Dynamical Systems in the Sensorimotor Loop: On the Interrelation Between Internal and External Mechanisms of Evolved Robot Behavior

Huelse, M., Wischmann, S., Manoonpong, P., Twickel, A.v., Pasemann, F.: Dynamical Systems in the Sensorimotor Loop: On the Interrelation Between Internal and External Mechanisms of Evolved Robot Behavior. In: M. Lungarella, F. Iida, J. Bongard, R. Pfeifer (Eds.) 50 Years of Artificial Intelligence, LNCS 4850, Springer, 186 - 195, 2007.

Plasmid biology of natural Lactococcus lactis strains and molecular mechanisms of bacteriophage-host interaction

Lacticin 3147, enterocin AS-48, lacticin 481, variacin, and sakacin P are bacteriocins offering promising perspectives in terms of preservation and shelf-life extension of food products and should find commercial application in the near future. The studies detailing their characterization and bio-preservative applications are reviewed. Transcriptomic analyses showed a cell wall-targeted response of Lactococcus lactis IL1403 during the early stages of infection with the lytic bacteriophage c2, which is probably orchestrated by a number of membrane stress proteins and involves D-alanylation of membrane lipoteichoic acids, restoration of the physiological proton motive force disrupted following bacteriophage infection, and energy conservation. Sequencing of the eight plasmids of L. lactis subsp. cremoris DPC3758 from raw milk cheese revealed three anti-phage restriction/modification (R/M) systems, immunity/resistance to nisin, lacticin 481, cadmium and copper, and six conjugative/mobilization regions. A food-grade derivative strain with enhanced bacteriophage resistance was generated via stacking of R/M plasmids. Sequencing and functional analysis of the four plasmids of L. lactis subsp. lactis biovar. diacetylactis DPC3901 from raw milk cheese revealed genes novel to Lactococcus and typical of bacteria associated with plants, in addition to genes associated with plant-derived lactococcal strains. The functionality of a novel high-affinity regulated system for cobalt uptake was demonstrated. The bacteriophage resistant and bacteriocin-producing plasmid pMRC01 places a metabolic burden on lactococcal hosts resulting in lowered growth rates and increased cell permeability and autolysis. The magnitude of these effects is strain dependent but not related to bacteriocin production. Starters’ acidification capacity is not significantly affected. Transcriptomic analyses showed that pMRC01 abortive infection (Abi) system is probably subjected to a complex regulatory control by Rgg-like ORF51 and CopG-like ORF58 proteins. These regulators are suggested to modulate the activity of the putative Abi effectors ORF50 and ORF49 exhibiting topology and functional similarities to the Rex system aborting bacteriophage λ lytic growth.

Stress-induced visceral pain in rodents: neurochemical, hormonal, immune and epigenetic mechanisms

Visceral pain is a debilitating disorder which affects up to 25% of the population at any one time. It is a global term used to describe pain originating from the internal organs, which is distinct from somatic pain. Currently the treatment strategies are unsatisfactory, with development of novel therapeutics hindered by a lack of detailed knowledge of the underlying mechanisms. The work presented in this thesis aimed to redress this issue and look in more detail at the molecular mechanisms of visceral pain in preclinical models. Stress has long been implicated in the pathophysiology of visceral pain in both preclinical and clinical studies. Here a mouse model of early-life stress-induced visceral hypersensitivity was validated. Moreover, mouse strain differences were also apparent in visceral sensitivity suggesting a possible genetic component to the underlying pathophysiology. Furthermore, gender and sex hormones were also implicated in stress sensitivity and visceral pain. Using the rat model of maternal separation, some of the epigenetic mechanisms underpinning visceral hypersensitivity, specifically the contribution of histone acetylation were unravelled. Glutamate has been well established in somatic pain processing, however, its contribution to visceral pain has not been extensively characterised. It was found that glutamate uptake is impaired in viscerally hypersensitive animals, an effect which could be reversed by treatment with riluzole, a glutamate uptake activator. Moreover, negative modulation of the metabotropic glutamate (mGlu) receptor 7 was sufficient to reverse visceral hypersensitivity in a stress sensitive rat strain, the Wistar Kyoto rat. Furthermore, toll-like receptor 4 (TLR4) was implicated in chronic stress-induced visceral hypersensitivity. Taken together, these findings have furthered our knowledge of the pathophysiology of visceral pain. In addition, we have identified glutamate transporters, mGlu7 receptor, histone acetylation and TLR4 as novel targets, amenable to pharmacological manipulation for the specific treatment of visceral pain.

C. elegans germline-deficient mutants respond to pathogen infection using shared and distinct mechanisms.

Reproduction extracts a cost in resources that organisms are then unable to utilize to deal with a multitude of environmental stressors. In the nematode C. elegans, development of the germline shortens the lifespan of the animal and increases its susceptibility to microbial pathogens. Prior studies have demonstrated germline-deficient nematodes to have increased resistance to gram negative bacteria. We show that germline-deficient strains display increased resistance across a broad range of pathogens including gram positive and gram negative bacteria, and the fungal pathogen Cryptococcus neoformans. Furthermore, we show that the FOXO transcription factor DAF-16, which regulates longevity and immunity in C. elegans, appears to be crucial for maintaining longevity in both wild-type and germline-deficient backgrounds. Our studies indicate that germline-deficient mutants glp-1 and glp-4 respond to pathogen infection using common and different mechanisms that involve the activation of DAF-16.

Biological and ecological mechanisms supporting marine self-governance: The Seri Callo de Hacha Fishery in Mexico

My goal was to describe how biological and ecological factors give shape to fishing practices that can contribute to the successful self-governance of a small-scale fishing system in the Gulf of California, Mexico. The analysis was based on a comparison of the main ecological and biological indicators that fishers claim to use to govern their day-to-day decision making about fishing and data collected in situ. I found that certain indicators allow fishers to learn about differences and characteristics of the resource system and its units. Fishers use such information to guide their day-to-day fishing decisions. More importantly, these decisions appear unable to shape the reproductive viability of the fishery because no indicators were correlated to the reproductive cycle of the target species. As a result, the fishing practices constitute a number of mechanisms that might provide short-term buffering capacity against perturbations or stress factors that otherwise would threaten the overall sustainability and self-governance of the system. The particular biological circumstances that shape the harvesting practices might also act as a precursor of self-governance because they provide fishers with enough incentives to meet the costs of organizing the necessary rule structure that underlies a successful self-governance system.

The removal of dyes from textile wastewater: a study of the physical characteristics and adsorption mechanisms of diatomaceous earth

The feasibility of using diatomite for the removal of the problematic reactive dyes as well as basic dyes from textile wastewater was investigated. Methylene blue, Cibacron reactive black and reactive yellow dyes were considered. Physical characteristics of diatomite such as pH(solution), pH(ZPC), surface area, Fourier transform infrared, and scanning electron microscopy were investigated. The surface area of diatomite was found to be 27.80 m(2) g(-1) and the pH(ZPC) occurred around pH of 5.4. The results indicated that the surface charge of diatomite decreased as the pH of the solution increased with the maximum methylene blue removal from aqueous solution occurring at basic pH of around (1011). Adsorption isotherms of diatomite with methylene blue, hydrolysed reactive black and yellow dyes were constructed at different pH values, initial dye concentrations and particle sizes. The experimental results were fitted to the Langmuir, Freundlich, and Henry models. The study indicated that electrostatic interactions play an important role in the adsorption of dyes onto diatomite. A model of the adsorption mechanism of methylene blue onto diatomite is proposed. (C) 2003 Elsevier Ltd. All rights reserved.

Contact and Culture: Mechanisms of Reconciliation in Northern Ireland and Israel

In Northern Ireland and Israel schools have long been recognised as key sites for addressing the problems of poor intergroup relations (see Dunn, 1990; Murray, 1985). The developments of integrated schools which welcome members of the main communities have been regarded as a key development which is likely to be instrumental in promoting more harmonious relations. Although the schools have been regarded in the media as a ‘good news story’ the qualitative processes through which teachers within these schools foster reconciliation is not always clear. The purpose of this chapter is thus to explore this question by drawing on contact theory and interviews with teachers in Northern Ireland and Israel.

Physical basis and biological mechanisms of gold nanoparticle radiosensitization

The unique properties of nanomaterials, in particular gold nanoparticles (GNPs) have applications for a wide range of biomedical applications. GNPs have been proposed as novel radiosensitizing agents due to their strong photoelectric absorption coefficient. Experimental evidence supporting the application of GNPs as radiosensitizing agents has been provided from extensive in vitro investigation and a relatively limited number of in vivo studies. Whilst these studies provide experimental evidence for the use of GNPs in combination with ionising radiation, there is an apparent disparity between the observed experimental findings and the level of radiosensitization predicted by mass energy absorption and GNP concentration. This review summarises experimental findings and attempts to highlight potential underlying biological mechanisms of response in GNP radiosensitization.