Description: This book chapter discusses the prediction of partition coefficients and permeability of drug molecules in biological systems with Abraham model solute descriptors derived from measured solubilities and water-to-organic solvent partition coefficients.

Description: This article discusses principal resonance contributors to high-valent, transition-metal alkylidene complexes. The results of ab initio calculations are reported for prototypical high-valent, alkylidene complexes. Stationary points on each potential energy surface are characterized and compared to experimental information where available; as long as a suitably flexible valence basis set is used, good agreement between theoretically calculated and experimentally determined geometries is obtained. The complexes of interest include group IVB (Ti, Zr and Hf) and group VB (Nb and Ta) alkylidenes with hydride ligands as well as models for the four-coordinate, olefin metathesis catalysts (Mo-, W-, and Re-alkylidenes) which have been recently synthesized and characterized. In light of the fact that much of the discussion concerning the reactivity of transition-metal carbene complexes has been presented in terms of the resonance contributors derived from rearranging the electrons in the M-C σ and π orbitals, the minima obtained from the portion of the study are then subjected to a further procedure to calculate these contributions. Resonance structures in which the carbon is the negative end of the M-C bond (i.e., nucleophilic resonance structures) contribute 50% to the ground-state wave function of these complexes. Those in which the carbon is formally neutral account for ...

Description: In this article, the authors introduce a new method for detecting scaling in time series. The method uses the properties of the probability flux for stochastic self-affine processes and is called the 'probability flux analysis' (PFA). The advantages of this method are: 1) it is independent of the finiteness of the moments of the self-affine process; 2) it does not require a binning procedure for numerical evaluation of the probability density function. These properties make the method particularly efficient for heavy tailed distributions in which the variance is not finite, for example, in Lévy α-stable processes. This utility is established using a comparison with the 'diffusion entropy' (DE) method.

Description: This article discusses projectile charge-state dependence of K-shell ionization by silicon ions. X-ray production cross sections measured in K-shell ionization of ₂₁Sc, ₂₂Ti, ₂₉Cu, and ₃₂Ge by 52-MeV ₁₄²⁸Si(+q) projectiles with q=7 to 14 are reported, which demonstrate, through their charge-state dependence, the validity of a recently developed electron-capture theory with a reduced binding effect. Furthermore, the data provide evidence for the applicability of the perturbed stationary-state theory of direct ionization for values of 0.44 ≤ Z₁/Z₂ ≤ 0.67.

Description: This report is on the workshop 'Transformative Research: Ethical and Societal Implications'. Workshop conversations cluster under the four headings of the history and definitions, promotion, evaluation, and integration of transformative research (TR): 1. History and Definitions: The National Science Board's 2007 report (NSB-07-32) on transformative research called for more effort directed at defining TR. The present report offers additional context and clarity regarding meanings of the term. But it also argues that there are virtues in leaving the term open to multiple interpretations. 2. Promotion: The report welcomes new mechanisms for promoting TR, such as NSF 'CREATIV' grants. It embraces additional means for promoting TR, such as increased emphasis on interdisciplinary research, and explores how different interpretations of how TR occurs imply different strategies for promoting TR. It also calls for increased attention to the broader societal impacts of TR at the levels of policy, of NSF programs, and of individual research projects. 3. Evaluation: The report emphasizes the need to develop means for evaluating attempts to promote TR. It also concludes that research should be directed toward evaluating transformative research at the project level. 4. Integration: The report suggests that consideration of the broader societal impacts of TR be ...