Natural history and information overload: The case of Linnaeus

Natural History can be seen as a discipline paradigmatically engaged in 'data-driven research.' Historians of early modern science have begun to emphasize its crucial role in the Scientific Revolution, and some observers of present day genomics see it as engaged in a return to natural history practices. A key concept that was developed to understand the dynamics of early modern natural history is that of 'information overload.' Taxonomic systems, rules of nomenclature, and technical terminologies were developed in botany and zoology to catch up with the ever increasing amount of information on hitherto unknown plant and animal species. In our contribution, we want to expand on this concept. After all, the same people who complain about information overload are usually the ones who contribute to it most significantly. In order to understand this complex relationship, we will turn to the annotation practices of the Swedish naturalist Carl Linnaeus (1707-1778). The very tools that Linnaeus developed to contain and reduce information overload, as we aim to demonstrate, facilitated a veritable information explosion that led to the emergence of a new research object in botany: the so-called 'natural' system.     

Evaluation of an electronic nose for the early detection of organic overload of anaerobic digesters

This study aimed at analysing the utilization of an electronic nose (e-nose) to serve as a specific monitoring tool for anaerobic digestion process, especially for detecting organic overload. An array of non specific metal oxide semiconductor gas sensors were used to detect process faults due to organic overload events in twelve 1.8-L anaerobic semi-continuous reactors. Three different load strategies were followed: (1) a cautious organic load (1.3 gVS L^?1 day^?1); (2) an increasing load strategy (1.3–5.3 gVS L^?1 day^?1) and (3) a cautious organic load with load pulses of up to 12 gVS L^?1 day^?1. A first monitoring campaign was conducted with three different substrates: sucrose, maize oil and a mix of sucrose/oil during 60 days. The second campaign was run with dry sugar beet pulp for 45 days. Hotelling’s T ² value and upper control limit to a reference set of digesters fed with a cautious OLR (1.3 gVS L^?1 day^?1) was used as indirect state variable of the reactors. Overload situations were identified by the e-nose apparatus with Hotelling’s T ² values at least four times higher in magnitude than the upper control limit of 23.7. These results confirmed that the e-nose technology appeared promising for online detection of process imbalances in the domain of anaerobic digestion.     

Pressure overload alters stress-strain properties of the developing chick heart

As a first step in investigating a control mechanism regulating stress and/or strain in the embryonic heart, this study tests the hypothesis that passive mechanical properties of left ventricular (LV) embryonic myocardium change with chronically increased pressure during the chamber septation period. Conotruncal banding (CTB) created ventricular pressure overload in chicks from Hamburger-Hamilton (HH) stage 21 (HH21) to HH27, HH29, or HH31. LV sections were cyclically stretched while biaxial strains and force were measured. Wall architecture was assessed with scanning electron microscopy. In controls, porosity-adjusted stress-strain relations decreased significantly from HH27 to HH31. CTB at HH21 resulted in significantly stiffer stress-strain relations by HH27, with larger increases at HH29 and HH31, and nearly constant wall thickness. Strain patterns, hysteresis, and loading-curve convergence showed few differences after CTB. Trabecular extent decreased with age, but neither extent nor porosity changed significantly after CTB. The stiffened stress-strain relations and constant wall thickness suggest that mechanical load may play a regulatory role in this response.     

Managing uncertainty: information and insurance under the risk of starvation

In an uncertain world, animals face both unexpected opportunities and danger. Such outcomes can select for two potential strategies: collecting information to reduce uncertainty, or insuring against it. We investigate the relative value of information and insurance (energy reserves) under starvation risk by offering model foragers a choice between constant and varying food sources over finite foraging bouts. We show that sampling the variable option (choosing it when it is not expected to be good) should decline both with lower reserves and late in foraging bouts; in order to be able to reap the reduction in uncertainty associated with exploiting a variable resource effectively, foragers must be able to afford and compensate for an initial increase in the risk of an energetic shortfall associated with choosing the option when it is bad. Consequently, expected exploitation of the varying option increases as it becomes less variable, and when the overall risk of energetic shortfall is reduced. In addition, little activity on the variable alternative is expected until reserves are built up early in a foraging bout. This indicates that gathering information is a luxury while insurance is a necessity, at least when foraging on stochastic and variable food under the risk of starvation.     

Health information for the developing world.

Doctors and other health professionals in developing countries are missing out on relevant information about health. A lot of the information they need is available in the developed countries, and those who have it are happy to share it with them. But transporting information, like food or medicines, from one part of the world to another is not an easy task nor is it the complete answer to the information drought. It is one thing to ferry books and journals from Europe to Africa and another to make relevant information available to the right person at the right time at an affordable cost.     

Autonomy: an information theoretic perspective

We present a tentative proposal for a quantitative measure of autonomy. This is something that, surprisingly, is rarely found in the literature, even though autonomy is considered to be a basic concept in many disciplines, including artificial life. We work in an information theoretic setting for which the distinction between system and environment is the starting point. As a first measure for autonomy, we propose the conditional mutual information between consecutive states of the system conditioned on the history of the environment. This works well when the system cannot influence the environment at all and the environment does not interact synergetically with the system. When, in contrast, the system has full control over its environment, we should instead neglect the environment history and simply take the mutual information between consecutive system states as a measure of autonomy. In the case of mutual interaction between system and environment there remains an ambiguity regarding whether system or environment has caused observed correlations. If the interaction structure of the system is known, we define a "causal" autonomy measure which allows this ambiguity to be resolved. Synergetic interactions still pose a problem since in this case causation cannot be attributed to the system or the environment alone. Moreover, our analysis reveals some subtle facets of the concept of autonomy, in particular with respect to the seemingly innocent system-environment distinction we took for granted, and raises the issue of the attribution of control, i.e. the responsibility for observed effects. To further explore these issues, we evaluate our autonomy measure for simple automata, an agent moving in space, gliders in the game of life, and the tessellation automaton for autopoiesis of Varela et al. [Varela, F.J., Maturana, H.R., Uribe, R., 1974. Autopoiesis: the organization of living systems, its characterization and a model. BioSystems 5, 187-196].