9,808 research outputs found
Wealth, Volume and Stock Market Volatility: Case of Hong Kong (1993-2001)
This paper attempts to answer the question of whether the gain and loss in property market speculations and rate of information flow play a significant role in stock market volatility in Hong Kong. To test for our wealth-volume-volatility hypothesis, two different measures of volatility: Absolute (absolute value of standard deviation from mean with monthly dimension) and conditional (EGARCH) are used and results are compared. In both measures we find evidence of a positive wealth effect on stock market volatility, in particular in the investment of upper luxury class of property in Hong Kong. To account for this result, we apply the newly developed conditional confidence theory. Although we fail to establish a volume-volatility relationship in our estimation, we offer additional dimensions to the explanation of our observation.
Corporate investment efficiency:The role of financial development in firms with financing constraints and agency issues in OECD non-financial firms
Accurate many-body electronic structure near the basis set limit: Application to the chromium dimer
We describe a method for computing near-exact energies for correlated systems with large Hilbert spaces. The method efficiently identifies the most important basis states (Slater determinants) and performs a variational calculation in the subspace spanned by these determinants. A semistochastic approach is then used to add a perturbative correction to the variational energy to compute the total energy. The size of the variational space is progressively increased until the total energy converges to within the desired tolerance. We demonstrate the power of the method by computing a near-exact potential energy curve for a very challenging molecule: the chromium dimer
Subcellular organization of UBE3A in human cerebral cortex.
BackgroundLoss of UBE3A causes Angelman syndrome, whereas excess UBE3A activity appears to increase the risk for autism. Despite this powerful association with neurodevelopmental disorders, there is still much to be learned about UBE3A, including its cellular and subcellular organization in the human brain. The issue is important, since UBE3A's localization is integral to its function.MethodsWe used light and electron microscopic immunohistochemistry to study the cellular and subcellular distribution of UBE3A in the adult human cerebral cortex. Experiments were performed on multiple tissue sources, but our results focused on optimally preserved material, using surgically resected human temporal cortex of high ultrastructural quality from nine individuals.ResultsWe demonstrate that UBE3A is expressed in both glutamatergic and GABAergic neurons, and to a lesser extent in glial cells. We find that UBE3A in neurons has a non-uniform subcellular distribution. In somata, UBE3A preferentially concentrates in euchromatin-rich domains within the nucleus. Electron microscopy reveals that labeling concentrates in the head and neck of dendritic spines and is excluded from the PSD. Strongest labeling within the neuropil was found in axon terminals.ConclusionsBy highlighting the subcellular compartments in which UBE3A is likely to function in the human neocortex, our data provide insight into the diverse functional capacities of this E3 ligase. These anatomical data may help to elucidate the role of UBE3A in Angelman syndrome and autism spectrum disorder
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