Evolution of Cooperation in Spatio-Temporal Evolutionary Games with Public Goods Feedback.

In biology, evolutionary game-theoretical models often arise in which players' strategies impact the state of the environment, driving feedback between strategy and the surroundings. In this case, cooperative interactions can be applied to studying ecological systems, animal or microorganism populations, and cells producing or actively extracting a growth resource from their environment. We consider the framework of eco-evolutionary game theory with replicator dynamics and growth-limiting public goods extracted by population members from some external source. It is known that the two sub-populations of cooperators and defectors can develop spatio-temporal patterns that enable long-term coexistence in the shared environment. To investigate this phenomenon and unveil the mechanisms that sustain cooperation, we analyze two eco-evolutionary models: a well-mixed environment and a heterogeneous model with spatial diffusion. In the latter, we integrate spatial diffusion into replicator dynamics. Our findings reveal rich strategy dynamics, including bistability and bifurcations, in the temporal system and spatial stability, as well as Turing instability, Turing-Hopf bifurcations, and chaos in the diffusion system. The results indicate that effective mechanisms to promote cooperation include increasing the player density, decreasing the relative timescale, controlling the density of initial cooperators, improving the diffusion rate of the public goods, lowering the diffusion rate of the cooperators, and enhancing the payoffs to the cooperators. We provide the conditions for the existence, stability, and occurrence of bifurcations in both systems. Our analysis can be applied to dynamic phenomena in fields as diverse as human decision-making, microorganism growth factors secretion, and group hunting.

Evolution of cooperation in multigame with environmental space and delay.

Replicator dynamics is widely used in evolutionary game theory, however, most previous studies on replicator dynamics focus on single games and ignore multiple social dilemmas encountered by individuals in a population. This paper uses replicator dynamics to construct a multigame system with environmental space and delay based on three social dilemmas. For the non-delayed and delayed multigame systems, rich dynamics for stability, bistability, transcritical bifurcation, Hopf bifurcation, and the direction, stability and periodic variation of periodic solutions are comprehensively investigated. Accordingly, we use numerical simulations to assist in exploring the effects of multigame, environmental space, and time delay on strategic dynamics. The results show that large proportions of snowdrift game and stag hunt game are conducive to the prosperity of cooperators, and defectors are easy to survive when the proportion of prisoner's dilemma is large. The cooperator gains the advantage of benefit distribution from environmental space, or the defector gets less benefit distribution as punishment, which will make pure cooperation the dominant strategy. Furthermore, environmental space can allow cooperation and defection to coexist oscillatingly. Interestingly, large delays reverse the coexistence of cooperation and defection to a situation dominated by the purely cooperative strategy.

Implementing caregiver management measures in general hospitals to prevent the COVID-19 pandemic.

AIM: To summarize the whole process management measures for caregivers of inpatients in a non-new coronavirus pneumonia designated hospital in China during the novel coronavirus pneumonia epidemic. The implementation of these measures is mainly to prevent the virus pandemic caused by crowd gathering. DESIGN: A quasi-experimental study. METHODS: Novel coronavirus pneumonia prevention and control measures were implemented in the 'pre-hospital link, hospitalization link and discharge link' for the whole process of the hospitalized patients' caregivers. To evaluate the effects by time point inspection, the results were fed back using information technology for quality improvement. RESULTS: The results of three time point inspections indicated that the management quality of many projects improved continuously (p < 0.05). From January to June of 2021, 20 departments implemented a facial recognition information management system. The ratio of patients/caregivers admitted was 1:0.528~1:0.965; It was found that it is effective to implement the whole process management measures. The facial recognition system plays a key role in the comprehensive management of the caregivers.

Hepatic Arterial Infusion Chemotherapy with Oxaliplatin and 5-Fluorouracil for Advanced Gallbladder Cancer.

PURPOSE: The aim of this study was to assess the safety and efficacy of hepatic arterial infusion chemotherapy (HAIC) with oxaliplatin and 5-fluorouracil for patients with advanced gallbladder cancer (GBC). MATERIALS AND METHODS: Twenty-six patients with advanced GBC, who underwent HAIC with oxaliplatin and 5-fluorouracil from January 2012 to July 2019, were enrolled in this retrospective study. The HAIC regimen consisted of infusions of oxaliplatin at 40 mg/m2 for 2 h, followed by 5-fluorouracil at 800 mg/m2 for 22 h on days 1-3 every 3-4 weeks. A maximum of six cycles of HAIC were applied for tumor control patients followed by maintenance with oral capecitabine or S-1. Overall survival (OS), progression-free survival (PFS), tumor response, and adverse events were investigated. RESULTS: Six of the 26 patients (23.1%) had failed systemic chemotherapy, 8/26 (30.8%) patients had failed various local therapies, and 9/26 (34.6%) patients had contraindications to systemic chemotherapy. The median OS was 13.5 months, and the median PFS was 10.0 months. The overall response rate was 69.2% (18/26), and disease control rate was 92.3% (24/26). Carcinoembryonic antigen (CEA) ≥ 10 U/ml (p = 0.003) and carbohydrate antigen 19-9 (CA19-9) ≥ 200 U/ml (p = 0.000) were independent risk factors for decreased survival. The most frequent Grade 3 or 4 treatment-related adverse event was liver dysfunction (4, 15.4%). CONCLUSION: HAIC with oxaliplatin and 5-fluorouracil is an acceptable and well-tolerated treatment for advanced gallbladder cancer even for patients in whom systemic chemotherapy had failed or is contraindicated. LEVEL OF EVIDENCE: Level 2, Observation Study with Dramatic Effect.