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Recent theoretical, methodological, and technological advances in the spatial sciences create an opportunity for social scientists to address questions about the reciprocal relationship between context (spatial organization, environment, etc.) and individual behavior. This emerging research community has yet to adequately address the new threats to the confidentiality of respondent data in spatially explicit social survey or census data files, however. This paper presents four sometimes conflicting principles for the conduct of ethical and high-quality science using such data: protection of confidentiality, the social-spatial linkage, data sharing, and data preservation. The conflict among these four principles is particularly evident in the display of spatially explicit data through maps combined with the sharing of tabular data files. This paper reviews these two research activities and shows how current practices favor one of the principles over the others and do not satisfactorily resolve the conflict among them, Maps are indispensable for the display of results but also reveal information on the location of respondents and sampling clusters that can then be used in combination with shared data files to identify respondents. The current practice of sharing modified or incomplete data sets or using data enclaves is not ideal for either the advancement of science or the protection of confidentiality. Further basic research and open debate are needed to advance both understanding of and solutions to this dilemma. [ABSTRACT FROM AUTHOR]

In early 1980, Irwin A. Rose, Avram Hershko, and Aaron Ciechanover published two papers in PNAS that reported the astounding observation that energy-dependent intracellular proteolysis was far more complicated than the previously accepted models of lysosomal proteolysis or the action of ATP-dependent proteases such as bacterial Ion. In fact, it has turned out to be even more complicated than they could have suspected. The general model of covalently attaching a small protein as a targeting signal has proved to be every bit as important to eukaryotic cells as the better understood modifications such as phosphorylation or acetylation. The key player in this modification, a small protein called ubiquitin (APF-1 in these papers), is the founding member of a large family of proteins containing the β-grasp fold and is used as a posttranslational targeting signal to modify the structure, function, and/or localization of other proteins. The story of this discovery is a textbook example of the confluence of intellectual curiosity, unselfish collaboration, chance, luck, and preparation. [ABSTRACT FROM AUTHOR]

Phase space can be constructed for N equal and distinguishable subsystems that could be probabilistically either weakly correlated or strongly correlated. If they are locally correlated, we expect the Boltzmann-Gibbs entropy SBG ≡ -kΣipi In pi to be extensive, i.e., SBG(N) ∞ N for N → ∞. In particular, if they are independent, SBG is strictly additive, i.e., SBG(N) = NSBG(1), ∇N. However, if the sub- systems are globally correlated, we expect for a vast class of systems, the entropy Sq ≡ k[1 - Σipig/(q - 1) (with S1 = SBG) for some special value of q ≠ 1 to be the one which is extensive [i.e., Sq(N) ∞ N for N → ∞]. Another concept which is relevant is strict or asymptotic scale-freedom (or scale-invariance), defined as the situation for which all marginal probabilities of the N-system coincide or asymptotically approach (for N → ∞) the joint probabilities of the (N - 1)-system. If each subsystem is a binary one, scale-freedom is guaranteed by what we hereafter refer to as the Leibnitz rule, i.e., the sum of two successive joint probabilities of the N-system coincides or asymptotically approaches the corresponding joint probability of the (N - 1)-system. The kinds of interplay of these various concepts are illustrated in several examples. One of them justifies the title of this paper. We conjecture that these mechanisms are deeply related to the very frequent emergence, in natural and artificial complex systems, of scale-free structures and to their connections with nonextensive statistical mechanics. Summarizing, we have shown that, for asymptotically scale-invariant systems, it is Sq with q ≠ 1, and not SBG, the entropy which matches standard, clausius-like, prescriptions of classical thermodynamics. [ABSTRACT FROM AUTHOR]

In this article, we begin by reviewing the concept of step migration that originated in E. G. Ravenstein's seminal papers "The Laws of Migration" (1885, 1889). As a result of the forces of the Industrial Revolution underway in 19th century Great Britain, migrants moved from farms to villages, from villages to towns, from towns to county seats, and thence to large cities. Throughout much of the industrialization era in the United States, net population movements similarly were upward within the urban hierarchy, and step migration today remains widespread throughout much of the still developing world. Our investigations of recent data and trends, however, suggest that the latest U.S. migration-pattern regime is a strongly contrasting one. Many of the major movements in the system of internal (or domestic) migration are flows down the urban hierarchy, although we note highly differentiated patterns for persons and households at specific stages of the life course. We make use of the newly defined metropolitan and micropolitan Core-Based Statistical Areas (CBSAs) and a seven-level size typology to tabulate origin-destination-specific migration flow data from both Census 2000 and IRS tax-return administrative records for the period 1995-2000. We discuss the causes for net movements being either upward or downward in the national urban hierarchy, including the effects of spatially focused immigration, and movement preferences at various ages, including migration in young adulthood associated with entering and leaving college and the military, as well as moves characteristic of the stages of family formation, childrearing, and retirement. [ABSTRACT FROM AUTHOR]

This article presents information on the various topics discussed in the October 25, 2005 issue of the journal "Proceedings of the National Academy of Sciences of the United States of America." It brings together a collection of seven papers representing work in emerging areas of spatial demography, with special reference to North America. Although place, density, and movement have always had a part in population studies, they have not often held center stage. Demographers' prime coordinates are the two time-like coordinates of time and age. The three space-like coordinates of physical location and the many-dimensional coordinates of social location have tended to play supporting roles.