Comprehending environmental and economic sustainability: Comparative analysis of stability principles in the biosphere and free market economy

Using the formalism of Lyapunov potential function it is shown that the stability principles for biomass in the ecosystem and for employment in economics are mathematically similar. The ecosystem is found to have a stable and an unstable stationary state with high (forest) and low (grasslands) biomass, respectively. In economics, there is a stable stationary state with high employment, which corresponds to mass production of conventional goods sold at low cost price, and an unstable stationary state with lower employment, which corresponds to production of novel goods appearing in the course of technological progress. An additional stable stationary state is described for economics, the one corresponding to very low employment in production of life essentials such as energy and raw materials. In this state the civilization currently pays 10% of global GDP for energy produced by a negligible minority of the working population (currently ~0.2%) and sold at prices greatly exceeding the cost price by 40 times. It is shown that economic ownership over energy sources is equivalent to equating measurable variables of different dimensions (stores and fluxes), which leads to effective violation of the laws of energy and matter conservation.Comment: 51 pages, 6 figure

Signatures of chaos in animal search patterns

One key objective of the emerging discipline of movement ecology is to link animal movement patternsto underlying biological processes, including those operating at the neurobiological level. Nonetheless,little is known about the physiological basis of animal movement patterns, and the underlying searchbehaviour. Here we demonstrate the hallmarks of chaotic dynamics in the movement patterns ofmud snails (Hydrobia ulvae) moving in controlled experimental conditions, observed in the temporaldynamics of turning behaviour. Chaotic temporal dynamics are known to occur in pacemaker neuronsin molluscs, but there have been no studies reporting on whether chaotic properties are manifest in themovement patterns of molluscs. Our results suggest that complex search patterns, like the Lévy walksmade by mud snails, can have their mechanistic origins in chaotic neuronal processes. This possibilitycalls for new research on the coupling between neurobiology and motor properties

Post-Menopausal Vaginal Hemorrhage Related to the Use of a Hop-Containing Phytotherapeutic Product

Two 54-year-old women developed abdominal cramps and vaginal hemorrhage as a result of endometrial hyperplasia during treatment with a hop-containing phytotherapeutic product (MenoCool®) for post-menopausal complaints. The women used the hop-containing phytotherapeutic product (418 mg of hop per tablet) twice daily (1 and 0.5 tablets by both patient A and B). Patient A developed abdominal cramps and vaginal hemorrhage after 2 months of use. After gynecological examination, she was diagnosed with endometrial hyperplasia. The patient was treated with a curettage. The hop-containing phytotherapeutic product was discontinued, and the patient recovered. Patient B developed abdominal pain/cramps and vaginal hemorrhage after 5 months of use. A cervix smear, internal examination, and ultrasound were performed. Due to the thickness of the endometrium, a pipelle endometrial biopsy was performed. Results showed no indication for cervix cancer. The use of MenoCool®was ceased; follow-up information received from the patient shortly thereafter indicated that she had almost entirely recovered from the abdominal pain/cramps and vaginal hemorrhage. Hop (Humulus lupulus) has phytoestrogenic properties that may be the cause of endometrial hyperplasia and subsequent vaginal hemorrhage. A Naranjo assessment score of 5 was obtained for both cases, indicating a probable relationship between the patient’s endometrial proliferation and subsequent vaginal hemorrhage and their use of the suspect drug

Spatial heterogeneity and irreversible vegetation change in semi-arid grazing systems

Recent theoretical studies have shown that spatial redistribution of surface water may explain the occurrence of patterns of alternating vegetated and degraded patches in semiarid grasslands. These results implied, however, that spatial redistribution processes cannot explain the collapse of production on coarser scales observed in these systems. We present a spatially explicit vegetation model to investigate possible mechanisms explaining irreversible vegetation collapse on coarse spatial scales. The model results indicate that the dynamics of vegetation on coarse scales are determined by the interaction of two spatial feedback processes. Loss of plant cover in a certain area results in increased availability of water in remaining vegetated patches through run-on of surface water, promoting within-patch plant production. Hence, spatial redistribution of surface water creates negative feedback between reduced plant cover and increased plant growth in remaining vegetation. Reduced plant cover, however, results in focusing of herbivore grazing in the remaining vegetation. Hence, redistribution of herbivores creates positive feedback between reduced plant cover and increased losses due to grazing in remaining vegetated patches, leading to collapse of the entire vegetation. This may explain irreversible vegetation shifts in semiarid grasslands on coarse spatial scales

Patterning in mussel beds explained by the interplay of multi-level selection and spatial self-organization

Cooperation, ubiquitous in nature, is difficult to explain from an evolutionary perspective. Many modeling studies strive to resolve this challenge, but their simplifying assumptions on population and interaction structure are rarely met in ecological settings. Here we use a modeling approach that includes more ecological detail to investigate evolution of cooperation in spatially self-organized mussel beds. Mussels cooperate with each other through aggregative movement and attachment using byssal threads. These cooperative behaviors shape the spatial structure of the mussel bed, which can range from scattered distributions to labyrinth-like patterns and dense mussel clumps. The spatial pattern in turn impacts an individual’s fitness at two levels: (i) proper attachment to neighboring individuals decreases predation risk, and (ii) attachment to a sufficiently large group prevents dislodgement by wave stress. Without this second level of selection, our simulations do typically not result in evolutionary attractors that lead to the labyrinth-like spatial patterns that are characteristic for natural mussel beds. Yet, when group-level selection is included, labyrinth-like patterns emerge under a wide range of conditions. Our model demonstrates that multiple selection factors working at different spatial scales – predation of individuals and dislodgement of entire mussel clumps – combinedly determine evolution of cooperative traits in mussels and thereby result in emergence of the labyrinth-like spatial patterns that we observe in natural mussel beds