Estimated glycemic index of rice increases with the release of new varieties in the middle reach of the Yangtze River

The amylose content of newly-released rice varieties has steadily decreased in rice-growing regions in the middle reach of the Yangtze River during 2006–2021, to parallel increasing consumption of soft-textured rice with low amylose content. We estimated the glycemic index of these newly-released rice varieties and reveal a significantly increasing trend, showing a 0.3 annual increase in estimated glycemic index of new rice varieties released each year. These results highlight the need to assess the potential health risks associated with the development of soft-textured rice with low amylose rice.

A Numerical Study of the Flow and Sediment Interaction in the Middle Reach of the Huai River

In recent years, the incoming sediments from upstream of the Huai River have continuously decreased. The relationship between flow and sediment has significantly changed. Therefore, the erosion and deposition characteristics of the river could be affected. To investigate this interaction between flow and sediment, the present study was conducted using the Wanglin section in the middle reach of the Huai River as the study site. A 1D hydrodynamic model was developed and validated using field data. Data from 1985–2014 were used as a continuous series while data from 2004–2014 were used as a repetitive series. The sediment variation and distribution processes at different locations were discussed. It was found that the river channel displayed several notable characteristics. In the flow direction, the channel had frontal erosion and backward deposition. The variation rate was relatively slow. With reduced sediment, the overall deposition at the Wanglin section was significantly mitigated. Future recommendations are provided based on the present simulation for flood mitigation along the Huai River.

Isotope Signs (234U/238U, 2H, 18O) of Groundwater: An Investigation of the Existence of Paleo-Permafrost in European Russia (Pre-Volga Region)

The isotopic (234U/238U, 2H, 18O) and chemical composition of groundwater on the right bank of the Volga River along the middle reach (European Russia) was studied down to a depth of 400 m. These data allow diagnosis of the presence of a three-component mixture. The first component is modern/young fresh recharge water of the Holocene age. It has the isotopic composition of water δ18O → −12.9 ‰ and δ2H → −90 ‰, close to modern precipitations, and the equilibrium isotopic composition of uranium 234U/238U → 1 (by activity). The second component is slightly salted water of the late or postglacial period with δ18O → −17.0 ‰ and δ2H → −119 ‰, and a small excess of uranium-234 234U/238U ≈ 4. The third component is meltwater formed as result of permafrost thawing. It is brackish water with δ18O ≈ −15.0 ‰ and δ2H ≈ −110 ‰, and a maximum excess of uranium-234 234U/238U ≈ 15.7. The salinity of this water is associated with an increase of the SO42−, Ca2+ and Na+ content, and this may be due to the presence of gypsum in water-bearing sediments, because the solubility of sulfates increases at near-zero temperature. We explain the huge excess of uranium-234 by its accumulation in the mineral lattice during the glacial age and quick leaching after thawing of permafrost.