Developing products on Internet time.

The rise of the World Wide Web has provided one of the most challenging environments for product development in recent history. The market needs that a product is meant to satisfy and the technologies required to satisfy them can change radically--even as the product is under development. In response to such factors, companies have had to modify the traditional product-development process, in which design implementation begins only once a product's concept has been determined in its entirety. In place of that traditional approach, they have pioneered a flexible product-development process that allows designers to continue to define and shape products even after implementation has begun. This innovation enables Internet companies to incorporate rapidly evolving customer requirements and changing technologies into their designs until the last possible moment before a product is introduced to the market. Flexible product development has been most fully realized in the Internet environment because of the turbulence found there, but the foundations for it exist in a wide range of industries where the need for responsiveness is paramount. When technology, product features, and competitive conditions are predictable or evolve slowly, a traditional development process works well. But when new competitors and technologies appear overnight, when standards and regulations are in flux, and when a company's entire customer base can easily switch to other suppliers, businesses don't need a development process that resists change--they need one that embraces it.

The effects of N-methyl-D-aspartate receptor blockade with MK-801 upon the relationship between cerebral blood flow and glucose utilisation.

The local cerebral circulatory and metabolic effects of MK-801, a selective non-competitive N-methyl-D-aspartate receptor antagonist have been examined in conscious rats with quantitative autoradiographic techniques using [14C]iodoantipyrine and [14C]2-deoxyglucose as tracers. Local cerebral blood flow (CBF) and local cerebral glucose utilisation (GU) were measured in 41 discrete neuroanatomical loci using identical criteria for region of interest localisation. Animals received either saline or MK-801 (0.5 mg/kg in saline) intravenously 10 min prior to the start of GU determination, or 15 min before the CBF measurement. MK-801 effects an immediate transient, elevation in mean arterial pressure (elevated by 30% from baseline) which returned rapidly to preinjection levels and a sustained moderate hypercapnia (arterial carbon dioxide tension increased by 16%) which persisted throughout the measurement periods. Statistically significant changes in GU were observed in 13 brain region structures after MK-801 administration. Glucose utilisation was significantly and markedly elevated with MK-801 in some limbic structures (particularly the hippocampus, posterior cingulate and entorhinal cortices), the inferior colliculus and most of the neocortex displayed moderate reductions in GU after MK-801 treatment. In the majority of brain regions (28 or the 41 studied), MK-801 minimally altered GU. There were widespread alterations in local CBF with MK-801 although in the majority of brain regions (24 of the 41 studied) there was no statistically significant alteration in CBF with MK-801. With one exception (the anterior thalamic nucleus), CBF was increased with MK-801 in all regions in which glucose use was elevated with the drug.(ABSTRACT TRUNCATED AT 250 WORDS)