Punish the thief:Coevolution of defense and cautiousness stabilizes ownership

Ownership of non-controllable resources usually has to be maintained by costly defense against competitors. Whether defense and thus ownership pays in terms of fitness depends on its effectiveness in preventing theft. We show that if the owners' willingness to defend varies in the population and information about it is available to potential thieves then the ability to react to this information and thus avoid being attacked by the owner is selected for. This can lead to a positive evolutionary feedback between cautiousness in intruders and aggressiveness in owners. This feedback can maintain ownership when the actual direct effectiveness of defense in reducing theft is very low or even absent, effectively turning defense into punishment. We conclude that the deterrence effect of defense in many situations could be stronger than that of prevention and that for many real-world scenarios the purpose of defense of resources might be to punish rather than to drive away intruders. Significance statement Many animals defend resources against conspecifics. Resource defense can usually only evolve if its costs are paid for by foiling attempts at theft. We show that if potential thieves can detect differences in aggressiveness between owners then cautious intruders and aggressive owners coevolve so that in the end even ineffective defense deters thieves and maintains ownership. This result greatly extends the number of situations in which we expect resource defense to evolve and has the potential to unify the concepts of defense and punishment

The effects of information on the formation of migration routes and the dynamics of migration

Most models of migration simply assume that migrants somehow make their way from their point of origin to their chosen destination. We know, however, that—especially in the case of asylum migration—the migrant journey often is a hazardous, difficult process where migrants make decisions based on limited information and under severe material constraints. Here we investigate the dynamics of the migration journey itself using a spatially explicit, agent-based model. In particular we are interested in the effects of limited information and information exchange. We find that under limited information, migration routes generally become suboptimal, their stochasticity increases, and migrants arrive much less frequently at their preferred destination. Under specific circumstances, self-organised consensus routes emerge that are largely unpredictable. Limited information also strongly reduces the migrants’ ability to react to changes in circumstances. We conclude, first, that information and information exchange is likely to have considerable effects on all aspects of migration and should thus be included in future modelling efforts and, second, that there are many questions in theoretical migration research that are likely to profit from the use of agent-based modelling techniques

The effects of information on the formation of migration routes and the dynamics of migration

Most models of migration simply assume that migrants somehow make their way from their point of origin to their chosen destination. We know, however, that—especially in the case of asylum migration—the migrant journey often is a hazardous, difficult process where migrants make decisions based on limited information and under severe material constraints. Here we investigate the dynamics of the migration journey itself using a spatially explicit, agent-based model. In particular we are interested in the effects of limited information and information exchange. We find that under limited information, migration routes generally become suboptimal, their stochasticity increases, and migrants arrive much less frequently at their preferred destination. Under specific circumstances, self-organised consensus routes emerge that are largely unpredictable. Limited information also strongly reduces the migrants’ ability to react to changes in circumstances. We conclude, first, that information and information exchange is likely to have considerable effects on all aspects of migration and should thus be included in future modelling efforts and, second, that there are many questions in theoretical migration research that are likely to profit from the use of agent-based modelling techniques

Chemoresistance acquisition induces a global shift of expression of aniogenesis-associated genes and increased pro-angogenic activity in neuroblastoma cells

BACKGROUND: Chemoresistance acquisition may influence cancer cell biology. Here, bioinformatics analysis of gene expression data was used to identify chemoresistance-associated changes in neuroblastoma biology. RESULTS: Bioinformatics analysis of gene expression data revealed that expression of angiogenesis-associated genes significantly differs between chemosensitive and chemoresistant neuroblastoma cells. A subsequent systematic analysis of a panel of 14 chemosensitive and chemoresistant neuroblastoma cell lines in vitro and in animal experiments indicated a consistent shift to a more pro-angiogenic phenotype in chemoresistant neuroblastoma cells. The molecular mechanims underlying increased pro-angiogenic activity of neuroblastoma cells are individual and differ between the investigated chemoresistant cell lines. Treatment of animals carrying doxorubicin-resistant neuroblastoma xenografts with doxorubicin, a cytotoxic drug known to exert anti-angiogenic activity, resulted in decreased tumour vessel formation and growth indicating chemoresistance-associated enhanced pro-angiogenic activity to be relevant for tumour progression and to represent a potential therapeutic target. CONCLUSION: A bioinformatics approach allowed to identify a relevant chemoresistance-associated shift in neuroblastoma cell biology. The chemoresistance-associated enhanced pro-angiogenic activity observed in neuroblastoma cells is relevant for tumour progression and represents a potential therapeutic target

Decarbonizing the German industrial thermal energy use with solar, hydrogen, and other options–Recommendations for the world

This paper is based on a position paper of the German Industry Association Concentrated Solar Power e.V. to the German government and discusses options on how to decarbonize the heat demand of the domestic industry. Among other option, concentration solar collectors are a suitable option in Germany, which has not been expected by many experts. The paper derives requirements that are needed to ensure a quick and sustainable way to decarbonize industrial heat demand. They are considered to also be relevant for many other countries that follow the same ambition to become climate neutral in the next decades

QPRT: a potential marker for follicular thyroid carcinoma including minimal invasive variant; a gene expression, RNA and immunohistochemical study

Background The differential diagnosis between follicular thyroid adenoma and minimal invasive follicular thyroid carcinoma is often difficult for several reasons. One major aspect is the lack of typical cytological criteria in well differentiated specimens. New marker molecules, shown by poly- or monoclonal antibodies proved helpful. Methods We performed global gene expression analysis of 12 follicular thyroid tumours (4 follicular adenomas, 4 minimal invasive follicular carcinomas and 4 widely invasive follicular carcinomas), followed by immunohistochemical staining of 149 cases. The specificity of the antibody was validated by western blot analysis Results In gene expression analysis QPRT was detected as differently expressed between follicular thyroid adenoma and follicular thyroid carcinoma. QPRT protein could be detected by immunohistochemistry in 65% of follicular thyroid carcinomas including minimal invasive variant and only 22% of follicular adenomas. Conclusion Consequently, QPRT is a potential new marker for the immunohistochemical screening of follicular thyroid nodules