Density variability of COVID-19 face mask litter: A cautionary tale for pandemic PPE waste monitoring.

Despite the requirement for data to be normally distributed with variance being independent of the mean, some studies of plastic litter, including COVID-19 face masks, have not tested for these assumptions before embarking on analyses using parametric statistics. Investigation of new data and secondary analyses of published literature data indicate that face masks are not normally distributed and that variances are not independent of mean densities. In consequence, it is necessary to either use nonparametric analyses or to transform data prior to undertaking parametric approaches.

First landscape-scale survey of the background level of COVID-19 face mask litter: Exploring the potential for citizen science data collection during a 'pollution pilgrimage' of walking a 250-km roadside transect.

The COVID-19 pandemic has generated a global problem through the cavalier or deliberate disposal of personal protective equipment (PPE) by the general public. This has raised concerns that the billions of discarded face masks pose a threat to wildlife through entanglement or, when broken down, through ingestion of derived microplastics. Previous quantitative surveys of the magnitude of such litter have focused on areas where people congregate, such as tourist beaches and large cities.

Upgrading Marine Ecosystem Restoration Using Ecological-Social Concepts.

Conservation and environmental management are principal countermeasures to the degradation of marine ecosystems and their services. However, in many cases, current practices are insufficient to reverse ecosystem declines. We suggest that , the science underlying the concepts and tools needed to restore ecosystems, must be recognized as an integral element for marine conservation and environmental management.

Electrocatalytic reactions mediated by N,N,N',N'-Tetraalkyl-1,4-phenylenediamine redox liquid microdroplet-modified electrodes: chemical and photochemical reactions In, and At the surface of, femtoliter droplets.

The electro-oxidation of electrolytically unsupported ensembles of N,N-diethyl-N',N'-dialkyl-para-phenylenediamine (DEDRPD, R = n-butyl, n-hexyl, and n-heptyl) redox liquid femtoliter volume droplets immobilized on a basal plane pyrolytic graphite electrode is reported in the presence of aqueous electrolytes. Electron transfer at these redox liquid modified electrodes is initiated at the microdroplet-electrode-electrolyte three-phase boundary. Dependent on both the lipophilicity of the redox oil and that of the aqueous electrolyte, ion uptake into or expulsion from the organic deposits is induced electrolytically.

Graphite powder and multiwalled carbon nanotubes chemically modified with 4-nitrobenzylamine.

We demonstrate that graphite powder and multiwalled carbon nanotubes (MWCNTs) can be derivatised by 4-nitrobenzylamine (4-NBA) simply by stirring the graphite powder or MWCNTs in a solution of acetonitrile containing 10 mM 4-NBA. We propose that 4-NBA partially intercalates at localised edge-plane or edge-plane-like defect sites and this hypothesis with a range of experimental data provided by electrochemistry in both aqueous and nonaqueous media, electron microscopy and X-ray powder diffraction.

Selective electrochemical glycosylation by reactivity tuning.

Electrochemical glycosylation of a selenoglycoside donor proceeds efficiently in an undivided cell in acetonitrile to yield beta-glycosides. Measurement of cyclic voltammograms for a selection of seleno-, thio-, and O-glycosides indicates the dependence of oxidation potential on the anomeric substituent allowing the possibility for the rapid construction of oligosaccharides by selective electrochemical activation utilising variable cell potentials in combination with reactivity tuning of the glycosyl donor. A variety of disaccharides are readily synthesised in high yield, but limitations of the use of selenoglycosides as glycosyl donors for selective glycosylation of thioglycoside acceptors are exposed.

Selective activation of glycosyl donors utilising electrochemical techniques: a study of the thermodynamic oxidation potentials of a range of chalcoglycosides.

A series of six chalcoglycosides (phenyl-2,3,4,6-tetra-O-benzoyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-seleno-beta-D-glucopyranoside, phenyl-2,3,4,6-tetra-O-benzyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzoyl-1-thio-beta-D-glucopyranoside, p-tolyl-2,3,4,6-O-benzyl-1-thio-beta-D-glucopyranoside, and phenyl-2,3,4,6-O-benzyl-beta-D-glucopyranoside) are voltammetrically interrogated in dimethyl sulfoxide, so as to determine their formal (i.e. thermodynamic) redox potentials.

Synthesis of fluorescence-labelled disaccharide substrates of glucosidase II.

The fluorescence-labelled disaccharides Glcalpha(1-->3)GlcalphaOR and Glcalpha(1-->3)ManalphaOR, both substrates for the glycoprotein-processing enzyme glucosidase II, were synthesised via the use of a n-pentenyl-derived linker at the anomeric position. This allowed incorporation of a pyrenebutyric acid label, via a sequence of oxidative hydroboration, mesylation, azide displacement, reduction with concomitant global deprotection, and peptide coupling. Selective activation of a fully armed thioglycoside in the presence of n-pentenyl glycosides was readily achieved by the use of methyl triflate as promoter.

Ontogenetic shift in crayfish δC as a measure of land-water ecotonal coupling.

Although ontogenetic changes in the carbon isotope ratios of marine fauna have been well studied those of freshwater organisms have not. As a result, we may have a less than adequate assessment of the incorporation of allochthonous detritus into freshwater foodwebs. This study found a δC range of 9‰ for crayfish (Orconectes virilis) from oligotrophic Canadian Shield lakes.