In object oriented database management systems, clustering has proven to be one of the most effective performance enhancement techniques. Existing clustering algorithms are mainly static, that is re-clustering the object base when the database is off-line. However, this type of re-clustering cannot be used when 24-hour database access is required. In such situations dynamic clustering is necess...

1 Department of Oral and Craniofacial Biology, Dental School, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America, 2 Department of Prosthodontics, Dental School, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America, 3 Department of Microbiology, Immunology, and Parasitology, School of Medicine, Louisi...

According to transaction cost economics, contracts are always incomplete and offer opportunities to defect. Some level of trust is a sine qua non for trade. If the seller is better informed about product quality than the buyer, the buyer has to rely on information the seller provides or has to check the information by testing the product or tracing the supply chain processes, thus incurring ext...

The rise and diversification of the dinosaurs in the Late Triassic, from 230 to 200 million years ago, is a classic example of an evolutionary radiation with supposed competitive replacement. A comparison of evolutionary rates and morphological disparity of basal dinosaurs and their chief "competitors," the crurotarsan archosaurs, shows that dinosaurs exhibited lower disparity and an indistingu...

Self-suucient and autonomous robots necessarily make their own decisions. As designers of robots we need ways of assessing their behaviour. A functional method, called the basic cycle which is based on the utility of the robot owner, is proposed to assess the robot's performance within an environmental niche. The method allows judgements to be made on the robot's use of time or energy, as well ...

China has made substantial health commitments to Africa in the past several decades. However, while much has been written regarding China-Africa aid overall, relatively little attention has been given to China's health aid. To better understand these investments, we provide an overview of the current framework and characteristics of China's health aid to Africa. China's health assistance has be...