Droughts as random events in the Maya lowlands

Because the values of most of the parameters controlling the occurrence and severity of a drought in a given location are unknown, and no periodicity has been observed, droughts can be considered random events. Running a random number generator within the limits of the annual rainfall variability relevant to the Maya lowlands, and defining a “Lean Year”, it is observed that strings of lean years occur quite frequently. Defining “Severe Drought”, “Disaster”, and “Catastrophe” based on the length of these strings, it is observed that a severe drought occurs on average every 32 years, a disaster occurs on average every 130 years, and a catastrophe on average every 500 years. These values fit the measured variability of the Yucatan climate, as observed in lake core sediments and in the post conquest written records. It also fits the average occurrence of “megadroughts” in the US Great Plains.The fit between the random occurrence model and the actual, “measured” occurrence of droughts supports the notion that for all practical purposes, droughts had been random events in the Maya region and could not be predicted. The lack of evident periodicity could be one of the reasons why means for long-term storage of food products were not developed there. It may also have affected the relationship between the priesthood and the general populace in that region.Since the method described here can be applied to any climatic region once the rainfall variability and the sensitivity of the local agriculture are known or can be estimated, if similar results are found they may probably have affected other regions with other ancient cultures in a similar way.     

Influence of seabird guano and camelid dung fertilization on the nitrogen isotopic composition of field-grown maize (Zea mays)

Organic fertilizers have the capacity to alter the nitrogen isotopic composition of plants. Camelid dung and seabird guano are two potentially important fertilizers in the agricultural systems of western South America, particularly Peru and Chile. This paper presents isotopic data (δ¹³C and δ¹⁵N) from field grown plants (maize, Zea mays) fertilized with the following four treatments: CO (control, no fertilizer applied), AS (ammonium sulfate, a chemical fertilizer), DU (camelid dung), and SG (seabird guano). Plants were grown in experimental plots in the Virú Valley, northern Peru. Plants fertilized with the chemical fertilizer presented very similar isotopic compositions compared to the control. Conversely, the camelid dung fertilized plants were characterized by higher δ¹⁵N values compared to the control plants (by 1.8 to 4.2‰ depending on the plant part). The seabird guano fertilized plants were greatly enriched in ¹⁵N in comparison to the control plants (by 11.3 to 20.0‰). The results of this study have important implications for the reconstruction of human diet using isotopic data derived from bone collagen and related tissues, particularly in the prehispanic Andes, but also in Europe and North America during the 19th century, when Peruvian seabird guano was used extensively. Specifically, the interpretation of the relative contributions of plant and animal protein to the diet on the basis of bulk isotopic compositions of bone collagen (or similar tissues) may be confounded by camelid dung fertilization if the carbon isotopic compositions of the two sources are similar. Likewise, the interpretation of the relative contributions of maize and marine protein may be confounded by seabird guano fertilization.     

Theory and methods in settlement studies

Ruth S. Tringham, ed. Ecology and Agricultural Settlements: An Ethnographic and Archaeological Perspective. Andover, Mass.: ‘Warner Modular Publications, 1973. Unpaginated (ca. vi + 146 pp.). Tables, figures, and notes. (paper).

Ruth S. Tringham, ed. Territoriality and Proxemics: Archaeological and Ethnographic Evidence for the Use and Organization of Space. Andover, Mass.: Warner Modular Publications, 1973. Unpaginated (ca. vi + 115 pp.). Tables, figures, and notes. (paper)

Ruth S. Tringham, ed. Urban Settlements: The Process of Urbanization in Archaeological Settlements. Andover, Mass.: Warner Modular Publications, 1973. Unpaginated (ca. vi + 122pp.). Tables, figures, andnotes. (paper).     

Power,Energy and Structure

Richard Newbold Adams. Energy and Structure: A Theory of Social Power. Austin and London: University of Texas Press, 1975. xviii + 353 pp. Figures, tables, references and index. $15.00 cloth, $4.95 paper.     

In the cause of science

Jane C. Steward and Robert F. Murphy, eds. Evolution and Ecology: Essays in Social Transformation by Julian H. Steward. Urbana: University of Illinois Press, 1977. ix +406 pp. Maps, figures, references, biographical notes. $12.95.     

Two AHA Sessions: The Revolutionary Mr. Kuhn and the Evolutionary Mr. Bertalanffy

Abstract

Quantitative methods of content analysis have become established in most subfields of political science, but remain relatively unutilized in studies of political theory, despite the exclusive focus of that subfield on textual sources. This article develops a variation of content analysis—termed usage analysis—and employs it to resolve a standing debate in scholarship on Cicero's political theory regarding the synonymy of the major Latin terms for the state (civitas and res publica). The resulting distinction between these concepts then informs an exposition of Cicero's ideal state not as the Roman Republic itself or the mixed constitution alone, but as a universal, everlasting political society supported by justice, a mixed constitution, and active citizenship.     

International Regimes and Commercial Hegemony: Control of the Arabian Littoral, 1800–1905

Herbert Hoover's Plan for Ending the Second World War; Joan Hoff Wilson

Modern Chinese Diplomatic History: A Guide to Research; Immanuel C.Y. Hsu     

Transit Access for Americans: A Proposal for the Next Stage of Implementing the Americans With Disabilities Act of 1990

Formany Americans with disabilities, transit is the only path to real opportunities. An open society for them depends upon increased transit services for all Americans. Many transit professionals, however, daunted by transit needs and worn down by their critics, wallow in cost issues, ignoring transit's real value to their communities. The key to improvement is to measure transit benefits that are intuitively obvious to most taxpayers. Empirically, accessible transit proves to be the most valuable transit to passengers and to other taxpayers as well.