Peter J. B. Brown

Hierarchical Aggregation Procedures for Interaction Data

Hierarchical aggregation procedures for interaction data are considered in relation to the design of spatial systems for operational versions of interaction models. Two types of application are examined, in general terms and with reference to real situations. These deal with cases such as the delimitation of subsystems for hierarchical models where the objective is to maximise the proportion of intrazonal interaction, and cases such as the definition of internal zoning systems where an objective is to minimise the proportion of intrazonal interaction. The application of the intramax procedure is illustrated with reference to the identification of migration subsystems within Greater London and the definition of labour-market areas within Merseyside, while the application of the intramin procedure is demonstrated with respect to the design of an internal zoning system for a work-trip model of the Wirral subsystem within Merseyside.

Characterisation of the soluble fraction of human syncytiotrophoblast microvillous plasma membrane-associated proteins

Syncytiotrophoblast microvillous plasma membrane (StMPM) preparations were obtained from human full-term placentae by previously published methods of cold saline extraction and phase centrifugation. Purity of these preparations was assessed by electron microscopy, enzyme analysis and hydroxyproline content. IgG, albumin, alkaline phosphatase, transferrin, ferritin and alpha 2-macroglobulin were consistently detected in the aqueous soluble fraction from sodium deoxycholate-solubilised StMPM preparations by antigenic or electrophoretic analysis, beta 2-Microglobulin was not detected in these preparations. Up to 21 discrete protein bands could be demonstrated by SDS--PAGE, and their molecular weights determined. Many of these components need to be further identified, including a glycoprotein of molecular weight 36 500 which was particularly prominent. The soluble fraction from StMPM preparations gave a single strong precipitin reaction in immunodiffusion against wheat germ agglutinin, but not against other lectins studied.

A Framework for Housing Market Area Delineation: Principles and Application

A review is presented of the requirements of a framework for the delineation of housing market areas (HMAs) in the context of undertaking a housing market assessment. This prompts adoption of a methodology that features an iterative application of information obtained from estate agents, to identify HMA cores, and a functional regionalisation of 2001 Census interward migration flows. The approach is demonstrated using data for North West England. The concluding section explores some implications of the HMA framework for policy and future research.

GIS and the analysis of spatially-referenced crime data: Experiences in Merseyside, U.K.

ABSTRACT This paper reports on the progress that has been made towards developing a GIS-based crime analysis and mapping system for used in the analysis of crime incident data recorded by the Merseyside Police force in north-west England. The system has been developed using resources from the British Urban Crime Fund; a spatially targeted anti-crime initiative aimed at reducing vehicle crime, domestic burglaries, drugs-related crime and public disorder in inner city areas. Discussion is focused on how a subset of GIS functions supported in the PC Arc View module can be employed to provide a convenient and immediately accessible means of highlighting patterns in crime statistics and the socio-demographic characteristics of areas with high levels of criminal activity.

Transferrin receptor affinity and iron transport in the human placenta

Transferrin receptor activity has been investigated on isolated human placental syncytiotrophoblast microvillous plasma membrane preparations following 3 M KCl washing of membranes to remove endogenous receptor-bound maternal transferrin. The calculated binding parameters for essentially apo- and diferric human transferrin, and also for rabbit transferrin, were closely comparable (ranges: Ka, 3.5 to 5.0 X 10(7) M-1; n, 2.6 to 4.0 X 10(14)/mg membrane protein). Iron transport in pregnancy is thus unlikely to involve a simple process of transferrin displacement following iron release at the placental trophoblast plasma membrane receptor site.

The spatial targeting of urban policy initiatives: a geodemographic assessment tool

Government frequently adopts an area-based approach to the targeting of urban policy initiatives as an indirect way of reaching the individuals that the initiatives are intended to help. The paper develops a method for assessing the success of this spatial targeting. It uses a geodemographic classification system to produce a generalised socioeconomic profile for a particular initiative. This profile can be used to examine the targeting of the initiative in different localities, in order to assess whether targeting has been inefficient (the targeted areas have been defined so that many of the people they contain are in fact not those for whom the initiative is intended) or incomplete (deserving cases have been missed because the initiatives boundaries have been drawn too tightly). The utility of the method is demonstrated by employing the P2 People and Places geodemographic system to assess the targeting of the Sure Start initiative in eight large provincial cities in England.

Epidermal growth factor receptors on isolated human placental syncytiotrophoblast plasma membrane

Receptor sites for mEGF that are specific, saturable and reversible have been demonstrated on isolated syncytiotrophoblast microvillous plasma membrane from term human placentae. Analysis of the binding data indicated the presence of two receptor populations. The high affinity population had 1.7 X 10(13) sites per mg membrane protein with an affinity constant (Ka) of 5.4 X 10(9)/M. The receptors of lower affinity had a Ka of 4.1 X 10(8)/M and 3.1 X 10(13) sites per mg membrane protein.

Isolation of a transferrin receptor structure from sodium deoxycholate-solubilized human placental syncytiotrophoblast plasma membrane

A human placental transferrin receptor structure has been isolated as a complex with doubly-radiolabelled (125I, 59Fe) human transferrin following gel filtration and affinity chromatography of sodium deoxycholate-solubilized protein from isolated syncytiotrophoblast microvillous plasma membrane vesicle preparations. The molecular weight of this complex has been determined to be 150 000 by Sepharose 6B gel filtration. The molecular weights of the constituent components of the complex have been determined by sodium dodecyl sulphate/polyacrylamide disc gel electrophoresis to be 80 000 (representing transferrin) and 65 000 (representing the deoxycholate-solubilized receptor structure). The binding activity of this placental transferrin receptor structure is maintained in sodium deoxycholate and is not requisite on being an integral component of the cell membrane.

APPLICATIONS OF GEODEMOGRAPHIC METHODS IN THE ANALYSIS OF HEALTH CONDITION INCIDENCE DATA

This paper describes how a geodemographic discriminator can be used in a variety of research contexts as a means of revealing the extent of variation in the incidence of phenomena among a population. The paper draws upon a number of applications of an approach to the use of area typologies in the investigation of a wide range of health conditions in North West England. For illustrative purposes, examples are presented which are based upon the analysis of data relating to the incidence of food poisoning in the Blackpool, Wyre, and Fylde District Health Authority area and the attendance of a drug abuse clinic in Liverpool. The first part of the paper sets the context for the application of these geodemographic methods by describing, briefly, some of the background to their development and use. The empirical section concludes with a brief discussion of refinements to the basic form of geodemographic analysis reported here.

Immunochemical identification of human trophoblast membrane antigens using monoclonal antibodies

Human trophoblast membrane antigens recognised by monoclonal antibodies (H310, H315, H316 and H317) have been identified using combinations of radioimmunoprecipitation, SDS-PAGE, electroblotting, chromatographic and ELISA-type techniques. H317 is known to identify heat-stable placental-type alkaline phosphatase and accordingly was shown to react with a protein of subunit Mr of 68 000. H310 and H316 both recognise an antigen with a subunit Mr of 34 000 under reducing conditions. In non-reducing conditions, the H310/316 antigen gave oligomers of a component of Mr 62 000. It is unknown whether this 62 000 dalton component is a dimer of the 34 000 dalton protein with either itself or a second protein chain of presumed Mr around 28 000. H315 recognises an antigen with subunit Mr of 36 000; in non-reducing conditions this component readily associates to oligomeric structures. The epitope recognised by H315 may be sensitive to SDS. The two proteins recognised by H310/316 and H315 have been termed the p34 and p36 trophoblast membrane proteins, respectively.