The two-and three-dimensional nucleation and the metal ion adsorption process are discussed as initial steps for electrocrystallization on the same or on a foreign substrate. The metal ion adsorption takes place in the underpotential range, which is more positive than the equilibrium potential of the nucleated metal/metal ion electrode. Thermodynamic considerations show that an overlapping of disturbing processes in the underpotential range can be characterized by a factor ZE, which is called charge-coverage coefficient or electrosorption valency. It is a function of different independent variables. The metal monolayer model is satisfied only in the simplest case for ZE :-Z (valency of metal ions in solution).The different experimental methods for determining the thermodynamics, kinetics, and structure of metal ion adsorbates are critically discussed. The most reliable thermodynamic results are obtained by the twin-electrode thinlayer technique. Kinetic data can be obtained by pulse measurements under potentiostatic-galvanostatic conditions. The structure of metal films can be determined by combining different methods including optical investigations.Results are given for different systems. In the systems Au/Ag +, Au/T1 +, and Au/Pb + + the metal monolayer model is practically valid. In the case of Cu + + ion adsorption on Au the redox reaction forming Cu + ions acts as a disturbing process. A cosorption of anions takes place in the system Ag/Pb + +. The formation of alloys in the underpotential range was observed in the systems Pt/Pb + + and Bi/Pb + + The structure of metal ion adsorbates must be in correlation with the nucleation phenomena at more negative potentials. In many systems no three-dimensional nucleation overvoltage is observed by using a quasi-steadystate experimental technique. The density of the crystal imperfections and the crystallographic orientation of the surface planes influence the metal ion adsorption process and the structure of films. The results obtained in the systems Ag (poly-and monocrystalline)/T1 + can be explained by assuming the formation of superlattices on the electrode surface.Kinetic investigations in the systems Au/Ag +, Au/T1 +, and Au/Pb § + show relatively high exchange current densities for the metal ion adsorption process. In these cases the experimental results can be explained by assuming surface diffusion of adions as the rate determining step in the adsorption process. In the system Au/Cu + +, a charge transfer step is rate determining, which probably forms precedingly Cu + ions.Crystallization phenomena play an important role in the case of cathodic metal deposition. They include different steps after the metal ion has passed through the electrochemical double layer and is still partially solvated. The final state can be described as the in-* Electrochemical Society Active Member. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 205.208.120.206 Downloaded on 2014-12-26 to IP ) unless CC L...

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In the biomedical context, policy makers face a large amount of potentially discordant evidence from different sources. This prompts the question of how this evidence should be aggregated in the interests of best-informed policy recommendations. The starting point of our discussion is Hunter and Williams' recent work on an automated aggregation method for medical evidence. Our negative claim is that it is far from clear what the relevant criteria for evaluating an evidence aggregator of this sort are. What is the appropriate balance between explicitly coded algorithms and implicit reasoning involved, for instance, in the packaging of input evidence? In short: What is the optimal degree of 'automation'? On the positive side: We propose the ability to perform an adequate robustness analysis (which depends on the nature of the input variables and parameters of the aggregator) as the focal criterion, primarily because it directs efforts to what is most important, namely, the structure of the algorithm and the appropriate extent of automation. Moreover, where there are resource constraints on the aggregation process, one must also consider what balance between volume of evidence and accuracy in the treatment of individual evidence best facilitates inference. There is no prerogative to aggregate the total evidence available if this would in fact reduce overall accuracy. B Nicolas Wüthrich