Gaps of Knowledge

The symposium upon which this volume is based was organized at a turning point in nitrosamine research. Almost all types of commercial products have been tested for volatile nitrosamines, and there have been a number of outstanding accomplishments of combined university-gov-emment-private industry actions to lower or eliminate volatile nitrosamines in those products found to be contaminated. However, there is still a major gap of knowledge with regard to compounds that are not amenable to analysis by gas chromatography, and this is clearly a frontier of current research. There are also many important questions regarding chemistry, mechanism of action, and relation to human disease whose answers lie in the future of research in this field. 

A large number of macroscopic properties of elastomer networks are closely related to the density of network junctions and the extent of their fluctuations. Qualitatively, any increase of network density causes an increase in stress, whereas fluctuations of network junctions leads to a decreasing stress. It is generally believed that a formation of additional network junctions resulting fi-om the presence of filler particles in the elastomer matrix is one of the reasons for the improvement of mechanical properties of filled elastomers. However, the application of macroscopic techniques does not provide reliable results for the network structure in filled elastomers. Furthermore, a lack of information exists on the dynamic behavior of adsorption junctions. The present study fills the gap of knowledge in this area. 

This chapter reviews secondary metabolites isolated from symbionts, organized by host taxonomy. It provides an overview of the different roles of these compounds in the chemical ecology of the interaction, if known, and discusses experimental techniques to study symbiotic systems as well as present gaps of knowledge. 

To fully realize the potential for further enhancement of productivity, which is generally assumed to be in the range of some 300% and to fully exploit the potential of RNAi, current and future studies thus aim at filling the actual gaps of knowledge and will be focused on... 

The Reverend Thomas Bayes [1702-1761] was a British mathematician and Presbyterian minister. He is well known for his paper An essay towards solving a problem in the doctrine of chances [14], which was submitted by Richard Price two years after Bayes death. In this work, he interpreted probability of any event as the chance of the event expected upon its happening. There were ten propositions in his essay and Proposition 3,5 and 9 are particularly important. Proposition 3 stated that the probability of an event X conditional on another event Y is simply the ratio of the probability of both events to the probability of the event Y. This is the definition of conditional probability. In Proposition 5, he introduced the concept of conditional probability and showed that it can be expressed regardless of the order in which the events occur. Therefore, the concern in conditional probability and Bayes theorem is on correlation but not causality. The consequence of Proposition 3 and 5 is the Bayes theorem even though this was not what Bayes emphasized in his article. In Proposition 9, he used a billiard example to demonstrate his theory. The work was republished in modern notation by G. A. Barnard [13]. In 1774, Pierre-Simon Laplace extended the results by Bayes in his article Memoire sur la probabilite des causes par les evenements (in French). He treated probability as a tool for filling up the gap of knowledge. The Bayes theorem is one of the most frequently encountered eponyms in the literature of statistics. 

Assessments of the effects/hazards to the marine environment, living resources and human activities, identification of gaps of knowledge and proposals for action with a view to filling such gaps. 

Increasingly, imaging techniques are playing a major role in the diagnosis and treatment of patients with lung disease. A number of the scans offered routinely in nuclear medicine departments are nonspecific and not fully validated. There is still a considerable gap of knowledge between the clinical usefulness of such scans and the elucidation of mechanisms of disease. 

Although the seismic behavior of beams, columns, and frames made of reinforced concrete has been studied experimentally and analytically much more thoroughly than that of walls or wall systems, there are still significant uncertainties and gaps of knowledge about it. Examples are listed under disadvantage no. 4 below. 

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