On-line high-precision carbon position-specific stable isotope analysis: a review

Since the first commercial availability of gas chromatographs coupled with a combustion furnace and an isotope ratio mass spectrometry in 1990, compound-specific stable isotope analysis of organic molecules has been at the origin of scientific breakthroughs in a wide range of research fields. The presence of non-reacting atoms, however, can mask changes in molecular stable isotopic signatures; position-specific isotope analysis (PSIA) is the study of intramolecular isotopic variations. After a brief consideration of the potential and prospect of this new level in isotopic studies, in this study, we review few existing custom-built systems for on-line PSIA using continuous flow isotope ratio mass spectrometry instrumentation and how researchers have addressed issues related to this technique. Molecular fragmentation processes observed and optimised for various molecules are also discussed for on-line PSIA, as it would provide information on their application to new compounds

Micro- and nanoplastic pollution of freshwater and wastewater treatment systems

Plastic waste is a widespread and persistent global challenge with negative impacts on the environment, economy, human health and aesthetics. Plastic pollution has been a focus of environmental research over the past few decades, particularly in relation to macroplastics that are easily visible by the naked eye. More recently, smaller plastic waste at the micro- and nanoscale has become of increasing concern, resulting in extensive investment in research to advance knowledge on the sources, distribution, fate and impact of these materials in aquatic systems. However, owing to their small sizes and a lack of unified methods, adequate quantitative and qualitative assessment has been difficult. Furthermore, most of the microplastic surveys available to date have focussed in the marine environment while scarce knowledge exists of freshwater systems. Because the majority of marine debris originates on land, the role of wastewater treatment systems and natural fluvial vectors in delivering these emerging contaminants to the environment should be explored. Considering fundamental aspects pertaining to microplastic sources, distribution, mobility and degradation in these systems is crucial for developing effective control measures and strategies to mitigate the discharge of these particles to the sea

Bioaugmentation mitigates the impact of estrogen on coliform-grazing protozoa in slow sand filters

Exposure to endocrine-disrupting chemicals (EDCs), such as estrogens, is a growing issue for human and animal health as they have been shown to cause reproductive and developmental abnormalities in wildlife and plants and have been linked to male infertility disorders in humans. Intensive farming and weather events, such as storms, flash flooding, and landslides, contribute estrogen to waterways used to supply drinking water. This paper explores the impact of estrogen exposure on the performance of slow sand filters (SSFs) used for water treatment. The feasibility and efficacy of SSF bioaugmentation with estrogen-degrading bacteria was also investigated, to determine whether removal of natural estrogens (estrone, estradiol, and estriol) and overall SSF performance for drinking water treatment could be improved. Strains for SSF augmentation were isolated from full-scale, municipal SSFs so as to optimize survival in the laboratory-scale SSFs used. Concentrations of the natural estrogens, determined by gas chromatography coupled with mass spectrometry (GC-MS), revealed augmented SSFs reduced the overall estrogenic potency of the supplied water by 25% on average and removed significantly more estrone and estradiol than nonaugmented filters. A negative correlation was found between coliform removal and estrogen concentration in nonaugmented filters. This was due to the toxic inhibition of protozoa, indicating that high estrogen concentrations can have functional implications for SSFs (such as impairing coliform removal). Consequently, we suggest that high estrogen concentrations could impact significantly on water quality production and, in particular, on pathogen removal in biological water filters

Microscopy and elemental analysis characterisation of microplastics in sediment of a freshwater urban river in Scotland, UK

Understanding of the sources, fate, and impact of microplastics (MPs, < 5 mm) remains limited, particularly in freshwater environments, while limited comparability across available surveys hinders adequate monitoring and risk assessment of these contaminants. Here, the distribution of microscopic debris in an urban river close to the marine environment in the West of Scotland was investigated to assess concentration and distribution of primary and secondary MPs. Also, the efficiency of light and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) was evaluated for characterisation and quantification of MPs sized 2.8 mm–11 μm. Bank sediment samples were collected twice from the River Kelvin in Glasgow and were size-fractionated and processed for extraction of MPs by density separation. Sample MPs spiking and use of procedural blanks allowed the influence of processing on field data quality to be considered. Total abundances were 161–432 MPs kg−1 dry sediment, with fibres as the dominant type, comprising > 88% of total counts. Nevertheless, fibres in blanks suggest potential contributions from atmospheric contamination. Moreover, fibres concentrated mainly in fractions < 0.09 mm suggesting that their fate may be influenced by drivers of fine sediment dynamics in rivers. While no primary MPs were observed, metallic and glass pellets were present in high abundances in settled material and could be easily misidentified by visual inspection, demonstrating that compositional analysis is needed to avoid analytical errors from MP misidentification and overestimation. SEM-EDS allowed for a quick screening of plastic vs non-plastic pellets and improved identification of smaller fragments, whereas more advanced techniques are needed for proper identification of fibres. This study is the first to report on MPs in freshwater rivers in Scotland and suggests that diffuse sources of pollution may be delivering secondary MPs to the river. Their sources, fate, and risk in these systems will thus warrant further attention

Systems biology approach to elucidation of contaminants biodegradation in complex samples- integration of high-resolution analytical and molecular tools

We present here a data-driven systems biology framework to the rational design of biotechnological solutions for contaminated environments with the aim of understanding the interactions and mechanisms underpinning the role of microbial communities in the biodegradation of contaminated soils. We have considered a multi-omics approach which employs novel in silico tools to combine high-throughput sequencing data (16S rRNA amplicons) with the chemical data including high-resolution analytical data generated by comprehensive two-dimensional gas chromatography (GCxGC). To assess this approach, we have considered a matching dataset with both microbiological and chemical signatures available for samples from two former manufactured gas plant sites. On this dataset, we applied the numerical procedures informed by ecological principles (predominantly diversity measures) as well as recently published statistical approaches that give discriminatory features and their correlations by maximizing the covariances between multiple datasets on the same sample space. In particular, we have utilized sparse projection to latent discriminant analysis and its derivative to multiple datasets, an N-integration algorithm called DIABLO. Our results indicate microbial community structure dependent on the contaminated environment and unravel promising interactions of some of the microbial species with the biodegradation potential. To the best of our knowledge, this is the first study that incorporates with microbiome an unprecedented high-level distribution of hydrocarbons obtained through GC x GC

Average daily flow of microplastics through a tertiary wastewater treatment plant over a ten-month period

Microplastics (MPs, <5 mm in size) are classified as emerging contaminants but treatment processes are not designed to remove these small particles. Wastewater treatment systems have been proposed as pathways for MPs pollution to receiving waters but quantitative and qualitative data on MP occurrence and transport remains limited, hindering risk assessment and regulation. Here, for the first time, the stepwise abundance and loading of MPs (60–2800 μm) in a tertiary wastewater treatment plant in the UK was assessed by sampling from May 2017 to February 2018. Microplastics were found in all sampling campaigns, with an average inflow of 8.1 × 108 (95% CI, 3.8 × 108 to 1.2 × 109) items day−1. Their prevalence decreased from influent to final effluent. Overall abundances decreased on average by 6%, 68%, 92%, and 96% after the pre-treatment, primary, secondary, and tertiary treatment stages respectively, although considerable variability occurred throughout the year. Sufficient particles remained in the treated effluent to generate an average discharge of 2.2 × 107 (95% CI, 1.2 × 107 to 3.2 × 107]) particles day−1 to the recipient river. Secondary MPs were predominant, while primary MP abundances were minimal. Fibres comprised 67% of all items, followed by films (18%) and fragments (15%). Chemical characterisation confirmed the presence of different types of polymers, with polypropylene fibres and fragments most abundant (23%). This research informs understanding of how wastewater effluent may channel MPs to the natural environment and their composition, and helps understand control points for optimising advanced treatment processes

BODIPY-labeled estrogens for fluorescence analysis of environmental microbial degradation

Biodegradation of estrogen hormone micropollutants is a well-established approach toward their remediation. Fluorescently labeled substrates are used extensively for rapid, near-real-time analysis of biological processes and are a potential tool for studying biodegradation processes faster and more efficiently than conventional approaches. However, it is important to understand how the fluorescently tagged surrogates compare with the natural substrate in terms of chemical analysis and the intended application. We derivatized three natural estrogens with BODIPY fluorophores by azide–alkyne cycloaddition click reaction and developed an analytical workflow based on simple liquid–liquid extraction and HPLC-PDA analysis. The developed methods allow for concurrent analysis of both fluorescent and natural estrogens with comparable recovery, accuracy, and precision. We then evaluated the use of BODIPY-labeled estrogens as surrogate substrates for studying biodegradation using a model bacterium for estrogen metabolism. The developed analytical methods were successfully employed to compare the biological transformation of 17β-estradiol (E2), with and without the BODIPY fluorescent tag. Through measuring the complete degradation of E2 and the transformation of BODIPY-estradiol to BODIPY-estrone in the presence of a co-substrate, we found that BODIPY-labeled estrogens are biologically viable surrogates for investigating biodegradation in environmental bacteria

Review of barriers women face in research funding processes in the UK

In the UK, women are underrepresented at the highest levels of academia in all subjects but Nursing, but particularly in Science, Technology, Engineering, and Math (STEM) (Advance HE, 2018). Research, and the funding that enables research, is a critical point of career progression. Women apply less often and for lower amounts of funding, and are less successful than male colleagues (UK Research and Innovation, 2018). The common explanations given that women have to apply for more and more often do not sufficiently explain the gender disparities in research funding. This review critically evaluates some of the barriers and biases women face in the process of applying for research funding in the UK. Institutional barriers such as women carrying a heavier burden of teaching and academic citizenship, and lack of support, mentoring and visible role models impact on women’s success in securing research funding. Systematic barriers exist at many levels, particularly for parents and carers. These range from the impact of taking maternity leave, to grant deadlines falling during or shortly after school holidays and the requirement to travel for interviews. The focus on track record in grant review, biased language used in evaluation materials and unconscious biases on the part of reviewers further impact differentially on women. Lack of freedom to travel, and thus to network or attend conferences can result in exclusion from multinational networks and the ability of parents to demonstrate an international profile. The policies and practices that impact on the ability of women to secure research funding must be reviewed and addressed with urgency for the benefit of the research community as a whole. Introduction Barriers Women Face in Research Funding Processes 3 Women are underrepresented in Science, Technology, Engineering, and Mathematics (STEM), with increasingly lower representation from school through academic careers to Professorial level (Blickenstaff, 2005). Eagly and Carli (2007) argues that addressing the problem of recruiting, retaining and progressing women at all career levels in STEM is important as a moral value, and beyond that, increasing women’s participation in a labour market dominated by men could be worth between £15-23 billion (Women and Work Commission, 2009) to the UK economy. Metaanalyses of evidence that women do not succeed to the same extent and pace as their male equivalents show that this is not due to gender differences in intelligence or ability (Hyde, 2005; Hyde, 2016) or even, contrary to popular belief, to motherhood, but rather that the difference in academic career progression between men and women is a result of socially interpreted, cultural differences (Kandola & Kandola, 2013; Santos & Dang Van Phu, 2019; Peel, Schlachta, & Alkhamesi, 2018; Thanacoody, Bartram, Berker, & Jacobs, 2006). These differences become particularly acute for black and ethnic minority women (Jones 2006, Rollock, 2019; Royal Society, 2014), for those with disabilities (Brown & Leigh, 2018; Royal Society, 2014), and those who identify as LGBTQ+ (Gibney, 2019; Wellcome, 2020) as these marginalised groups face further systemic discrimination and career attainment gaps. We note in particular that there is very little data available in the literature or elsehwere on funding disparities faced by those whose gender identities are non-binary, or those who are trans. Intersectionality is a term which was originally coined to describe the ways in which race, gender and class combine to multiply barriers in the workplace for black, working class women (Crenshaw, 1989). This extends to academia and STEM in particular. For instance, in 2019, only 35 out 19,285 UK professors were Black women (as identified by The Higher Education Statistics Agency - HESA). Indeed black women are three times less likely to be professor than white women and half as likely as black men, demonstrating the compounding effects of intersectionality. Barriers Women Face in Research Funding Processes 4 The aim of this literature review is to critically assess the systemic barriers and biases that affect women in the processes relating to applying for and obtaining research funding, a key factor in career progression in STEM academia. Taking an intersectional approach to examining these barriers allows us to take into account how ‘race/ethnicity, class, gender, sexuality, religion, citizenship, ability, and age’, shapes the ‘structural dynamics of power and inequality’, including within academia (Tefera, Powers & Fischman, 2018

Detection of Organic Molecules using Asymmetric Plasmonic Nanostructures

We demonstrate the fabrication and characterization of an array of plasmonic metamaterial nanostructures based on asymmetric split H (ASH) resonators on a zinc selenide substrate that produce plasmonic resonances matched with the molecular vibrations of an organic material. Estrogenic hormones; 17β-Estradiol (E2) and Estrone (E1) were chosen as analytes for coupling with the plasmonic resonances. The experimental results show there is a good match with the molecular bond resonances of the C-H, C=O and C=C observed in estrogen and we have also shown that it is possible to differentiate the molecular bond resonance spectrum of E2 in a mixture with E1

A review of barriers women face in research funding processes in the UK

No abstract available