Effects of straw and silicon soil amendments on some foliar and stem-base diseases in pot-grown winter wheat

Four foliar and two stem-base pathogens were inoculated onto wheat plants grown in different substrates in pot experiments. Soils from four different UK locations were each treated in three ways: (i) straw incorporated in the field at 10 t ha−1 several months previously; (ii) silicon fertilization at 100 mg L−1 during the experiment; and (iii) no amendments. A sand and vermiculite mix was used with and without silicon amendment. The silicon treatment increased plant silica concentrations in all experiments, but incorporating straw was not associated with raised plant silica concentrations. Blumeria graminis and Puccinia recondita were inoculated by shaking infected plants over the test plants, followed by suitable humid periods. The silicon treatment reduced powdery mildew (B. graminis) substantially in sand and vermiculite and in two of the soils, but there were no effects on the slight infection by brown rust (P. recondita). Phaeosphaeria nodorum and Mycosphaerella graminicola were inoculated as conidial suspensions. Leaf spot caused by P. nodorum was reduced in silicon-amended sand and vermiculite; soil was not tested. Symptoms of septoria leaf blotch caused by M. graminicola were reduced by silicon amendment in a severely infected sand and vermiculite experiment but not in soil or a slightly infected sand and vermiculite experiment. Oculimacula yallundae (eyespot) and Fusarium culmorum (brown foot rot) were inoculated as agar plugs on the stem base. Severity of O. yallundae was reduced by silicon amendment of two of the soils but not sand and vermiculite; brown foot rot symptoms caused by F. culmorum were unaffected by silicon amendment. The straw treatment reduced severity of powdery mildew but did not detectably affect the other pathogens. Both straw and silicon treatments appeared to increase plant resistance to all diseases only under high disease pressure.

From probiotics to prebiotics and a healthy digestive system

Ingestion of probiotics can be recommended as a preventative approach to maintaining intestinal microflora balance and thereby enhance 'well-being'. Undoubtedly, probiotic bacteria will vary in their efficacy. The literature indicates positive results in over 50 human trials with prevention/treatment of infections the most frequently reported. In theory increased levels of probiotics may induce a 'barrier' influence against common pathogens. Mechanisms of effect are likely to include the excretion of acids (lactate, acetate), competition for nutrients and gut receptor sites, immuno-modulation and the formation of specific antimicrobial agents. An alternative, or additional, approach is the prebiotic concept. This takes the view that probiotics are present indigenous to the gut and that a rational approach towards increasing their numbers would be to consume food ingredients (carbohydrates) that have a selective metabolism in the lower gut. A prebiotic is 'a nondigestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the colon that can improve the host health.' In particular, the ingestion of fructo-oligosaccharides, galacto-oligosaccharides, and lactulose has shown to stimulate bifidobacteria in the lower gut.

A value chain approach to animal diseases risk management: technical foundations and practical framework for field application

Classical risk assessment approaches for animal diseases are influenced by the probability of release, exposure and consequences of a hazard affecting a livestock population. Once a pathogen enters into domestic livestock, potential risks of exposure and infection both to animals and people extend through a chain of economic activities related to producing, buying and selling of animals and products. Therefore, in order to understand economic drivers of animal diseases in different ecosystems and to come up with effective and efficient measures to manage disease risks from a country or region, the entire value chain and related markets for animal and product needs to be analysed to come out with practical and cost effective risk management options agreed by actors and players on those value chains. Value chain analysis enriches disease risk assessment providing a framework for interdisciplinary collaboration, which seems to be in increasing demand for problems concerning infectious livestock diseases. The best way to achieve this is to ensure that veterinary epidemiologists and social scientists work together throughout the process at all levels.

Aluminium and human breast diseases

The human breast is exposed to aluminium from many sources including diet and personal care products, but dermal application of aluminium-based antiperspirant salts provides a local long-term source of exposure. Recent measurements have shown that aluminium is present in both tissue and fat of the human breast but at levels which vary both between breasts and between tissue samples from the same breast. We have recently found increased levels of aluminium in noninvasively collected nipple aspirate fluids taken from breast cancer patients (mean 268±28 g/l) compared with control healthy subjects (mean 131±10 g/l) providing evidence of raised aluminium levels in the breast microenvironment when cancer is present. The measurement of higher levels of aluminium in type I human breast cyst fluids (median 150g/l) compared with human serum (median 6g/l) or human milk (median 25g/l) warrants further investigation into any possible role of aluminium in development of this benign breast disease. Emerging evidence for aluminium in several breast structures now requires biomarkers of aluminium action in order to ascertain whether the presence of aluminium has any biological impact. To this end, we report raised levels of proteins that modulate iron homeostasis (ferritin, transferrin) in parallel with raised aluminium in nipple aspirate fluids in vivo, and we report overexpression of mRNA for several S100 calcium binding proteins following long-term exposure of MCF-7 human breast cancer cells in vitro to aluminium chlorhydrate.

Digestive and physiologic effects of a wheat bran extract, arabino-xylan-oligosaccharide, in breakfast cereal

Objective: We assessed whether a wheat bran extract containing arabino-xylan-oligosaccharide (AXOS) elicited a prebiotic effect and influenced other physiologic parameters when consumed in ready-to-eat cereal at two dose levels. Methods: This double-blind, randomized, controlled, crossover trial evaluated the effects of consuming AXOS at 0 (control), 2.2, or 4.8 g/d as part of ready-to-eat cereal for 3 wk in 55 healthy men and women. Fecal microbial levels, postprandial serum ferulic acid concentrations, and other physiologic parameters were assessed at the beginning and end of each condition. Results: The median bifidobacteria content of stool samples (log10/grams of dry weight [DW]) was found to be higher in the subjects consuming the 4.8-g/d dose (10.03) than in those consuming 2.2 g/d (9.93) and control (9.84, P < 0.001). No significant changes in the populations of other fecal microbes were observed, indicating a selective increase in fecal bifidobacteria. Postprandial ferulic acid was measured at 120 min at the start and end of each 3-wk treatment period in subjects at least 50 y old (n = 37) and increased in a dose-dependent manner (end-of-treatment values 0.007, 0.050, and 0.069 μg/mL for the control, AXOS 2.2 g/d, and AXOS 4.8 g/d conditions, respectively, P for trend < 0.001). Conclusion: These results indicate that AXOS has prebiotic properties, selectively increasing fecal bifidobacteria, and increases postprandial ferulic acid concentrations in a dose-dependent manner in healthy men and women.