It has been proposed that an increased mutation rate (indicated by the frequency of hypermutable isolates) has facilitated the emergence of Escherichia coli O157:H7. Analysis of the divergence of 12 genes shows no evidence that the pathogen has undergone an unusually high rate of mutation and molecular evolution.

Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE) and 100 mg L-1 kinetin solution alone...

Different influenza subtypes can evolve at very different rates, but the causes are not well understood. In this paper, we explore whether differences in transmissibility between subtypes can play a role if there are fitness constraints on antigenic evolution. We investigate the problem using a mathematical model that separates the interaction of strains through cross-immunity from the process ...

The future development of air traffic management (ATM), set by the ATM 2000+ Strategy, involves a structural revision of ATM processes, a new ATM concept and a system approach for the ATM network. This requires ATM services to go through significant structural, operational and cultural changes that will contribute towards the ATM 2000+ Strategy. Moreover, from a technology viewpoint, future ATM...

Human capabilities play an important part in the emergence from stagnation to modern economic growth. Historical and macroeconomic studies show substantial effects for nutrition and health on income levels and, for poorer countries, on rates of growth, implying divergence. Cross-country examination of the joint dynamics of life expectancy and income shows that a stratified emergence from stagna...

When can an information technology (IT) offshoring relationship be considered a success and failure at the same time? The literature is rich with offshoring relationships that have been described as being successful or as a failure. However, success or failure is often in the eye of the beholder. When evaluating offshoring success we propose that both process and outcome criteria be considered,...

The emergence of a knowledge-based view of clusters and its implications for cluster governance 5 Abstract This chapter examines the knowledge component in cluster literature from its origins to the present. A chronological perspective is deployed in order to shed light on how the concept of clusters has evolved. Given the increasing interest in clusters as knowledge repositories, and the appar...

Climate change can disrupt plant-pollinator interactions when shifts in the timing of pollinator activity and flowering occur unequally (i.e., phenological asynchrony). Phenological asynchrony between spring-emerging solitary bees spring-flowering plants may cause to experience food deprivation that affect their reproductive success. However, mechanisms underlying effects on bee reproduction re...

Sediment deposition is a common phenomenon in the estuary area. Pot control experiments were conducted to evaluate interaction effects of sediment burial depth and salt stress on seed germination early seedling growth Suaeda salsa (L.) Pall., an pioneer species tidal wetland near Yellow River Delta. The results showed that percentage emergence, emergence rate, height, branch number, shoot bioma...