313 research outputs found
Capital Gains Taxes and Asset Prices: The Impact of Tax Awareness and Procrastination
We argue that the impact of capital gains taxation on asset pricing depends on the tax awareness of market participants. While institutional investors should be generally well-informed about tax regulations, private investors have only limited tax knowledge and resources. As a result, market reactions on tax law changes may be delayed if a considerable fraction of market participants is not fully tax-aware. In line with our argument, we find evidence that the introduction of a previously announced German flat tax on private capital gains in 2009 resulted in a temporarily strong and significant increase of trading volumes, daily returns and asset prices. Our research implies that tax law changes provide an opportunity for well-informed investors to generate arbitrage benefits. Corresponding to our estimate, the capital gains tax resulted in an increase demand for shares of 160 % as well as in an price surplus of about 7.4 % within the last two trading days 2008
Osteopontin regulates human glioma cell invasiveness and tumor growth in mice
Human malignant glioma cells are characterized by local invasion. In the present study, we investigated the role of osteopontin (OPN) in the invasiveness of human glioma cells isolated from grade IV tumors. We found that the expression levels of OPN in these cell lines paralleled matrix metalloproteinase-2 (MMP-2) expression and cell invasiveness potential. When U87MG glioma cells (with a high-OPN expression level) were stably transformed with specific small hairpin RNA to knock down OPN expression, MMP-2 secretion, cell invasiveness, and tumor growth in implanted brains were dramatically reduced. Conversely, forced expression of OPN in GBM-SKH glioma cells (which expressed OPN at a low level) increased MMP-2 secretion, enhanced cell invasiveness, and increased tumor growth in a rodent xenograft model. Expression of OPN was associated with increased expression of vimentin and decreased expression of glial fibrillary acidic protein. Treatment of glioma cells with 5-aza-2ā²-deoxycytidine (5-aza-dC) suppressed OPN expression in a concentration-dependent manner. Suppression of OPN expression by 5-aza-dC was associated with reductions in MMP-2 secretion, vimentin expression, cell invasion, intravasation, and tumor growth. These data suggest that OPN may play important roles in regulating cell invasion in glioma cells and that 5-aza-dC may serve as a therapeutic agent for human gliomas
Helicity-dependent cross sections for the photoproduction of pairs from nucleons
The double-polarization observable and helicity-dependent cross sections
, have been measured for the photoproduction of
pairs off quasi-free protons and neutrons at the Mainz MAMI accelerator
with the Crystal Ball/TAPS setup. A circularly polarized photon beam was
produced by bremsstrahlung from longitudinally polarized electrons and impinged
on a longitudinally polarized deuterated butanol target. The reaction products
were detected with an almost covering calorimeter. The results reveal
for the first time the helicity- and isospin-dependent structure of the reaction. They are compared to predictions from
reaction models in view of nucleon resonance contributions and also to a refit
of one model that predicted results for the proton and for the neutron target.
The comparison of the prediction and the refit demonstrate the large impact of
the new data.Comment: Submitted to Phys. Rev. Let
Khoe-San genomes reveal unique variation and confirm the deepest population divergence in Homo sapiens
Abstract: The southern African indigenous Khoe-San populations harbor the most divergent lineages of all living peoples. Exploring their genomes is key to understanding deep human history. We sequenced 25 full genomes from five Khoe-San populations, revealing many novel variants, that 25% of variants are unique to the Khoe-San, and that the Khoe-San group harbors the greatest level of diversity across the globe. In line with previous studies, we found several gene regions with extreme values in genome-wide scans for selection, potentially caused by natural selection in the lineage leading to Homo sapiens and more recent in time. These gene regions included immunity-, sperm-, brain-, diet-, and muscle-related genes. When accounting for recent admixture, all Khoe-San groups display genetic diversity approaching the levels in other African groups and a reduction in effective population size starting around 100,000 years ago. Hence, all human groups show a reduction in effective population size commencing around the time of the Out-of- Africa migrations, which coincides with changes in the paleoclimate records, changes that potentially impacted all humans at the time
The Long-Term Consequences of the Global 1918 Influenza Pandemic: A Systematic Analysis of 117 IPUMS International Census Data Sets
Several country-level studies, including a prominent one for the United States, have identified long-term effects of in-utero exposure to the 1918 influenza pandemic (also known as the Spanish Flu) on economic outcomes in adulthood. In-utero conditions are theoretically linked to adult health and socioeconomic status through the fetal origins or Barker hypothesis. Historical exposure to the Spanish Flu provides a natural experiment to test this hypothesis. Although the Spanish Flu was a global phenomenon, with around 500 million people infected worldwide, there exists no comprehensive global study on its long-term economic effects. We attempt to close this gap by systematically analyzing 117 Census data sets provided by IPUMS International. We do not find consistent global long-term effects of influenza exposure on education, employment and disability outcomes. A series of robustness checks does not alter this conclusion. Our findings indicate that the existing evidence on long-term economic effects of the Spanish Flu is likely a consequence of publication bias
Learning from Trade Through Innovation: Causal Link Between Imports, Exports and Innovation in Spanish Microdata
The paper explores the learning from trade hypothesis. Standardized research approach searchs for learning effects from trade focusing solely on exports, whereby firm's learning effects are accounted in the firm of total factor productivity improvements. In contrast, this papers defines a firm learning from trade in tfirms of introduction of either new products or processes induced by its import and export links with foreign markets. By using microdata for a large sample of Spanish firms, including data on innovation and trade, we find clear sequencing between imports, exports and innovation. The results suggest that firms learn primarily from import links, which enables them to innovate products and processes and to dress up for starting to export. In a sequence, exporting may enable firms to introduce further innovations. These positive learning effects from trade, however, seem to be limited to small and partially medium firms only. On the other side, firms that are closer to the relevant technological frontier seem to benefit more from trading activities in tfirms of innovation than the technological laggard firms
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