A dynamic framework for contractors to measure the performance of highway maintenance based on grey theory.

Highway maintenance performance measurement is the key to implementing performance-based contracting (PBC). However, contractors have struggled with accurately understanding client intent and translating performance goals into measurable indicators. To make PBC successfully applied, this study proposes a dynamic performance measurement framework of highway routine maintenance based on grey theory. A performance indicator system is established based on the organizational structure of highway assets and the bill of quantities in the real world. In addition, a statistical analysis using the data about maintenance cost and highway condition score has been conducted to ascertain the weights and thresholds assigned to various indicators. As a result, the performance indicators, their corresponding weights, and thresholds can be flexibly adjusted to accommodate diverse periods and areas. Then, the grey theory has been employed to evaluate the comprehensive performance level of service within a region. This framework is experimented with using the data of three maintenance areas in Shaanxi Province, China: Qiaogouwan, Huaziping, and Ansai. At the end of the process, comparison and sensitivity analysis are conducted. The results demonstrate the model's reasonability and robustness, providing valuable tools for contractors to assess the performance of highway maintenance in meeting client specifications.

Designing and synthesizing peptide-based quorum sensing modulators.

Quorum sensing (QS) is a density-dependent bacterial communication system that uses small molecules as regulatory modulators. Synthetic changes to these molecules can up-or-down-regulate this system, leading to control of phenotypes, like competence and virulence factor production, that have implications in human health. In this chapter, a methodology for library design and screening of synthetic autoinducing peptides (AIPs) to uncover QS SARs is delineated. Additionally, procedures for the synthesis, purification and analysis of linear and cyclic AIPs are detailed. This includes solutions for potential synthetic challenges including diketopiperazine formation when using N-methyl amino acids and cyclization of peptides containing N-terminal cysteine residues. These procedures have and are currently being applied to develop potent QS modulators in Streptococcus pneumoniae, Bacillus cereus, Streptococcus gordonii and Lactiplantibacillus plantarum.