Evaluation of the VIDAS Listeria (LIS) immunoassay for the detection of Listeria in foods using demi-Fraser and Fraser enrichment broths, as modification of AOAC Official Method 999.06 (AOAC Official Method 2004.06).

A multilaboratory study was conducted to compare the VIDAS LIS immunoassay with the standard cultural methods for the detection of Listeria in foods using an enrichment modification of AOAC Official Method 999.06. The modified enrichment protocol was implemented to harmonize the VIDAS LIS assay with the VIDAS LMO2 assay. Five food types--brie cheese, vanilla ice cream, frozen green beans, frozen raw tilapia fish, and cooked roast beef--at 3 inoculation levels, were analyzed by each method. A total of 15 laboratories representing government and industry participated. In this study, 1206 test portions were tested, of which 1170 were used in the statistical analysis. There were 433 positive by the VIDAS LIS assay and 396 positive by the standard culture methods. A Chi-square analysis of each of the 5 food types, at the 3 inoculation levels tested, was performed. The resulting average Chi square analysis, 0.42, indicated that, overall, there are no statistical differences between the VIDAS LIS assay and the standard methods at the 5% level of significance.

Internal migration patterns for U.S. foreign-born, 1985-1990.

"Using 1990 census data, this paper calculates the flow [of the foreign-born population in the United States] between states and from abroad; also, a multinomial logistic regression model of destination choice is estimated for resettlers and for migrants from abroad. There are three major findings. Firstly, Florida and California are the largest recipients of foreign-born resettlers; New York is the biggest loser of secondary migrants. Secondly, the presence of large communities of Mexicans in California and Cubans in Florida are very attractive to both resettlers and migrants from abroad. Thirdly, immigrants that are most in need of ethnic support networks (i.e. new arrivals or immigrants with low human capital resources) are most likely to choose one of the traditional immigration states as a destination."

Nativity concentration and internal migration among the foreign-born.

Are immigrants who live in states where large numbers of their compatriots reside more or less likely to migrate than those who live in other states? Using 1980 U.S. Census data to address that question, the analysis shows that nativity concentration deters interstate migration but not migration within the same state. Residing in a state where fellow nationals live is a more important determinant of internal migration than human capital, immigration status, or a state's unemployment rate. New York State residence in 1975 also promotes interstate migration. This research suggests that social dimensions should be taken into account in modeling internal migration of the foreign-born.

Internal migration for recent immigrants to Canada.

"This study examines the extent to which internal migration among recent immigrants to Canada is affected and constrained by characteristics related to admission. By examining measures of information and personal ties, it may be possible to establish that migration behavior is rational regardless of economic incentives." It is suggested that "internal migration in the first year after arrival is strongly affected by characteristics such as admission status, destination at arrival, reason for immigration, and area of origin. With increasing length of residence in Canada, though, the effect of these admission factors on internal migration behavior diminishes." This is a revised version of a paper originally presented at the 1992 Annual Meeting of the Population Association of America.

The systems approach to international migration: an application of network analysis methods.

"The objective of this article is to apply formal network analysis to the systems approach [to the study of international migration]. Network analysis will allow two of the four methodological issues to be considered. First, clique and centrality analysis methods will be used to examine the definition and development of ties within an international migration system over time. Second, quadratic assignment procedure (QAP) regression techniques will be used to address the influence of macro factors on international migration flows....[We use] the European Union as a network of migration interest...." (SUMMARY IN FRE AND SPA)