Siegfried Bauer

Soil nutrient balance studies have become increasingly influential in policy discussions about soil fertility management and sustainable agriculture in developing countries. However, such studies, particularly in the context of Nepal, have often overlooked socio‐economic characteristics of farm households that may have a significant influence upon soil nutrient balances. This study, therefore, estimates the balances of three macronutrients—nitrogen (N), phosphorus (P), and potassium (K)—and analyzes the impact of socio‐economic factors on each of them applying a Seemingly Unrelated Regression (SUR) model. The results indicate that farm households in the study area had an average annual surplus of 31 ± 73 kg ha⁻¹ N but an annual deficit of 20 ± 53 kg ha⁻¹ P and 45 ± 64 kg ha⁻¹ K. Socio‐economic variables, such as distance to the market center, distance to plot from the homestead, possession of sloping farming plots, and having received training on nutrient management showed a negative impact on the nutrient balances. In contrast, male‐headed households, family size, and the use of improved composting methods showed a positive impact on nutrient balances. The study suggests that increased supply of organic sources of P and K via improved composting, better accessibility to inorganic P and K fertilizer through improved marketing infrastructure, and site‐specific fertilizer recommendations more accountable to the changing pattern of cultivation in mid‐hill region may contribute to reducing the trend of nutrient mining. Further, gender‐sensitive extension services are needed to provide female‐headed households with better knowledge and skills to manage their soil nutrients.

In his Discorsi, Galileo aimed to correct centuries of Aristotelian “unreason” concerning the physics of falling objects by introducing a thought experiment that pointed out contradictions when combinations of one light and one heavy body are dropped. Inspired by Galileo's story, we sought to formulate research questions and design experiments for students to enable independent learning based on the history of science. The experiments involve commonly used or inexpensive equipment and free software, and show that Aristotle and Galileo did not disagree about falling objects, but were focusing on different kinds of motion. We assess data generated by high-speed video motion tracking of the fall of various combinations of simple handmade paper cones, following closely the discussion between Simplicio, Salviati and Sagredo in the Discorsi, and demonstrate that every statement in Galileo's reductio ad absurdum holds true and that his argument is in fact free of contradiction.

In situ perovskite nanocrystal formation within nanoporous thin films allows emission color tuning in optoelectronic devices.

Large-bandwidth, low-operation-voltage, and uniform organic amplifiers are fabricated on ultrathin foils. By the integration of short-channel OTFTs and AlO_x capacitors, organic amplifiers with a bandwidth of 25 kHz are realized, demonstrating the highest gain-bandwidth product (GBWP) reported to date. Owing to material and process advancements, closed-loop architectures operate at frequencies of several kilohertz with an area smaller than 30 mm².