Inhibition of surface bound carbonate stabilization of tetragonal zirconia

Water is known to initiate a tetragonal to monoclinic phase transformation in zirconia particles. Carbonates on the zirconia surface react with water molecules and hence reduce the transformation rate. This study investigates the possibility of inhibition of the reaction between surface carbonates and water in order to increase the transformation rate in the zirconia crystals. It was found possible to limit the reaction by reacting the surface carbonates with alcohols, a thiol and a primary amide prior to reaction with water. It was also concluded that di- and trialcohols are able to stabilize the tetragonal phase, probably as a result of induced lattice strain.     

Application of multilocus enzyme electrophoresis in studies of the epidemiology of Listeria monocytogenes in Denmark

BACKGROUND: Intercellular adhesion molecule-1 (ICAM-1) is expressed on follicular dendritic cells (FDC), and the ICAM-1/LFA-1 pathway is essential for affinity selection of activated B-cells in germinal centers (GC). The expression of ICAM-1 has been studied by immunostaining methods in GC, but not in neoplastic follicles (NF). METHODS: The authors studied the expression of ICAM-1 by the avidin-biotin-peroxidase complex (ABC) method with frozen sections in GC of reactive nodes (n = 22) and NF of follicular lymphomas (n = 19), in comparison with FDC staining. RESULTS: GC stained uniformly for ICAM-1, with staining intensity varying little from node to node, and follicular borders were well demarcated from the surroundings. Endothelial cells within GC did not stain whereas those outside stained strongly. In contrast, NF stained variably from tumor to tumor, and in any given tumor. Characteristically, follicular borders were not demarcated, and stained areas were difficult to define due to the lack of demarcation, with the exception of large cell type with diffuse areas (n = 2). Endothelium of intrafollicular vessels stained prominently (12 of 19), and appeared to contribute to the staining intensity of the follicles. FDC staining revealed a meshwork pattern in GC which was similar to that of ICAM-1. The FDC mesh-work pattern was present in 15 tumors. The pattern was remarkably uniform with sharply defined borders, which contrasted starkly to the variable staining and lack of follicular borders in the ICAM-1 stain of the same tumors. CONCLUSIONS: The staining pattern of follicles for ICAM-1 was similar to that for FDC in reactive nodes, but distinct from the latter in follicular lymphomas. An appropriate expression of ICAM-1 appears to be essential for normal GC, as the alteration of the expression coincides with the malignant transformation of GC. The altered expression of ICAM-1 may be useful in distinguishing NF from reactive GC.     

Straight-line Assimilation in Leaving Home? A Comparison of Turks,Somalis and Danes

The purpose of this paper is to test the evidence for spatial assimilation and straight-line assimilation in the transition of leaving home in Denmark. Based on data from the extensive Danish registers, the paper analyses the home-leaving patterns of Danes, Turkish immigrants, Turkish descendants and Somali immigrants. Two main findings emerged. First, while spatial segregation patterns of home-leavers were clear, inter-generational mobility did take place, supporting the notion of straight-line assimilation. Second, inter-generational effects were identified. While there was no indication that parental socio-economic situation affected the spatial segregation of home-leavers, substantial effects were found for the share of ethnic minorities in the parental neighbourhood: the higher the share of ethnic minorities, the higher the hazard for moving to an ethnic neighbourhood and the lower the hazard for moving to a non-ethnic neighbourhood. Similarity in the patterns of natives and the ethnic minority groups indicates that the processes taking place might be about more than assimilation between generations.     

The incidence of Listeria spp. in faeces of Danish pigs and in minced pork meat

One hundred and seventy-two samples of pig faeces, collected at a slaughterhouse, were investigated for Listeria species. Three of the samples (1.7%) contained L. monocytogenes, while L. innocua was demonstrated in four other samples. The 172 samples represented pigs from 72 herds, 14 (19%) of which were SPF herds. Listeria was not demonstrated in any of the samples from the SPF herds representing 24% of all samples investigated. This indicates that the incidence of L. monocytogenes in SPF herds might be very low. In 51 samples of minced pork, Listeria spp. were demonstrated in 32 samples, L. monocytogenes in six samples, L. innocua in 26 samples, and L. seeligeri in one sample. In comparison with similar findings in cattle faeces and minced beef, the conclusion was drawn that faecal contamination may play an important r?le in the dissemination of L. monocytogenes in raw meats.     

Modelling relations between instrumental and sensory measurements in factorial experiments

In connection with the sensory evaluation of foods, chemical or physical measurements of the relevant sensory properties are often sought. The data available for testing whether one particular instrumental measurement is linearly related to a sensory variable usually arise from a factorial experiment rather than from some random sub-population. Thus, to calibrate the two variables properly and to test whether a linear relationship is compatible with the data, we need a statistical model that reflects the design. The ultrastructural model suggested by Dolby (Biometrika 63, 39–50, 1976) is one such model. Furthermore, this model allows for random variation in both of the variables considered. In this paper it is shown how testing and estimation may be carried out using this model, although the methods suggested are not optimal. Finally, it is argued that the use of factorial designs in this connection is sensible, or even necessary, despite the complications that it leads to in terms of statistical modelling and analysis.