A Mössbauer study on solid krypton precipitates in aluminium

Mossbauer spectroscopy on the 9.40 keV transition Kr-83 is used to obtain information about solid Kr precipitates in Al. Three different (RbI)-Rb-83 sources differing in water content were used, which, when measured against a solid Kr absorber, show a quadrupole component in addition to a dominating single line. An analytical deconvolution technique is presented which takes care of the source characteristics. The spectra of Kr bubbles in Al obtained by high-dose implantation show two components: a single line from Kr atoms inside the bubble and a quadrupole split component from Kr at the Kr-Al interface. Spectra were taken as a function of temperature. The total absorption area could be fitted very well assuming a simple Debye model, yielding a Debye temperature of THETA(D)T = 101 (2) K. A decomposition of the total area in the areas of quadrupole and single-line components yields Debye temperatures of THETA(D)Q = 98(6) K and THETA(D)S = 90(10) K respectively

Safety and cost-effectiveness of shortening hospital follow-up after breast cancer treatment

BACKGROUND: In the Netherlands, the first 5 years of follow-up after treatment for breast cancer are carried out in hospital with yearly mammography. After this, for patients aged over 60 years who have undergone mastectomy, there is a shift of care to the National Screening Programme (NSP) for mammography every 2 years. After breast-conserving therapy follow-up is perfomed by the general practitioner (GP), with mammography every second year and physical examination annually. The aim of this study was to evaluate the clinical effects and costs of four different strategies for follow-up after breast cancer treatment. METHODS: An extended and validated simulation model for breast cancer follow-up was used. The current guidelines for follow-up (baseline strategy) and three less intensive follow-up strategies were evaluated. The main outcome measure was the detection rate of small tumours (2 cm or smaller) and associated costs for each strategy. RESULTS: Shortening the follow-up time in hospital by shifting care to the NSP or GP after 2 years instead of 5 years of hospital follow-up, lowering the age of referral to the NSP or GP from 60 to 50 years, and termination of annual physical examination by the GP after hospital follow-up did not decrease the detection of small tumours. In addition, a substantial decrease in costs was observed with simplified follow-up. CONCLUSION: Decreasing hospital follow-up time, lowering the age of referral to the NSP or GP, and termination of annual physical examinations would lead to a substantial reduction in costs while maintaining the possibility of detecting small breast cancers. Copyright (c) 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd

Ecology and biogeography of plant communities associated with the post Plio-Pleistocene relict Rhododendron ponticum subsp. baeticum in southern Spain

17 pages, 5 figures, 5 tables, 79 references.Aims Rhododendron ponticum L. is reputed to be a post Plio-Pleistocene relict plant species with a disjunct distribution that comprises the Iberian Peninsula to the west and the Euxinian region plus some restricted Mediterranean areas to the east. We analysed the ecological range (of subsp. baeticum) in the western area (Aljibe Mountains, north of the Strait of Gibraltar) to understand the factors determining the present area limitation. Location Sierra del Aljibe, north of the Strait of Gibraltar (Iberian Peninsula). Methods We selected 20 riparian sites where R. ponticum is common, and compiled data on the ecological diversity of associated woody species and ferns. We established a 500-m main transect in each site, along the stream or river course, in which we placed five 20-m-long plots at regular intervals. We recorded physiographic habitat features, woody plants and fern abundance, and the number of R. ponticum individuals. Results Rhododendron ponticum in southern Spain is restricted to riparian forests in acidic soils (pH 4.0–6.4), and is mainly found on the banks of inclined and enclosed streams. In our inventory we recorded 59 woody taxa and 12 ferns, with R. ponticum being the dominant species of the understorey (mean abundance 78.6%). The communities are characterized by a high incidence of the humid warm temperate element, both in number of species (18.8 ± 3.7 per site) and abundance; meanwhile, the presence of the modern Mediterranean element (mean number of species 3.4 ± 3.8 per site) appears to be favoured by disturbance. These ecological–historical groups of taxa also show distinct patterns of typological habit, frequency of endemism, infrageneric diversity and geographical range. Populations of R. ponticum are characterized by a very variable density of seedlings in many sites, and the virtual lack of juveniles. Main conclusions Riparian forests of the Aljibe Mountains constitute a refuge for R. ponticum where the species persists, but populations appear to be in decline. The narrow ecological range of R. ponticum in the area strongly contrasts with its wide amplitude in the eastern natural area, mainly the Euxinian region, where R. ponticum probably finds better conditions due to the environmental heterogeneity of the region, and the lack of a hot dry season.Financial support provided by DGICYT-DGESIC grants PB91-0894 and PB95-1144, FED- ER-CICYT grant 1FD97-0743-CO3-03, and GIASA I & II research contracts as a part of environmental compensating tasks for construction of the A-381 highway.Peer reviewe