Article
Mathematics, Interdisciplinary Applications
Luhe Yang, Lianzhong Zhang
Summary: The study focuses on the evolution of cooperation on a two-dimension square lattice by introducing an exogenous variable that promotes cooperation. The modified model shows stricter conditions for the emergence and maintenance of cooperation, and can be applied in scenarios with environmental feedback.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Ecology
Constantinos Xenophontos, W. Stanley Harpole, Kirsten Kuesel, Adam Thomas Clark
Summary: Cheaters in microbial communities can stabilize the community and potentially be a precursor to cooperation rather than extinction.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2022)
Article
Biology
Maxwell N. Burton-Chellew, Victoire D'Amico
Summary: Through experiments on 489 participants, it was found that individuals were more motivated to learn and imitate successful behaviors, rather than common behaviors. The results indicated that social learning discouraged costly cooperation, even when individuals could observe a stable, pro-social level of cooperation.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2021)
Article
Mathematics, Applied
Jinhua Zhao, Xianjia Wang, Lei Niu, Cuiling Gu
Summary: This paper examines the Nash equilibrium of the climate change dilemma in cases of discrete and continuous contribution, showing that zero contribution becomes the main equilibrium point as the number of players increases. A dynamic model based on Particle Swarm Optimization algorithm is proposed, indicating that decision-making based on historical information can significantly increase average contribution levels.
APPLIED MATHEMATICS AND COMPUTATION
(2021)
Article
Multidisciplinary Sciences
Isaiah Paolo A. Lee, Omar Tonsi Eldakar, J. Peter Gogarten, Cheryl P. Andam
Summary: Prosocial behavior is widespread in nature despite the costs for cooperative individuals. The stability of cooperation in populations is often maintained through enforcement. This study proposes that homologous recombination serves as a mechanism for cooperation in bacteria. Using an agent-based model, the researchers demonstrate how changes in recombination rates affect the proportion of cooperating cells in a public goods game. The findings show the influence of recombination on the persistence of cooperative behavior in bacteria.
Article
Mathematics, Interdisciplinary Applications
Ji Quan, Junyu Yu, Xia Li, Xianjia Wang
Summary: We propose a conditional strategy that allows for switching between social excluders and loners in the spatial public goods game. Through multi-agent-based simulation, we investigate the effect of this strategy on cooperation level from different perspectives. Results show that the introduction of this conditional strategy can facilitate the evolution of cooperation, with lower tolerance parameter leading to increased cooperation. However, the strategy might fail under high tolerance parameters due to exclusion costs and exclusion probabilities. Moreover, smaller exclusion costs or larger exclusion probabilities have a stronger impact on promoting cooperation under the same tolerance parameter.
CHAOS SOLITONS & FRACTALS
(2023)
Article
Physics, Multidisciplinary
C. Xu, P. M. Hui
Summary: This study investigates cooperative behavior in a population engaged in Public Goods Games (PGG) with players in dynamic groups of various sizes and memberships. It proposes a learning mechanism for switching strategy based on comparing payoffs between two randomly chosen players. Analytical and numerical simulations confirm that cooperation can be promoted by adjusting the multiplicative factor and group size distribution. The findings highlight the role of smaller groups in promoting cooperation in a PGG setting.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2023)
Article
Mathematics, Applied
Hsuan-Wei Lee, Colin Cleveland, Attila Szolnoki
Summary: Punishing those who refuse to participate in common efforts is a known way to maintain cooperation, but it can make punishers vulnerable and jeopardize effectiveness. Hiring special players to monitor and punish defectors as an alternative using a tax-based fund is suggested. The level of tax and punishment fines are crucial factors in determining coexistence with cooperators or defectors and achieving optimal outcomes.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Environmental Studies
Sina A. Klein, Luisa K. Horsten, Benjamin E. Hilbig
Summary: Previous research shows that framing pro-environmental behavior as beneficial for others can increase pro-environmental behavior, especially when prosocial and pro-environmental motives conflict. Social framing outperforms environmental framing in promoting pro-environmental behavior when prosocial and pro-environmental motives are in conflict.
JOURNAL OF ENVIRONMENTAL PSYCHOLOGY
(2022)
Article
Mathematics, Interdisciplinary Applications
Tianyu Ren, Junjun Zheng
Summary: Altruistic sanctions play a crucial role in promoting cooperation in human society, and introducing a tolerance-based expulsion mechanism can significantly enhance cooperation, stabilize it under negative conditions, and determine the optimal threshold for implementation of expulsion.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Mathematics, Interdisciplinary Applications
Maja Duh, Marko Gosak, Matjaz Perc
Summary: The structure of networks plays a crucial role in determining the evolution of cooperation, with random geometric graphs in hyperbolic spaces promoting the development of public cooperation. Heterogeneous networks are more conducive to the success of cooperators compared to homogeneous networks. Both assortative and disassortative mixing on hyperbolic networks impair the success of cooperators, especially at low mixing frequencies.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Multidisciplinary Sciences
Jung-Shen B. Tai, Saikat Mukherjee, Thomas Nero, Rich Olson, Jeffrey Tithof, Carey D. Nadell, Jing Yan
Summary: Biofilm formation is a crucial mode of growth for bacteria, achieved through cell-cell and cell-surface adhesion. This study demonstrates the vulnerability of diffusible biofilm matrix proteins to exploitation and highlights the importance of biofilm spatial structure, sharing mechanisms, and environmental conditions in maintaining the evolutionary stability of producing these components. The findings have implications for understanding cooperative behaviors in bacterial communities.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Economics
Felix Koelle, Simone Quercia
Summary: The importance of empirical and normative expectations for cooperative behavior is investigated in this paper. It is found that when others' contributions are known, people tend to have a strong norm of conditional cooperation, but when there is strategic uncertainty, empirical and normative expectations diverge substantially.
JOURNAL OF ECONOMIC BEHAVIOR & ORGANIZATION
(2021)
Article
Economics
Jerome Hergueux, Nicolas Jacquemet, Stephane Luchini, Jason F. Shogren
Summary: Public good games are essential in addressing environmental challenges. Many individuals support the norm of reciprocity, but self-serving bias in reciprocation is also observed. This paper argues that weak reciprocity may not be a preference, but rather a symptom of the trade-off between truthful revelation of reciprocal preference and economic incentives. The study finds that offering players the opportunity to sign a truth-telling oath improves cooperation, with subjects under oath behaving more consistently with their expectations and normative views.
ENVIRONMENTAL & RESOURCE ECONOMICS
(2022)
Article
Mathematics, Interdisciplinary Applications
Attila Szolnoki, Xiaojie Chen
Summary: In a public goods game, reinvesting the results of common effort and adding it to the pool for the next round can change players' strategies, especially in structured populations where the last round is crucial for achieving full cooperation. In such cases, it may be advantageous for defectors to support the first round and enjoy the extra benefit of accumulated contributions.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Ecology
Jaime Gonzalez, Manuel Salvador, Ozhan Ozkaya, Matt Spick, Kate Reid, Catia Costa, Melanie J. Bailey, Claudio Avignone Rossa, Rolf Kummerli, Jose Jimenez
Summary: The rapid emergence of antibiotic resistant bacterial pathogens is a critical problem in healthcare, requiring the development of novel treatments. Recent research suggests that manipulating the uptake of public goods instead of their production could lead to the development of "Trojan horse" candidates for infiltrating pathogen populations.
Article
Ecology
Elena Butaite, Jos Kramer, Rolf Kummerli
Summary: In soil and pond communities of Pseudomonas bacteria collected over geographical scales from 0.5 to 50 m, variation in pyoverdine production and related genes were found to significantly impact local adaptation of bacteria. This impact was primarily determined by phylogenetic relatedness between interacting isolates rather than geographical distance. Horizontal transfer of receptor genes may erode the effect of phylogenetic relatedness in local pond communities. Overall, common ancestry is the main predictor of siderophore-mediated social interactions among pseudomonads.
JOURNAL OF EVOLUTIONARY BIOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Alexandre R. T. Figueiredo, Andreas Wagner, Rolf Kummerli
Summary: Experimental evolution of bacteria producing a model public good, iron-scavenging siderophore pyoverdine, revealed rapid evolution of social traits in divergent directions, with strong selection for increased cooperation in environments with reduced individual dispersal. Regulatory link between pyoverdine production and quorum-sensing was established, showing that increased cooperation in one trait may be associated with the loss of another social trait.
Article
Immunology
Selina Niggli, Tobias Wechsler, Rolf Kuemmerli
Summary: In polymicrobial infections, Pseudomonas aeruginosa and Staphylococcus aureus frequently co-occur, and their interactions can complicate disease progression and treatment options. Through single-cell time-lapse fluorescence microscopy, it was discovered that S. aureus often outcompetes P. aeruginosa on solid substrates, accelerating microcolony growth and compromising P. aeruginosa growth before physical contact. Different S. aureus strains exhibited varying levels of competitiveness, with P. aeruginosa responding to S. aureus attack by showing increased directional growth and expedited expression of quorum sensing regulators.
FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY
(2021)
Article
Biochemical Research Methods
Karoline Rehm, Vera Vollenweider, Rolf Kummerli, Laurent Bigler
Summary: Microbial secondary metabolites, especially siderophores, have great potential in drug discovery, plant protection, and biotechnology. However, the identification and structural elucidation of siderophores are underexplored due to the lack of high-throughput analytical protocols. In this study, a dedicated method using UHPLC-HR-MS/MS was established for rapid localization and structural elucidation of pyoverdines, a type of siderophore. The method was successfully validated and applied to discover novel pyoverdine peptide chains in bacterial cultures.
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
(2022)
Article
Ecology
Alexandre R. T. Figueiredo, Ozhan Ozkaya, Rolf Kummerli, Jos Kramer
Summary: The study reveals that siderophores play a significant role in shaping invasion dynamics in bacterial communities.
Article
Ecology
Subham Mridha, Rolf Kuemmerli
Summary: Bacteria often cooperate by secreting beneficial public goods, but specialization in producing a single public good does not necessarily result in beneficial division of labor. Cheating can occur in specialist communities under stringent iron limitation, but stability can be maintained through negative frequency-dependent selection. Fine-tuned regulatory mechanisms in generalists might be favored by natural selection over division of labor.
JOURNAL OF EVOLUTIONARY BIOLOGY
(2022)
Article
Biology
Subham Mridha, Rolf Kuemmerli
Summary: Tracking the growth and gene expression of the bacterium Pseudomonas aeruginosa at the single-cell level provides insights into social behaviors among cells in clonal groups. The study reveals that while there is some coordination in bacterial groups, individual cells exhibit high heterogeneity in gene expression. As cell density increases, gene expression becomes more homogenized and there is a shift in investment towards different public goods. The expression of genes for different public goods is positively associated across cells and correlates with cellular metabolic states.
COMMUNICATIONS BIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Karoline Rehm, Vera Vollenweider, Rolf Kuemmerli, Laurent Bigler
Summary: Siderophores are iron-chelating molecules produced by bacteria and other microbes, playing essential roles in infection virulence, bacterial community assembly, and plant protection. However, the lack of rapid analytical procedures has hindered the identification of the chemical structures of these bio-active molecules. This study presents a new method using trapped ion mobility spectrometry to rapidly identify and characterize pyoverdines, a group of siderophores. The collision cross sections (CCS) and mass determination of pyoverdines were successfully recorded, providing a high-throughput analysis option.
Article
Microbiology
Priyanikha Jayakumar, Alexandre R. T. Figueiredo, Rolf Kummerli
Summary: Pseudomonas aeruginosa populations undergo extensive genetic adaptation and diversification in various environments. Mutations in the quorum sensing (QS) system affect the expression of virulence factors and public goods. This study found that mutations in different QS systems lead to diverging effects on the QS trait profile, potentially impacting fitness and virulence.
Review
Biotechnology & Applied Microbiology
Meghna Swayambhu, Rolf Kuemmerli, Natasha Arora
Summary: Recent advancements in next-generation sequencing technologies combined with machine learning have shown the potential of microbiome-based analyses in various fields such as clinical diagnostics and forensic sciences. In the field of forensics, microbial markers found in biological stains left at crime scenes can provide crucial information for crime scene reconstruction, including the bodily origin, time since deposition, and donor(s) of the stain. Despite the promising results, there is a need to address the gaps in comprehensive assessment of the method's limitations and the establishment of a standard operating procedure before integrating microbiome-based analyses into routine forensic casework.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Rolf Kuemmerli
Summary: Iron is essential for bacterial growth and survival, and bacteria have developed various mechanisms to solubilize and acquire iron from the environment. This review focuses on the iron uptake mechanisms of Pseudomonas spp., including direct uptake of ferrous iron, production of iron-chelating siderophores, exploitation of siderophores from other microbial species, and use of iron-chelating compounds from plants and animals. The review also discusses how these mechanisms affect interactions between bacteria in microbial communities and with their hosts, suggesting that diverse iron uptake repertoires might provide an advantage in the competition for iron.
Article
Biochemistry & Molecular Biology
Priyanikha Jayakumar, Stephen A. Thomas, Sam P. Brown, Rolf Kummerli
Summary: Bacteria can coordinate cooperative actions through quorum sensing (QS), but it is unclear whether individuals coordinate their actions or whether group phenotypes simply reflect the sum of their noisy members. This study found that gene expression during QS is noisy and shows segregation into different states during the initiation phase. Mathematical models suggest that gene expression segregation can be driven by molecular resource limitations and function as a temporary bet-hedging strategy in unpredictable environments.
Article
Biochemistry & Molecular Biology
Karoline Rehm, Vera Vollenweider, Shaohua Gu, Ville-Petri Friman, Rolf Kuemmerli, Zhong Wei, Laurent Bigler
Summary: In this study, a novel citrate-based siderophore called chryseochelin A was identified and found to promote the health and growth of plants. The structure of this siderophore, along with its unstable isomer chryseochelin B and fatty acid derivative chryseochelin C, was elucidated using NMR spectroscopy and mass spectrometry. It was demonstrated that chryseochelin A can reduce the access to iron of the plant pathogenic bacterium Ralstonia solanacearum, indicating its potential in plant protection.
Article
Microbiology
George A. O'Toole, Aurelie Crabbe, Rolf Kummerli, John J. LiPuma, Jennifer M. Bomberger, Jane C. Davies, Dominique Limoli, Vanessa V. Phelan, James B. Bliska, William H. DePas, Lars E. Dietrich, Thomas H. Hampton, Ryan Hunter, Cezar M. Khursigara, Alexa Price-Whelan, Alix Ashare, Robert A. Cramer, Joanna B. Goldberg, Freya Harrison, Deborah A. Hogan, Michael A. Henson, Dean R. Madden, Jared R. Mayers, Carey Nadell, Dianne Newman, Alice Prince, Damian W. Rivett, Joseph D. Schwartzman, Daniel Schultz, Donald C. Sheppard, Alan R. Smyth, Melanie A. Spero, Bruce A. Stanton, Paul E. Turner, Chris van der Gast, Fiona J. Whelan, Rachel Whitaker, Katrine Whiteson, Matthew R. Parsek
Summary: The workshop discussed the development of new models to study polymicrobial infections in the airways of cystic fibrosis patients, proposing three frameworks to address this complex issue that could be generally useful in developing new model systems for other infectious diseases.
