An ad-hoc network is perceived as a community of autonomous devices that interconnect, interact and collaborate with each other. Ad-hoc networks have dynamic topologies and cannot rely on a continuous connection to the Internet. This introduces difficult security issues when attempting to provide authentication, membership management and access control. Thus, the users have to rely on other pee...

GPS is widely used in aviation for lateral navigation via receiver autonomous integrity monitoring (RAIM). New methodologies are currently being investigated to create an advanced form of RAIM, called ARAIM that would also be capable of supporting vertical navigation. The vertical operations being targeted have tighter integrity requirements than those supported by RAIM. Consequently, more stri...

Background Urban renewal has become an important issue in Hong Kong, which is experiencing considerable population growth pressures and urban decay in various districts. Ho et al. [1] noted that urban renewal often creates not only environmental problems such as demolition waste, but also social problems such as destruction of existing social networks and the fabric of long-established communit...

Mitogen-activated protein (MAP) kinases represent a group of serine/threonine protein kinases playing a central role in signal transduction processes in eukaryotic cells. Using a strategy based on the complementation of the thermosensitive autolytic phenotype of slt2 null mutants, we have isolated a Candida albicans homolog of Saccharomyces cerevisiae MAP kinase gene SLT2 (MPK1), which is invol...

Coded aperture imaging uses many pinholes to increase the SNR for intrinsically weak sources when the radiation can be neither reflected nor refracted. Effectively, the signal is multiplexed onto an image and then decoded, often by computer, to form a reconstructed image. We derive the modulation transfer function (MTF) of such a system employing uniformly redundant arrays (URA). We show that t...

In this paper, we describe a 3.8-kb molecular construct that we have used to disrupt yeast genes. The construct consists of a functional yeast URA3 gene flanked by 1.1-kb direct repeats of a bacterial sequence. It is straightforward to insert the 3.8-kb segment into a cloned target gene of interest and then introduce the resulting disruption into the yeast genome by integrative transformation. ...

We have generated a site-specific 17 bp insertion within a 38 kb chick globin gene cluster by employing the recombination abilities of Saccharomyces cerevisiae. This gene cluster contains four beta-type globin genes which share a high degree of sequence homology. In this procedure, a small fragment of beta A-globin DNA containing a 17 bp insertion is subcloned into a URA3-based yeast integratin...