A point mutation (E115K) resulting in slower growth of Escherichia coli DH5alpha and XL1-Blue in minimal media was identified in the purB gene, coding for adenylosuccinate lyase (ASL), through complementation with an E. coli K-12 genomic library and serial subcultures. Chromosomal modification reversing the mutation to the wild type restored growth phenotypes in minimal media.

In this paper, we present a new duplex scheme, called Zipper, for discrete multitone (DMT)-based very high bit-rate digital subscriber line (VDSL) systems on copper wires. This scheme divides the available bandwidth by assigning different subcarriers for the upstream and downstream directions. It has high flexibility to divide the capacity between the up and downstream, as well as good coexiste...

In Japan, FTTH users will soon overtake ADSL users [1], [2]. This means that the main technology of broadband access systems has moved from metallic systems such as ADSL to optical systems. PON (Passive Optical Network) is the most popular technology for optical broadband access systems because PON can provide optical access services at low cost by sharing transmission equipment [3]. However, P...

This paper presents measurements and analysis of broadband Internet access service networks using a highspeed IP meter with a GPS (Global Positioning System) timestamp component. The authors performed measurements of traffic in a commercial IPv6 access service on ADSL (Asymmetrical Digital Subscriber Line) as a typical broadband access service network. This paper describes the measurement confi...

The use of modern technology from non-standard sources allows IT centres to find temporary solutions for operational needs, for example to provide access quickly to a networking infrastructure for the local scientific community. This paper describes the experiences of GWDG with ADSL equipment. Although originally a consumer technology it can also be used in a scientific environment. Despite of ...