MicroMass Communications (United States)

Isobaric interferences in environmental samples can compromise trace LC-MS analysis of polar organic chemicals when using single quadrupole instruments in selected ion monitoring (SIM) mode. HPLC-MS/MS with triple quadrupole instruments in multiple reaction monitoring (MRM) mode is the conventional approach for increasing selectivity and improving sensitivity. Time-of-flight (ToF) MS offers an alternative approach with higher mass resolving power and full spectral sensitivity. Extracts from STP effluent were evaluated for PPCPs using three different types of Micromass, Inc. mass spectrometers: a single quadrupole (LCZ™), a triple quadrupole (Quattro LC™), and an orthogonal acceleration ToF instrument (LCT™). HPLCToF-MS provided significant S/N improvement over SIM analysis for each of the analytes detected and approached S/N values afforded by MRM analysis. In addition, the ToF was also able to identify non-target analytes based on accurate mass measurements and associated elemental composition calculation as illustrated by the detection and confirmation of a polyethylene glycol (PEG) homologous series in STP influent. Limited dynamic range on the ToF as compared to the quadrupole was partially corrected for using digital dead time correction (DDTC).

After an ultrashort pulse (or an ultrawideband signal) has propagated a sufficiently large distance into a dispersive, attenuative material its spatiotemporal dynamics settle into a relatively simple (or mature) behavior for the remainder of the propagation. In this so-called mature dispersion regime the field becomes locally quasimonochromatic with fixed local frequency, wavelength, and attenuation in small regions of space that propagate with their own characteristic constant velocity (Sherman and Oughstun 1995). The modern asymptotic description of the dynamical evolution of an ultrashort electromagnetic pulse (or an ultrawideband electromagnetic signal) as it propagates through a homogeneous, isotropic, locally linear, temporally dispersive medium provides a detailed characterization of the entire temporal field evolution for all propagation distances that are in the mature dispersion regime (Oughstun and Sherman 1994). The accuracy of this asymptotic approximation is discussed.

The Internet represents a substantial advance in information exchange and presents the healthcare industry with a significant opportunity to fundamentally enhance the manner in which individuals manage their relative wellness. As the World Wide Web matures, usage patterns are becoming more precisely defined. These patterns can be examined and used to enhance accessibility and encourage user loyalty to a particular site. The internet, coupled with future technology advances, could enable healthcare providers to offer individually tailored disease management programmes, adapt to patient needs in real-time and deliver vast amounts of information with virtually no fulfilment costs. However, a planned and well co-ordinated approach is needed if the benefits of this new communication medium are to be fully realised. If this is achieved, Web-based disease management could be a cost-effective means of lowering patient health risk and an excellent asynchronous link between patient and provider.

As informatics technology advances, a growing number of research trials on tailored communications provide an accumulation of promising evidence to support their efficacy. These trials also reveal gaps and opportunities for future research. The scope and boundaries of tailoring must be redefined in terms of both new technology and the trade-offs between complexity, demand burden on participants, and the minimal information required for effective and efficient tailoring. Basic and methods research is needed to broaden theory, develop a common language, standardize measures, and isolate the key mediating mechanisms that facilitate tailored communications. Applied research must consider more rigorous research designs for efficacy trials and conduct more effectiveness trials to investigate the mechanisms of technology transfer to enhance large-scale diffusion of tailored communications. The role of contextual variables needs to be examined, as well as their interaction with different population groups, and also the channels, modes, and methods of tailored message delivery. Research is also needed on the feasibility of tailoring across clusters of multiple risk factors to identify the commonalities, differences, and interrelations among diverse behaviors. The potential cost-effectiveness of tailored communications must also be examined. No matter how efficacious, tailored communications delivered to large populations (i.e. mass-customization) will not make a public health impact unless proven to be practical and cost-efficient.

As microprocessors become more widely used in consumer products of ever-increasing complexity, there has arisen a need for a low cost magnetic tape peripheral. Such a peripheral is used to store both programs and data. A new, re-entrant tape cartridge about the size of a book of matches, capable of storing in excess of 500,000 bits of data, will be described. Its mating transport is x 3 x 1 ?and has only three moving parts. Data encoding schemes requiring minimal electronics and operating over wide tape speed fluctuations will be outlined. While designed as a self-clocking, single-track digital system, the MicroVox Digital Data Storage System can be equipped with a second track for audio effect. This paper describes bulk program tape duplication techniques and unique system configuration to minimize bootlegging. Finally, it reviews several current applications.