ALBERT

Notes: Coexisting Ca-poor and Ca-rich pyroxenes in granulites at Cape Riche, in the Precambrian Albany-Fraser Province, Western Australia, are dominantly chemically homogeneous within individual samples, suggesting a major episode of equilibration. However, occasional grains in a few samples contain exsolved domains interpreted as relics of an earlier, higher-T assemblage. Pyroxene pairs in ten, presumably isothermal, samples from a restricted area are used to (i) assess the suitability of several versions of the two-pyroxene thermometer for application to metamorphic rocks, and (ii) determine the thermal history of the Cape Riche pyroxenes.The various versions of the two-pyroxene thermometer applied to the well-equilibrated homogeneous pyroxene grains show poor to good precision and yield mean temperatures varying widely from 683° to 893°C, in the following order of increasing T: Lindsley (1983; opx version), 683°± 11°C; Kretz (1982; KD version), 705°± 19°C; Ross & Huebner (1975), 709°± 30°C; Kretz (1982; solvus version), 735°± 24°C; Fonarev & Graphchikov (1982; opx version), 〈750°C; Lindsley (1983; cpx version), 784°± 40°C; Fonarev & Graphchikov (1982; cpx version), ~820°± 30°C; Wood & Banno (1973), 849°± 16°C; Powell (1978), 854°± 23°C; Wells (1977), 893°± 10°C. Independent T estimates, based on mafic assemblages and garnet-biotite thermometry, suggest that the major episode of metamorphism occurred at 700-800°C (P ~ 5 kbar). Therefore the Wells, Powell, Wood & Banno and Fonarev & Graphchikov (cpx) temperatures are almost certainly too high. In the absence of a more precise independent T estimate it is difficult to assess the relative merits of the results obtained from the remaining versions of the two-pyroxene thermometer, none of which can be unequivocally demonstrated to be seriously in error, though the Lindsley (opx) T is probably too low. Other significant shortcomings evident in the results include the relatively poor precision obtained from the three methods based on purely graphical representation of the augite limb of the solvus (i.e., the Ross & Huebner, Fonarev & Graphchikov (cpx) and Lindsley (cpx) versions), and the apparent dependence of derived T on Mg/Fe2+ ratio for the Powell, Wood & Banno and Lindsley (cpx) methods.For the bulk compositions of exsolved domains, the different versions of the two-pyroxene thermometer yield mean temperatures 23° to 82°C (overall mean, 65°C) higher than for homogeneous grains in the same samples. These exsolved domains are interpreted as relics of a higher-T (peak?) metamorphic assemblage, rather than an igneous precursor.

Notes: This paper reports the detailed results of a comparison of the distribution and redistribution of income in seven countries using the Luxembourg Income Study (LIS) database. Use of LIS facilitates comparisons of inequality in respect to similarly-defined variables, permits methodological alternatives to be used, and allows the countries to be compared on aspects of income ranking and policy equity in ways not otherwise possible.The results indicate a pattern of inequality in which Sweden is the most equal, followed by Norway, the U.K. and Canada, while among the less equal countries Israel is generally more equal than Germany-or the USA., whose relative inequality depends on the measure chosen. Use of the LIS database also allows a more detailed explanation of these results, noting, for example, the role of cash benefits in increasing equality in Sweden and the U.K., and in aiding the bottom quintile in Germany; and the important part played by self-employment income in contributing to the high top quintile shares in Germany and Israel, and in rendering the Norwegian distribution less equal than that of its Scandinavian neighbour.The wealth of the database, however, means that methodological issues need to be treated both more explicitly and more carefully than is possible with more restrictive data. To interpret the data also requires a considerable degree of knowledge about the institutional features of tax and social provisions in each country, so that an income microdatabase could usefully be completed by one focused on the details of such provisions.

Notes: Seismic reflection methods are being developed at the University of Manitoba to aid in determining fine crustal structure in the Precambrian of Manitoba and northwestern Ontario. Present-day environmental concern as well as mineshaft conditions necessitate the detonation of several smaller charges repeated, say, I times and followed by ‘vertical’ stacking. To obtain the familiar √I improvement in signal-to-noise (S:N) amplitude ratio applying the straight-sum (SS) method, one assumes, among other things, that both S:N ratio and signal variance are the same on all traces. Dropping these assumptions, as we must for our data, it becomes necessary to apply weighting coefficients to optimize the S:N ratio of the stacked trace. We still assume the signal shapes to be the same for repeated shots, so for the jth trace on the record of the ith shot we model the time series as: tij=ai (sj+nij); where ai is a scaling factor. The proper weights wi are then shown to be proportional to σsi/σ2ni where σ2 is variance, or to γi/ai where γi is S:N power ratio.Applying the weighted-stack (WS) method gives S:N amplitude ratios which are, on average, 55% of the optimal ratios expected from WS theory compared with only 24% for the SS method. The 45% shortfall in WS performance is ascribed mainly to trace-alignment (or time-delay) errors. Varying noise levels on individual traces, slight dissimilarity of signal shape, and correlated noise may also contribute to a lesser extent (in decreasing order of significance). This WS method appears to strike a good practical balance between S:N improvement and processing efficiency.

Notes: The influence of tall fescue (Festuca arundinacea Schreb.) on germination and seedling growth of birdsfoot trefoil (Lotus corniculatus L.) was evaluated during 1983-85 at Manhattan, Kansas. Studies were designed to evaluate tall fescue cv. Kentucky-31 for possible allelopathic compounds, determine the effects of tall fescue on the germination, seedling growth and yield of birdsfoot trefoil, and to characterize the chemical properties of tall fescue. Fescue produced allelopathic compounds, particularly during the spring and autumn months when it was actively growing. The greatest trefoil inhibition occurred with fescue plant extracts prepared during the autumn (September and October). The concentration of fescue extracts influenced trefoil germination, with greater inhibition as fescue concentration increased. In a sand medium under greenhouse conditions, fescue extracts prepared in spring and autumn reduced trefoil growth by 50 and 56%, respectively, with no inhibition during the summer months. Under field conditions, full strength fescue extracts reduced trefoil plant populations by 14 and 57% with spring and autumn prepared extracts, respectively. Fescue competition reduced sod-seeded trefoil plants per unit area by 17 and 31% for spring and autumn seeding, respectively. Full strength fescue extracts reduced trefoil seedling growth by an average of 37%, and trefoil dry matter yields by 53%.

Notes: Tax Increment Financing (TIF) is a popular yet controversial tool that allows local governments to use property tax revenue to fund the public costs of economic development. Since TIF gives one local government the power to affect the tax bases of the overlapping jurisdictions, there is uncertainty and argument on the part of government officials and taxpayers as to who really finances the program. To evaluate the alternative contentions, this paper presents a general methodology that identifies which taxpayers in which locations fund the TIF's expenditures, and sets forward the conditions under which such a local economic development policy can be beneficial to taxpayers. The paper applies the model to study the TIF program currently active in downtown Des Moines, Iowa. The evidence indicates that the taxpayers in the entire metropolitan area subsidized the downtown activities in the early years, but now pay lower property tax rates due to the city's TIF-financed urban revitalization program.

Notes: In this article the authors report the results of small group discussions with some 415 first-line supervisors in the mining industry. The results are compared with those from a number of earlier studies of mining. Changes which have affected the supervisory position are described, and the role of behavioural research in industry is discussed in relation to both organizational analysis and to training.

Notes: It is widely believed that large size creates problems for industrial relations and, conversely, that small size is beneficial. There has been little research relating size and workers' attitudes—this article reports the findings from a study in 24 factories in British manufacturing industry.

Notes: In this article the author assesses the difficulties facing democracy in the British Retail Co-operative Movement, with special reference to the role of employees on boards of directors.