Outbreak of Mycobacterium tuberculosis infection among captive Asian elephants in a Swedish zoo

Between 2001 and 2003, there was an outbreak of tuberculosis in a Swedish zoo which involved elephants, giraffes, rhinoceroses and buffaloes. Cultures of trunk lavages were used to detect infected elephants, tuberculin testing was used in the giraffes and buffaloes, and tracheal lavage and tuberculin testing were used in the rhinoceroses. The bacteria isolated were investigated by spoligotyping and restriction fragment length polymorphism. Five elephants and one giraffe were found to have been infected by four different strains of Mycobacterium tuberculosis.     

Inter-regional comparisons of production technology in Canada's timber harvesting industries

Enhanced productivity in the logging industry is one of the key factors that determine the competitiveness of the forest products sector. Policy measures to improve efficiency must therefore start at the timber harvesting stage. This study analyzed and compared the production technologies in the timber harvesting industries of British Columbia (B.C.), Ontario, and Quebec, which are Canada's largest timber producing provinces. The study used annual data of log output and four inputs: labour, capital, energy, and materials from 1961 to 1999. Six models, encompassing different restrictions on the long-run translog cost function, were applied to each industry to determine the best technology for that industry. The cost function that best described each industry's technology was used to estimate own- and cross-price elasticities, input substitution elasticities, scale effects, technological change and bias, and total factor productivity. The production technologies of B.C. and Quebec were best described by homothetic, linearly homogeneous functions, while that of Ontario was found to be non-homothetic. Based on the Morishima elasticities of substitution, the results in general indicated inelastic substitution among all the four factor inputs. As a result the industries had limited options to make input adjustments with respect to changes in relative input prices; and hence required output levels were maintained at higher production costs. All three provincial industries exhibited biased technological changes, saving on capital and labour, and intensively using energy and materials. Labour and capital therefore recorded higher productivity than energy and materials over all provinces; consequently, efforts at improving the efficiency of the logging industries should focus on increasing the productivity of the latter inputs. Scale effects ranged from 2.17 in B.C. to 1.44 in Quebec implying that the timber harvesting industries appeared to have had the greatest potential for cost reduction through output expansion. In a competitive market structure, the strategic policy implication of these scale effects is that low-cost producers force high-cost industries out, leading to industrial concentration. The low levels of technological change in the timber harvesting industries observed in this study may reflect these industrial concentration problems. Policies that reduce the rental cost of capital, such an increase in investment tax credits and cuts in the corporate income tax rates have the potential to increase productivity and hence improve on the timber industry's competitive position.     

Alum Sludge Dewatering Using Moringa oleifera as a Conditioner

An active component of Moringa oleifera (MO) has been used in comparison with synthetic polymers and alum for the conditioning of chemical sludge from a drinking water treatment plant. The comparison was based on dewatering characteristics of the conditioned sludge determined by capillary suction time (CST), specific resistance to filtration (SRF), sand column drainage and shear strength tests. The results indicated that MO showed comparable conditioning effect as alum. Polyelectrolytes were more effective than MO and alum. Sludge conditioned with MO and alum, as in dual chemical conditioning, showed better results than MO alone. According to CST, SRF and sand drainage results, optimum doses for MO, alum and polyelectrolytes were 125, 63, and 1.8 kg/t, respectively. Comparison of the two polyelectrolytes showed that the cationic polyelectrolyte was more effective. For sand drainage tests both polyelectrolytes improved the drainage rate by 2 orders of magnitude. MO and alum improved the drainage rate by about 4.2 times. On the other hand, the improvements in cake solids concentration were similar for all the chemical conditioners. Flocs from MO and alum were relatively stronger compared to those of the polyelectrolytes. From the results of the study it could be concluded that MO alone or in combination could be effectively used and replace alum for dewatering of chemical sludge.     

Effects of tax incentives on long-run capital formation and total factor productivity growth in the Canadian sawmilling industry

The goal of this study was to analyze effects of tax incentives on long-run dynamics of total factor productivity (TFP) growth and capital formation in the Canadian sawmilling industry over a 40-year period (1961–2000). Simulated tax incentives involved increasing capital cost allowance and investment tax credit and reducing corporate income tax. The production technology was specified as a function of capital, labor, energy, sawlogs, and a time dependent technological progress variable. A translog multilateral index number model was applied to measure and analyze TFP.Two analytical phases were followed. In the first phase, without the tax incentives, we analyzed annual levels and growth rates of TFP1; and parametrically examined effects of output growth and time dependent technology on the growth of TFP1. Over the study period, the average annual growth rate of TFP1 was 2%; and the parametric results revealed that the marginal effects of each of output growth and technological progress on TFP1 growth were highly significant. The second phase involved recalculation of the rental price of capital to estimate effects of the simulated tax incentives on capital formation and growth of TFP (= TFP2). As expected, the average annual share of capital in total cost with the tax incentives rose to 12% from 9% without the tax incentives. The average annual capital intensity also rose to real $15,263.70 with the incentives from real $10,402.91 without the incentives. Most importantly, higher capital formation, motivated by the tax incentives, raised aggregate quantity of the inputs significantly, leading to a slightly lower TFP2 than TFP1, because output was unchanged. In short, the data validated the hypothesis that tax incentives do indeed spur capital formation and TFP growth.