Comparative Dating Of Attine Ant And Lepiotaceous Cultivar Phylogenies Reveals Coevolutionary Synchrony And Discord

The mutualistic symbiosis between fungus-gardening ants and their cultivars has made fundamental contributions to our understanding of the coevolution of complex species interactions. Reciprocal specialization and vertical symbiont cotransmission are thought to promote a pattern of largely synchronous coevolutionary diversification in attines. Here we test this hypothesis by inferring the first time-calibrated multigene phylogeny of the lepiotaceous attine cultivars and comparing it with the recently published fossil-anchored phylogeny of the attine ants. While this comparison reveals some possible cases of synchronous origins of ant and fungal clades, there were a number of surprising asynchronies. For example, leaf-cutter cultivars appear to be significantly younger than the corresponding ant genera. Similarly, a clade of fungi interacting with primitive fungus-gardening ants-thought to be ancestral to the more derived leaf-cutter symbionts-appears instead to be a more recent acquisition from free-living stock. These macroevolutionary patterns are consistent with recent population-level studies suggesting occasional acquisition of novel cultivar types from environmental sources and horizontal transmission of cultivars between different ant species. Horizontal transmission events, even if rare, appear to form loose ecological connections between diffusely coevolving ant and fungus lineages that permit punctuated changes in the topology of the mutualistic ant-fungus interaction network.Integrative Biolog

AN EVALUATION OF CONSUMER PESTICIDE RESIDUE CONCERNS AND RISK INFORMATION SOURCES

Marginal probability effects of demographic variables on consumer concerns about pesticide residues were assessed as well as the likelihood of consumer beliefs given different channels of information on produce safety and risks. This was done using maximum likelihood estimation (MLE) of ordered logit models. The empirical results showed that pesticide residue concern levels appeared to be lower for more highly educated and high income households. Safety information from the academic community was found to have the highest likelihood of acceptance by consumers.Risk and Uncertainty,

The Role of Sunk Costs in Digitalization – Empirical Evidence from Accounting and Finance

IT investments are researched in theory and practice from different theoretical perspectives. In accounting and finance, corporate practice in particular shows that large IT investments are either not made or are abandoned during the investment and implementation process. In our view, the economic role of sunk costs has not been given sufficient attention in the literature to date. From a theoretical point of view, the objective or subjective assumption of sunk costs could be a barrier against the adoption of new digital technologies. This paper can partly support this thesis on the basis of empirical data

One Single Click is enough – an Empirical Study on Human Threats in Family Firm Cyber Security

The present study focuses on the tension between human versus technical risks in German companies. It examines how employees counter cybercrime and how this affects the company. Aim is to analyze human threats in family businesses and to create opportunities to use the human factor as an opportunity in the context of technological change. For this, an empirical study among 184 German firms was conducted. In general, the results demonstrate an insufficient awareness of the topic in the companies. Although companies are aware of the need for trained employees, there is a backlog of demand for workshops and awareness raising. Employees are detected as the main security risk, especially in family businesses. Better employee training is therefore indispensable. However, even training courses cannot prevent employees from making mistakes in the area of cyber security. Therefore, it can be emphasized that additional organizational security measures are necessary

Special Interest Groups Versus Voters and the Political Economics of Attention

We examine whether representatives are more likely to serve long-term campaign donors instead of constituents during times of low media attention to politics. Based on 425 roll calls between 2005 and 2014 in the US House of Representatives, we show that representatives are more likely to vote with special interests and against constituency interests when the two are in conflict. Importantly, the latter effect is significantly larger when there is less attention on politics due to exogenous newsworthy events. The opportunistic behavior seems not to be mediated by short-term scheduling of sensitive votes right after distracting events