BIOLOGICAL SYSTEMS AS ORGANIZATIONAL PARADIGMS†

It is suggested that biological systems provide the best source of paradigms for the consideration of the kinds of organizations which we find in human systems; social, political or economic. A brief review of the several ways in which biological activities can be mathematically modelled is given, together with indications of the manner in which these ideas can be extended and applied beyond biology.     

WEAKENING STRONG BLACK POLITICAL EMPOWERMENT: IMPLICATIONS FROM ATLANTA'S 2009 MAYORAL ELECTION

Atlanta is perhaps the city with the greatest degree of black political empowerment (BPE) in the United States. Yet in 2009 a relatively weak white mayoral candidate nearly won the general and runoff elections over a field of stronger black candidates. Why? Treating Atlanta as a prototypical case, the article examines factors that undermine the capacity of blacks to retain control of mayoralties in strong BPE cities, with an emphasis on disruptions to black electorates, discontent among black citizens, and reinvestment in electoral politics by whites at the local level.     

Symmetrical overhead in flow networks

Recent work by one of the authors has identified the average mutual information and the conditional entropy as two measures from information theory that are useful in quantifying the system organization and incoherence, respectively. While the scaled average mutual information, or network ascendency, is inherently symmetrical with respect to inputs and outputs, the scaled conditional entropy, or overhead, remains asymmetrical. Employing the joint entropy, instead of the conditional entropy, to characterize the overhead, results in a symmetrical overhead and also permits the decomposition of the system capacity, or complexity, into components useful in following the response of the whole system to perturbations.     

URBAN POLICY,PRESS, AND PLACE: CITY‐MAKING IN FLORIDA'S MIAMI‐DADE COUNTY

This article enhances the notion of city‐making by explicating its communicative processes and functions within the press. Through a quantitative content analysis and qualitative textual analysis of Miami Herald news coverage related to incorporation and annexation policies and practices over a period of 3 years, we argue for a stronger implication of the press in coverage of local policy‐ and place‐making. Through a quantitative content analysis of 437 articles from the Miami Herald about communities affected by incorporation and annexation and a qualitative textual analysis of 51 articles related to general coverage of geographic policy‐making in Miami‐Dade County over a 3‐year period, we argue that this coverage reveals the press as being a central feature and function of policy‐making through the lens of city‐making.     

COMPLEXITY AND ERROR IN SOCIAL DYNAMICS

A model of cultural dynamics based on the work of Colin Renfrew is briefly described. It is shown how the general concepts of complexity and error pertain to this kind of cultural model. In particular, it is suggested that conflict in cultural contexts arises through the generation of diverse simple models of the culture, created by different members of the culture. We indicate how general system-theoretic concepts can thus be brought to bear on problems of conflict in and between cultures.     

Milling parameter optimization through a discrete variable transformation

Although milling is one of the most common chip metal removal processes, little has been done to aid in identifying the optimum operational conditions for milling processes. In this paper, a mathematical model for milling operations is developed and the five primary control variables identified. The model is then decomposed and an efficient optimization procedure developed for control variable identification.     

Minimal realizations of transfer-function matrices by means of matrix continued fraction

The matrix continued fraction technique is utilized to obtain the minimal realization of a transfer-function matrix with various inputs and outputs. If the ratio of the rank and the order of a square transfer-function matrix is an integer and there are no numerically ill-conditional elements in the matrix, then the matrix Routh algorithm is applied for the minimal realization. A method is also presented to deal with ill-conditional cases.     

c4-Heptenal: An Influential Volatile Compound in Boiled Potato Flavor

Analysis of headspace volatile concentrates from freshly boiled Russet Burbank potatoes revealed a variety of lipid oxidation products including t2,c6-nonadienal which is further degraded to c4-heptenal through a water-mediated retro-aldol condensation reaction. Dilute aqueous solutions of c4-heptenal exhibited boiled potato-like aromas, and at relatively high concentrations (greater than 0.7 ppb) added c4-heptenal contributed distinct staling-type flavor defects to both fresh, mashed potatoes and reconstituted dehydrated potatoes. When added at levels between 0.1–0.4 ppb, c4-heptenal enhanced overall earthy, potato-like flavors in freshly boiled mashed potatoes, but these levels caused stale flavors in reconstituted dehydrated potatoes.