Nutritional quality regulates postnatal wing morph in pea aphids.

Aphids can produce winged or wingless offspring in response to environmental changes. Host nutrition is one of the extensively studied environmental factors influencing the plasticity of wing morphs of aphids. In this study, we found that the pea aphid, Acyrthosiphon pisum, produced a low proportion of winged offspring when fed on plants, but a significantly higher proportion on the artificial diet. Interestingly, when newly born nymphs were transferred back to the artificial diet after feeding on plants for six hours or longer, most nymphs became wingless. These results suggest that the wing morph state of pea aphids can change postnatally, potentially determined by the nutritional quality of their food. Furthermore, aphids feeding on the artificial diet exhibited higher levels of glucose and stronger insulin signaling activity compared with aphids on plants. Conversely, the amino acid levels were lower, and TOR signaling was weaker in aphids fed on the artificial diet. Insulin and the target of rapamycin (TOR) are the primary nutrient-sensing signaling pathways involved in controlling organism growth and have been implicated in regulating aphid wing morph plasticity. We tested whether these nutrient responsive pathways were involved in postanal wing determination of aphids. However, reducing amino acid content in the diet or inhibiting TOR with rapamycin resulted in a decrease of the winged morph, suggesting that the lower amino acid levels or TOR activity was not responsible for the higher proportion of winged morph on the artificial diet. These results suggest that nutritional quality, particularly sugars like sucrose and glucose, may regulate the postnatal wing morph of the pea aphid, likely via the insulin signaling pathway.

Hydrothermally formed functional niobium oxide doped tungsten nanorods.

Nanorod forms of metal oxides are recognized as one of the most remarkable morphologies. Their structure and functionality have driven important advancements in a vast range of electronic devices and applications. In this work, we postulate a novel concept to explain how numerous localized surface states can be engineered into the bandgap of niobium oxide nanorods using tungsten. We discuss their contributions as local state surface charges for the modulation of a Schottky barrier height, the relative dielectric constant and their respective conduction mechanisms. Their effects on hydrogen gas molecule interaction mechanisms are also examined herein. We synthesized niobium tungsten oxide (Nb17W2O25) nanorods via a hydrothermal growth method and evaluated the Schottky barrier height, ideality factor, dielectric constant and trap energy level from the measured I-V versus temperature characteristics in the presence of air and hydrogen to show the validity of our postulations.

Nature-inspired construction, characterization, and photocatalytic properties of single-crystalline tungsten oxide octahedra.

Karstification is adopted to develop a new synthetic strategy for single-crystalline WO(3) octahedra bound with {111} facets from irregular-shaped commercial WO(3) particles.