A generally covariant system can be deparametrized by means of an “extrinsic” time, provided that the metric has a conformal “temporal” Killing vector and the potential exhibits a suitable behavior with respect to it. The quantization of the system is performed by giving the well ordered constraint operators which satisfy the algebra. The searching of these operators is enlightened by the metho...

The Gaussian Diffusion Approximation proposes that the distribution of displacements Δx for a particle diffusing through a complex fluid has a Gaussian dependence on Δx. We demonstrate from experimental evidence and computer simulations that this approximation is generally incorrect in complex fluids. As a result, experimental studies that have used the Gaussian Diffusion Approximation to inter...

ion, of course, presupposes conceptualization, and analytical foci usually revolve around ‘‘sensitizing’’ concepts that ‘‘suggest directions along which to look’’ thus providing ‘‘a general sense of relevance and guidance in approaching empirical instances’’ (Blumer, 1954:7). ‘‘Every science,’’ notes Simmel ([1908] 1959:313; [1917] 1950:11, 21), ‘‘rests upon an abstraction inasmuch as it consid...

Several important aspects of the antimicrobial resistance problem have not been treated extensively in previous monographs on this subject. This section very briefly updates information on these topics and suggests how this information is of value in assessing the contributions of human and agricultural use of antimicrobial agents on the problem of increasing antimicrobial resistance. The overa...

Despite scientific uncertainty regarding the relative safety of inhaling e-cigarette aerosol and flavorings, some consumers regard the U.S. Food and Drug Administration's "generally recognized as safe" (GRAS) designation as evidence of flavoring safety. In this study, we assessed how college students' perceptions of e-cigarette flavoring safety are related to understanding of the GRAS designati...

The extent and strength of epistasis is commonly unresolved in genetic studies, and observed epistasis is often difficult to interpret in terms of biological consequences or overall genetic architecture. We investigated the prevalence and consequences of epistasis by analyzing four body composition phenotypes--body weight, body fat percentage, femoral density, and femoral circumference--in a la...