Stochastic games are a framework for investigating long-term interdependence of multi-agent systems with environmental feedback. When the number of environmental states is one, they are reduced to repeated games. In repeated games, zero-determinant (ZD) strategies attract much attention in evolutionary game theory, since they can unilaterally control payoffs. Especially, fair ZD strategies unilaterally equalize the payoff of the focal player and the average payoff of the opponents, and they were found in several games including the social dilemma games. Although the existence condition of ZD strategies in repeated games was specified, its extension to stochastic games remains largely unclear. Here, we investigate the existence condition of fair ZD strategies in the periodic prisoner’s dilemma game, which is one of the simplest stochastic games. The periodic prisoner’s dilemma game consists of two environmental states and the two states alternate deterministically. Whereas each stage game is not necessarily the prisoner’s dilemma game, the whole game can be regarded as the prisoner’s dilemma game on average. We show that fair ZD strategies do not necessarily exist in the periodic prisoner’s dilemma game, in contrast to the repeated prisoner’s dilemma game. Furthermore, we also prove that the Tit-for-Tat strategy, which imitates the opponent’s action, is not necessarily a fair ZD strategy in the periodic prisoner’s dilemma game, whereas the Tit-for-Tat strategy is always a fair ZD strategy in the repeated prisoner’s dilemma game. Our results highlight difference between ZD strategies in the periodic prisoner’s dilemma game and those in the standard repeated prisoner’s dilemma game.
In the present study the impact of a prolonged dose-delivery time on tumour control was evaluated by using a mathematical tumour model calibrated with in vivo tumour volume data. While in vitro studies have reported reduced radiobiological effects with extended dose-delivery time, the in vivo relevance remains uncertain. Here, such effects were explored across various fractionation protocols and temporal delivery conditions. A biologically based mathematical model was developed using tumour volume data from CT26 murine models subjected to different radiation protocols (5 × 2 Gy, 1 × 7 Gy, and 3 × 4 Gy). The model integrated microdosimetric kinetic modelling (MKM) and ordinary differential equations to simulate tumour dynamics. Simulations were conducted for dose-delivery times of 0, 10, 30, 60, and 120 min, and the changes in tumour volume relative to instantaneous delivery (0 min) were evaluated. All protocols exhibited increased tumour volumes with longer delivery times. The 1 × 7 Gy protocol showed the highest effect, with a 5
Phospholipid vesicle (liposome) offers an aqueous compartment surrounded by lipid bilayer membranes. Various enzyme molecules were reported to be encapsulated in liposomes. The liposomal enzyme shows peculiar catalytic activity and selectivity to the substrate in the bulk liquid, which are predominantly derived from the substrate permeation resistance through the membrane. We reported that the quaternary structure of bovine liver catalase and alcohol dehydrogenase was stabilized in liposomes through their interaction with lipid membranes. The method and condition for preparing the enzyme-containing liposomes with well-defined size, lipid composition, and enzyme content are of particular importance, because these properties dominate the catalytic performance and stability of the liposomal enzymes.
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by excessive collagen deposition and irreversible scarring. Reliable animal models are essential for elucidating IPF pathogenesis and evaluating antifibrotic therapies. However, conventional bleomycin (BLM) models generally induce only transient and moderate fibrosis. Considering the profibrotic role of eosinophils, we developed a novel IPF model using the spontaneous eosinophilic mutant Yama mice strain to achieve persistent and severe fibrosis. Male Yama and C57BL/6 mice (6 weeks old, n = 24) received eight intranasal administrations of BLM (2 mg/kg) at two-week intervals, while controls received saline. Peripheral eosinophil counts were monitored, and tissues were analyzed histologically and biochemically. Yama mice exhibited a sharp eosinophil peak after the first BLM exposure, followed by a gradual decline. Histological analysis revealed markedly enhanced fibrosis, greater collagen deposition, and higher Ashcroft scores in Yama mice than in C57BL/6 mice. Alcian blue-PAS-positive fibroblast foci, a characteristic feature of human IPF, were abundant in Yama mice. Immunohistochemistry demonstrated increased expression of eosinophil cationic protein (ECP). Moreover, mRNA expression of Th2 cytokines (IL-4, IL-5, IL-13) and profibrotic mediators (IL-6, Col1a1) was significantly higher in Yama mice. However, the pronounced fibrotic changes, TGF-beta expression exhibited only a modest increase in Yama mice, suggesting that fibrosis might develop via pathways not totally dependent on conventional TGF-beta signaling. This repeated BLM administration model successfully reproduces the key pathological features of severe IPF and emphasizes the pivotal contribution of eosinophils to fibrogenesis.
Zircon U-Pb dating was conducted on granite, granodiorite, and gabbro from the central part of Yamaguchi Prefecture, Southwest Japan. The granodiorite and gabbro are recognized as components of the Susuma-Nagaho Plutonic Complex (SNPC). The zircon U-Pb dating yielded ages of 103 Ma for the granite and 92 Ma for the granodiorite and gabbro. These ages coincide with the magmatic flare-up event documented in Southwest Japan. A compiled dataset of Cretaceous gabbro-diorite from Southwest Japan shows that initial-epsilon Nd values (epsilon NdI) decrease progressively to as low as -5.1 between 107 and 90 Ma. In addition, Th/La ratios exhibit a negative correlation with initial-Nd isotopic ratios. These geochemical trends, together with their temporal variation, suggest that subducted sediments increasingly interacted with the mantle wedge, producing progressively enriched mantle sources throughout the Cretaceous. This secular change may reflect variations in plate motion, such as change in the rate of subduction.
