Recent studies have shown genotypic variation in sensitivity of leaflet CO2 exchange rate (CER) to cool night temperatures. However, no information is currently available on the relative importance ...of this trait for successful peanut production in a cool, short-season environment. The objectives of this study were to examine the physiological basis of genotype adaptation to a cool, short-season environment and to assess the importance of genotypic differences in sensitivity to low night temperatures in that adaptation. Eight genotypes were grown in the field at Delhi, Ontario in 1991, and six of these eight were grown in 1992. Phenological development was monitored, dry matter (DM) accumulation was determined from destructive samples, and radiation use efficiency (RUE) was calculated from measurements of fractional interception of incident photosynthetically active radiation (PAR). Accumulated degree-days in 1991 (1245 degrees C d from sowing to frost) greatly exceeded those in 1992 (885 degrees C d), despite similar calendar-day duration. Only five genotypes matured in 1991 and two in 1992. The degree-days required to reach key reproductive stages including maturity varied considerably among genotypes and between seasons. Seasonal variation was probably due to effects of low temperatures on continuity of reproductive development and the proportion of total kernels that were mature at harvest. Total DM was reduced by 30 to 50% in 1992, compared with 1991, whereas pod and kernel yields were reduced by 40 to 75 and 38 to 83%, respectively. The lower DM in 1992, and genotypic differences in both seasons, were due primarily to the amount of incident PAR intercepted by canopies (i.e., 520-790 MJ m-2 in 1991 and 360-480 MJ m-2 in 1992). The RUE was 13 to 24% lower during 1992, compared with 1991, with relative genotype RUE generally consistent with CER sensitivity to low night temperature.
This paper presents an approach to the evaluation and validation of mass spectrometry data for construction of an `early warning' diagnostic procedure. We describe implementation of a designed ...experiment and place emphasis on the consistent and correct use of validation based evaluation - which is a key requirement to achieve unbiased assessment of the ability of mass spectrometry data for diagnosis in this setting. Strict adherence to validation as a scientific principle will however typically imply that the analyst must make choices. Like all choices in statistical analysis, validation comes at a cost! We present a detailed and extensive discussion of the issues involved and propose that much greater emphasis and requirement for validation would enter clinical proteomic science.
To answer research questions concerning the course of disease and the optimal treatment of hereditary breast cancer, genetic typing together with the clinical and tumour characteristics of breast ...cancer patients are an important source of information. Part of the incidence of breast cancer can be explained by BRCA1 and BRCA2 germline mutations, which with current techniques can be retrospectively analysed in stored, paraffin-embedded tissue samples. In view of the implications of BRCA1- or BRCA2-carrier status for patients and other family members and the lack of clear legal regulations regarding the procedures to be followed when analysis is performed on historical material and no individual informed consent can be asked from the patients, an appropriate procedure for coding such data or rendering it anonymous is of great importance. By using the coding procedure described in this article, it becomes possible to follow and to work out in greater detail the guidelines of the code for 'Proper secondary use of human tissue' of the Federation of Biomedical Scientific Societies and to use these valuable databases again in the future.
Controlled environment studies have shown that peanut (Arachis hypogaea L.) leaf CO2 exchange rates (CER) are sensitive to night temperatures 20 degrees C and that genotypes vary in their ability to ...acclimate after exposure to continuous cool nights. Our objectives were to investigate the relationship between minimum air temperature (Tmin) and leaflet CER for peanut genotypes grown in the field and to determine the extent of differences between Tmin and minimum canopy temperatures under existing climatic conditions. Eight peanut genotypes were grown in the field at Delhi, Ontario, in 1991 and six genotypes common to the 1991 study were sown in 1992. Leaflet CER was recorded on a number of occasions in both seasons, and canopy temperatures were recorded under both clear and overcast conditions at night during 1992. Variation in leaflet CER between sampling dates was large in 1992 (e.g., 1.5-36.0 micromoles m-2 s-1 for Early Bunch) but small in 1991. Effects of Tmin could account for 73 to 95% of the CER variation in 1992, depending on genotype. Genotypes differed significantly in CER response to Tmin in 1992, with relative tolerance to low Tmin of OAC Ruby OAC Garroy all other genotypes. The cultivar OAC Ruby showed a reduction in CER of approximately 25% when Tmin fell from 20 to 5 degrees C. In contrast, Early Bunch, Chico, VA910212, and OAC Tango did not differ from each other and were relatively sensitive to low Tmin, with CER reduced by approximately 55% for the same reduction in Tmin. After Tmin of 20 degrees C, however, CER of sensitive genotypes was 17% higher than that of OAC Ruby. Canopy minimum temperatures at Delhi were 1 to 3 degrees C cooler than Tmin, primarily due to radiative cooling. Microclimate differences between environments will affect the magnitude of differences between Tmin and Tmin (leaf) and therefore affect the utility of Tmin-CER relationships developed here
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