The ulcerogenic effect of bile and bile acid in rats during immobilization stress

The effect of different concentrations of oxen bile and individual bile acids or their sodium salts on the gastric mucosa of rats was investigated in combination with immobilization stress. A statistically significant higher frequency of ulcers was only determined in the application of 10% oxen bile. Dosages on 10% sodium glycocholic acid demonstrated strong toxic damage with atonic dilation of the stomach and extensive mucosal bleeding

Exploring bacterial pathogen community dynamics in freshwater beach sediments: A tale of two lakes

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154434/1/emi14860.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154434/2/emi14860_am.pd

Formation of the Neoarchean Bad Vermillion Lake Anorthosite Complex and Spatially Associated Granitic Rocks at a Convergent Plate Margin, Superior Province, Western Ontario, Canada

The Bad Vermilion Lake Anorthosite Complex (henceforth, the BVLA Complex) in western Ontario is one of the well-exposed, anorthosite-bearing, Archean layered intrusions in the Superior Province, Canada. This study presents new whole-rock major and trace element data for the various units of the Complex, oxygen isotope data for the anorthosite, and major and trace element data for the spatially associated granitic rocks intruding the BVLA Complex to constrain their petrogenetic and geodynamic origin. Zircons from granitic rocks have yielded a 207Pb/206Pb age of 2716 ± 18 Ma, constraining the minimum intrusion age of the Complex. Despite deformation and greenschist facies metamorphism, primary igneous textures are locally well preserved in the BVLA Complex. Its whole-rock major and trace elemental compositions and the oxygen isotopic systematics appear not to have been substantially modified by deformation and metamorphism. Mantle-like oxygen isotope signatures and major and trace element compositions are inconsistent with significant crustal contamination of the BVLA Complex during its emplacement. The existence of primary calcic igneous plagioclase, coherent negative Nb anomalies (Nb/Nb* = 0.08–0.88), and geochemical similarities between gabbros from the BVLA Complex and gabbros from Cenozoic arcs collectively suggest an intra-oceanic subduction zone geodynamic setting for the Complex. Near-flat REE patterns in the various units of the BVLA Complex suggest that they were derived from melting of a shallow source beneath a subarc mantle wedge. Trends in immobile major (e.g.,MgO) and trace (e.g., Zr) element data indicate that the mineralogical composition of the Complex can be explained by fractional crystallization and accumulation of olivine, orthopyroxene, clinopyroxene, plagioclase and possibly amphibole. Compositionally, the bordering granitic rocks are A2-type and strongly enriched in Th and REE (\u3e100 times chondrite) and depleted of Ba, Sr, Eu and Ti. We suggest that they formed in a post-collisional, extensional, tectonic regime following emplacement of the BVLA Complex in an oceanic arc

Investigating sources and sinks of N2O expression from freshwater microbial communities in urban watershed sediments

Wastewater treatment plants (WWTPs) serve as point-source inputs for a variety of nutrients often dominated by nitrogenous compounds as a result of anthropogenic influence. These effluents can impact biogeochemical cycles in freshwater estuaries, influencing microbial communities in both the water and sediment compartments. To assess the impact of point source nutrients, a transect of sediment and pore water samples were collected from 4 locations in the Little River Sub-watershed including locations above and below the Little River Pollution Control Plant (LRPCP). Variation in chemistry and microbial community/gene expression revealed significant influences of the effluent discharge on the adjacent sediments. Phosphorus and sulfur showed high concentrations within plume sediments compared to the reference sediments while nitrate concentrations were low. Increased abundance of denitrifiers Dechloromonas, Dok59 and Thermomonas correlating with increased expression of nitrous-oxide reductase suggests a conversion of N2O to N2 within the LRPCP effluent sediments. This study provides valuable insight into the gene regulation of microbes involved in N metabolism (denitrification, nitrification, and nitrite reduction to ammonia) within the sediment compartment influenced by wastewater effluent. © 2017 Elsevier Lt

Biogeochemical Characterization of Metal Behavior from Novel Mussel Shell Bioreactor Sludge Residues

Acid mine drainage (AMD) remediation commonly produces byproducts which must be stored or utilized to reduce the risk of further contamination. A mussel shell bioreactor has been implemented at a coal mine in New Zealand, which is an effective remediation option, although an accumulated sludge layer decreased efficiency which was then removed and requires storage. To understand associated risks related to storage or use of the AMD sludge material, a laboratory mesocosm study investigated the physio-chemical and biological influence in two conditions: anoxic storage (burial deep within a waste rock dump) or exposure to oxic environments (use of sludge on the surface of the mine). Solid phase characterization by Scanning Electron Microscopy (SEM) and selective extraction was completed to compare two environmental conditions (oxic and anoxic) under biologically active and abiotic systems (achieved by gamma irradiation). Changes in microbial community structure were monitored using 16s rDNA amplification and next-generation sequencing. The results indicate that microbes in an oxic environment increase the formation of oxyhydroxides and acidic conditions increase metal mobility. In an oxic and circumneutral environment, the AMD sludge may be repurposed to act as an oxygen barrier for mine tailings or soil amendment. Anoxic conditions would likely promote the biomineralization of sulfide minerals in the AMD sludge by sulfate reducing bacteria (SRB), which were abundant in the system. The anoxic conditions reduced the risk of trace metals (Zn) associated with oxides, but increased Fe associated with organic material. In summary, fewer risks are associated with anoxic burial but repurposing in an oxic condition may be appropriate under favorable conditions

Wege ins Institut – Wege aus dem Institut

In der Beilage zu dieser Ausgabe des HJK erläutern Studierende eine studentische Perspektive auf das Institut und das Studium und konzentrieren sich dabei auf die Themen Wissen und Wissensproduktion: Sie fragen einerseits danach, welches Wissen Studierende ins Studium mitbringen und welches Potenzial dieses im Laufe des Studiums noch entwickeln kann. Auf der anderen Seite erkunden sie, wie kulturanthropologische Forschung und Wissensproduktion in der Gesellschaft wirken. Die Autor*innen dieser Beilage befassen sich zudem bei der Frage nach Zukunftsfähigkeit mit der Funktion von wissenschaftlicher Sprache und ihrer Rolle bei Vermittlung von Wissen. Die Zugänglichkeit von Wissen sehen sie als essentiell für die Gestaltung der Gesellschaft und das positive Einwirken auf kritische Gegebenheiten und Missstände

Improving our Understanding of Environmental Stress Impacts and Responses of the Microbiome

Over the course of this century, it will be important to identify cost effective/low maintenance solutions for treating contaminants in receiving watersheds. Adopting these strategies will involve a better understanding of what defines a “natural” environment compared to these contaminated sites. Traditional geochemical testing and standard microbial community analyses (e.g., DNA profiling) or using isolates can be limited with respect to their ability to infer real-time, active processes of bacterial communities. In recent years the application of genomics to identify the microbial microbiome in anthropogenic stressed conditions has advanced considerably. In many cases, the activity of microorganisms will directly impact the chemical conditions in both surface and subsurface water column and contaminated sediment environments controlling the fate of nutrients and contaminants alike. Questions arise such as:What are the baselines or reference systems that can be used?What indices can be used to study the long-term and short-term controls on the mobility, cycling, and bioavailability of toxic metals and organic contaminants?In many cases the balance of chemical oxidizing and reducing components in water will control the development of chemical and nutrient gradients observed in either natural and/or applied systems (e.g., constructed wetlands or bioreactors). In these cases, biogeochemical systems will determine the direction and onset of specific metabolic pathways as defined by their favorable thermodynamic outcome, an issue for most bioremediators (i.e., microorganisms). Also, the degree of chemical alteration (toxicity or degradation products) can be directly linked to the proportion of their biological activity. In this presentation, contrasting case studies highlighting natural (baseline) and anthropogenically impacted landscapes will be discussed. The focus will be on identifying and linking physicochemical processes to microbial community function using emerging omics for geochemical applications and ascertaining novel contaminant bioindicators.

Mikrobearbeitung mit dem Funkenerosionsverfahren am Beispiel einer Zahnradpumpe

Miniaturisierte Verdrängerpumpen sind eine neue Alternative in der Mikrohydraulik. Zu den geeigneten Herstellverfahren gehört die Funkenerosion

Investigating Microbial Triggers of Nitrous Oxide Emissions in Agriculturally Influenced Aquatic Ecosystems

The agricultural sector in Canada is responsible for approximately 9% of greenhouse gas (GHG) emissions in Canada, accounting for 54 MT of carbon dioxide (CO2), as well as 31% of methane (CH4) and 75% of national nitrous oxide (N2O) emissions in 2021 (Environment and Climate Change Canada 2021). However, these estimates do not include the indirect GHG emissions that occur in agriculturally impacted waterways. Ontario is home to over 45 000 kilometers of agricultural drainage ditches, with tile drains directly connecting terrestrial and aquatic environments. Microbial biogeochemical cycles in the causeways experience fluxes of nutrients leading to hotspots for GHG at the sediment-water interfaces. Along with fluxes of nutrients, the causeways are regularly disturbed by anthropogenic effects (e.g., dredging, removal of vegetative buffers) and increasing frequency of storm events. Previous studies have used static chambers to evaluate GHG emissions from aquatic systems (Mu et al. 2022, Xiao et al. 2016). However, this approach can be time consuming and labour intensive and is impractical in aquatic systems due potential extensive underestimation of fluxes from diffusion. To resolve driving factors contributing to GHG in these systems a detailed study investigating the activity of the microbial community is warranted. In this study we hypothesize microbial activity within the sediment will correlate with N2O emissions. To test the response of the microbial community a combination of molecular approaches (i.e., qPCR and Ion torrent) targeting archaeal and bacterial nitrifiers and denitrifies was used. These functional responses were evaluated with respect to N2O emissions, which were measured in the field at the time of sampling using Unisense N2O probes. In this study, N2O sensor response was calibrated to a functional gene index for rapid risk assessment of GHG hotspots

Umgang mit atomar kleinen Strukturen. Mikrosysteme erfordern eine Revolution der Produktionstechnik

Mikrosystemtechnik gilt als die Schlüsseltechnologie der Zukunft. Sie wird die nächste Revolution der industriellen Produktion auslösen. Noch sind nur wenige Mikrosysteme entwickelt, denn die Möglichkeiten dieser neuen Technologie sind bisher kaum vorstellbar. Der Montage und Handhabung in der Mikrosystemtechnik galt eine Expertenbefragung des Fraunhofer-Instituts für Produktionstechnik und Automatisierung (IPA), Stuttgart, im ersten Quartal 1993. Interviewt wurden 56 Firmen und Institute. Davon waren 60 Prozent Produktentwickler und -hersteller, 30 Prozent Systemlieferanten und 10 Prozent Institute