Monitoring international migration flows in Europe. Towards a statistical data base combining data from different sources

The paper reviews techniques developed in demography, geography and statistics that are useful for bridging the gap between available data on international migration flows and the information required for policy making and research. The basic idea of the paper is as follows: to establish a coherent and consistent data base that contains sufficiently detailed, up-to-date and accurate information, data from several sources should be combined. That raises issues of definition and measurement, and of how to combine data from different origins properly. The issues may be tackled more easily if the statistics that are being compiled are viewed as different outcomes or manifestations of underlying stochastic processes governing migration. The link between the processes and their outcomes is described by models, the parameters of which must be estimated from the available data. That may be done within the context of socio-demographic accounting. The paper discusses the experience of the U.S. Bureau of the Census in combining migration data from several sources. It also summarizes the many efforts in Europe to establish a coherent and consistent data base on international migration. The paper was written at IIASA. It is part of the Migration Estimation Study, which is a collaborative IIASA-University of Groningen project, funded by the Netherlands Organization for Scientific Research (NWO). The project aims at developing techniques to obtain improved estimates of international migration flows by country of origin and country of destination

A Sensitive High-Throughput Assay for Evaluating Host-Pathogen Interactions in Cryptococcus neoformans Infection

Background: Cryptococcus neoformans causes serious disease in immunocompromised individuals, leading to over 600,000 deaths per year worldwide. Part of this impact is due to the organism’s ability to thwart what should be the mammalian hosts ’ first line of defense against cryptococcal infection: internalization by macrophages. Even when C. neoformans is engulfed by host phagocytes, it can survive and replicate within them rather than being destroyed; this ability is central in cryptococcal virulence. It is therefore critical to elucidate the interactions of this facultative intracellular pathogen with phagocytic cells of its mammalian host. Methodology/Principal Findings: To accurately assess initial interactions between human phagocytic cells and fungi, we have developed a method using high-throughput microscopy to efficiently distinguish adherent and engulfed cryptococci and quantitate each population. This method offers significant advantages over currently available means of assaying hostfungal cell interactions, and remains statistically robust when implemented in an automated fashion appropriate for screening. It was used to demonstrate the sensitivity of human phagocytes to subtle changes in the cryptococcal capsule, a major virulence factor of this pathogen. Conclusions/Significance: Our high-throughput method for characterizing interactions between C. neoformans and mammalian phagocytic cells offers a powerful tool for elucidating the relationship between these cell types durin

Convergence and related properties for a modified biproportional matrix problem

This paper establishes the convergence of iterative routines formatrix balancing in which some row and some column totals must equal prespecified positive numbers. This balancing procedure is called a modified biproportional problem. Applications of the procedure are cited, various theoretical properties discussed, and its relationship with the full biproportional problem, treated in an earlier paper (Macgill, 1977a), is noted.

A consideration of Johnson's Q-discrimination analysis

In this paper an elementary exploration is given of some of the features of Q -discrimination analysis, an adaptation by Johnson of Atkin's Q -analysis for use in clustering work. The method is summarised. It is shown how the performance of the method varies considerably, depending upon whether the data involved are integer or noninteger, over a given range of values, and on whether they are ordinal or interval. An ambiguity over the criteria for determining discrimination levels is also considered.

Structural analysis of social data: a guide to Ho's Galois lattice approach and a partial respecification of Q-analysis

A pedagogic exposition of Ho's Galois lattice approach for analysing social data is given in this paper. This provides a basis for respecifying Atkin's Q -analysis in a way that is believed to be more powerful, more economical, and accessible to a wider audience. Concepts of traffic and eccentricity are reexamined, but more generally, the suggested respecification may enhance the utility of Q -analysis and broaden its applicability, while remaining true to its underlying ethos.

Simple hybrid input - output models: a graphical approach

It is shown how the familiar Leontief input - output model, and the less familiar supply driven input - output model, may be formulated in terms of weighted digraph analysis. The two models concerned have hitherto been used essentially independently of each other with apparently no simple framework within which they can be combined. The graphical analysis presented below, however, enables them to be combined within a single framework, thus forming a new, hybrid, input - output model framework.