened gums when sectioned transversally. ‘Young Vine Decline’ (YVD), historically including the condition now known as Petri disease, is a term still used widely in California to describe unexpectedly poor performance of young vines exhibiting symptoms that include those associated with Petri disease. Examination of more than eight hundred thousand dormant nursery vines as well as new and established declining vineyards demonstrated that nursery stock defects and mechanical and biotic vineyard stresses were frequently associated with YVD in California. Rootstock shaft lesions and weak roots were most commonly associated with YVD in very young vineyards, while root system contamination by nematodes and fungal pathogens was frequently associated with YVD in older vineyards

Extragalactic Relativistic Jets and Nuclear Regions in Galaxies

Past years have brought an increasingly wider recognition of the ubiquity of relativistic outflows (jets) in galactic nuclei, which has turned jets into an effective tool for investigating the physics of nuclear regions in galaxies. A brief summary is given here of recent results from studies of jets and nuclear regions in several active galaxies with prominent outflows.Comment: 5 pages; contribution to ESO Astrophysical Symposia, "Relativistic Astrophysics and Cosmology", eds. B. Aschenbach, V. Burwitz, G. Hasinger, B. Leibundgut (Springer: Heidelberg 2006

Efficient loading of a He* magneto-optic trap using a liquid He cooled source

We report loading large numbers (up to 3×10⁹) of metastable triplet helium atoms into a magneto-optical trap using an atomic beam derived from a liquid He (LHe) cooled dc discharge source. Moreover, we compare the effect of liquidN₂ cooling to LHe cooling the source and demonstrate that LHe cooling offers a significant increase in performance

Bose-Einstein condensation of metastable helium: some experimental aspects

We describe our recent realization of BEC using metastable helium. All detection is done with a micruchannel plate which detects the metastables or ions coming from the trapped atom cloud. This discussion emphasizes some of the diagnostic experiments which were necessary to quantitatively analyse our results.Comment: 5 pages, 3 figure