Factor demand flexibility in the primary aluminium industry: Evidence from stagnating and expanding regions

The purpose of the paper is to analyse and compare short-run factor demand responses to price changes in the primary aluminium industry in Western Europe and the Africa-Middle East (AME) region. We outline a Translog variable cost function model, which is estimated employing a panel data set at the individual smelter level over the time period 1990-2003. The empirical results show evidence of limited - but far from insignificant - price-induced factor demand responses in the short-run. Overall aluminium smelters in the AME-region show evidence of higher estimated short-run own- and cross-price elasticities than their competitors in Western Europe, at least when it comes to labour and electricity demand. One important reason for this result is the greater number of pot lines with slightly different technologies at each smelter as well as the more intense use of the Prebake technology in the AME-region making retrofits in existing plants less costly than in Western Europe. The results also suggest that in both regions the demand for electricity has over time become less sensitive to short-run price changes, while the labour and material demand responses to price changes have increased but only in the AME-region. The liberalisation of the Western European electricity markets in combination with the rigid labour markets in this part of the world suggest that the shift in production capacity from the western world to the AME-region as well as China may continue.     

Interrupted aortic arch type A with 22q11 deletion: prenatal detection of an unusual association

Interrupted aortic arch is a rare, severe congenital heart defect subdivided into three types, A, B and C, according to the site of interruption. Type C is by far the least common form of interrupted aortic arch (less than 5% of cases), type A is commonly an isolated defect whereas type B is frequently associated with 22q11 deletion. Differentiation of interrupted aortic arch type A from type B by prenatal echocardiography is possible but difficult; it needs to be done on the basis of observation of reliable morphological indicators which point to the correct diagnosis. Here we report the first case of prenatal diagnosis of interrupted aortic arch type A associated with 22q11 deletion. The significance of this association is not yet clear, since 22q11 genes mainly affect embryonic cardiovascular morphogenesis of those regions whose development is critically dependent on neural crest cell migration and function, affected in type B defect but not in type A. Copyright © 2002 John Wiley & Sons, Ltd.     

Trisomy 16 confined to the placenta

Two cases with trisomy 16 confined to the placenta are presented. Prenatal diagnosis was indicated because of fetal growth retardation. In case 1, a phenotypically normal but small-for-date boy was born. In case 2, the fetus turned out to be triploid on cordocentesis. In both instances the trisomy 16 was recovered from the placenta. Recovery indicates that the abnormality was present in the placenta during the time of fetal growth retardation, which supports an aetiological relationship. Strict appliance of the current models cannot readily explain the observed discrepancies. In case 2, a chimeric placenta as a result of a vanishing twin is assumed. Cases of placental trisomy 16 published after 1988 are reviewed. It is concluded that confined placental trisomy 16 can cause intrauterine growth retardation if present in both the direct preparation and the villus culture. The chances of finding a chromosomally abnormal fetus (mosaic trisomy 16, triploidy) after diagnosis of trisomy 16 in chorionic villi are low but warrant further investigations.     

Analysis of chromosome 21 copy number in uncultured amniocytes by fluorescence in situ hybridization using a cosmid contig

A comparison of the use of chromosome 21-specific libraries, DOP-PCR 21 paints, yeast artificial chromosome (YAC) clones, single cosmids, and a 21q cosmid contig as probes for the detection of the copy number of chromosome 21 in interphase cells by fluorescence in situ hybridization shows that the cosmid contig is a satisfactory probe for interphase analysis of chromosome 21. The contig cCMP21.a, which is 55 kb in length, is highly chromosome 21-specific and produces intense, compact signals in a high proportion of interphase cells. A retrospective blind analysis of coded uncultured amniotic fluid samples correctly detected four trisomy 21 cases out of 49 samples.     

Input–output analysis in an oil-rich economy: The case of Azerbaijan

This paper aims to provide empirical research to identify the linkages between final demand–total output, final demand–total supply, value-added ratios and prices, and also to analyze total factor productivity growth using input–output framework for 25 sectors. Studying the input–output tables for 2001 and 2006, the research estimates impact and response multipliers of non-oil sectors, as well as non-oil trading sectors. The results are important from the view of development of non-oil trading sectors and diversification of the economy in order to avoid the “resource curse”.     

A simple mineral market model: Can it produce super cycles in prices?

This paper develops a stylized supply–demand model for a mineral/nonrenewable commodity. It embodies important distinctions between short-run and long-run mineral supply and the derived demand for minerals as intermediate goods in production sectors with differing intensities of use. This framework is used to address the question: under what conditions might one expect to observe super cycles (i.e. cycles with a period of 20–70 years) in minerals prices? A plausible time path for GDP$GDP$ growth and the structural transformation that accompanies economic development in an emerging region is specified. Using these drivers and reasonable supply and demand parameters, price dynamics are simulated. The result is an asymmetric price cycle with a peak price that is about 250% above trend and an expansion phase that lasts for about 20 years. Thus, this simple model is capable of producing a single cycle with a frequency and amplitude in the range estimated in the empirical literature on super cycles. As other regions reach the development ‘take-off' phase, additional super cycles should emerge.