The entry of Cd into the food chain is of concern as it can cause chronic health problems. To investigate the relationship between soil properties and the concentration of Cd in wheat (Triticum aestivum L.) and harley (Hordeum vulgare L.) grain, we analyzed 162 wheat and 215 barley grain samples collected from paired soil and crop surveys in Britain, and wheat and barley samples from two long-term sewage sludge experiments. Cadmium concentrations were much lower in barley grain than in wheat grain under comparable soil conditions. Multiple regression analysis showed that soil total Cd and pH were the significant factors influencing grain Cd concentrations. Significant cultivar differences in Cd uptake were observed for both wheat and barley. Wheat grain Cd concentrations could be predicted reasonably well from soil total Cd and pH using the following model: log(grain Cd) = a + b log(soil Cd) - c(soil pH), with 53% of the variance being accounted for. The coefficients obtained from the data sets of the paired soil and crop surveys and from long-term sewage sludge experiments were similar, suggesting similar controlling factors of Cd bioavailability in sludge-amended or unamended soils. For barley, the model was less satisfactory for predicting grain Cd concentration (22% of variance accounted for). The model can be used to predict the likelihood of wheat grain Cd exceeding the new European Union (EU) foodstuff regulations on the maximum permissible concentration of Cd under different soil conditions, particularly in relation to the existing Directive and the proposed new Directive on land applications of sewage sludge.

The ATLAS experiment sensitivity to top quark Flavour Changing Neutral Current (FCNC) decays was studied at LHC using tt events. While one of the top quarks is expected to follow the dominant Standard Model decay t → bW , the other decays through a FCNC channel, i.e. t → Zu(c), t → γu(c) or t → gu(c). Different types of analyses, applied to each FCNC decay mode, were compared. The FCNC branching ratio sensitivity (assuming a 5σ signal significance) and 95% confidence level limits on the branching ratios (in the hypothesis of signal absence) were obtained.

The PAH content of soils from a long-term agricultural experiment that received 25 separate sewage sludge applications from 1942 to 1961 is presented along with data from an untreated control plot and a plot that received repeated applications of farmyard manure. Archived plough layer (0-23 cm) soil samples were collected, stored, and processed in the same manner between 1942 and 1984 (i.e., before, during, and after sludge amendments) and samples of the applied sludges were available for analysis. Soil concentrations increased between 1942 and 1960 on the sludge-amended plot and subsequently showed a steady decline. By 1984 the sludge-amended plot still contained over 3 times more £PAH than the corresponding control soil. By 1960 ~70% of the £PAH load added in the sludge was unaccounted for; this had increased to nearly 85% by 1984. Some compound-specific trends are apparent in the data; generally, the higher molecular weight PAHs have been more persistent. It is argued that biodegradation and transboundary transfers due to ploughing are the two main loss mechanisms.

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A new growth medium which closely approximates the composition of the soil solution is presented. This soil solution equivalent (SSE) medium contains the following components (millimolar):