Electrochemical Analysis of Changes in Iron Oxide Reducibility during Abiotic Ferrihydrite Transformation into Goethite and Magnetite.

Electron transfer to ferric iron in (oxyhydr-)oxides (hereafter iron oxides) is a critical step in many processes that are central to the biogeochemical cycling of elements and to pollutant dynamics. Understanding these processes requires analytical approaches that allow for characterizing the reactivity of iron oxides toward reduction under controlled thermodynamic boundary conditions. Here, we used mediated electrochemical reduction (MER) to follow changes in iron oxide reduction extents and rates during abiotic ferrous iron-induced transformation of six-line ferrihydrite.

PolyGlcNAc-containing exopolymers enable surface penetration by non-motile Enterococcus faecalis.

Bacterial pathogens have evolved strategies that enable them to invade tissues and spread within the host. Enterococcus faecalis is a leading cause of local and disseminated multidrug-resistant hospital infections, but the molecular mechanisms used by this non-motile bacterium to penetrate surfaces and translocate through tissues remain largely unexplored. Here we present experimental evidence indicating that E.

Photochemical Transformation of Poly(butylene adipate- co-terephthalate) and Its Effects on Enzymatic Hydrolyzability.

Biodegradable polyesters are being increasingly used to replace conventional, nondegradable polymers in agricultural applications such as plastic film for mulching. For many of these applications, poly(butylene adipate- co-terephthalate) (PBAT) is a promising biodegradable material. However, PBAT is also susceptible to photochemical transformations.

Exposure to Pesticides and Health Effects on Farm Owners and Workers From Conventional and Organic Agricultural Farms in Costa Rica: Protocol for a Cross-Sectional Study.

Background: Pesticide use is increasing in low- and middle-income countries (LMICs) including Costa Rica. This increase poses health risks to farm owners, farm workers, and communities living near agricultural farms.

Objective: We aimed to examine the health effects associated with occupational pesticide exposure in farm owners and workers from conventional and organic smallholder farms in Costa Rica.

C- and N-Isotope Analysis of Desphenylchloridazon by Liquid Chromatography-Isotope-Ratio Mass Spectrometry and Derivatization Gas Chromatography-Isotope-Ratio Mass Spectrometry.

The widespread application of herbicides impacts surface water and groundwater. Metabolites (e.g.

The role of plasticity in the evolution of cryptic pigmentation in a freshwater isopod.

Cryptic pigmentation of prey is often thought to evolve in response to predator-mediated selection, but pigmentation traits can also be plastic, and change with respect to both abiotic and biotic environmental conditions. In such cases, identifying the presence of, and drivers of trait plasticity is useful for understanding the evolution of crypsis. Previous work suggests that cryptic pigmentation of freshwater isopods (Asellus aquaticus) has evolved in response to predation pressure by fish in habitats with varying macrophyte cover and coloration.

Lifetime extension of humpback whale skin fibroblasts and their response to lipopolysaccharide (LPS) and a mixture of polychlorinated biphenyls (Aroclor).

Marine mammals, such as whales, have a high proportion of body fat and so are susceptible to the accumulation, and associated detrimental health effects, of lipophilic environmental contaminants. Recently, we developed a wild-type cell line from humpback whale fibroblasts (HuWa). Extensive molecular assessments with mammalian wild-type cells are typically constrained by a finite life span, with cells eventually becoming senescent.

Diatom evidence of 20th century ecosystem change in Lake Baikal, Siberia.

Lake Baikal has been experiencing limnological changes from recent atmospheric warming since the 1950s, with rising lake water temperatures, reduced ice cover duration and reduced lake surface-water mixing due to stronger thermal stratification. This study uses lake sediment cores to reconstruct recent changes (c. past 20 years) in Lake Baikal's pelagic diatom communities relative to previous 20th century diatom assemblage records collected in 1993 and 1994 at the same locations in the lake.

Daphnia galeata responds to the exposure to an ichthyosporean gut parasite by down-regulation of immunity and lipid metabolism.

Background: Regulatory circuits of infection in the emerging experimental model system, water flea Daphnia and their microparasites, remain largely unknown. Here we provide the first molecular insights into the response of Daphnia galeata to its highly virulent and common parasite Caullerya mesnili, an ichthyosporean that infects the gut epithelium. We generated a transcriptomic dataset using RNAseq from parasite-exposed (vs.

Membrane stripping enables effective electrochemical ammonia recovery from urine while retaining microorganisms and micropollutants.

Ammonia recovery from urine avoids the need for nitrogen removal through nitrification/denitrification and re-synthesis of ammonia (NH) via the Haber-Bosch process. Previously, we coupled an alkalifying electrochemical cell to a stripping column, and achieved competitive nitrogen removal and energy efficiencies using only electricity as input, compared to other technologies such as conventional column stripping with air. Direct liquid-liquid extraction with a hydrophobic gas membrane could be an alternative to increase nitrogen recovery from urine into the absorbent while minimizing energy requirements, as well as ensuring microbial and micropollutant retention.

A single Gal4-like transcription factor activates the Crabtree effect in Komagataella phaffii.

The Crabtree phenotype defines whether a yeast can perform simultaneous respiration and fermentation under aerobic conditions at high growth rates. It provides Crabtree positive yeasts an evolutionary advantage of consuming glucose faster and producing ethanol to outcompete other microorganisms in sugar rich environments. While a number of genetic events are associated with the emergence of the Crabtree effect, its evolution remains unresolved.

From Water Source to Tap of Ceramic Filters-Factors That Influence Water Quality Between Collection and Consumption in Rural Households in Nepal.

The study assessed changes in water quality between the water source and the tap of locally produced low cost ceramic water filters used by a community living in hygienically critical conditions in a remote mountainous area in Western Nepal. Data was collected from 42 rural households during two visits. The effectiveness of filter handling on its performance was assessed through microbiological analysis, structured household interviews and structured observations.

Introducing the H2020 AQUACROSS project: Knowledge, Assessment, and Management for AQUAtic Biodiversity and Ecosystem Services aCROSS EU policies.

The AQUACROSS project was an unprecedented effort to unify policy concepts, knowledge, and management of freshwater, coastal, and marine ecosystems to support the cost-effective achievement of the targets set by the EU Biodiversity Strategy to 2020. AQUACROSS aimed to support EU efforts to enhance the resilience and stop the loss of biodiversity of aquatic ecosystems as well as to ensure the ongoing and future provision of aquatic ecosystem services. The project focused on advancing the knowledge base and application of Ecosystem-Based Management.

Tree rings reveal globally coherent signature of cosmogenic radiocarbon events in 774 and 993 CE.

Though tree-ring chronologies are annually resolved, their dating has never been independently validated at the global scale. Moreover, it is unknown if atmospheric radiocarbon enrichment events of cosmogenic origin leave spatiotemporally consistent fingerprints. Here we measure the C content in 484 individual tree rings formed in the periods 770-780 and 990-1000 CE.

Thermal stress and energy metabolism in two circumtropical decapod crustaceans: Responses to acute temperature events.

Extreme events associated with global warming, such as ocean heat waves, can have contrasting fitness consequences for different species, thereby modifying the structure and composition of marine communities. Here, we examined the effects of a laboratory simulated heat wave on the physiology and performance of two Indo-Pacific crustacean species: the shrimp Rhynchocinetes durbanensis and the hermit crab Calcinus laevimanus. We exposed the crustaceans to a control temperature or to a +5 °C temperature (25 °C vs 30 °C) for two consecutive weeks, and weekly analyzed protective proteins, antioxidant activity, and lipid peroxides in muscle and visceral mass.

Two analytical approaches quantifying the electron donating capacities of dissolved organic matter to monitor its oxidation during chlorination and ozonation.

Electron-donating activated aromatic moieties, including phenols, in dissolved organic matter (DOM) partially control its reactivity with the chemical oxidants ozone and chlorine. This comparative study introduces two sensitive analytical systems to directly and selectively quantify the electron-donating capacity (EDC) of DOM, which corresponds to the number of electrons transferred from activated aromatic moieties, including phenols, to the added chemical oxidant 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radical cation (i.e.

Accounting for variation in rainfall intensity and surface slope in wash-off model calibration and prediction within the Bayesian framework.

Exponential wash-off models are the most widely used method to predict sediment wash-off from urban surfaces. In spite of many studies, there is still a lack of knowledge on the effect of external drivers such as rainfall intensity and surface slope on wash-off predictions. In this study, a more physically realistic "structure" is added to the original exponential wash-off model (OEM) by replacing the invariant parameters with functions of rainfall intensity and catchment surface slope, so that the model can better represent catchment and rainfall conditions without the need for lookup tables and interpolation/extrapolation.

Generality of associations between biological richness and the rates of metabolic processes across microbial communities.

Biological richness is positively associated with the rates of some metabolic processes performed by microbial communities. It remains unclear, however, whether these positive associations are a general feature of the metabolic processes performed by microbial communities or whether they are specific to certain types of metabolic processes. For example, it was hypothesized that the strength of any particular positive association depends on how many different genotypes within a microbial community perform the metabolic process of interest (i.

Ecological influence of sediment bypass tunnels on macroinvertebrates in dam-fragmented rivers by DNA metabarcoding.

Sediment bypass tunnels (SBTs) are guiding structures used to reduce sediment accumulation in reservoirs during high flows by transporting sediments to downstream reaches during operation. Previous studies monitoring the ecological effects of SBT operations on downstream reaches suggest a positive influence of SBTs on riverbed sediment conditions and macroinvertebrate communities based on traditional morphology-based surveys. Morphology-based macroinvertebrate assessments are costly and time-consuming, and the large number of morphologically cryptic, small-sized and undescribed species usually results in coarse taxonomic identification.

Comprehensive Toxic Plants-Phytotoxins Database and Its Application in Assessing Aquatic Micropollution Potential.

The production of toxic plant secondary metabolites (phytotoxins) for defense is a widespread phenomenon in the plant kingdom and is even present in agricultural crops. These phytotoxins may have similar characteristics to anthropogenic micropollutants in terms of persistence and toxicity. However, they are only rarely included in environmental risk assessments, partly because a systematic overview of phytotoxins is missing.