Assimilation in Multilingual Cities

We characterise how the assimilation patterns of minorities into the strong and the weak language differ in a situation of asymmetric bilingualism. Using large variations in language composition in Canadian cities from the 2001 and 2006 Censuses, we show that the differences in the knowledge of English by immigrant allophones (i.e. the immigrants with a mother tongue other than English and French) in English-majority cities are mainly due to sorting across cities. Instead, in French-majority cities, learning plays an important role in explaining differences in knowledge of French. In addition, the presence of large anglophone minorities deters much more the assimilation into French than the presence of francophone minorities deters the assimilation into English. Finally, we find that language distance plays a much more important role in explaining assimilation into French, and that assimilation into French is much more sensitive to individual characteristics than assimilation into English. Some of these asymmetric assimilation patterns extend to anglophone and francophone immigrants, but no evidence of learning is found in this case

The Effect of Immigrant Peers in Vocational Schools

This paper provides new evidence on how the presence of immigrant peers in the classroom affects native student achievement. The analysis is based on longitudinal administrative data on two cohorts of vocational training students in Italy's largest region. Vocational training institutions provide the ideal setting for studying these effects because they attract not only disproportionately high shares of immigrants but also the lowest ability native students. We adopt a value added model, and exploit within-school variation both within and across cohorts for identification. Our results show small negative average effects on maths test scores that are larger for low ability native students, strongly non-linear and only observable in classes with a high (top 20%) immigrant concentration. These outcomes are driven by classes with a high average linguistic distance between immigrants and natives, with no apparent role played by ethnic diversity

Metal Distribution and Metal Site Partitioning, Mobile Bay Surface Sediments

Bulk concentrations of 35 metals in 87 Mobile Bay sediment samples were determined by ICP-MS analysis in order to evaluate the possible extent of metal contamination in the bay. The relative concentrations of most metals have a similar distribution. A1, As, Ba, Be, Cr, Co, Cu, Fe, La, Pb, Mg, Mn, Ni, P, Nb, K, Sc, Na, Th, Sn, Ti, U, V, Y, Zn, and Zr generally display higher values in northern and southern mid-bay zones extending east-west across the bay, as well as in patches in eastern Bon Secour Bay (SE Mobile Bay) and north of the Morgan Peninsula beach ridges (central southernmost Mobile Bay). These are all parts of the bay that are floored by finegrained sediments (clays and silty clays), evidencing the known relation between clay minerals and elevated metal content. Plots of concentrations of the metals listed above (except for uranium) vs. the percentage of clay in the sediment further confirm that metal values tend to increase as clay percent increases. Ca and Sr show elevated values in three areas spatially related to living or dead oyster reefs. Molybdenum and cadmium values generally are low throughout the bay, but Mo values are somewhat higher off Dog River. Sb, Bi, Au, Ag, and W were all below detection limits. Metal site partitioning for Cr, P, Pb, and Zn in 12 of the sediment samples was performed to assess potential metal availability for sorption by the biota. A sequential extraction procedure modified from Brannon et al. (1976) was used to separate the samples into pore water, soluble salts, exchangeable/adsorbed, carbonate, reducible / sulfide, oxide, and residual fractions. Higher concentrations of Cr, P, Pb, and Zn were distributed among the latter three (most insoluble) fractions. Cr, P, and Pb were most concentrated in the residual fraction, but highest Zn values were found in the oxide fraction. One anomalous sample (a silty clay from industrialized Dog River) had unusually high zinc values in all fractions except the pore water and residual phases, both of which contained essentially no Zn. The partitioning results indicate that Cr, P, and Pb in most samples are not readily available for bioaccumulation, but zinc held in an oxide phase could be mobilized under low Eh conditions

Engineering geological characterisation of the Barzaman Formation, with reference to coastal Dubai, UAE

This paper describes the pedogenically altered fluvial deposits comprising the Barzaman Formation, UAE. This formation is composed of a sequence of rocks dominated by variably cemented conglomerates thought to be middle Miocene to Pliocene in age. The well-established descriptive scheme currently used for describing the formation is reviewed and a simple visual descriptive lithological classification is proposed based on the three principal lithological components visible in a hand specimen: mottled white calcisiltite matrix/cement, palygorskite rich marl and clasts derived from the Oman Mountains (gabbro, chert and weathered ultramafic rock). Data on the mineralogy and microstructure of the rock constituents is presented and some implications for the geotechnical characterisation of the formation are briefly discussed