Two different R gene loci co-evolved with Avr2 of Phytophthora infestans and confer distinct resistance specificities in potato.

Late blight, caused by the oomycete pathogen Phytophthora infestans, is the most devastating disease in potato. For sustainable management of this economically important disease, resistance breeding relies on the availability of resistance (R) genes. Such R genes against P. infestans have evolved in wild tuber-bearing Solanum species from North, Central and South America, upon co-evolution with cognate avirulence (Avr) genes. Here, we report how effectoromics screens with Avr2 of P. infestans revealed defense responses in diverse Solanum species that are native to Mexico and Peru. We found that the response to AVR2 in the Mexican Solanum species is mediated by R genes of the R2 family that resides on a major late blight locus on chromosome IV. In contrast, the response to AVR2 in Peruvian Solanum species is mediated by Rpi-mcq1, which resides on chromosome IX and does not belong to the R2 family. The data indicate that AVR2 recognition has evolved independently on two genetic loci in Mexican and Peruvian Solanum species, respectively. Detached leaf tests on potato cultivar 'Désirée' transformed with R genes from either the R2 or the Rpi-mcq1 locus revealed an overlapping, but distinct resistance profile to a panel of 18 diverse P. infestans isolates. The achieved insights in the molecular R - Avr gene interaction can lead to more educated exploitation of R genes and maximize the potential of generating more broad-spectrum, and potentially more durable control of the late blight disease in potato.

Effects of dynamic sitting interventions on tissue oxygenation in individuals with spinal cord disorders.

STUDY DESIGN: An explorative cross-sectional study. OBJECTIVES: The objective of this study was to investigate the possibility of imposing dynamic sitting behavior on individuals with spinal cord disorders by using the Dynasit chair and to investigate its effect on the (sub-)cutaneous tissue oxygenation. SETTING: Rehabilitation Centre het Roessingh, Enschede, the Netherlands. SUBJECTS: Ten male subjects with a spinal cord disorder. METHODS: The Dynasit chair, an experimental simulator chair, containing mechanical concepts for postural adjustments, regulation of tuberal load and pelvic rotation, was developed to allow individuals with a spinal cord disorder to sit in a dynamic way. An experiment was carried out in which a dynamic sitting pattern was imposed. The sitting pattern consisted of series of actuated changes in posture, tuberal load and pelvic orientation. Effects of these changes on (sub-)cutaneous buttock tissue oxygenation were investigated by transcutaneous measurement of tissue oxygenation. RESULTS: Nonparametric statistical analyses were carried out on nine subjects that completed the study. Results showed significant positive effects (P<0.05) of actuated changes in tuberal load on the cutaneous and subcutaneous tissue oxygenation. CONCLUSION: The Dynasit chair is effective in imposing dynamic sitting behavior in individuals with a spinal cord disorder and consequently might reduce the chance of tissue degradation.

Lower limb amputation. Part 2: Rehabilitation--a 10 year literature review.

Ten years after the ISPO consensus conference on amputation surgery, a search of relevant publications in the Rehabilitation-prosthetics-literature over the years 1990-2000 was performed. The main key-words in this research were: "lower limb, amputation, human and rehabilitation". One hundred and four (104) articles were assessed by reading and from these the authors selected 24 articles. These articles are summarised, under several subheadings in this review article, focussing especially on quality of life, functional outcome and predictive factors.