Evolutionary dynamics and fixation probabilities in directed networks

We investigate the evolutionary dynamics in directed and/or weighted networks. We study the fixation probability of a mutant in finite populations in stochastic voter-type dynamics for several update rules. The fixation probability is defined as the probability of a newly introduced mutant in a wild-type population taking over the entire population. In contrast to the case of undirected and unweighted networks, the fixation probability of a mutant in directed networks is characterized not only by the degree of the node that the mutant initially invades but by the global structure of networks. Consequently, the gross connectivity of networks such as small-world property or modularity has a major impact on the fixation probability.Comment: 7 figure

An Empirical Study on the Impact of Prior Information Provision Methods on Participants’ Perceptions in Tasting Marketing

The ENTER 2022 eTourism Conference, January 11-14, 2022Tasting events are a typical example of a tourism experience that utilizes alcohol. However, it has not been sufficiently demonstrated how the prior information given to customers at tasting events affects their perception of the tasting and its marketing effects. In this study, we conducted a tasting experiment of a new Japanese sake product in California, the USA to clarify how information given to participants in advance can affect their perception of the tasting, satisfaction, and word-of-mouth intention related to the new sake product, and compared the effects of the following types of prior information: 1) no information, 2) written information, 3) video explained by a man, and 4) video explained by a woman. The results show that presenting information makes a difference in its impact as opposed to providing no information. When prior information was presented in written form, various perspectives significantly influenced the satisfaction and recommended intention more than in the cases of video. On the other hand, in the cases of video, the number of significant paths was reduced, but the influence on word-of-mouth intention was greater than in the case of written information. This study contributes to the development of a theory and empirical evidence that takes into account prior information in tasting marketing in tourism

Intracellular oxygen tension limits muscle contraction-induced change in muscle oxygen consumption under hypoxic conditions during Hb-free perfusion.

Under acute hypoxic conditions, the muscle oxygen uptake (mV˙O2) during exercise is reduced by the restriction in oxygen-supplied volume to the mitochondria within the peripheral tissue. This suggests the existence of a factor restricting the mV˙O2 under hypoxic conditions at the peripheral tissue level. Therefore, this study set out to test the hypothesis that the restriction in mV˙O2 is regulated by the net decrease in intracellular oxygen tension equilibrated with myoglobin oxygen saturation (∆PmbO2) during muscle contraction under hypoxic conditions. The hindlimb of male Wistar rats (8 weeks old, n = 5) was perfused with hemoglobin-free Krebs-Henseleit buffer equilibrated with three different fractions of O2 gas: 95.0%O2, 71.3%O2, and 47.5%O2 The deoxygenated myoglobin (Mb) kinetics during muscle contraction were measured under each oxygen condition with a near-infrared spectroscopy. The ∆[deoxy-Mb] kinetics were converted to oxygen saturation of myoglobin (SmbO2), and the PmbO2 was then calculated based on the SmbO2 and the O2 dissociation curve of the Mb. The SmbO2 and PmbO2 at rest decreased with the decrease in O2 supply, and the muscle contraction caused a further decrease in SmbO2 and PmbO2 under all O2 conditions. The net increase in mV˙O2 from the muscle contraction (∆mV˙O2) gradually decreased as the ∆PmbO2 decreased during muscle contraction. The results of this study suggest that ΔPmbO2 is a key determinant of the ΔmV˙O2

Endurance training facilitates myoglobin desaturation during muscle contraction in rat skeletal muscle.

At onset of muscle contraction, myoglobin (Mb) immediately releases its bound O2 to the mitochondria. Accordingly, intracellular O2 tension (PmbO2) markedly declines in order to increase muscle O2 uptake (mVO2). However, whether the change in PmbO2 during muscle contraction modulates mVO2 and whether the O2 release rate from Mb increases in endurance-trained muscles remain unclear. The purpose of this study was, therefore, to determine the effect of endurance training on O2 saturation of Mb (SmbO2) and PmbO2 kinetics during muscle contraction. Male Wistar rats were subjected to a 4-week swimming training (Tr group; 6 days per week, 30 min × 4 sets per day) with a weight load of 2% body mass. After the training period, deoxygenated Mb kinetics during muscle contraction were measured using near-infrared spectroscopy under hemoglobin-free medium perfusion. In the Tr group, the VmO2peak significantly increased by 32%. Although the PmbO2 during muscle contraction did not affect the increased mVO2 in endurance-trained muscle, the O2 release rate from Mb increased because of the increased Mb concentration and faster decremental rate in SmbO2 at the maximal twitch tension. These results suggest that the Mb dynamics during muscle contraction are contributing factors to faster VO2 kinetics in endurance-trained muscle

Breast Cancer with Cartilaginous and/or Osseous Metaplasia Diagnosed by Lymph Nodal Metastasis:A Case Report

Breast cancer with cartilaginous and/or osseous metaplasia is a type of metaplastic carcinomas and is a rare disease. We report the case of a 49 year-old female who underwent right mastectomy for a large breast tumor. Histological examinations revealed a mixed tumor with both stromal and epithelial elements;the stroma showed poor differentiated spindle-shape and multiform cells with a massive osseous matrix, and atypical epithelial cells, which mainly existed on the surface of the cysts, showed nucleic atypia. The tumor was diagnosed as a malignant phyllodes tumor with osteosarcomatous differentiation;it was not identified as a metaplastic carcinoma because of the lack of proof of a cancerous component. Two years after a mastectomy, swelling of the axillary lymph nodes was found and a biopsy was performed. Histological findings for the lymph node indicated a metastasis of the invasive ductal carcinoma. The primary tumor was re-examined and was considered to be the origin of the lymph nodal metastasis. Lymph nodal metastasis of cancer proved that the primary tumor had cancerous potential, and the pathological diagnosis was altered to a breast cancer with cartilaginous and/or osseous metaplasia.</p

Removing Diethylphthalate (DEP) from Water Systems using Zeolites and Mesoporous Materials

In order to remove diethylphthalate (DEP) molecules from water systems, zeolites of faujasite (FAU), ferrierite (FER), mordenite (MOR), and mesoporous silica (MCM-41) were employed in this study. 1H nuclear-magnetic-resonance (NMR) spectra showed that FAU was effective in eliminating DEP from aqueous solutions. In addition, solid-state 1H NMR spectra with a magic-angle-spinning (MAS) rate of 30 kHz revealed that a larger amount of DEP was adsorbed on FAUs with higher Si/Al ratios. Our NMR spectra also showed that a chemical shift of the signal assigned to water molecules adsorbed on the FAUs is linked to the amount of DEP adsorption. 1H MAS NMR spectra also revealed that DEP molecules prefer to adsorb on the four-membered ring site rather than the center or/and window of the supercage in FAUs. Since porous materials are frequently present in ground and water systems such as rivers, ponds, and lakes, this study also showed that DEP could adsorb onto soils in aquatic environments and remain in the water system for a long time

Quantification of myoglobin deoxygenation and intracellular partial pressure of O2 during muscle contraction during haemoglobin-free medium perfusion

金沢大学人間社会研究域人間科学系Although the O2 gradient regulates O2 flux from the capillary into the myocyte to meet the energy demands of contracting muscle, intracellular O2 dynamics during muscle contraction remain unclear. Our hindlimb perfusion model allows the determination of intracellular myoglobin (Mb) saturation () and intracellular oxygen tension of myoglobin () in contracting muscle using near infrared spectroscopy (NIRS). The hindlimb of male Wistar rats was perfused from the abdominal aorta with a well-oxygenated haemoglobin-free Krebs-Henseleit buffer. The deoxygenated Mb (Δ[deoxy-Mb]) signal was monitored by NIRS. Based on the value of Δ[deoxy-Mb], and were calculated, and the time course was evaluated by an exponential function model. Both and started to decrease immediately after the onset of contraction. The steady-state values of and progressively decreased with relative work intensity or muscle oxygen consumption. At the maximal twitch rate, and were 49% and 2.4 mmHg, respectively. Moreover, the rate of release of O2 from Mb at the onset of contraction increased with muscle oxygen consumption. These results suggest that at the onset of muscle contraction, Mb supplies O2 during the steep decline in, which expands the O2 gradient to increase the O2 flux to meet the increased energy demands. © 2010 The Physiological Society

NIRS measurement of O(2) dynamics in contracting blood and buffer perfused hindlimb muscle.

金沢大学人間社会研究域人間科学系In order to obtain evidence that Mb releases O(2) during muscle contraction, we have set up a buffer-perfused hindlimb rat model and applied NIRS to detect the dynamics of tissue deoxygenation during contraction. The NIRS signal was monitored on hindlimb muscle during twitch contractions at 1 Hz, evoked via electrostimulator at different submaximal levels. The hindlimb perfusion was carried out by perfusion of Krebs Bicarbonate buffer. The NIRS still detected a strong signal even under Hb-free contractions. The deoxygenation signal (Delta[deoxy]) was progressively increased at onset of the contraction and reached the plateau under both blood- and buffer-perfused conditions. However, the amplitude of Delta[deoxy] during steady state continued to significantly increase as tension increased. The tension-matched comparison of the Delta[deoxy] level under buffer-perfused and blood perfused conditions indicate that Mb can contribute approximately 50% to the NIRS signal. These results clarify the Mb contribution to the NIRS signal and show a falling intracellular PO(2) as workload increases