Preparation of fibril nuclei of beta-amyloid peptides in reverse micelles.

We report the preparation of protofibrils from oligomeric Aß40 aggregates, which have been incubated under spatially constrained conditions. The molecular structure of the resultant protofibrils is highly homogeneous, suggesting that the phenomenon of structural polymorphism commonly observed in Aß40 fibrils may be largely due to multiple nucleation events.

Fibrillization of ß-Amyloid Peptides via Chemically Modulated Pathway.

The aggregation of ß-amyloid peptides is closely associated with Alzheimer's disease. We have used liposomes to modulate the early aggregation events of 40-residue ß-amyloid peptides. The spatial confinement provided by liposomes leads to the formation of nonfibrillar aggregates of ß-amyloid peptides. These on-pathway ß-sheet intermediates were used to seed the fibrillization of the monomer peptides. Solid-state NMR spectroscopy revealed that the resultant fibrils have a more uniform structure than those formed in liposome-free solution.

Use of a GIS-based hybrid artificial neural network to prioritize the order of pipe replacement in a water distribution network.

A methodology based on the integration of a seismic-based artificial neural network (ANN) model and a geographic information system (GIS) to assess water leakage and to prioritize pipeline replacement is developed in this work. Qualified pipeline break-event data derived from the Taiwan Water Corporation Pipeline Leakage Repair Management System were analyzed. "Pipe diameter," "pipe material," and "the number of magnitude-3( + ) earthquakes" were employed as the input factors of ANN, while "the number of monthly breaks" was used for the prediction output. This study is the first attempt to manipulate earthquake data in the break-event ANN prediction model. Spatial distribution of the pipeline break-event data was analyzed and visualized by GIS. Through this, the users can swiftly figure out the hotspots of the leakage areas. A northeastern township in Taiwan, frequently affected by earthquakes, is chosen as the case study. Compared to the traditional processes for determining the priorities of pipeline replacement, the methodology developed is more effective and efficient. Likewise, the methodology can overcome the difficulty of prioritizing pipeline replacement even in situations where the break-event records are unavailable.