Mode Choice in a Hub-and-Spoke Network: A Zero-One Linear Programming Approach

While research has tackled the hub-and-spoke network design problem, that research has overlooked the air-truck modal integration issue which is a common feature of real express delivery systems. This paper devises integer linear programs to represent the mode and route assignment aspects of the operational problem. The model is solved under four different levels of delivery schedule, and the results show that as the promised delivery schedule is relaxed, not only does the use of truck routes become more desirable, but also interesting adjustments in mode and hub assignment occur. Consider the case of hubs in Los Angeles and Dayton. As the time constraints are relaxed, cities such as Minneapolis and New Orleans originally linked by air to Los Angeles, switch to Dayton because cheaper truck routes become feasible.     

Classical Central Places as Protected Thresholds

Previous research efforts demonstrate the use of location covering in the spatial structuring of central places within a single-good context. In a multilevel context, this paper similarly develops a mathematical programming approach to the siting of central places based on the “protection” of inner (or threshold) markets. The objective function maximizes both market coverage of demand and market overlap, subject to an upper bound on market overlap; this allows the formation of different market structures consistent with the various K-valued central place systems of Christaller and Lösch. Siting examples serve to illustrate the working of the protected threshold model in isotropic settings. Furthermore, ways in which the present model might be extended for other situations are examined.     

DO METROPOLITAN AREAS MEAN ANYTHING? A RESEARCH NOTE*

This note analyzes whether central cities and suburbs of a metropolitan area relate to each other in a meaningful way. Specifically, it analyzes whether there is a factor specific to the metropolitan area in central-city and suburban growth once national and regional factors have been taken into account. Data are analyzed for growth of metropolitan areas from 1960 to 1980.     

Mining sick: Creatively unsettling normative narratives about industry,environment, extraction,and the health geographies of rural,remote, northern,and Indigenous communities in British Columbia

Rural, remote, northern, and Indigenous communities on Turtle Island are routinely—as Cree Elder Willie Ermine says—pathologized. Social science and health scholarship, including scholarship by geographers, often constructs Indigenous human and physical geographies as unhealthy, diseased, vulnerable, and undergoing extraction. These constructions are not inaccurate: peoples and places beyond urban metropoles on Turtle Island live with higher burdens of poor health; Indigenous peoples face systemic violence and racism in colonial landscapes; rural, remote, northern, and Indigenous geographies are sites of industrial incursions; and many rural and remote geographies remain challenging for diverse Indigenous peoples. What, however, are the consequences of imagining and constructing people and places as “sick”? Constructions of “sick” geographies fulfill and extend settler (often European white) colonial narratives about othered geographies. Rural, remote, northern, and Indigenous geographies are discursively “mined” for narratives of sickness. This mining upholds a sense of health and wellness in southern, urban, Euro‐white‐settler imaginations. Drawing from multi‐year, relationship‐based, cross‐disciplinary qualitative community‐informed experiences, and anchored in feminist, anti‐colonial, and anti‐racist methodologies that guided creative and humanities‐informed stories, this paper concludes with different stories. It unsettles settler‐colonial powers reliant on constructing narratives about sickness in others and consequently reframes conversations about Indigenous well‐being and the environment.     

Archaeometric analysis of ceramic production in Tiwanaku state (c.500–1000 ce): An exploratory study

The chemical and mineralogical characterization of seven ceramic fragments produced within Tiwanaku state (c.500–1000 ce ) is reported. The instrumental techniques used included X‐ray elemental and mineralogical chemical analysis, Raman spectroscopy, and scanning and light microscopy. The results indicate there are several clay types, although they show similarities, such as the use of a plant‐based temper. The red colour of the decoration is hematite, and manganese oxides such as jacobsite are present in the black. The white colour is a mixture of gypsum and clay, and the orange is a mixture of hematite and clay. The use of colours, the quality of the clays and the temperatures reached during pottery firing point to expertise in ceramic production and to complex decision‐making processes. The multi‐elemental archaeometric approach documented here could become an important tool to shed a light on ancient ceramic technology and the internal variance of Tiwanaku pottery.     

From commodity to money: The rise of silver coinage around the Ancient Mediterranean (sixth–first centuries bce)

The reasons why the Western Mediterranean, especially Carthage and Rome, resisted monetization relative to the Eastern Mediterranean are still unclear. We address this question by combining lead (Pb) and silver (Ag) isotope abundances in silver coinage from the Aegean, Magna Graecia, Carthage and Roman Republic. The clear relationships observed between ¹⁰⁹Ag/¹⁰⁷Ag and ²⁰⁸Pb/²⁰⁶Pb reflect the mixing of silver ores or silver objects with Pb metal used for cupellation. The combined analysis of Ag and Pb isotopes reveals important information about the technology of smelting. The Greek world extracted Ag and Pb from associated ores, whereas, on the Iberian Peninsula, Carthaginians and Republican‐era Romans applied Phoenician cupellation techniques and added exotic Pb to Pb‐poor Ag ores. Massive Ag recupellation is observed in Rome during the Second Punic War. After defeating the Carthaginians and the Macedonians in the late second century bce , the Romans brought together the efficient, millennium‐old techniques of silver extraction of the Phoenicians, who considered this metal a simple commodity, with the monetization of the economy introduced by the Greeks.