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Background/aims To establish a rat model mimicking human bile reflux for studying the pathological effects of chronic bile reflux. Materials and methods The duodenum of Sprague-Dawley rats was transected below the opening of the common bile duct, and a gastrojejunostomy was performed at the greater curvature of the forestomach. After the rats demonstrated bile reflux for 1 year, we studied the pathological features of the glandular stomach and forestomach mucosa. We also studied the effect of bile reflux on gastrin expression in the glandular stomach mucosa by using immunohistochemistry. Results Chronic bile reflux caused significant hyperplasia and expansion of gastric glands in the glandular stomach. Dysplasia and cancer formation also developed, but the incidence was significantly lower than that reported in the literature. Intestinal metaplasia and ulceration in the glandular stomach were also rare. In the forestomach, the squamous epithelium showed significant hyperplasia and keratinization along with keratin pearls and keratocysts. Intestinal metaplasia was rare and no tumorigenesis was observed. Chronic bile reflux significantly increased gastrin expression in the glandular stomach mucosa. Conclusions When simulating the physiological bile reflux pathway, chronic bile reflux caused hyperplasia and expansion of gastric glands in the glandular stomach and squamous epithelial hyperplasia and keratinization in the forestomach.

To evaluate the effectiveness and recent safety of emergency and selective percutaneous coronary intervention (PCI) in elderly patients (80 years old) with acute myocardial infarction (AMI). 120 elderly patients with coronary heart disease (CHD) were divided into AMI group (with 55 cases) and non-myocardial infarction group (control group with 65 cases). Among the AMI group, there were 18 cases underwent emergency PCI within 12 hours after the onset, (AMI emergency PCI group), the rest 37 cases were AMI selective PCI group. In the control group, 2 cases had stable angina pectoris, 59 cases unstable angina pectoris and 4 patients old myocardial infarction. The lesions were classified according to the practice guidelines of American College of Cardiology/American Heart Association (ACC/AHA). The hospitalized major adverse cardiac events (MACE) and complications in the patients were recorded and statistically analyzed. The AMI group had a higher total Gensini score, lower left ventricular ejection fraction (LVEF), less mean stents and contrast agent dosage and shorter operation time, compared with the control group. The difference was statistically significant. Though the average postoperative length of stay in AMI emergency PCI group was longer than that of AMI selective PCI group, but the difference had no statistical significance. To all the included patients, there were 50 cases with lesions in one branch, 43 cases in two branches and 27 cases in three branches. And the immediate PCI success ratio in AMI group was lower than that in control group (80% VS. 96.9%, P= 0.003), without significant difference in the distribution number of diseased vessels and complete reconstruction ratio (P0.05). The incidence of the total complications in AMI emergency PCI group was higher, compared with the non-emergency group (with 102 cases) and AMI selective PCI group (P0.001, P=0.039); and the occurrence rate of complication in AMI group was higher than that of the control group (P0.001). The emergency PCI for elder patients with AMI is safe and worthy of promotion.

The ability of chitosan and oligochitosan to enhance ginger (Zingiber officinale) resistance to rhizome rot caused by Fusarium oxysporum in storage was investigated. Both chitosan and oligochitosan at 1 and 5g/L significantly inhibited rhizome rot, with the best control at 5g/L. Chitosan and oligochitosan applied at 5g/L also reduced weight loss, measured as a decrease in fresh weight, but did not affect soluble solids content or titratable acidity of rhizomes. The two compounds applied at 5g/L induced β-1,3-glucanase and phenylalanine ammonia-lyase enzyme activity and the transcript levels of their coding genes, as well as the total phenolic compounds in rhizome tissues. Therefore, the ability of chitosan and oligochitosan to reduce rot in stored rhizomes may be associated with their ability to induce defense responses in ginger. These results have practical implications for the application of chitosan and oligochitosan to harvested ginger rhizomes to reduce postharvest losses.

Labour productivity growth in the Canadian electronic and electrical product manufacturing industry declined, from 21% per year in the period 1997–2000, to negative 4% per year in the period 2000–2006. This paper investigates if the restructuring and the reallocation of market share and resource within the industry following the bursting of the tech bubble in 2000 contributed to the slowdown in productivity growth. The reallocation may be a result of change in the composition of constituent sub-industries (industry mix), the entry of new firms and the exit of existing firms, and/or the growth and decline in continuing firms. This paper shows that the slowdown in productivity growth in the Canadian electronic and electrical product industry was mainly due to weaker productivity performance of the sub-industries, which can largely be traced to the decline in labour productivity growth of continuing plants. It finds that the reallocation had some impact, but it was not the primary factor behind the d...

Offshoring becomes an increasingly important strategy for Canadian businesses to compete in domestic and international markets. It is facilitated by advances in transportation and communications te...

Labour productivity growth in the Canadian business sector has averaged less than 1.0 percent since 2000, more than 40 percent below the average growth rate during 1981–2000. On the other hand, labour productivity growth accelerated in the U.S. in the post-2000 period compared to the average growth prior to 2000. Available research shows that the divergence in labour productivity growth was entirely due to the gap in multifactor productivity (MFP) growth. This paper looks at the possible role of information and communications technologies (ICTs) in the recent productivity growth divergence between the two countries. Using data on 33 industries over the period 1987–2000, it examines empirically the impact of ICTs on MFP growth in Canada and the U.S., taking into account ICT-related investments in intangibles and the issue of endogeneity of the explanatory variables. The regression results suggest that ICT capital is not a significant determinant of MFP growth in Canada and the U.S., implying that i...

Advanced technologies are commonly thought to be complementary to skills. Firms that adopt new technologies (for example, computer-aided design and control) and at the same time invest in skills (for example, training in computer literacy and technical skills) are expected to realize greater productivity gains than those that do not. To validate this expectation, this paper first identifies the combinations of technologies and types of training that are commonly undertaken by firms, presumably as part of their strategies to effectively utilize the adopted technologies and to improve their economic performance. This paper then estimates the relationship between these common technology-training combinations and productivity performance. It shows that these combinations are associated with higher productivity.

Offshoring has become increasingly important for businesses, especially manufacturing firms, to compete in domestic and international markets. This paper empirically studies the association between offshoring, productivity, and plant characteristics by focusing on the geographical dimension of plants' business activities. Using data from Statistics Canada's Survey of Innovation 2005 and Annual Surveys of Manufacturers, we show that material offshoring is strongly associated with firms' outward-oriented business activities (including foreign operation, investing in foreign M&E, and exporting), even after controlling for geographic advantages and industry- and plant-specific effects. For R&D offshoring, we find that it is mainly associated with investment in foreign M&E. In addition, this paper shows that material offshoring is positively associated with productivity and that the association is significantly larger for material offshoring to Asia Pacific countries than for material offshoring to the U.S. and other locations.

This paper analyzes the reasons for the Canada-US labour productivity gap, which is mainly explained by the multifactor productivity (MFP) gap. Based on panel data for 41 industries, the regression results show that differences in the machinery and equipment (M&E) capital-labour ratio, trade openness, and capacity utilization explain differences in the Canada-US MFP gap across industries. The M&E capital intensity gap is the dominant source of the MFP gap. Lower wages, R&D intensity, and skills levels, as well as higher investment goods prices in Canada are the major determinants of the M&E capital intensity gap.

Innovation is a complex process and has multiple dimensions. In assessing the linkage between innovation and productivity, most of studies, due to data limitations, use only one single indicator to measure innovation. This paper argues that this practice may systematically bias against certain groups of companies or industries since they often engage in different innovation activities to achieve their different business objectives. To better measure innovation, this paper develops an innovation index, a linear combination of multiple innovation indicators based on a latent variable model. The proposition is supported by evidence from a rich micro dataset for Canadian manufacturing firms.

This paper considers the microfoundations of agglomeration economies, in particular agglomeration economies that arise from uncertainty. The paper begins with a simple model that captures several sorts of uncertainty-driven agglomeration. These include competitive instability, the need for skilled workers, and technological innovativeness. The model's key result is that firms facing more uncertainty will agglomerate with each other in large cities or industry clusters. Firms facing less uncertainty will be found in small cities or outside of clusters. The paper tests these ideas by employing survey data to see if establishments in large cities or industry clusters describe themselves as facing these sorts of uncertainty. The empirical results are consistent with the existence of all three of the agglomerative forces mentioned above. However, the forces operate in different ways. Competitive instability and technological innovativeness are associated with city size, while skill-orientation is associated with industry clustering.

This paper attempts to shed light on the complex relationship between innovation and competition. Traditional measures of product market competition using industry statistics are often challenged and found wanting. Using the Statistics Canada 1999 Survey of Innovation, this paper develops new measures of competition by arguing that firms’ perceptions about their competitive environment are important for innovation and are better measures of firm-specific competition. It shows that the relationship can be positive or negative, depending on specific competition perception and specific innovation activity. In addition, it shows that firms tend to bundle process innovation with product innovation, implying that the economic value of process innovation is likely embodied in product innovation.

This paper studies the direct impact of labour force ageing on productivity growth in 10 Canadian provinces over the period 1981–2001, with an outlook to 2046. It shows that older workers are, on average, less productive than younger workers and that labour force ageing has a modest negative direct impact on productivity growth in Canada. The impact has increased since the middle of the 1990s, will peak in 2001–11, and tail off afterwards. During the peak period, productivity growth in Canada will be reduced by 0.13 to 0.23 percentage points per year, with Newfoundland being hit the hardest. JEL classification: J21, O47

In this paper, we estimate the impacts of product market competition and skill shortages on the productivity level performance of Canadian manufacturing firms. We use firms’ perceptions of their competitive environment from the Statistics Canada 1999 Survey of Innovation to measure product market competition and skill shortages. We argue in the paper that such perceptions are important for productivity level performance. After controlling for other factors, we find that product market competition has a positive impact on the performance of medium-sized and large-sized firms, and that skill shortages have a negative impact on the performance of small-sized and medium-sized firms.

This paper examines the trend in the importance of small producers in the Canadian and U.S. manufacturing sectors from the early 1970s to the late 1990s in order to investigate whether there was a common North American trend in changes in plant size. It finds that small plants in both countries increased their share of employment up to the 1990s, but their share remained stable in the 1990s. Small plants increased their share of output up to the 1990s, but then saw their share of output decline. Over the entire time period, their share of output increased less than their share of employment and, therefore their relative labour productivity has fallen. The similarity in the trends in the two countries suggests that causes of this phenomenon should be sought in similarities such as the technological environment rather than in country-specific factors like unionization or trade intensities.

Empirical studies commonly use research and development (R&D) to measure innovation and often find, especially in Canada, no strong link between productivity and innovation. In this article, we model innovation as an unobservable latent variable that underlies four indicators: R&D, patents, technology adoption, and skills. We find that these indicators are reasonably good measures of innovation for aggregate manufacturing. However, except for skills, the reliability of the indicators for innovation differs among individual industries. Our innovation indexes, based on the latent variable model, show that most manufacturing industries became more innovative over the 1980–1997 period. The pace of innovation in the electrical and electronic products industry accelerated during the 1990s. In addition, we show that the new measure of innovation has a positive and statistically significant impact on productivity. It takes from 1 to 3 years, depending on the industry, for innovation to generate an impact on produ...

In this paper we propose a decomposition technique to examine the sources of industrial contribution to aggregate labour productivity growth. We show that in terms of pure labour productivity growth, the manufacturing and service sectors contributed equally to the aggregate Canada-U.S. labour productivity growth gap during the 1987–98 period. But, in terms of total industrial contributions, which also take into account the contributions from a change in relative size, the service sector was the largest contributor. We also find that high labour productivity growth industries did not attract resources from stagnant industries – a phenomenon consistent with Baumol's cost disease of stagnant industries. JEL Classification: O47, C43

Chlorogenic acid (CGA), abundant in coffee and particular fruits, can modulate hypertension and vascular dysfunction. Hypoxia-induced pulmonary artery smooth muscle cells (PASMCs) proliferation has been tightly linked to vascular remodeling in pulmonary arterial hypertension (PAH). Thus, the present study was designed to investigate the effect of CGA on hypoxia-induced proliferation in cultured rat PASMCs. The data showed that CGA potently inhibited PASMCs proliferation and DNA synthesis induced by hypoxia. These inhibitory effects were associated with G1 cell cycle arrest and down-regulation of cell cycle proteins. Treatment with CGA reduced hypoxia-induced hypoxia inducible factor 1α (HIF-1α) expression and trans-activation. Furthermore, hypoxia-evoked c-Src phosphorylation was inhibited by CGA. In vitro ELISA-based tyrosine kinase assay indicated that CGA was a direct inhibitor of c-Src. Moreover, CGA attenuated physical co-association of c-Src/Shc/Grb2 and ERK2 phosphorylation in PASMCs. These results suggest that CGA inhibits hypoxia-induced proliferation in PASMCs via regulating c-Src-mediated signaling pathway. In vivo investigation showed that chronic CGA treatment inhibits monocrotaline-induced PAH in rats. These findings presented here highlight the possible therapeutic use of CGA in hypoxia-related PAH.

An analysis of Canadiancorporate income tax revenues during the 1984–94 periodshows a relative shifting of tax revenue shares between Canadianand foreign-controlled corporations, and a substantial changein the debt levels of foreign-controlled corporations, as wellas Canadian-based multinationals. We claim that these changesmay have been associated with the tax reforms undertaken by theUnited States and Canada in the mid-1980s resulting in the relativechange in the tax rates between the two countries. We also hypothesizethat if this difference persists and in Canadian-controlled corporationscontinue to aggressively expand abroad, the Canadian corporatetax base could experience further pressure.

The implementation of the Free Trade Agreement in 1989 between Canada and the United States, followed by the North America Free Trade Agreement in 1994, has intensified competition between Canadian and U.S. firms as well as provided more opportunities for them. This study presents a snapshot of the competitive position of Canadian industries relative to U.S. industries in 1995. In addition, the study analyzes how the Canadian private business sector's competitiveness has evolved relative to its U.S. counterpart between 1961 and 1995. In order to compare international competitiveness between the two countries, we first construct purchasing-power parities for output and inputs by industry using bilateral CanadaU.S. commodity price data (Dale W. Jorgenson and Masahiro Kuroda, 1995; Lee and Tang, 1999).1 We estimate purchasing-power parities for capital input based on the relative prices of investment goods, taking into account the flow of capital services per unit of capital stock.2 We use hourly labor compensation rates disaggregated by 112 worker types in the two countries to estimate purchasing-power parities for labor input.3 These purchasing-power parities take into account differences between Canada and the United States in the composition of output and inputs for each industry considered, thereby allowing comparisons of both prices and quantities of output and inputs in Canada with those in the United States.

Most OECD economies, including that of Canada, experienced a slowdown in economic growth from the 1961–1973 period to the 1973– 1988 period, and to the 1988–1995 period. Consequently, progress in the standard of living, as measured by GDP per capita, also slowed down in most OECD countries over the three subperiods. This paper analyses the sources of output growth in 122 industries and in the private business sector to gain an additional perspective on the slowdown of the Canadian economy. We adopt the constant-quality indexes of capital and labor inputs introduced by Dale W. Jorgenson and Zvi Griliches (1967) and later used extensively in Jorgenson et al. (1987), Jorgenson (1995a, b), and Jorgenson and Eric Yip (2000) to identify the sources of growth. These measures allow us to take into account the changing composition of the labor force and the capital stock. At the industry level, we adjust for capital quality by aggregating the capital stock across five asset types by means of the rental prices of capital rather than the asset prices of capital. The use of rental prices allows us to incorporate differences in depreciation rates and tax treatment across different asset types for each industry. At the same time, we combine hours worked by each type of worker using the share of labor compensation to reflect labor quality. At the aggregate level, we apply the same framework by aggregating the capital stock across different asset types and hours worked across different types of workers. A number of studies have compared Canada’s economic growth performance with that of its competitors using this framework (Chrysostom Dougherty, 1991; Dougherty and Jorgenson, 1997; Jorgenson and Yip, 2000). However, this is the first attempt at using this framework to assess Canada’s economic performance at the industry level.

We introduce a side-payment scheme, maximum victim benefit, that promotes ‘stable’ international environmental agreements. In developing this scheme, we incorporate the equity position that victims of pollution should benefit from pollution control. The result is a scheme which picks a unique element in the core; it maximizes the benefits to the victims of pollution and ensures that polluters are willing to join the scheme.

Canada’s deterioration in labor productivity performance in the post-2000 period, especially relative to the United States, has been a major concern for policy makers. From an industrial structure perspective, this article shows that the faster loss of the manufacturing base in Canada than in the United States and the deterioration in the productivity performance of Canadian large manufacturing firms relative to their US counterparts were the main factors associated with the widening Canada–US labor productivity gap in the post-2000 period.

We studied the effects of high concentration of chromium (Cr) stress on physiological and biochemical characters and accumulation of Cr in Pingyang Tezao tea [Camellia sinensis (L) O. Kutze 'Pingyangtezao'] through a pot experiment. The results show that the indicators of photosynthesis were all suppressed with increasing Cr stress, and antioxidation and protection systems were destroyed. We also discovered that the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased, while the content of proline (Pro) and malondialdehyde (MDA) and relative conductivities increased. The accumulating Cr in all organs had a positive correlation with Cr concentration. Deposition of Cr in organs was in the following order: stubble > root > leave > stem > branch ≈ new stem (a bud and two leaves). We conclude that high concentration of Cr stress had strong inhibition and damage to the normal metabolism and cell implement structure, as well as on the function of tea plant.

This paper proposes a logistics alliance model of cooperative mechanism integrated by formation, implementation and constraint mechanisms by focusing on the study of "leader-member" logistics alliance. The empirical analysis demonstrates that this model reflects the general law of logistics alliance synergy.

Feature models are used in member product configuration in software product lines. A valid product configuration must satisfy two kinds of constraints, multiplicity of each variation point and dependencies among the variants in a product line. The combined impact of the two kinds of constrains on product configuration should be well understood. In this paper we propose a measurement, called V ariationRank, that combines the two kinds of constraints to assess the complexity of variation points in software product lines. Based on the measurement wean identify those variation points with the highest impact on product configurations in a product line. This information could be used as guidance in product configuration as well as for feature model optimization in software product lines. A case study is presented and discussed in this paper as well.

The Canadian service sector has performed well in recent years in terms of labour and multifactor productivity growth, both in absolute terms and relative to the United States, offsetting much of the poorer performance of the manufacturing sector. Service sector labour productivity growth has also shown a marked acceleration in both Canada and the United States in recent years relative to earlier periods. The objective of this paper is to identify the factors behind this relative Canadian success story. The sources of the acceleration in service sector labour productivity growth were different in the two countries. In Canada, increased multifactor productivity growth was responsible for 70 per cent of the labour productivity growth acceleration. In the United States, on the other hand, increased capital intensity and intermediate input intensity were the most important contributors to the service sector labour productivity growth acceleration. In Canada, the contribution of capital intensity growth to service sector labour productivity growth actually fell between 1981-1995 and 1995-2000. The factor driving Canada’s superior service sector labour productivity growth has been better multifactor productivity growth, suggesting a productivity convergence to the U.S. level. A faster pace of human capital accumulation relative to the United States, as measured by growth in the proportion of workers with a university degree, fostered the catch-up process of Canadian service industries.

This paper examines the trend in the importance of small producers in the Canadian and U.S. manufacturing sectors from the early 1970s to the late 1990s. It finds similar trends in both countries. Small plants increased their share of employment up to the 1990s but their share remained stable in the 1990s. Small plants increased their share of output up to the 1990s but then saw their share of output decline. Over the entire time period, their share of output increased less than their share of employment and, therefore, their relative labour productivity has fallen. The similarity in the trends in the two countries suggests that causes of this phenomenon should be sought in similarities such as the technological environment rather than in country specific factors like unionization or trade intensities.

This paper examines the trend in the importance of small producers in the Canadian and U.S. manufacturing sectors from the early 1970s to the late 1990s in order to investigate whether there was a common North American trend in changes in plant size. It finds that small plants in both countries increased their share of employment up to the 1990s, but their share remained stable in the 1990s. Small plants increased their share of output up to the 1990s, but then saw their share of output decline. Over the entire time period, their share of output increased less than their share of employment and, therefore, their relative labour productivity has fallen. The similarity in the trends in the two countries suggests that causes of this phenomenon should be sought in similarities such as the technological environment rather than in country-specific factors like unionization or trade intensities.

L’objectif de cet article est de mesurer la competitivite des industries canadiennes par rapport a leurscontreparties americaines. Nos resultats suggerent que les recentes bonnes nouvelles en matiere d’economieet une solide performance commerciale masquent les problemes de la competitivite du Canada. La progressionsoudaine des exportations et un fort accroissement de l’excedent commercial ont ete generes en grandepartie par la prosperite de l’economie des Etats-Unis et la forte reelle devalorisation du dollar canadien faceau dollar americain, et non par une quelconque amelioration de la competitivite sous-jacente. En fait, leCanada a perdu beaucoup de terrain au profit des Etats-Unis en ce qui concerne la productivite, determinantfondamental de la competitivite sous-jacente. La performance relativement faible du Canada en termesd’accumulation de capitaux, d’innovation, de main-d’œuvre hautement qualifiee, de l’importance plus grandedes petites entreprises dans l’economie et d’un ralentissement du passage aux industries de la NouvelleEconomie, tous ces facteurs ont contribue aux difficultes que connaissent la productivite et la competitivite.The objective of this paper is to evaluate the competitive position of Canadian industries vis-a-vis theirAmerican counterparts. Our results suggest that recent good economic news and a strong trade performancemask Canada’s competitiveness difficulties. The export surge and a big increase in the trade surplus werelargely the result of a strong US economy and a large real depreciation of the Canadian dollar vis-a-vis theUS dollar, but were not due to any improvement in underlying competitiveness. As a matter of fact, Canadalost substantial ground to the United States in productivity, the fundamental determinant of the underlyingcompetitiveness. Canada’s relatively weak performance in terms of capital accumulation, innovation, highlyskilled labour, greater importance of small-sized firms in the economy and a slower shift to New Economyindustries all have contributed to its productivity and competitiveness difficulties.

Using firm-level data, this paper examines the R&D intensity (R&D per unit of output) of foreign-controlled and Canadian-controlled firms based in Canada. The empirical results suggest that foreign-controlled firms, after accounting for the influence of other factors, are less R&D-intensive than Canadian-controlled firms, and this gap has not narrowed during the past ten years. On average, R&D intensity tends to be higher in high-tech and export-oriented firms, compared to low and medium technology and non-exporting firms. However, despite a lower R&D intensity, foreign-controlled firms based in Canada are more productive and pay higher wages than Canadian-controlled firms. These results in turn suggest that foreign-controlled firms benefit heavily from technology and knowledge transfer from their parent companies.