The Effect on Attribute Prediction of Location Uncertainty in Spatial Data

A datum is considered spatial if it contains location information. Typically, there is also attribute information, whose distribution depends on its location. Thus, error in location information can lead to error in attribute information, which is reflected ultimately in the inference drawn from the data. We propose a statistical model for incorporating location error into spatial data analysis. We investigate the effect of location error on the spatial lag, the covariance function, and optimal spatial linear prediction (that is, kriging). We show that the form of kriging after adjusting for location error is the same as that of kriging without adjusting for location error. However, location error changes entries in the matrix of explanatory variables, the matrix of co‐variances between the sample sites, and the vector of covariances between the sample sites and the prediction location. We investigate, through simulation, the effect that varying trend, measurement error, location error, range of spatial dependence, sample size, and prediction location have on kriging after and without adjusting for location error. When the location error is large, kriging after adjusting for location error performs markedly better than kriging without adjusting for location error, in terms of both the prediction bias and the mean squared prediction error.     

False Antitheses? Marxism,Nature and Actor‐Networks

This paper stages an encounter between two critical approaches that have been central to the recent "greening" of left geography. The theoretical and normative claims of the first approach, eco-Marxism, have been subject to sometimes biting criticism from advocates of the second approach, actor-network theory (ANT). Taking a nonorthodox Marxist perspective, I argue that the ANT critique of political economy approaches to nature is overstated and only partly defensible. By distinguishing between different modalities of eco-Marxism and ANT, I show the seeming standoff between the two approaches to society-nature relations to be false. Splitting the difference between a weak version of ANT and a relational version of eco-Marxism yields a political economy approach to socionature that arguably avoids the excesses of strong modalities of ANT and dualistic forms of eco-Marxism. By seeking to bridge the apparent gap between Marxism and ANT, the paper avoids reducing either approach to society-nature relations to one fixed position or theoretical-normative "essence". Instead, a particular modality of ANT is used to address the weaknesses of certain extant versions of eco-Marxism. The resulting synthesis offers conceptual tools with which Marxists can still critique a pervasive mode of human relationality to nature–namely, capitalist–while multiplying the actors and complicating the politics involved in approaching the society-environment nexus.     

THE ORIGIN OF THE OAK RIDGES AND ORANGEVILLE MORAINES OF SOUTHERN ONTARIO

T he O rangeville and Oak Ridges moraines have long been considered the main Iandforms constructed during the initial deglaciation of southern Ontario. Recent mapping and stratigraphic studies indicate that they were deposited rather later than the initial phase of deglaciation. This note briefly describes some of these recent developments.     

Cluster analysis of the coprolites from antelope house: Implications for anasazi diet and cuisine

This paper reports on a cluster analysis of 155 coprolites from Antelope House, a prehistoric Anasazi site in Canyon de Chelly, Arizona. The analysis revealed three primary clusters; whole kernel maize, milled maize, and nonmaize, which we believe to represent seasonal- and preference-related cuisine. Protein residue analysis on a subsample of the specimens added depth to the analysis.     

BAYESIAN SMOOTHING OF RATES IN SMALL GEOGRAPHIC AREAS*

ABSTRACT. An enormous amount of socio-economic and public-health data come as rates (e.g., unemployment, per capita income, mortality rates, census undercount) reported in small geographic areas. The U.S. Census Bureau regularly publishes data series at the county level, although the county is often a small area chosen for administrative convenience rather than by design. The reported rates can be regarded as a noisy representation of the true geographic distribution of rates over the small areas. This article presents a Bayesian statistical method of smoothing raw rates. In order to illustrate the important features of the method, a data set on undercoverage in the 1980 U.S. Census will be used.     

Evidence of an Eleventh-Century AD Cola Nitida Trade into the Middle Niger Region

Kola nut (Cola cf. nitida) and Safou fruit (Dacryodes edulis) remains have been discovered in eleventh- to fourteenth-century archaeological contexts at Togu Missiri near Ségou in Mali. These remains are evidence of early trade in perishable foodstuffs from the West African forest zone into the Middle Niger region. On the basis of these finds, this paper argues that long-distance trade links were well established by the end of the first millennium AD. It thereby supports the hypothesis that dates the inception of trade between the West African forest zone and the savanna regions to the first millennium AD. The circumstances of the find are discussed, as are the implications for our understanding of the wider exchange network based on the Niger River system in the late first and early second millennium CE.

     

Archaeogenetic study of prehistoric rice remains from Thailand and India: evidence of early <Emphasis Type="Italic">japonica</Emphasis> in South and Southeast Asia

We report a successful extraction and sequencing of ancient DNA from carbonized rice grains (Oryza sativa) from six archaeological sites, including two from India and four from Thailand, ranging in age from ca. 2500 to 1500 BP. In total, 221 archaeological grains were processed by PCR amplification and primary-targeted fragments were sequenced for comparison with modern sequences generated from 112 modern rice populations, including crop and wild varieties. Our results include the genetic sequences from both the chloroplast and the nuclear genomes, based on four markers from the chloroplast and six from the nuclear genome. These markers allow differentiation of indica rice from japonica rice, the two major subspecies of Asian rice (O. sativa) considered to have separate geographical origins. One nuclear marker differentiates tropical and temperate forms of subspecies japonica. Other markers relate to phenotypic variation selected for under domestication, such as non-shattering, grain stickiness (waxy starch) and pericarp colour. Recovery and identification of sequences from nuclear markers was generally poor, whereas recovery of chloroplast sequences was successful, with at least one of four markers recovered in 61 % of archaeological grains. This allowed for successful differentiation of indica or japonica subspecies variety, with japonica identified in all the Thai material and a mixture of indica and japonica chloroplasts in the two Indian assemblages. Rice subspecies was also assessed through conventional archaeobotanical methods relying on grain metrics, based on measurements from 13 modern populations and 499 archaeological grains. Grain metrics also suggest a predominance of japonica-type grains in the Southeast Asian sites and a mixture of japonica and indica in the Indian sites with indica in the minority. The similar results of grain metrics and ancient DNA (aDNA) affirm that grain measurements have some degree of reliability in rice subspecies identification. The study also highlights the great potential of ancient DNA recovery from archaeological rice. The data generated in the present study adds support to the model of rice evolution that includes hybridization between japonica and proto-indica.