Predicting Problem-Solving Performance Using Concept Map

A growing community of researchers applies the concept map for elicitation and representation individual’s knowledge structure especially within knowledge-intensive processes in organizations. As an extension of prior works on concept map, this study aims to explore a new indicator of structural properties of concept map from an information entropy perspective to predict an individual’s problem-solving performance. From the information processing view of problem-solving, Information Theory provides the framework to formulate a new indicator called EntropyAvg. A controlled experiment was carried out to validate the predictive ability of the new indicator. The results demonstrate that EntropyAvg is able to estimate an individual’s problem-solving performance beyond two other widely adopted indicators, i.e., complexity and integration. The theoretical and practical contributions of this study are also discusse

Financial Development, Econmic Growth and R&D Cyclical Movement

This paper builds up an endogenous growth model à la Aghion and Howitt (1992) and Boucekkine et al (2005). We assume that R&D firms use only investment good as input, instead of final good as hypothesized in the above two models. We show that investment price will be a negative function of aggregate quality index; and thus decline over time. In this model, subsidy on R&D has growth-enhancing effect. Moreover, this model predicts unambiguously that R&D is procyclical

Convergence in Health Care Expenditure of 14 EU Countries: New Evidence from Non-linear Panel Unit Root Test

This paper attempts to examine the convergence hypothesis of health care expenditure per capita of 14 European Union (EU) countries during the 1975–2008 period by applying the Cerrato et al., (2009) nonlinear panel unit root test. Although the conventional linear panel unit root tests reject the null uniformly, the Cerrato et al., (2009) test shows evidence that one cannot reject the null hypothesis of unit root for health care expenditures of each country relative to the EU average, after taking nonlinearity into account. Our results are robust using different reference countries. The empirical findings imply that the exisitng “ EU health policy reforms” and “ European law on health care provision” may not able to encourage greater health care convergence in EU

China

Economic development processes in post-1949 China can be divided into two periods. In the first, 1950-70, the economy was extensively and intensively controlled by the state with a priority for developing heavy industries. In the second, since the 80s and known as the \u27reform period,\u27 the Chinese economy has increasingly been integrated with the world economy and relying on light (rural) industries as the prime motor of economic growth. Yet, in both these periods, Chinese policymakers shared the same \u27developmental\u27 philosophy in which social costs, that is the reproduction costs of human labour and nature, are largely ignored. The following is a critical sketch of government policies and their impact on the domestic population in these two periods

A R&D Based Real Business Cycle Model

The New Keynesian Real Business Cycle model with staggered price adjustment is augmented with a R&D producing sector. Two sources of economic shocks are considered, namely random paritcipation (perturbances to value of alternative investment opportunities in another sector) and financial intermediation (shocks to the cost of raising capital in the financial intermediation market). We find that, when comparing to the baseline model, both models can explain pro-cyclical R&D spending. Additionally, the investment oversensitivity problem is corrected. However, only the financial intermediation model is consistent with the observed finding that volatility of R&D is larger than that of investment and output

The Conditional CAPM, Cross-Section Returns and Stochastic Volatility

Bansal and Yaron (2004) demonstrate, by calibration, that the Consumption-Based Capital Asset Pricing Model (CCAPM) can be rescued by assuming that consumption growth rate follows a stochastic volatility model. They show that the conditional equity premium is a linear function of conditional consumption and market return volatilities, which can be estimated handily by various Generalized Autoregressive Conditonal Heterskedasticity (GARCH) and Stochastic Volatility (SV) models.We find that conditional consumption and market volatilities are capable of explaining cross-sectional return differences. The Exponential GARCH (EGARCH) volatility can explain up to 55% variation of return and the EGARCH model augmented with (cay) ̂ -a cointegrating factor of consumption, labor income and asset wealth growth- greatly enhance model performance. We proceed to test another hypothesis: if Bansal and Yaron estimator is an unbiased estimator of true conditional equity premium, then the instrumental variables for estimating conditional equity premium should no longer be significant.We demonstrate that once the theoretical conditional risk premium is added to the model, it renders all instrumental variables redundant. Also, the model prediction is consistent with observed declining equity premium

An Examination of Sports Event Sentiment: Microeconomic Evidence from Borsa Istanbul

This paper examines the impact of international soccer matches on the Turkish stock market using firm level and sorted portfolio data, i.e. microeconomic evidence. Applying the Edmans et al. (2007) estimation method, we find a significant negative loss effect. However, once using panel data analysis and modeling spatial and temporal effects explicitly, we not only reject the null hypothesis of the sports sentiment effect, but also find that the international soccer games virtually have no power explaining stock return variation. The same conclusions are made when replacing win/loss dummies with unexpected win (loss) variable and sorting portfolio returns by market capitalization, past returns and volatility. Although we found mild evidence that sports events could affect the variance of sorted portfolio returns, there is very limited micro-evidence to support the 'overreaction' hypothesis of individual investors using Borsa Istanbul data

Prolonged exposure to bacterial toxins downregulated expression of toll-like receptors in mesenchymal stromal cell-derived osteoprogenitors

<p>Abstract</p> <p>Background</p> <p>Human mesenchymal stromal cells (MSCs, also known as mesenchymal stem cells) are multipotent cells with potential therapeutic value. Owing to their osteogenic capability, MSCs may be clinically applied for facilitating osseointegration in dental implants or orthopedic repair of bony defect. However, whether wound infection or oral microflora may interfere with the growth and osteogenic differentiation of human MSCs remains unknown. This study investigated whether proliferation and osteogenic differentiation of MSCs would be affected by potent gram-positive and gram-negative derived bacterial toxins commonly found in human settings.</p> <p>Results</p> <p>We selected lipopolysaccharide (LPS) from <it>Escherichia coli </it>and lipoteichoic acid (LTA) from <it>Streptococcus pyogenes </it>as our toxins of choice. Our findings showed both LPS and LTA did not affect MSC proliferation, but prolonged LPS challenge upregulated the osteogenic differentiation of MSCs, as assessed by alkaline phosphatase activity and calcium deposition. Because toll-like receptors (TLRs), in particularly TLR4 and TLR2, are important for the cellular responsiveness to LPS and LTA respectively, we evaluated their expression profiles serially from MSCs to osteoblasts by quantitative PCR. We found that during osteogenic differentiation, MSC-derived osteoprogenitors gradually expressed TLR2 and TLR4 by Day 12. But under prolonged incubation with LPS, MSC-derived osteoprogenitors had reduced TLR2 and TLR4 gene expression. This peculiar response to LPS suggests a possible adaptive mechanism when MSCs are subjected to continuous exposure with bacteria.</p> <p>Conclusion</p> <p>In conclusion, our findings support the potential of using human MSCs as a biological graft, even under a bacterial toxin-rich environment.</p

Anti-oxidative effects of the biennial flower of Panax notoginseng against H2O2-induced cytotoxicity in cultured PC12 cells

<p>Abstract</p> <p>Background</p> <p><it>Radix notoginseng </it>is used in Chinese medicine to improve blood circulation and clotting; however, the pharmacological activities of other parts of <it>Panax notoginseng </it>have yet to be explored. The present study reports the anti-oxidative effects of various parts of <it>Panax notoginseng</it>.</p> <p>Methods</p> <p>Various parts of <it>Panax notoginseng</it>, including the biennial flower, stem-leaf, root-rhizome, fiber root and sideslip, were used to prepare extracts and analyzed for their anti-oxidation effects, namely suppressing xanthine oxidase activity, H₂O₂-induced cytotoxicity and H₂O₂-induced ROS formation.</p> <p>Results</p> <p>Among various parts of the herb (biennial flower, stem-leaf, root-rhizome, fiber root and sideslip), the water extract of the biennial flower showed the strongest effects in (i) inhibiting the enzymatic activity of xanthine oxidase and (ii) protecting neuronal PC12 cells against H₂O₂-induced cytotoxicity. Only the water extracts demonstrated such anti-oxidative effects while the ethanol extracts did not exert significant effects in suppressing xanthine oxidase and H₂O₂-induced neuronal cytotoxicity.</p> <p>Conclusions</p> <p>The present study demonstrates the biennial flower of <it>Panax notoginseng </it>to have neuroprotection effect on cultured neurons and the underlying protection mechanism may involve anti-oxidation.</p

Reexamining Sports-Sentiment Hypothesis: Microeconomic Evidences from Borsa Istanbul

This paper examines the impact of international soccer matches on the Turkish stock market using firm-level and sorted-portfolio data. Applying Edmans et al. (2007) estimation method, we found a significant negative loss effect. However, once using panel data analysis as well as modeling spatial and temporal effects explicitly, the sports-sentiment effect disappeared. The same conclusions could be made by replacing win (loss) dummies with unexpected win (loss) variables, removing Monday matches, dropping sports-related firms, and sorting portfolio returns by market capitalization and past returns. Hence, there is very limited micro-evidence to support the ‘overreaction’ hypothesis of individual investors using Borsa Istanbul data. However, we found evidence that sporting events have a larger impact on stock return volatility for firms with smaller market capitalization and lower past returns