High‐Throughput Near‐Infrared Reflectance Spectroscopy for Predicting Quantitative and Qualitative Composition Phenotypes of Individual Maize Kernels

Near‐infrared reflectance (NIR) spectroscopy can be used for fast and reliable prediction of organic compounds in complex biological samples. We used a recently developed NIR spectroscopy instrument to predict starch, protein, oil, and weight of individual maize (Zea mays) seeds. The starch, protein, and oil calibrations have reliability equal or better to bulk grain NIR analyzers. We also show that the instrument can differentiate quantitative and qualitative seed composition mutants from normal siblings without a specific calibration for the constituent affected. The analyzer does not require a specific kernel orientation to predict composition or to differentiate mutants. The instrument collects a seed weight and a spectrum in 4–6 sec and can collect NIR data alone at a 20‐fold faster rate. The spectra are acquired while the kernel falls through a glass tube illuminated with broad spectrum light. These results show significant improvements over prior single‐kernel NIR systems, making this instrument a practical tool to collect quantitative seed phenotypes at high throughput. This technology has multiple applications for studying the genetic and physiological influences on seed traits.     

Seroprevalence of anaplasmosis among cattle in Switzerland in 1998 and 2003: no evidence of an emerging disease

Anaplasma marginale infection in Europe has been limited to the Mediterranean and eastern countries, to Austria and to very sporadic cases in Switzerland. There are no reports of its occurrence in the countries north of Switzerland. A severe outbreak of anaplasmosis in August 2002 in a cattle farm in the canton Grisons, Switzerland, north of the Alps, with more than 300 cattle that had to be culled, came unexpected and gave reason to hypothesize presence of an increased yet undetected prevalence of A. marginale in Switzerland. Randomly selected bovine serum samples collected in 1998 and 2003 were tested using a competitive inhibitory ELISA (cELISA) to test the hypothesis. Our validation of the diagnostic sensitivity and specificity of this test, done in the outbreak herd, yielded 99.2 and 83.3%, respectively, probably underestimating the true specificity. The true seroprevalence of anaplasmosis in Swiss cattle determined by cELISA was likely to be zero with upper 95% confidence limits of 2.49% in the canton Grisons and 1.17% in the rest of Switzerland, respectively, in 1998. For 2003, these estimates were even lower. There was no significant difference in apparent prevalences between 1998 and 2003. In search of a possible reservoir, three chamoises out of 46 free ranging wild ruminants from the Swiss National Park, Grisons, tested positive in the cELISA. This reaction is in accordance with A. marginale or a cross reacting agent such as Anaplasma ovis. From our results we conclude that the hypothesis of an increased prevalence of anaplasmosis in cattle in Switzerland must be rejected.     

Genetic relationships and evolution in Cucurbita as viewed with simple sequence repeat polymorphisms: the centrality of C. okeechobeensis

Genetic relationships among 88 accessions from nine of the dozen species of Cucurbita (Cucurbitaceae) were assessed from polymorphisms at 74 SSR (simple sequence repeat) loci originating from C. pepo and C. moschata, yielding a total of 315 alleles distributed among 17 linkage groups, with an average of 4.3 alleles per locus. Genetic distance (GD) values were calculated, a principal coordinate analysis conducted, and a dendrogram constructed. Average within-species genetic distance values ranged from 0.07 for C. ecuadorensis and C. ficifolia to 0.46 for C. pepo. Each species was clearly defined, as all mean within-species GD values were lower than the respective mean between-species GD values. C. okeechobeensis had the most central position in the genus Cucurbita, with the lowest average GD to the other species, 0.61. C. foetidissima, the only xerophytic species examined, was the most distant, with a mean GD of 0.73 to the other species. C. pepo and C. ficifolia were the most outlying of the mesophytic species. Mean across-species GDs generally corresponded with crossability. However, there were some outstandingly low GD values between particular accessions of Cucurbita pepo, the economically most important species, and disease-resistant wild species, particularly C. okeechobeensis but also C. foetidissima. The results suggest that more intensive search and collection of C. okeechobeensis populations would likely yield genotypes that are more compatible with C. pepo. Moreover, successful application of genetic resources in the genus Cucurbita might be facilitated by using GD values obtained from SSR polymorphisms as a guide in choosing parents for interspecific crossing.     

Development of a monitoring program for antibiotic resistance in bacteria from Swiss food-producing animals

Resistant bacteria from food-producing animals may compromise the success of antibiotic treatment in animals and in humans. Therefore, the level of antibiotic resistance in bacteria from farm animals and its development over time needs to be monitored. In Switzerland, a monitoring program for antibiotic resistance is currently being developed. Pilot-monitoring programs were conducted in selected animal species in order to obtain current data on antibiotic resistance. The data on the prevalence of bacteria and antibiotic resistance in poultry were used to optimize the sampling plan. The influence of sampling more farms compared to sampling more animals per farm on the prevalence estimate for antibiotic resistance was analyzed by a Monte Carlo simulation model. Accounting for the costs for sample collection, transportation and laboratory analysis of the samples, the number of samples to be taken at the respective step in the production line was optimized. Optimization was defined as maximizing the precision of the prevalence estimate while minimizing the costs. The model will be expanded to other bacterial and animal species in the future.     

Alcohol and dietary fibre intakes affect circulating sex hormones among premenopausal women

BACKGROUND: The association of alcohol and fibre intake with breast cancer may be mediated by circulating sex hormone levels, which are predictors of breast cancer risk. OBJECTIVE: To evaluate the relationship of alcohol and dietary fibre intake with circulating sex hormone levels among premenopausal women. METHODS: A total of 205 premenopausal women completed a validated food-frequency questionnaire at baseline and after 2 years; blood samples taken at the same time were analysed for circulating sex hormone concentrations, including oestrone (E1), oestradiol (E2), free E2, progesterone, androstenedione and sex hormone-binding globulin, by radioimmunoassay. We used mixed models to estimate least-square means of sex hormone concentrations for alcohol intake categories and quartiles of dietary intake. RESULTS: After adjustment for covariates, alcohol consumption was moderately associated with higher circulating oestrogen levels; those who consumed more than one drink per day had 20% higher E2 (Ptrend=0.07) levels than non-drinkers. In contrast, higher dietary fibre intake was associated with lower serum levels of androstenedione (-8% between the lowest and highest quartiles of intake, Ptrend=0.06), but not oestrogens. Similarly, consumption of fruits (-12%, Ptrend=0.03), vegetables (-9%, Ptrend=0.15) and whole grains (-7%, Ptrend=0.07) showed inverse associations with androstenedione levels. CONCLUSIONS: The consistency of the observed differences in sex hormone levels associated with alcohol and fibre-rich foods indicates that these nutritional factors may affect sex hormone concentrations and play a role in breast cancer aetiology and prevention.