Taming the pion condensation in QCD at finite baryon density: a numerical test in a random matrix model

In the Monte Carlo study of QCD at finite baryon density based upon the phase reweighting method, the pion condensation in the phase-quenched theory and associated zero-mode prevent us from going to the low-temperature high-density region. We propose a method to circumvent them by a simple modification of the density of state method. We first argue that the standard version of the density of state method, which is invented to solve the overlapping problem, is effective only for a certain ‘good’ class of observables. We then modify it so as to solve the overlap problem for ‘bad’ observables as well. While, in the standard version of the density of state method, we usually constrain an observable we are interested in, we fix a different observable in our new method which has a sharp peak at some particular value characterizing the correct vacuum of the target theory. In the finite-density QCD, such an observable is the pion condensate. The average phase becomes vanishingly small as the value of the pion condensate becomes large, hence it is enough to consider configurations with π+ ≃ 0, where the zero mode does not appear. We demonstrate an effectiveness of our method by using a toy model (the chiral random matrix theory) which captures the properties of finite-density QCD qualitatively. We also argue how to apply our method to other theories including finite-density QCD. Although the example we study numerically is based on the phase reweighting method, the same idea can be applied to more general reweighting methods and we show how this idea can be applied to find a possible QCD critical point

Effect of Beginning Date of Intermittent Low Temperature Treatments on Flowering of Tray-grown Strawberry 'Nyoho'

　Intermittent low temperature storage is expected to be a new artificial flower-inducing treatment and becoming to be a practical procedure as it does not require expensive equipment or much energy cost. Tray-grown ‘Nyoho’ plants were placed in a refrigerator (15°C, in the dark) for 3 days and then transferred to a further outdoor shelter for 3 days. Plants were transferred at noon and this cycle was repeated twice (3D/3D). Such 3D/3D treatments were begun on August 22, 25, 28, 31, and September 3and the effectiveness on flowering was determined for 2 years. Both in 2012 and 2013, treatments begun before August 28 were less effective compared to the treatments begun on August 28 or later. Continuous 6 days of 15°C storage (6D) was effective to some extent, but 6D from August 25 was apparently less effective compared to those begun later. Both in intermittent and continuous treatments for ‘Nyoho’, it was confirmed that any flower-inducing effect became relatively small and unstable when the treatments were begun before 28 August in Okayama

Comparison of LEDs, Fluorescent Lamps and Incandescent Bulbs for Long-day Treatment of Forcing Strawberries as Affected by Respective Color Temperature

Long day (LD) treatment is frequently applied for horticultural crops, including strawberry, and sufficient effect similar to 4 to 6hours of day time elongation in the evening can be achieved by 1 to 3hours of night break in the mid night. Incandescent lamps (IC) have long been an important light source, but the general incandescent lamps are out of production and have been replaced with LED or florescent lamps (FL). Thus, we compared light sources and their color temperature (2,800K, warm white similar to IC; 6,500K, daylight) in different lighting programs. The effectiveness of 3 and 4cycles of alternate intermittent lighting, 30min on/30min off, were equal to and larger than 2hours of night break, respectively. Measured intensity of illumination (lux) at the canopy surface by 2,800K LED (6.9W) and FL (12W) was 1.50 and 0.95times as large as IC (54W), but leaf growth under LED and FL was similar to and less vigorous than IC, respectively. On the other hand, intensity values of illumination by 6,500K LED (6.9W) and FL (12W) were both 1.20times as large as 2,800K ones, but 6,500K light sources were much less effective compared to 2,800K ones. Daylight type LED and FL which have higher luminance efficiency but emit less red light compared to warm white ones, are not suitable as alternative light sources for IC

Monte Carlo approach to nonperturbative strings -- demonstration in noncritical string theory

We show how Monte Carlo approach can be used to study the double scaling limit in matrix models. As an example, we study a solvable hermitian one-matrix model with the double-well potential, which has been identified recently as a dual description of noncritical string theory with worldsheet supersymmetry. This identification utilizes the nonperturbatively stable vacuum unlike its bosonic counterparts, and therefore it provides a complete constructive formulation of string theory. Our data with the matrix size ranging from 8 to 512 show a clear scaling behavior, which enables us to extract the double scaling limit accurately. The ``specific heat'' obtained in this way agrees nicely with the known result obtained by solving the Painleve-II equation with appropriate boundary conditions.Comment: 15 pages, 10 figures, LaTeX, JHEP3.cls; references added, typos correcte

Inactivation of Chk2 and Mus81 Leads to Impaired Lymphocytes Development, Reduced Genomic Instability, and Suppression of Cancer

Chk2 is an effector kinase important for the activation of cell cycle checkpoints, p53, and apoptosis in response to DNA damage. Mus81 is required for the restart of stalled replication forks and for genomic integrity. Mus81Δex3-4/Δex3-4 mice have increased cancer susceptibility that is exacerbated by p53 inactivation. In this study, we demonstrate that Chk2 inactivation impairs the development of Mus81Δex3-4/Δex3-4 lymphoid cells in a cell-autonomous manner. Importantly, in contrast to its predicted tumor suppressor function, loss of Chk2 promotes mitotic catastrophe and cell death, and it results in suppressed oncogenic transformation and tumor development in Mus81Δex3-4/Δex3-4 background. Thus, our data indicate that an important role for Chk2 is maintaining lymphocyte development and that dual inactivation of Chk2 and Mus81 remarkably inhibits cancer

Contribution of Strigolactones to the Inhibition of Tiller Bud Outgrowth under Phosphate Deficiency in Rice

Strigolactones (SLs) or SL-derived metabolite(s) have recently been shown to act as endogenous inhibitors of axillary bud outgrowth. SLs released from roots induce hyphal branching of arbuscular mycorrhizal (AM) fungi that facilitate the uptake of inorganic nutrients, such as phosphate (Pi) and nitrate, by the host plants. Previous studies have shown that SL levels in root exudates are highly elevated by Pi starvation, which might contribute to successful symbiosis with AM fungi in the rhizosphere. However, how endogenous SL levels elevated by Pi starvation contribute to its hormonal action has been unknown. Here, we show that tiller bud outgrowth in wild-type rice seedlings is inhibited, while root 2′-epi-5-deoxystrigol (epi-5DS) levels are elevated, in response to decreasing Pi concentrations in the media. However, the suppression of tiller bud outgrowth under Pi deficiency does not occur in the SL-deficient and -insensitive mutants. We also show that the responsiveness to exogenous SL is slightly increased by Pi deficiency. When Pi-starved seedlings are transferred to Pi-sufficient media, tiller bud outgrowth is induced following a decrease in root epi-5DS levels. Taken together, these results suggest that elevated SL levels by Pi starvation contribute to the inhibition of tiller bud outgrowth in rice seedlings. We speculate that SL plays a dual role in the adaptation to Pi deficiency; one as a rhizosphere signal to maximize AM fungi symbiosis for improved Pi acquisition and the other as an endogenous hormone or its biosynthetic precursor to optimize shoot branching for efficient Pi utilization