Zeitlich gestaffeltes Effektmonitoring mit limnischen Wirbellosen zur biologischen Erfolgskontrolle des Ausbaus einer kommunalen Kläranlage mit einer vierten Reinigungsstufe

Im Rahmen der vorliegenden Dissertation, integriert in das BMBF-Verbundprojekts SchussenAktivplus „Reduktion von Mikroverunreinigungen und Keimen durch weitergehende Behandlung von Kläranlagenabläufen und Mischwasser aus Regenüberlaufbecken verschiedener Größe zur weiteren Verbesserung der Gewässerqualität des Bodenseezuflusses Schussen“, wurden die Auswirkungen der Aufrüstung einer Kläranlage mit einer vierten Reinigungsstufe mittels limnischer Invertebraten untersucht. Die in die Schussen, dem größten Bodensee-Zufluss Baden- Württembergs, einleitende Kläranlage Langwiese (Ravensburg, AZV Mariatal) wurde im Herbst 2013 mit einer Pulveraktivkohlestufe aufgerüstet. Die Dissertation befasst sich mit der Bewertung des Gesundheitszustands von Flohkrebsen und der Integrität des Makrozoobenthos in der Schussen, anhand eines zeitlich gestaffelten Effektmonitorings ober- und unterhalb der Kläranlage Langwiese sowie im Referenzgewässer Argen, jeweils vor (2010-2012) und nach (2014-2017) Ausbau der Kläranlage. Untersuchungen mit Flohkrebsen zeigen deutlich, dass der Ausbau der Kläranlage Langwiese mit einer Pulveraktivkohlestufe zu einer Reduktion toxischer und endokriner Effekte unterhalb der Kläranlage geführt hat. Auch auf Ebene der makrozoobenthischen Lebensgemeinschaft wurden positive Veränderungen nach dem Ausbau der Kläranlage festgestellt

Impact of a Wastewater Treatment Plant Upgrade on Amphipods and Other Macroinvertebrates: Individual and Community Responses

In the present study, we investigated the efficiency of additional wastewater treatment based on powdered activated carbon and its benefit for the ecosystem of a connected river system in the catchment area of Lake Constance, Southern Germany. We focused on the overall health status of gammarids and the integrity of the macrozoobenthic community. Samples were taken up- and down-stream of a wastewater treatment plant (WWTP), as well as before and after its upgrading. The investigations showed that both sex ratio and fecundity of gammarids, as well as the macrozoobenthic community were affected by the effluent prior to the WWTP upgrade. After the upgrade, gammarids from the downstream site did not differ any longer from those collected upstream of the WWTP with respect to the investigated health parameters. Furthermore, the overall number of taxa and, particularly, the number of sensitive taxa within the macrozoobenthic community downstream of the WWTP increased considerably. Therefore, we conclude that the additional treatment with powdered activated carbon was highly efficient to improve invertebrate health and community integrity

SchussenAktivplus: reduction of micropollutants and of potentially pathogenic bacteria for further water quality improvement of the river Schussen, a tributary of Lake Constance, Germany

The project focuses on the efficiency of combined technologies to reduce the release of micropollutants and bacteria into surface waters via sewage treatment plants of different size and via stormwater overflow basins of different types. As a model river in a highly populated catchment area, the river Schussen and, as a control, the river Argen, two tributaries of Lake Constance, Southern Germany, are under investigation in this project. The efficiency of the different cleaning technologies is monitored by a wide range of exposure and effect analyses including chemical and microbiological techniques as well as effect studies ranging from molecules to communities

Experimental simulation of environmental warming selects against pigmented morphs of land snails

H-R.K. and R.T. were gratefully hosted by INRA-PACA, Avignon, France, during the time of fieldwork in 2017. We gratefully acknowledge assistance in the field and with the open-top chamber experiments by Nik Triebskorn and Tim Triebskorn. The 35 field sites were sampled within the 2018 European Theba survey initiated by H-R.K and Thomas Knigge, Le Havre University, France. We also thank Menno Schilthuizen, Leiden University, the Netherlands, and another anonymous reviewer for constructive remarks on a previous manuscript version. Open access funding enabled and organized by ProjektDEAL.In terrestrial snails, thermal selection acts on shell coloration. However, the biological relevance of small differences in the intensity of shell pigmentation and the associated thermodynamic, physiological, and evolutionary consequences for snail diversity within the course of environmental warming are still insufficiently understood. To relate temperature‐driven internal heating, protein and membrane integrity impairment, escape behavior, place of residence selection, water loss, and mortality, we used experimentally warmed open‐top chambers and field observations with a total of >11,000 naturally or experimentally colored individuals of the highly polymorphic species Theba pisana (O.F. MÜLLER, 1774). We show that solar radiation in their natural Mediterranean habitat in Southern France poses intensifying thermal stress on increasingly pigmented snails that cannot be compensated for by behavioral responses. Individuals of all morphs acted neither jointly nor actively competed in climbing behavior, but acted similarly regardless of neighbor pigmentation intensity. Consequently, dark morphs progressively suffered from high internal temperatures, oxidative stress, and a breakdown of the chaperone system. Concomitant with increasing water loss, mortality increased with more intense pigmentation under simulated global warming conditions. In parallel with an increase in mean ambient temperature of 1.34°C over the past 30 years, the mortality rate of pigmented individuals in the field is, currently, about 50% higher than that of white morphs. A further increase of 1.12°C, as experimentally simulated in our study, would elevate this rate by another 26%. For 34 T. pisana populations from locations that are up to 2.7°C warmer than our experimental site, we show that both the frequency of pigmented morphs and overall pigmentation intensity decrease with an increase in average summer temperatures. We therefore predict a continuing strong decline in the frequency of pigmented morphs and a decrease in overall pigmentation intensity with ongoing global change in areas with strong solar radiation.ProjektDEA

Effect of cholesterol on the dipole potential of lipid membranes

The membrane dipole potential, ψd, is an electrical potential difference with a value typically in the range 150 – 350 mV (positive in the membrane interior) which is located in the lipid headgroup region of the membrane, between the linkage of the hydrocarbon chains to the phospholipid glycerol backbone and the adjacent aqueous solution. At its physiological level in animal plasma membranes (up to 50 mol%), cholesterol makes a significant contribution to ψd of approximately 65 mV; the rest arising from other lipid components of the membrane, in particular phospholipids. Via its effect on ψd, cholesterol may modulate the activity of membrane proteins. This could occur through preferential stabilization of protein conformational states. Based on its effect on ψd, cholesterol would be expected to favour protein conformations associated with a small local hydrophobic membrane thickness. Via its membrane condensing effect, which also produces an increase in ψd, cholesterol could further modulate interactions of polybasic cytoplasmic extensions of membrane proteins, in particular P-type ATPases, with anionic lipid headgroups on the membrane surface, thus leading to enhanced conformational stabilization effects and changes to ion pumping activity.Australian Research Counci

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements