Iterative Schwarz-Christoffel Transformations Driven by Random Walks and Fractal Curves

Stochastic Loewner evolution (SLE) is a differential equation driven by a one-dimensional Brownian motion (BM), whose solution gives a stochastic process of conformal transformation on the upper half complex-plane \H. As an evolutionary boundary of image of the transformation, a random curve (the SLE curve) is generated, which is starting from the origin and running in \H toward the infinity as time is going. The SLE curves provides a variety of statistical ensembles of important fractal curves, if we change the diffusion constant of the driving BM. In the present paper, we consider the Schwarz-Christoffel transformation (SCT), which is a conformal map from \H to the region \H with a slit starting from the origin. We prepare a binomial system of SCTs, one of which generates a slit in \H with an angle $\alpha \pi$ from the positive direction of the real axis, and the other of which with an angle $(1-\alpha) \pi$. One parameter $\kappa >0$ is introduced to control the value of $\alpha$ and the length of slit. Driven by a one-dimensional random walk, which is a binomial stochastic process, a random iteration of SCTs is performed. By interpolating tips of slits by straight lines, we have a random path in \H, which we call an Iterative SCT (ISCT) path. It is well-known that, as the number of steps $N$ of random walk goes infinity, each path of random walk divided by $\sqrt{N}$ converges to a Brownian curve. Then we expect that the ISCT paths divided by $\sqrt{N}$ (the rescaled ISCT paths) converge to the SLE curves in $N \to \infty$. Our numerical study implies that, for sufficiently large $N$, the rescaled ISCT paths will have the same statistical properties as the SLE curves have, supporting our expectation.Comment: RevTeX4, 21 pages, 12 figure

Temperature Changes in Brown Adipocytes Detected with a Bimaterial Microcantilever

AbstractMammalian cells must produce heat to maintain body temperature and support other biological activities. Methods to measure a cell’s thermogenic ability by inserting a thermometer into the cell or measuring the rate of oxygen consumption in a closed vessel can disturb its natural state. Here, we developed a noninvasive system for measuring a cell’s heat production with a bimaterial microcantilever. This method is suitable for investigating the heat-generating properties of cells in their native state, because changes in cell temperature can be measured from the bending of the microcantilever, without damaging the cell and restricting its supply of dissolved oxygen. Thus, we were able to measure increases in cell temperature of <1 K in a small number of murine brown adipocytes (n = 4–7 cells) stimulated with norepinephrine, and observed a slow increase in temperature over several hours. This long-term heat production suggests that, in addition to converting fatty acids into heat energy, brown adipocytes may also adjust protein expression to raise their own temperature, to generate more heat. We expect this bimaterial microcantilever system to prove useful for determining a cell’s state by measuring thermal characteristics

Causal assessment of smoking and tooth loss: A systematic review of observational studies

<p>Abstract</p> <p>Background</p> <p>Tooth loss impairs oral function. The aim of the present review was to evaluate the causal association between smoking and tooth loss on the basis of high-quality studies.</p> <p>Methods</p> <p>Relevant literature was searched and screened, and the methodological quality was assessed. Information on the strength of the association between smoking and tooth loss, the dose-response relationship and natural experimental data was collected and evaluated with respect to consistency and study design.</p> <p>Results</p> <p>Our literature search yielded 496 citations, and 6 cross-sectional and 2 cohort high-quality studies examining 58,755 subjects in four countries. All studies reported significant associations, although the strength of the association was usually moderate. Four studies reported dose-response relationships between exposure to smoking and the risk of developing tooth loss. A decrease in the risk of tooth loss for former smokers was evident in six studies. Interpretation of evidence for each element was consistent, despite some shortcomings regarding study type and population.</p> <p>Conclusions</p> <p>Based on the consistent evidence found with the existing biological plausibility, a causal association between smoking and tooth loss is highly likely. Further studies using a cohort design and different populations are necessary to confirm this association.</p

Industrial associations as ideational platforms : why Japan resisted American-style shareholder capitalism

Significant wage and treatment differentials between regular workers in long-term employment and precarious non-regular workers have been a major political issue in Japan since the mid-1990s. I argue this phenomenon was caused by Japanese society’s resistance to American neoliberal hegemony. Why has Japan resisted it, and how has the resistance resulted in the rapid increase in the working poor? I contend anti-liberal, anti-free market norms of Japanese society centred on ‘systemic support’ have bolstered resistance to convergence in order to prevent capitalist dominance from severing long-term social ties, such as management-labour cooperation. My broadened definition of systemic support incorporates dominant elites’ support and protection of subordinates in exchange for their loyalty and obedience. This paper will explore reasons for the resistance to convergence by examining an ideational conflict within Japanese elites between the market liberalisation and anti-free market camps, particularly between two major industrial associations, Keidanren and Keizai Doyukai, which have played a key role as ‘ideational platforms’ for Japanese corporate society. Under the Hashimoto (1996-8) and Koizumi (2001-6) administrations, the market liberalisation camp gained influence, but since 2006, both the anti-free market camp and its subordinates (e.g. regular workers) have driven anti-neoliberal backlash

Cerium X-ray Spectra without Filtering and their Application to High-contrast Angiography

The cerium-target x-ray tube is useful in order to perform cone-beam K-edge angiography because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast media. The x-ray generator consists of a main controller, an x-ray tube unit with a high-voltage circuit and an insulation transformer, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.2×0.8 mm. Sharp cerium K-series characteristic x rays were observed without using a filter, and the x-ray intensity was 209μGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 0.40 mA. Angiography was performed with a computed radiography system using iodine-based microspheres 15 μm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 μm with high contrasts