Quantitative analysis of biochar in field soil

Biochar is used with increasing frequency as a soil amendment because of its potentially beneficial effects on soil carbon sequestration, crop yield, nutrient leaching and greenhouse gas emissions. Simple methods for the analysis of biochar in soil, however, are currently unavailable. Therefore, we have adapted the “loss on ignition” method for this purpose. The technique requires knowledge of the proportions of both biochar and biochar-free soil that are lost on ignition. One can use values determined prior to the amendment of the soil with biochar, assuming that the values do not change after biochar is incorporated in the soil. We tested these assumptions. Over the course of 15 months, the assumptions proved to be valid under our test conditions. The technique accurately determined a wide range of biochar concentrations in field soil.     

The effect of cordycepin on brain oxidative stress and protein expression in streptozotocin-induced diabetic mice

Diabetes mellitus (DM) is characterized by metabolic disorders and psychological deficits, including cognitive decline. Here, we investigated the effect of cordycepin on oxidative stress and protein expression in the brains of diabetic mice. Twenty-four mice were divided into four groups, one comprising untreated healthy mice (N); one comprising healthy mice treated with cordycepin (24 mg/kg body weight) (N+Cor); one comprising untreated DM mice; and one comprising DM mice treated with cordycepin (24 mg/kg body weight) (DM+Cor). After 14 days of treatment, cognitive behavior was assessed using the novel object recognition (NOR) test. The brain levels of oxidative stress markers (glutathione, catalase, and superoxide dismutase) were examined using the respective detection kits. Protein expression in brain tissues was assessed by liquid chromatography with tandem mass spectrometry (LC–MS/MS); the functions of the identified proteins were annotated by PANTHER, while major protein–protein interactions were assessed using STITCH. We found that cordycepin treatment significantly decreased body weight and food and water intake in the DM+Cor group compared with that in the DM group; however, no differences in blood glucose levels were found between the two groups. Cordycepin treatment significantly reversed cognitive decline in diabetic mice in the NOR test and ameliorated antioxidant defenses. Additionally, we identified ULK1 isoform 2, a protein associated with cognitive function via the activated AMPK and autophagic pathways, as being uniquely expressed in the DM+Cor group. Our findings provide novel insights into the cellular mechanisms underlying how cordycepin improves cognitive decline in diabetic mice.     

General principles in the community ecology of ectomycorrhizal fungi

Introduction

Knowledge of the factors that determine ectomycorrhizal fungal community structure is essential in many areas of practical significance including conservation, habitat restoration, prevention or amelioration of species invasions, and the prediction of responses to climate change. With respect to these goals, however, community ecology, in general, and ectomycorrhizal fungal community ecology, in particular, have been rather disappointing.

Discussion

Indeed, some feel that community ecology is, at best, an esoteric discipline and, at worst, an inane one. But there is hope. As we apply what has been learned about other organisms concerning the relationships between functional traits and success (abundance), it may be possible to elucidate general principles that govern much of the structuring of ectomycorrhizal fungal communities.

Conclusion

A hierarchical model of ectomycorrhizal fungal community structure is presented that involves abiotic filtering of immigrant propagules based on functional traits, followed by interspecific competition as ameliorated by disturbance and habitat partitioning, the outcomes of which are dependent on functional traits.