Sensitivity of jarrah (Eucalyptus marginata) to phosphate, phosphite, and arsenate pulses as influenced by fungal symbiotic associations

Many plant species adapted to P-impoverished soils, including jarrah (Eucalyptus marginata), develop toxicity symptoms when exposed to high doses of phosphate (Pi) and its analogs such as phosphite (Phi) and arsenate (AsV). The present study was undertaken to investigate the effects of fungal symbionts Scutellospora calospora, Scleroderma sp., and Austroboletus occidentalis on the response of jarrah to highly toxic pulses (1.5 mmol kg−1 soil) of Pi, Phi, and AsV. S. calospora formed an arbuscular mycorrhizal (AM) symbiosis while both Scleroderma sp. and A. occidentalis established a non-colonizing symbiosis with jarrah plants. All these interactions significantly improved jarrah growth and Pi uptake under P-limiting conditions. The AM fungal colonization naturally declines in AM-eucalypt symbioses after 2–3 months; however, in the present study, the high Pi pulse inhibited the decline of AM fungal colonization in jarrah. Four weeks after exposure to the Pi pulse, plants inoculated with S. calospora had significantly lower toxicity symptoms compared to non-mycorrhizal (NM) plants, and all fungal treatments induced tolerance against Phi toxicity in jarrah. However, no tolerance was observed for AsV-treated plants even though all inoculated plants had significantly lower shoot As concentrations than the NM plants. The transcript profile of five jarrah high-affinity phosphate transporter (PHT1 family) genes in roots was not altered in response to any of the fungal species tested. Interestingly, plants exposed to high Pi supplies for 1 day did not have reduced transcript levels for any of the five PHT1 genes in roots, and transcript abundance of four PHT1 genes actually increased. It is therefore suggested that jarrah, and perhaps other P-sensitive perennial species, respond positively to Pi available in the soil solution through increasing rather than decreasing the expression of selected PHT1 genes. Furthermore, Scleroderma sp. can be considered as a fungus with dual functional capacity capable of forming both ectomycorrhizal and non-colonizing associations, where both pathways are always accompanied by evident growth and nutritional benefits

How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations

Genetic loci associated with heart rate variability and their effects on cardiac disease risk

Reduced cardiac vagal control reflected in low heart rate variability (HRV) is associated with greater risks for cardiac morbidity and mortality. In two-stage meta-analyses of genome-wide association studies for three HRV traits in up to 53,174 individuals of European ancestry, we detect 17 genome-wide significant SNPs in eight loci. HRV SNPs tag non-synonymous SNPs (in NDUFA11 and KIAA1755), expression quantitative trait loci (eQTLs) (influencing GNG11, RGS6 and NEO1), or are located in genes preferentially expressed in the sinoatrial node (GNG11, RGS6 and HCN4). Genetic risk scores account for 0.9 to 2.6% of the HRV variance. Significant genetic correlation is found for HRV with heart rate (-0.74 < r(g) < -0.55) and blood pressure (-0.35 < r(g) < -0.20). These findings provide clinically relevant biological insight into heritable variation in vagal heart rhythm regulation, with a key role for genetic variants (GNG11, RGS6) that influence G-protein heterotrimer action in GIRK-channel induced pacemaker membrane hyperpolarization

Erratum: Genetic loci associated with heart rate variability and their effects on cardiac disease risk

Correction to article number 15805 published in June 2017 in Nature Communications, vol 8

Erratum: Genetic loci associated with heart rate variability and their effects on cardiac disease risk

Correction to article number 15805 published in June 2017 in Nature Communications, vol 8

Toxicological findings in driver and motorcyclist fatalities in Scotland 2012-2015

Fatal motor vehicle crashes (MVCs) continue to be a common occurrence worldwide. This paper presents a retrospective analysis of the toxicological investigation of drivers and motorcyclists fatally injured in MVCs in Scotland from 2012 to 2015. One hundred and eighteen cases with full toxicological analysis, i.e., alcohol, drugs of abuse and prescription drugs, were examined. Of those 118 MVC cases, 74 (63%) were car drivers, 32 (27%) were motorcyclists and the remaining were drivers of other vehicles such as large goods vehicles. The majority of deceased drivers and motorcyclists were male (N = 104, 88%). For the toxicological findings, 51 (43%) were negative, and of the 67 (57%) positive cases, alcohol and cannabinoids were the most frequently detected substances, followed by opiates and benzodiazepines. Fifteen percent of all drivers and motorcyclists were over the prescribed blood alcohol limit at the time of analysis. In comparison to previous reports of drug use by drivers in Scotland, benzodiazepines and NPS were less common findings in fatally injured drivers and motorcyclists than in drivers suspected of being impaired

Modeling time patterns of forest soil acidification for various deposition scenarios

A soil acidification model has been developed to estimate long-term chemical changes in soil and soil water in response to changes in atmospheric deposition. Major model outputs include base saturation, pH and the Al/BC ratio, where BC stands for divalent base cations. The processes accounted for are restricted to geochemical interactions, including weathering of carbonates, silicates and aluminum hydroxides, cation exchange and CO2 equilibria. With the exception of silicate weathering, all processes are described by equilibrium reactions. Model parameters mainly refer to equilibrium constants for the various processes, while model variables include the amounts of base cations and aluminum in carbonates, hydroxides, the exchange complex and in soil solution. The model behavior in the different buffer ranges between pH 7 and pH 3 has been evaluated by analyzing the response of an initially calcareous soil to a constant high acid load (5000 molc ha−1 yr−1) over a period of 500 years. In calcareous soils, weathering is fast and the pH remains high (near 7) until the carbonates are exhausted. In non-calcareous soils the response in the range between pH 7 and pH 4 mainly depends on the initial amount of exchangeable base cations. Although the model cannot be strictly verified for its ultimate use of long-term predictions, it can be used as a tool to obtain a conceptual understanding of long-term soil responses for the broad concern of resource managers and policy makers. Therefore it will be linked to the Regional Acidification Information and Simulation model (RAINS) to analyze the impact of various emission scenarios on a European scale