626 research outputs found
Kinetic market models with single commodity having price fluctuations
We study here numerically the behavior of an ideal gas like model of markets
having only one non-consumable commodity. We investigate the behavior of the
steady-state distributions of money, commodity and total wealth, as the
dynamics of trading or exchange of money and commodity proceeds, with local (in
time) fluctuations in the price of the commodity. These distributions are
studied in markets with agents having uniform and random saving factors. The
self-organizing features in money distribution are similar to the cases without
any commodity (or with consumable commodities), while the commodity
distribution shows an exponential decay. The wealth distribution shows
interesting behavior: Gamma like distribution for uniform saving propensity and
has the same power-law tail, as that of the money distribution, for a market
with agents having random saving propensity.Comment: RevTeX4, 6 pages, 5 eps figures, accepted in Eur. Phys. J.
Ideal-gas like market models with savings: quenched and annealed cases
We analyze the ideal gas like models of markets and review the different
cases where a `savings' factor changes the nature and shape of the distribution
of wealth. These models can produce similar distribution of wealth as observed
across varied economies. We present a more realistic model where the saving
factor can vary over time (annealed savings) and yet produces Pareto
distribution of wealth in certain cases. We discuss the relevance of such
models in the context of wealth distribution, and address some recent issues in
the context of these models.Comment: 2-col RevTeX4, 4 pages, 1 eps figure; Proc. APFA5 Conference, Torino,
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Kinetic Exchange Models for Income and Wealth Distributions
Increasingly, a huge amount of statistics have been gathered which clearly
indicates that income and wealth distributions in various countries or
societies follow a robust pattern, close to the Gibbs distribution of energy in
an ideal gas in equilibrium. However, it also deviates in the low income and
more significantly for the high income ranges. Application of physics models
provides illuminating ideas and understanding, complementing the observations.Comment: 15 pages, 20 eps figures, EPJ class; To be published as "Colloquium"
in Eur Phys J
DNA resection in eukaryotes: deciding how to fix the break
DNA double-strand breaks are repaired by different mechanisms, including homologous
recombination and nonhomologous end-joining. DNA-end resection, the first step in
recombination, is a key step that contributes to the choice of DSB repair. Resection, an
evolutionarily conserved process that generates single-stranded DNA, is linked to checkpoint
activation and is critical for survival. Failure to regulate and execute this process results in
defective recombination and can contribute to human disease. Here, I review recent findings on
the mechanisms of resection in eukaryotes, from yeast to vertebrates, provide insights into the
regulatory strategies that control it, and highlight the consequences of both its impairment and its
deregulation
Vesnarinone, a differentiation inducing drug, directly activates p21waf1 gene promoter via Sp1 sites in a human salivary gland cancer cell line
We previously demonstrated that a differentiation inducing drug, vesnarinone induced the growth arrest and p21waf1 gene expression in a human salivary gland cancer cell line, TYS. In the present study, we investigated the mechanism of the induction of p21waf1 gene by vesnarinone in TYS cells. We constructed several reporter plasmids containing the p21waf1 promoter, and attempted to identify vesnarinone-responsive elements in the p21waf1 promoter. By the luciferase reporter assay, we identified the minimal vesnarinone-responsive element in the p21waf1 promoter at −124 to −61 relative to the transcription start site. Moreover, we demonstrated by electrophoretic mobility shift assay that Sp1 and Sp3 transcription factors bound to the vesnarinone-responsive element. Furthermore, we found that vesnarinone induced the histone hyperacetylation in TYS cells. These results suggest that vesnarinone directly activates p21waf1 promoter via the activation of Sp1 and Sp3 transcription factors and the histone hyperacetylation in TYS cells
Entrepreneurs, Chance, and the Deterministic Concentration of Wealth
In many economies, wealth is strikingly concentrated. Entrepreneurs–individuals with ownership in for-profit enterprises–comprise a large portion of the wealthiest individuals, and their behavior may help explain patterns in the national distribution of wealth. Entrepreneurs are less diversified and more heavily invested in their own companies than is commonly assumed in economic models. We present an intentionally simplified individual-based model of wealth generation among entrepreneurs to assess the role of chance and determinism in the distribution of wealth. We demonstrate that chance alone, combined with the deterministic effects of compounding returns, can lead to unlimited concentration of wealth, such that the percentage of all wealth owned by a few entrepreneurs eventually approaches 100%. Specifically, concentration of wealth results when the rate of return on investment varies by entrepreneur and by time. This result is robust to inclusion of realities such as differing skill among entrepreneurs. The most likely overall growth rate of the economy decreases as businesses become less diverse, suggesting that high concentrations of wealth may adversely affect a country's economic growth. We show that a tax on large inherited fortunes, applied to a small portion of the most fortunate in the population, can efficiently arrest the concentration of wealth at intermediate levels
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