UNLABELLED The type status is described of 404 taxa classified within the family Bulimulidae (superfamily Orthalicoidea) and kept in the London museum. Lectotypes are designated for Bulimus aurifluus Pfeiffer, 1857; Otostomus bartletti H. Adams, 1867; Helix cactorum d'Orbigny, 1835; Bulimus caliginosus Reeve, 1849; Bulimus chemnitzioides Forbes, 1850; Bulimus cinereus Reeve, 1849; Helix cora d'...

Atmospheric trends of the halon gases from polar firn air C. E. Reeves, W. T. Sturges, G. A. Sturrock, K. Preston, D. E. Oram, J. Schwander, R. Mulvaney, J.-M. Barnola, and J. Chappellez School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK Physics Institute, University of Berne, Berne, Switzerland British Antarctic Survey, Natural Environment Research Council, Cambr...

This paper extends the Lotka system of stable population equations to any population. The authors present this new general system and describe its duality with the recent Preston-Coale system. They derive these results by considering the calculus of change on the surface of population density defined over age and time. They show that analysis of this Lexis surface leads to all the known fund...

In this article we use spatial birth-death processes to estimate the number of states k of a switching model. Following Preston (1976) and Stephens (1998) matching the detailed balance condition for the underlying birth-death process results in an unique invariant probability measure with the corresponding stationary distribution of the number of states. This concept could be easily integrated ...

A total of 969 isolates of Campylobacter jejuni originating in the Preston, Lancashire postcode district over a 3-year period were characterized using multi-locus sequence typing. Recently developed statistical methods and a genetic model were used to investigate temporal, spatial, spatio-temporal and genetic variation in human C. jejuni infections. The analysis of the data showed statistically...

Demographic Studies, Duke University. An early version of this paper was presented at the Nobel Symposium in Economics, December 5-7, Lund, Sweden, 1991. I wish to acknowledge comments on this earlier draft by Nancy Birdsall, John Bongaarts, Martin Bronfenbrenner, A. W. Coats, Ansley J. Coale, Peter J. Donaldson, Richard A. Easterlin, Dennis Hodgson, Nathan Keyfitz, Geoffrey McNicoll, Thomas W....

Clinical Challenges provides readers with a forum to discuss creative clinical solutions to challenging patient care problems. Case studies or problem descriptions may be submitted with or without discussion or solutions. References, tables, figures, and illustrations can be included. Materials or inquiries should be directed to Oncology Nursing Forum Associate Editor Nancy Jo Bush, RN, MN, MA,...

Building on Preston and Campbell's two-sex model of intergenerational transmission, this article provides a theoretical analysis of the dynamics of the racial distribution in black-white-mulatto systems. The author shows that "bounded" patterns of racial classification and switching imply long-run racial homogeneity in the absence of differential reproduction. Beyond the theoretical analysis, t...