n engl j med 360;26 nejm.org june 25, 2009 2693 levels.1 Overloaded primary care practices, whose doctors are aptly compared to hamsters on a treadmill, struggle to provide prompt access and high-quality care. Three major factors contribute to this crisis. First, primary care physicians earn far lower incomes than procedural specialists, reducing career attractiveness for medical students with ...

Wireless Sensor Networks (WSNs) have been used mainly to collect environmental data and send it to a base station. Routing protocols are needed to efficiently direct the information flows to the base station. Since sensor nodes have strict energy constraints, data gathering and communication schemes for WSNs need to be designed for an efficient utilization of the available resources. An emergen...

In Focus • THE JOURNAL OF CELL BIOLOGY S o far, defi nitive proof of the existence of lipid rafts in vivo has slipped through researchers’ fi ngers. Although their results probably won’t settle the debate over whether such structures exist, Toulmay and Prinz reveal that yeast produce raft-like domains in a surprising place (1). The original raft hypothesis held that the plasma membrane harbors ...

Recently, civil infrastructure and lifeline networks have been stressed by significant natural hazards and human errors leading to malfunction. Earthquakes and tsunamis, hurricanes and floods, blackouts and satellite failures have evidenced the vulnerability of these growing networks threatening the business continuity and economy of several communities. Characterization of the performance and ...