Iskanje po katalogu digitalne knjižnice

Opis: Evolutionary game theory in the realm of network science appeals to a lot of research communities, as it constitutes a popular theoretical framework for studying the evolution of cooperation in social dilemmas. Recent research has shown that cooperation is markedly more resistant in interdependent networks, where traditional network reciprocity can be further enhanced due to various forms of interdependence between different network layers. However, the role of mobility in interdependent networks is yet to gain its well-deserved attention. Here we consider an interdependent network model, where individuals in each layer follow different evolutionary games, and where each player is considered as a mobile agent that can move locally inside its own layer to improve its fitness. Probabilistically, we also consider an imitation possibility from a neighbor on the other layer. We show that, by considering migration and stochastic imitation, further fascinating gateways to cooperation on interdependent networks can be observed. Notably, cooperation can be promoted on both layers, even if cooperation without interdependence would be improbable on one of the layers due to adverse conditions. Our results provide a rationale for engineering better social systems at the interface of networks and human decision making under testing dilemmas.
Ključne besede: cooperation, interdependent networks, mobile agents, prisoner's dilemma, snowdrift game, game theory, mobility, rational agents
Objavljeno v DKUM: 15.01.2025; Ogledov: 0; Prenosov: 0
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Opis: True hamsters are a small subfamily (Cricetinae) containing only 19 species which are endemic to the Palaearctic region. Despite such low species richness, general public is well familiar with hamsters, primarily knowing them as pets, experimental laboratory animals and species of conservation concern. The present work is a compilation integrating achievements of the genomic era with the traditional taxonomy. The aim was to provide an authoritative and up-to-date taxonomic guide to the animal group, which is of great interest to experts engaged in medical zoology, epidemiology, biostratigraphy, zooarchaeology, evolutionary research, population ecology, animal systematics, biodiversity conservation, museum collection management and many more biological subdisciplines. The most significant original contribution is perhaps revision of the family-group taxa with naming 2 new subtribes and 2 new tribes. The text is supplemented by 120 illustrations and over 700 references. Morphological details of skull and dentition of each of the 19 species are depicted, and their distributions are mapped in detail. The book will allow the user to interpret intelligently the taxonomic system of Cricetinae and to follow taxonomic progress with a critical eye.
Ključne besede: taxonomy, nomenclature, morphology, karyology, molecular systematics, species delimitation, subspecies, zoogeography, distribution modelling
Objavljeno v DKUM: 14.01.2025; Ogledov: 0; Prenosov: 12
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Opis: Summarized by the efcient market hypothesis, the idea that stock prices fully refect all available information is always confronted with the behavior of real-world markets. While there is plenty of evidence indicating and quantifying the efciency of stock markets, most studies assume this efciency to be constant over time so that its dynamical and collective aspects remain poorly understood. Here we defne the time-varying efciency of stock markets by calculating the permutation entropy within sliding time-windows of log-returns of stock market indices. We show that major world stock markets can be hierarchically classifed into several groups that display similar long-term efciency profles. However, we also show that efciency ranks and clusters of markets with similar trends are only stable for a few months at a time. We thus propose a network representation of stock markets that aggregates their short-term efciency patterns into a global and coherent picture. We fnd this fnancial network to be strongly entangled while also having a modular structure that consists of two distinct groups of stock markets. Our results suggest that stock market efciency is a collective phenomenon that can drive its operation at a high level of informational efciency, but also places the entire system under risk of failure.
Ključne besede: collective dynamics, social physics, econophysics, stock market
Objavljeno v DKUM: 14.01.2025; Ogledov: 0; Prenosov: 2
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Opis: European semi-dry grasslands are habitats of high conservation value. Therefore, research into the mechanisms of community assembly is important for their effective management. Using data from 76 vegetation plots of calcareous and acidic semi-dry grasslands in continental Slovenia, the author analysed the composition of plant traits, focusing on less studied belowground traits. Community-weighted means were calculated for nine plant functional traits: life form, growth form, clonal growth organ (CGO) type, persistence of connection in CGO, number of clonal offspring shoots, lateral spreading distance, role of CGO, bud bank, CSR strategy. The results showed that both grassland communities were characterized by high local persistence (perennial plants with long-lived connections between ramets). Acidic grasslands had more species with rosettes, rhizomes and stress-tolerators, indicating more stressful conditions, probably due to low pH. Mesic grassland species with numerous stolons and longer lateral spread were also characteristic of acidic grasslands. Calcareous grasslands hosted more competitors, plants with leafy stems and plants with perennial main roots. This study contributes to a deeper understanding of grassland processes and provides a basis for future investigations of belowground plant traits and their function.
Ključne besede: biodiversity, community assembly, permanent grassland, plant traits, ecosystem functions, Natura 2000, Festuco-Brometea
Objavljeno v DKUM: 08.01.2025; Ogledov: 0; Prenosov: 5
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Opis: Collective risks permeate society, triggering social dilemmas in which working toward a common goal is impeded by selfish interests. One such dilemma is mitigating runaway climate change. To study the social aspects of climate-change mitigation, we organized an experimental game and asked volunteer groups of three different sizes to invest toward a common mitigation goal. If investments reached a preset target, volunteers would avoid all consequences and convert their remaining capital into monetary payouts. In the opposite case, however, volunteers would lose all their capital with 50% probability. The dilemma was, therefore, whether to invest one's own capital or wait for others to step in. We find that communicating sentiment and outlook helps to resolve the dilemma by a fundamental shift in investment patterns. Groups in which communication is allowed invest persistently and hardly ever give up, even when their current investment deficits are substantial. The improved investment patterns are robust to group size, although larger groups are harder to coordinate, as evidenced by their overall lower success frequencies. A clustering algorithm reveals three behavioral types and shows that communication reduces the abundance of the free-riding type. Climate-change mitigation, however, is achieved mainly by cooperator and altruist types stepping up and increasing contributions as the failure looms. Meanwhile, contributions from free riders remain flat throughout the game. This reveals that the mechanisms behind avoiding collective risks depend on an interaction between behavioral type, communication, and timing.
Ključne besede: social dilemma, free riding, climate change, negotiation, group size, COVID-19
Objavljeno v DKUM: 07.01.2025; Ogledov: 0; Prenosov: 2
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