Markov Models of Inertia and Dynamism on Two Contiguous Ohio Landscapes

This study examined landcover change during 1940–1988 in two contiguous landscapes of approximately 12,400 hectares in central Ohio, USA: an inertial till plain area and a more dynamic moraine area. Agriculture dominated both landscapes throughout, however, the cover of natural vegetation and urban-suburban development increased over time on the moraine while natural vegetation decreased and agriculture increased on the till plain. Markov process models for landcover change were constructed for three 14–17-year time intervals and for the entire forty-eight-year study period. Probabilities of self-replacement for agricultural lands (0.91–0.97) were higher and those for forests (0.54–0.65) lower than those reported for other landscapes. Predictions of landcover percentages for fifty years in the future were made using Markov process models derived from actual cover changes in 1940–1957, 1971–1988, and 1940–1988. All three models produced similar predictions for the inertial till plain area. In contrast, the three models' predictions differed considerably for the moraine area. Only the 1971–1988 transition matrix was sensitive to increases in urbanization and reforestation which began on the moraine in the 1970s. These results indicate that reliance on lengthy study intervals and net rates of change can obscure spatial and temporal patterns of landcover change that are caused by natural and socioeconomic factors operating on shorter time scales.     

Book Reviews

Ken Booth and Steve Smith (eds), International Relations Theory Today, Cambridge: Polity Press, 1995. xii + 367pp. $39.95 (paper).

Christine Sylvester, Feminist Theory and International Relations in a Postmodern Era. Cambridge: Cambridge University Press, 1994. xi + 265pp. $47.50 (paper).

Stephanie Lawson (ed.), The New Agenda for Global Security: Cooperating for Peace and Beyond. St. Leonards: Allen & Unwin/Department of International Relations, RSPAS, Australian National University, 1995. xi + 217pp. $24.95.

Anne O. Krueger, Economic Policies at Cross‐Purposes: The United States and Developing Countries. Washington, DC: Brookings Institution, 1993. xii + 253pp. $US36.95 (cloth).

Robert L. Paarlberg, Leadership Abroad Begins at Home: U.S. Foreign Economic Policy After the Cold War. Washington, DC: Brookings Institution, 1995. xxv + 115pp. $US28.95 (cloth); $US10.95 (paper).

Tony Brenton, The Greening of Machiavelli: The Evolution of International Environmental Politics. London: Royal Institute of International Affairs/Earthscan, 1994. xvii + 282pp. $UK14.95 (paper).

John Charmley, Churchill's Grand Alliance: The Anglo‐American Special Relationship, 1940–1957. London: Hodder & Stoughton, 1995. xv + 427pp. $55.00 (cloth).

Victor A. Kremenyuk, Conflicts In and Around Russia. Nation‐Building in Difficult Times. Westport: Greenwood Press, 1994. xiv + 159pp. $US49.95 (cloth).

Alexander Johnston, Sipho Shezi and Gavin Bradshaw (eds), Constitution‐making in the New South Africa. London and New York: Leicester University Press, 1993. viii + 272pp. $UK 39.50.

Ramesh Thakur, The Politics and Economics of India's Foreign Policy. London: Hurst and Company; New York: St. Martin's Press, 1994. xi + 306pp. No price given.

Francis Seow, To Catch a Tartar: A Dissident in Lee Kuan Yew's Prison (with a foreword by C.V. Devan Nair). Yale Southeast Asia Studies Monograph 42, New Haven: Yale Centre for International and Area Studies, 1994. xxxiii + 293pp. $50.00 (paper).

Brij Lal, Robert Kiste and Kerry Howe (eds), The Tides of History: The Pacific Islands in the 20th Century. St Leonards: Allen & Unwin, 1994. xviii + 475pp. $34.95 (paper).

LaMond Tullis, Unintended Consequences—Illegal Drugs and Drug Policies in Nine Countries. Boulder, CO: Lynne Rienner, 1995. ix + 229pp. $US42.00 (cloth).

The United Nations and Cambodia 1991–1995, The United Nations Blue Books Series, Vol. II. New York: Department of Public Information, United Nations, 1995. 352pp. $US29.95 (paper).

‘Atu Emberson‐Bain (ed.), Sustainable Development or Malignant Growth? Perspectives of Pacific Island Women. Suva, Fiji: Marama Publications, 1994. 290pp. No price given.

Payam Akhavan and Robert Howse (eds), Yugoslavia, the Former and Future: Reflections by Scholars front the Region. Washington, DC and Geneva: The Brookings Institution and The United Nations Research Institute for Social Development, 1995. xxviii + 188pp. $US32.95 (cloth) $US 12.95 (paper).

David Camroux, ‘Looking East’ . . . and Inwards: Internal Factors in Malaysian Foreign Relations during the Mahathir Era 1981–1994. Australia‐Asia Papers No. 72. Griffith University: Centre for the Study of Australia‐Asia Relations, 1994. iii + 62pp. $10.00.     

X-RAY FLUORESCENCE AND DENSITY MEASUREMENTS ON SURFACE-TREATED ROMAN SILVER COINS*

Some 630 Roman silver coins excavated at Augusta Raurica (Switzerland) have been analysed by non-destructive X-ray fluorescence and X-ray diffraction. Furthermore, the density and the weight have been determined. The measured average density of plated and massive depletion-silvered coins is lower than the density calculated from the chemical composition, whereas massive coins display equal values for both of the densities. Based on experimental X-ray investigations of modern silver (tempering, acid treatment, production of corrosion layers), the nature of corrosion products on silver, their impact on surface analysis, and aspects of wearing-off by circulation are briefly discussed.     

ELECTRON SPIN RESONANCE THERMOMETRY APPLIED TO QUARTZITE COBBLES FROM VERGELEGEN SLAVE LODGE,SOMERSET WEST,SOUTH AFRICA

This paper describes the use of electron spin resonance spectroscopy to estimate the degree of heating of quartzite cobbles from hearths on the floor of the archaeological remains of an eighteenth-century Dutch colonial slave lodge. A novel technique based on the comparison of line intensities for the E’and O^-₂ centres in quartz distinguished successfully between cobbles which had been heated to estimated temperatures ranging from 300 °C to 450° C and controls from an adjacent stream bed. This inexpensive and simple technique could be applied to a wide range of archaeological problems involving the thermal history of objects consisting of or containing quartz.     

A MIXED-FREQUENCY MODEL OF REGIONAL OUTPUT*

ABSTRACT. This paper proposes a new method for estimating a monthly regional production model. The technique involves treating the region's monthly industrial output as a latent variable, which is in turn a function of capital (prosed by energy usage) and labor inputs. Annual observations on regional value added correspond to the summation of the unobservable monthly series over the 12 months, while changes in the national Industrial Production index help infer the series' month-to-month fluctuations. The model is estimated using the Kalman filter and the method of maximum likelihood. The estimates are used to compute monthly indices of regional value added for 15 individual 2-digit industries, and for the aggregate manufacturing sector in the Seventh Federal Reserve District. In a comparison of out-of-sample forecasting accuracy, the mixed-frequency model outperforms both the traditional parametric Cobb-Douglas and nonparametric Atlanta methods over the 1988–89 forecasting horizon.