@article{AltmannBrandtKloskaetal.2002, author = {Altmann, Thomas and Brandt, Stephan Peter and Kloska, Sebastian and Kehr, Julia}, title = {Using array hybridization to monitore gene expression at the single cell level}, year = {2002}, language = {en} } @article{VernesiPecchioliTiedemannetal.2002, author = {Vernesi, C. and Pecchioli, E. and Tiedemann, Ralph and Randi, E. and Bertorelle, G.}, title = {The genetic structure of natural and reintroduced roe deer (Capreolus capreolus) populations in the Alps and central Italy, with reference to the mitochondrial DNA phylogeography of Europe}, issn = {0962-1083}, year = {2002}, language = {en} } @article{FischerLienertSchnelleretal.2002, author = {Fischer, Markus and Lienert, J. and Schneller, J. and Diemer, M.}, title = {Local extinctions of the wetland specialist Swertia perennis : a revistation study based on herbarium records}, year = {2002}, language = {en} } @article{ShertzerEllnerFussmannetal.2002, author = {Shertzer, Kyle W. and Ellner, Stephen P. and Fussmann, Gregor F. and Hairston, Nelson G.}, title = {Predator-prey cycles in an aquatic microcosm : testing hypotheses of mechanism}, year = {2002}, abstract = {1. Fussmann et al. (2000) presented a simple mechanistic model to explore predator-prey dynamics of a rotifer species feeding on green algae. Predictions were tested against experimental data from a chemostat system housing the planktonic rotifer Brachionus calyciflorus and the green alga Chlorella vulgaris. 2. The model accurately predicted qualitative behaviour of the system (extinction, equilibria and limit cycles), but poorly described features of population cycles such as the period and predator-prey phase relationship. These discrepancies indicate that the model lacked some biological mechanism(s) crucial to population cycles. 3. Here candidate hypotheses for the 'missing biology' are quantified as modifications to the existing model and are evaluated for consistency with the chemostat data. The hypotheses are: (1) viability of eggs produced by rotifers increases with food concentration, (2) nutritional value of algae increases with nitrogen availability, (3) algal physiological state varies with the accumulation of toxins in the chemostat and (4) algae evolve in response to predation. 4. Only Hypothesis 4 is compatible with empirical observations and thus may provide important insight into how prey evolution affects predator- prey dynamics.}, language = {en} } @article{FussmannHeber2002, author = {Fussmann, Gregor F. and Heber, Gerd}, title = {Food web complexity and chaotic population dynamics}, year = {2002}, abstract = {In mathematical models, very simple communities consisting of three or more species frequently display chaotic dynamics which implies that long-term predictions of the population trajectories in time are impossible. Communities in the wild tend to be more complex, but evidence for chaotic dynamics from such communities is scarce. We used supercomputing power to test the hypothesis that chaotic dynamics become less frequent in model ecosystems when their complexity increases. We determined the dynamical stability of a universe of mathematical, nonlinear food web models with varying degrees of organizational complexity. We found that the frequency of unpredictable, chaotic dynamics increases with the number of trophic levels in a food web but decreases with the degree of complexity. Our results suggest that natural food webs possess architectural properties that may intrinsically lower the likelihood of chaotic community dynamics.}, language = {en} } @article{NistorOsvikDavidssonetal.2002, author = {Nistor, C. and Osvik, A. and Davidsson, R. and Rose, Andreas and Wollenberger, Ursula and Pfeiffer, Dorothea and Emneus, J. and Fiksdal, L.}, title = {Detection of escherichia coli water by culture-based amperometric and luminometric methods}, year = {2002}, language = {en} } @article{NistorRoseFarreetal.2002, author = {Nistor, C. and Rose, Andreas and Farre, M. and Stoica, L. and Wollenberger, Ursula and Ruzgas, T. and Pfeiffer, Dorothea and Barcelo, Damia and Gorton, Lo and Emneus, J.}, title = {In-field monitoring of cleaning efficiency in waste water treatment plants using two phenolsensitive biosensors}, year = {2002}, language = {en} } @article{KamjunkeSchmidtPflugmacheretal.2002, author = {Kamjunke, Norbert and Schmidt, Katja and Pflugmacher, Stephan and Mehner, Thomas}, title = {Consumption of cyanobacteria by roach (Rutilus rutilus) : useful or harmful to the fish?}, year = {2002}, abstract = {1. The ability of roach to use cyanobacterial food is generally believed to be one reason for the dominance of roach over perch in eutrophic European lakes. The aim of this study was to test whether cyanobacteria really are a suitable food for juvenile roach. Special attention was paid to differences between the two cyanobacteria species Aphanizomenon and Microcystis which are common in eutrophic lakes and are ingested by roach there. 2. We performed growth and behaviour experiments with juvenile roach fed with zooplankton and the different cyanobacteria. Growth rate with Aphanizomenon was lower than with Daphnia but significantly higher than without food, whereas growth rate with Microcystis was as low as without food. 3. In cultivation experiments of roach faeces, Microcystis was found not to have been digested and grew exponentially after passing through the gut whereas Aphanizomenon stayed at low biomass. Differences in growth were not related to the toxin content of cyanobacteria. Investigations of roach motility showed no differences whether fed Aphanizomenon or Microcystis. 4. In contrast to Microcystis, Aphanizomenon can be regarded as a suitable food source for juvenile roach probably due to its better digestability. We conclude that the ability to feed on cyanobacteria is not a general competitive advantage for roach, but the outcome depends on the species composition of the cyanobacteria.}, language = {en} } @article{KamjunkeMendoncaHardewigetal.2002, author = {Kamjunke, Norbert and Mendonca, Rebeca and Hardewig, Iris and Mehner, Thomas}, title = {Assimilation of different cyanobacteria as food and the consequences for internal energy stores of juvenile roach}, year = {2002}, abstract = {Juvenile roach (Rutilus rutilus L.) fed on the cyanobacterium Aphanizomenon were able to maintain liver glycogen and muscle protein concentrations. In contrast, internal energy stores of fish fed on the cyanobacterium Microcystis were degraded. However, liver glycogen was higher than in starved fish, suggesting that roach was able to obtain some nutrients (probably carbohydrates) from the mucus cover of Microcystis. Weak assimilation of radiolabeled Microcystis by roach was detectable, and assimilation rates increased with increasing proportion of Aphanizomenon in a mixture of both cyanobacteria. We conclude that the incomplete digestion of Microcystis was the main reason for the negative growth rates of roach when fed on this cyanobacterium species.}, language = {en} } @article{HairstonFussmann2002, author = {Hairston, Nelson G. and Fussmann, Gregor F.}, title = {Lake ecosystems}, year = {2002}, abstract = {Lakes are discrete, largely isolated ecosystems in which the interplay between physical, biogeochemical and organismal processes can be studied, understood, and put to use in effective management.}, language = {en} } @article{GaedkeHochstaedterStraile2002, author = {Gaedke, Ursula and Hochst{\"a}dter, Silke and Straile, Dietmar}, title = {Interplay between energy limitation and nutritional deficiency: Empirical data and food web models}, year = {2002}, abstract = {Due to differences in the biochemical composition of autotrophs and their grazers, food quality can strongly influence herbivore population dynamics. Under nutrient depleted conditions the carbon to nutrient ratios of autotrophs can increase to such an extent that consumers become nutrient rather than energy limited. Estimating the importance of this effect in situ in pelagic food webs is complicated by the omnivory of many consumers and rapid nutrient recycling. Isolated predator-prey studies inadequately represent this interaction, instead an ecosystem perspective is required. We used seven years of data from large, deep Lake Constance to develop seasonally resolved flux models of the pelagic food web and analyze the balance between energetic and nutrient constraints. The carbon (C) and phosphorus (P) flows were simultaneously quantified and balanced. C represented food quantity/energy. P was taken as a surrogate of food quality, because algal C:P ratios exceeded the threshold above which P limitation of herbivores is predicted by stoichiometric theory throughout summer and autumn. Primary production exceeded bacterial C production by a factor of 3 but autotrophs and bacteria took up approximately equal amounts of P during summer and autumn. As a consequence the C and P supply of suspension-feeding zooplankton was decoupled: Consumer C demands were largely met by phytoplankton whereas P was mostly obtained from bacteria and their protist predators. The degree of consumer P deficiency varied according to supplementation of their algal diet with P-enriched bacteria or bacterivores. This favored the occurrence of omnivores, i.e. organisms that minimized P deficiencies at the cost of enhanced energy limitation. In contrast with previous perceptions, P remineralization during P depleted summer conditions was dominated by bacterivorous flagellates, carnivorous crustaceans and fish, which fed on prey with an elemental composition similar to their own, whereas herbivores contributed only 30\% of P cycling despite their large biomass and C production. Our results suggested a co- limitation of predominantly herbivorous consumers by C and P and a mutual dependence of the two types of deficiency at the individual and system level. This pattern is not specific to pelagic systems but appears to be applicable across ecosystem types.}, language = {en} } @article{KoschorreckFroemmichenHerzsprungetal.2002, author = {Koschorreck, Matthias and Fr{\"o}mmichen, Ren{\´e} and Herzsprung, Peter and Tittel, J{\"o}rg and Wendt-Potthoff, Katrin}, title = {Function of straw for in situ remediation of acidic mining lakes}, issn = {0049-6979}, year = {2002}, language = {en} } @article{IgnatovShishniashviliGeetal.2002, author = {Ignatov, S. and Shishniashvili, D. and Ge, Bixia and Scheller, Frieder W. and Lisdat, Fred}, title = {Amperometric biosensor based on a functionalized gold electrode for the detection of antioxidants}, year = {2002}, language = {en} } @article{Greil2002, author = {Greil, Holle}, title = {K{\"o}rperproportionen und ihr Bezug zum biologischen Alter}, isbn = {3-412-03102-x}, year = {2002}, language = {de} } @article{SchefflerNoth2002, author = {Scheffler, Christiane and Noth, Veronika}, title = {Bewegungsanalyse von Alltagssituationen}, isbn = {3-412-03102-x}, year = {2002}, language = {de} } @article{LeiWollenbergerBistolasetal.2002, author = {Lei, Chenghong and Wollenberger, Ursula and Bistolas, Nikitas and Guiseppi-Eli, A. and Scheller, Frieder W.}, title = {Electron transfer of hemoglobin at electrodes modified with colloidal clay nanoparticles}, year = {2002}, language = {en} } @article{ButtermeyerPhilippMalletal.2002, author = {Buttermeyer, R. and Philipp, A. W. and Mall, J. W. and Ge, Bixia and Scheller, Frieder W. and Lisdat, Fred}, title = {In vivo measurement of oxygen derived free radicals during reperfusion injury}, year = {2002}, language = {en} } @article{KoschorreckTittel2002, author = {Koschorreck, Matthias and Tittel, J{\"o}rg}, title = {Benthic photosynthesis in an acidic mining lake (pH 2.6).}, year = {2002}, language = {en} } @article{StoellnerSchellerWarsinke2002, author = {Stoellner, Daniela and Scheller, Frieder W. and Warsinke, Axel}, title = {Activation of cellulose membranes with 1,1{\"i}-carbonyldiimidazole or 1-cyano-4-4-dimethylaminopyridinium tetrafluoroborate as a basis for the development of immunosensors}, year = {2002}, language = {en} } @article{NiessnerBroekaertEinaxetal.2002, author = {Nießner, Reinhard and Broekaert, J. and Einax, J. W. and Scheller, Frieder W. and St{\"o}cklein, Walter F. M.}, title = {Trendbericht analytische Biochemie 2000/2001}, year = {2002}, language = {de} }