Future directions predicting/understanding

Elevation predictions from tectonic models alone only provide simple guidance because topography is the product of complex reactions among climate, erosion and tectonics. Paleoelevation techniques discussed in this volume measure different aspects either directly or indirectly of topography some techniques are sensitive to local elevation, some to relief, and some rely on proxies of environmental variables. Future directions may include measurement of different variables of the tectonic-climate-erosion system independently from one another and understanding the interaction between them. From these relationships, directly or indirectly, the geodynamic processes may be further constrained. 

Future Directions. Hofiftnann (2) wrote in 1982, It is hoped that in the course of time enough analysis will be done to confirm relationships between analysis and response to specific treatments. In 1987, Grattan and Clarke (7) stated, We are able to analyse wood chemically and give it a detailed biological description, but at present it is very difficult, except in the most general terms, to understand what this predicts for the treatment. ... 

To seek compounds with optimal characteristics for external and internal transfer on a rational basis requires an understanding of pesticide availance and how this is influenced by physico-chemical and biophysical properties to predict the most effective compounds then requires a knowledge of the relationship between these properties and molecular structure. This paper briefly reviews the considerable progress which has been made in these directions and the prospects for future advance. 

This has provided computational chemistry with a unique opportunity to influence the development of silicon chemistry not only by providing interpretations to experimental findings but more importantly by making predictions and directing future experiments. Indeed in the last decade theoretical calculations played a major and sometimes even a crucial role in the development of silicon chemistry [5]. In this paper we hope to demonstrate the importance of theory for understanding and predicting the properties and chemistry of silylenes and of disilenes. 

Advances in the understanding of the immunobiology of skin sensitization have led to the establishment of predictive in vivo tests which not only identify sensitizing hazards but also characterize their potency. Recently, appreciation of the underlying biology has also resulted in the development of mechanistically based in vitro alternatives which offer the prospect of the replacement of current in vivo methods. Assays under active validation include the Direct Peptide Reactivity Assay (DPRA), the human Cell Line Activation Test (h-CLAT), and KeratinoSens. None of the methods have a sufficient level of accuracy or freedom from applicability domain limitations to allow them to act as a standalone replacement. Consequently, it will be necessary to consider how to deploy these assays, perhaps in combination and/or in a structured assessment of skin sensitization hazard, to ensure at least the same level of predictive accuracy as the in vivo methods. However, a challenge remains the capacity of these methods to provide potency information on skin-sensitizing chemicals has yet to be assessed. This is an essential requirement for future risk assessment without use of animal models if we are to retain the same level of human health protection that is currently delivered. 

Finally it seems appropriate in this summary to attempt to extrapolate from the status of the current MCSCF methods reviewed here and to predict the direction of future developments. There are several forces at work in the developments of the last few years that are likely to remain in place in the future. The increased availability of computer resources to computational chemists will tend to fuel the quest for more accurate calculations and for the qualitative understanding of the results of ever more sophisticated calculations. The MCSCF method will be central to this development because it... 

---