A Nef reaction has been developed that is conducted under mildly basic conditions with molecular oxygen as an oxidant, without the need for metal additives. Whereas nitroalkanes are converted into ketones in good yield, nitroalkenes are transformed into α,β-unsaturated ketones in one-pot by double-bond isomerization followed by the oxygen-mediated Nef reaction. The reaction protocol is both mild and general, and tolerates acid- and base-labile functionality or protecting groups. When oxygen-saturated solvents are employed, the reaction completes within 20 min. Mechanistically, the addition of nitronate ion and molecular oxygen is proposed to proceed initially through a single-electron transfer event, as indicated by radical clock experiments. This ultimately generates a putative 1,1-dioxirane, which reacts further with another nitronate ion to generate the ketone. Involvement of a 1,1-dioxirane is supported by intramolecular trapping experiments with sulfide at the γ-position of the nitro-moiety.

Highly enantioselective synthesis of tetrahydrofurans was accomplished via a formal [3 + 2] cycloaddition reaction of succinaldehyde, which acts as a three-carbon unit. The reaction consists of the domino reaction of the diarylprolinol-mediated aldol reaction of succinaldehyde followed by an intramolecular acetalization reaction.

The purpose of this research is to investigate the colonization process of woody plants, mainly Elaeagnus umbellata , on an alternating bar in a downstream reach of the Nakagawa River, Tokushima, Japan, and also to clarify their influences on hydrogeomorphic features and flood flows in the reach. Based on field vegetation survey and inspection of aerial photographs, it is shown that the colonization started in the late 1970s, and thereafter, the total cover-rate of the woody communities has been increased up to 50% after rather abrupt expansion occurred three times at intervals of about 6 years. The record of flood discharge indicates that seed dispersal of Eaeagrais umbellata due to autumnal floods is closely related to the above-mentioned abrupt expansion. It is found that the woody communities have caused characteristic changes in river-bed configuration of the reach and, through numerical calculations, that they have come to significantly raise the flood stage.

Airport radars using GPS or radio waves are often used to sense aircraft flight positions. These techniques can be applied for sensing in a wide range of areas, but they tend to be interrupted due to the radar blind spots resulting from the low flight altitude in the vicinity of an airfield. For managing or investigating aircraft operations, three-dimensional measurement in the local area from the ground is effective. So, we have developed an IoT camera system installed with a fisheye lens and measured the flight path of aircraft passing overhead at multiple points near the end of the runway. As a result, it was found that our camera system can detect continuous flight paths even if the flight altitude is low.

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