Aggregation and Ecological Effects in Geographically Based Data

Statistics calculated using the means of geographic areas can differ substantially from the corresponding statistics based on data from individuals. Analysts who base their conclusions about individual-level relationships on area-level analyses run the risk of committing the ecological fallacy. Statistical models are proposed that capture the essential features of the structure of a population composed of geographically defined groups and can encompass grouping processes and contextual effects. These models are used to show how small effects in the analysis of individual-level data can be magnified substantially when the corresponding analysis based on aggregated data is carried out. Thus the source of aggregation effects is exposed. While aggregation effects have been studied by many authors, no general approach has been offered to the problem of adjusting an area-level analysis so as to correct for aggregation effects and hence remove, or at least reduce, the bias that leads to the ecological fallacy. The statistical models proposed are used to provide an approach to this problem. Data from the 1991 U.K. Census of Housing and Population are used to illustrate the size of the aggregation effects and the extent to which the proposed adjustments succeed in their objective.     

Charcot and aphasia

Whereas the beginning part of Charcot's career was occupied with a rigorous and unerring devotion to the anatomo-clinical method, his later career shared attention with physiologic and psychological analyses of hysteria. The seeming paradox between these differing approaches to neurologic study can be better understood by an analysis of Charcot's work on aphasia. This area of study grew out of Charcot's larger research effort on cerebral localization, but was not well known, because most of his lectures on aphasia were never widely published or distributed in either French or English. In analyzing aphasia, Charcot began with anatomic lesions, but gradually incorporated cases of hysterical aphasia, as evidence of dynamic lesions of the same brain areas. Although aphasia never represented a prominent area of study for Charcot, it held a particularly important place in his career first because it provided this transition between anatomic and physiologic approaches to neurologic research, and second because it permitted a natural two-way passage between the topics of cerebral localization and hysteria.     

LEAD ISOTOPE CHARACTERISTICS OF THE CYPRUS COPPER ORE DEPOSITS APPLIED TO PROVENANCE STUDIES OF COPPER OXHIDE INGOTS

Nearly 200 new lead isotope analyses of sulphidic and oxidized ores from 26 copper mines on Cyprus show that the mines from different geological regions group in five distinctive isotopic groups, each with a substructure, related to the geological history of the ore formation. Comparison of lead isotope compositions of Bronze Age artefacts with these data can in many cases reveal the actual mines from which the copper for particular artefacts was obtained. The particular case of the provenance of the copper for 78 Late Bronze Age copper ‘oxhide ingots’found in Cyprus, Crete, Greece, Sardinia, Turkey and Bulgaria is discussed. The data show that all oxhide ingots so far analysed, dating to the fourteenth century BC and later, were made of copper consistent isotopically with only one mining region in the geographical north of Cyprus, and especially the Apliki mine. The study provides further evidence which supports the validity of the conventional approach to the use of lead isotope analysis for provenancing metals; this evidence is antithetical to recent suggestions of a model for the production of copper oxhide ingots which involved widespread mixing of copper from a number of ore sources throughout the Mediterranean.     

KIMMERIDGE JET—A POTENTIAL NEW SOURCE FOR BRITISH JET

Archaeological artefacts identified as jet are often assumed to have originated from the principal British source, which is at Whitby in Yorkshire. Geological samples of jet have also been found within the Kimmeridge Blackstone in Dorset—a seam of oil shale which has been worked since prehistoric times to produce artefacts similar to those made from jet. This paper discusses the geology and geochemistry of jet samples from both Whitby and Kimmeridge, and shows that the geological samples can be discriminated by differences in their organic components, as elucidated by Fourier transform infrared spectroscopy and pyrolysis-gas chromatography/mass spectrometry.     

Migration Under Uncertainty: “Try Your Luck” or “Wait and See”

Two types of uncertainty enter into the migration decision. First, current conditions in the destination region may not be observable. Second, the future evolution of conditions in both the origin and destination regions may be unknown. The first type of uncertainty can encourage speculative or “try your luck” migration, whereas uncertainty about the future acts in the opposite direction, deterring relocation. This paper presents a dynamic optimizing model of migration that incorporates both types of uncertainty. The model shows that in equilibrium uncertainty about the future is likely to be more important than uncertainty about present conditions in the decision to relocate.     

Masked Popery and Pyrrhonian Uncertainty: The Early Scottish Covenanters on Arminianism

In Jacobean and Caroline Scotland there was little Arminianism to be found, whether in its Remonstrant (Dutch) or Laudian (English) versions. Nevertheless, the representation of this teaching by a few Scottish divines, its more strenuous advocacy in England, and reports of its spread in Europe unnerved those who would lead the covenanting movement after 1638.
Arminianism represented a two-pronged threat to the Calvinist covenanting vision. Its attempt at moderation in the theological strife of the time approximated a compromise with, if not a surrender to, popery. But Arminianism also suffered from an identification with the scepticism then fermenting in European philosophy. The decay of a providential worldview undercut the national self-image of Scotland at the forefront of resurgent Reformed religion. The significance of free will threatened the individual's assurance of election. The loss of certainty about theological authority, accepting the individual's right to interpret the Bible and to express his views publicly, shattered the ideal of a religiously uniform society. Thus considered, the persistent interest in Arminianism provides a useful perspective on the mind of the covenanting movement.     

The unique decline of mortality in revolutionary France

This article seeks to draw historians' attention to a neglected reconstruction of the French population and its mortality rates developed by the Institut National d'Etudes Démographiques in the 1970s. The reconstruction shows a sharp decline in French mortality rates, beginning in the 1790s and continuing through the 1820s. This conflicts with recent historiography stressing the negative effects of the Revolution. This article contends that the reconstruction is plausible and that the French mortality decline was unique in Europe in this period. In turn, this suggests that the Revolution had a much more favorable impact than many historians would have us believe.     

FIBS in Archaeobotany: Functional Interpretation of Weed Floras in Relation to Husbandry Practices

The application of “FIBS” (Functional Interpretation of Botanical Surveys) to the interpretation of archaeobotanical weed floras, as evidence of past husbandry practices, is explored. To illustrate the potential of the approach, present-day cereal fields in N. Spain are analysed in terms of the functional attributes of the weed species represented in dry-farmed and irrigated fields. Functional attributes are identified which relate in predictable ways to the quality of plant growth and the severity of drought. These attributes are successful in discriminating dry-farmed and irrigated fields. This investigation opens up the way for more general application of the method in the archaeobotanical study of crop husbandry. FIBS (a) permits the “translation” of ecological information from one group of species to another, via functional attributes, and (b) through an understanding of the ecological processes involved, provides a potential mechanism for reconstructing extinct agricultural regimes for which modern analogues do not exist. This presents an alternative to the traditional use of ecological indices (which are open to circularity of interpretation) or phytosociological groupings (for which there may not have been exact parallels in the past). The relevance of particular functional attributes to husbandry methods other than irrigation now needs to be explored in order to develop the methodology for general application to archaeobotanical weed assemblages.