A standardised sampling protocol for robust assessment of reach-scale fish community diversity in wadeable New Zealand streams

The New Zealand fish fauna contains species that are affected not only by river system connectivity, but also by catchment and local-scale changes in landcover, water quality and habitat quality. Consequently, native fish have potential as multi-scale bioindicators of human pressure on stream ecosystems, yet no standardised, repeatable and scientifically defensible methods currently exist for effectively quantifying their abundance or diversity in New Zealand stream reaches. Here we report on the testing of a back-pack electrofishing method, modified from that used by the United States Environmental Protection Agency, on a wide variety of wadeable stream reaches throughout New Zealand. Seventy-three first- to third-order stream reaches were fished with a single pass over 150-345 m length. Time taken to sample a reach using single-pass electrofishing ranged from 1-8 h. Species accumulation curves indicated that, irrespective of location, continuous sampling of 150 stream metres is required to accurately describe reach-scale fish species richness using this approach. Additional species detection beyond 150 m was rare (<10%) with a single additional species detected at only two out of the 17 reaches sampled beyond this distance. A positive relationship was also evident between species detection and area fished, although stream length rather than area appeared to be the better predictor. The method tested provides a standardised and repeatable approach for regional and/or national reporting on the state of New Zealand's freshwater fish communities and trends in richness and abundance over time

Dose-dependent synergistic and antagonistic mutation responses of binary mixtures of the environmental carcinogen benzo[a]pyrene with food-derived carcinogens

Cooking food at high temperatures produces genotoxic chemicals and there is concern about their impact on human health. DNA damage caused by individual chemicals has been investigated but few studies have examined the consequences of exposure to mixtures as found in food. The current study examined the mutagenic response to binary mixtures of benzo[a]pyrene (BaP) with glycidamide (GA), BaP with acrylamide (AC), or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) with GA at human-relevant concentrations (sub-nM). The metabolically competent human MCL-5 cells were exposed to these chemicals individually or in mixtures and mutagenicity was assessed at the thymidine kinase (TK) locus. Mixture exposures gave dose-responses that differed from those for the individual chemicals; for the BaP-containing mixtures, an increased mutation frequency (MF) at low concentration combinations that were not mutagenic individually, and decreased MF at higher concentration combinations, compared to the calculated predicted additive MF of the individual chemicals. In contrast, the mixture of PhIP with GA did not increase MF above background levels. These data suggest BaP is driving the mutation response and that metabolic activation plays a role; in mixtures with BaP the increased/decreased MF above/below the expected additive MF the order is PhIP > AC > GA. The increase in MF at some low concentration combinations that include BaP is interesting and supports our previous work showing a similar response for BaP with PhIP, confirming this response is not limited to the BaP/PhIP combination. Moreover, the lack of a mutation response for PhIP with GA relative to the response of the individual chemicals at equivalent doses is interesting and may represent a potential avenue for reducing the risk of exposure to environmental carcinogens; specifically, removal of BaP from the mixture may reduce the mutation effect, although in the context of food this would be significantly challenging

Istraživanje oksidativnog stresa i genotoksičnosti slatkovodnih riba Cyprinus Carpio nakon izloženosti subletalnoj dozi triazofosa

Triazophos (TAP), an organophosphorus insecticide, is widely used in agricultural practice for controlling various insect pests. The present research work aimed to elucidate the impact of TAP on the antioxidant status and DNA content of the freshwater fish Cyprinus carpio. The fish were grouped into batches (n=6) and received a sublethal dose of 0.3mg/L for a duration of 1 (E1), 10 (E2), 20 (E3) and 30 days (E4). Another group, devoid of any toxicant, was maintained as the control (C). Changes in the enzymatic threshold of the selected antioxidants and malondialdehyde (MDA) levels suggested the conformation of oxidative stress in the livers of the freshwater fish C. carpio due to TAP exposure. Additionally, comet assays and micronucleus tests performed on the peripheral blood of the fish suggested increased damage in the form of the percentage of tail DNA formation and a high frequency of micronucleus as compared to the control. A positive correlation was seen between the decline in antioxidant activity, the elevation in MDA and the comet length and micronucleus frequency. The study thus highlights the impact of TAP on antioxidant levels in the livers and genotoxicity in the blood of the freshwater fish C. carpio. The findings of the study confirm that the antioxidant status, along with the comet assay and micronucleus tests could be used as tools in determining the potential genotoxicity due to the TAP impact. It is therefore suggested that extensive use of TAP should be avoided as it may contribute to the decline in the C. carpio population in its natural habitats.Triazofos (TAP) je organofosforni insekticid koji se široko koristi u poljoprivrednoj praksi za suzbijanje raznih štetnih insekata. Cilj ovog istraživanja bio je procjeniti utjecaj TAP-a na antioksidativni status i DNK slatkovodne ribe Cyprinus carpio. Ribe su razvrstane u skupine (n = 6) u kojima su primale subletalnu dozu TAP-a 0.3mg/L u trajanju od 1 (E1), 10 (E2), 20 (E3) i 30 dana (E4). Druga skupina, koja nije izložena TAP-u, smatrana je kontrolnom (C). Promjene enzimskog praga odabranih antioksidansa i razina malondialdehida (MDA) potvrdile su da izloženost TAP-u izaziva oksidativni stres u jetrama slatkovodne ribe C. carpio. Osim toga, komet analize i mikronukleusni testovi provedeni na perifernoj krvi riba ukazali su da u eksperimentalnih skupina u odnosu na kontrolu postoji povećani postotak oštećenja u obliku DNK repa i povećane učestalosti mikronukleusa. Uočena je pozitivna korelacija između pada antioksidativne aktivnosti, porasta MDA, duljine kometa i učestalosti mikronukleusa. Uzevši u obzir navedeno, istraživanje naglašava utjecaj TAP-a na razine antioksidansa u jetrama i genotoksičnost u krvi slatkovodne ribe C. carpio. Rezultati potvrđuju da se antioksidativni status, zajedno s kometnim testom i mikronukleusnim testovima, može koristiti kao alat za određivanje potencijalne genotoksičnosti TAP-a. Stoga se predlaže izbjegavanje široke uporaba TAP-a koja bi mogla doprinijeti smanjenju populacije C. carpio u njezinim prirodnim staništima

A Categorical Approach to Groupoid Frobenius Algebras

In this paper, we show that \C{G}-Frobenius algebras (for \C{G} a finite groupoid) correspond to a particular class of Frobenius objects in the representation category of D(k[\C{G}]), where D(k[\C{G}]) is the Drinfeld double of the quantum groupoid k[\C{G}].Comment: final version; to appear in Applied Categorical Structure

Collateral impacts of pandemic COVID-19 drive the nosocomial spread of antibiotic resistance: a modelling study

Background: Circulation of multidrug-resistant bacteria (MRB) in healthcare facilities is a major public health problem. These settings have been greatly impacted by the Coronavirus Disease 2019 (COVID-19) pandemic, notably due to surges in COVID-19 caseloads and the implementation of infection control measures. We sought to evaluate how such collateral impacts of COVID-19 impacted the nosocomial spread of MRB in an early pandemic context. Methods and findings: We developed a mathematical model in which Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and MRB cocirculate among patients and staff in a theoretical hospital population. Responses to COVID-19 were captured mechanistically via a range of parameters that reflect impacts of SARS-CoV-2 outbreaks on factors relevant for pathogen transmission. COVID-19 responses include both “policy responses” willingly enacted to limit SARS-CoV-2 transmission (e.g., universal masking, patient lockdown, and reinforced hand hygiene) and “caseload responses” unwillingly resulting from surges in COVID-19 caseloads (e.g., abandonment of antibiotic stewardship, disorganization of infection control programmes, and extended length of stay for COVID-19 patients). We conducted 2 main sets of model simulations, in which we quantified impacts of SARS-CoV-2 outbreaks on MRB colonization incidence and antibiotic resistance rates (the share of colonization due to antibiotic-resistant versus antibiotic-sensitive strains). The first set of simulations represents diverse MRB and nosocomial environments, accounting for high levels of heterogeneity across bacterial parameters (e.g., rates of transmission, antibiotic sensitivity, and colonization prevalence among newly admitted patients) and hospital parameters (e.g., rates of interindividual contact, antibiotic exposure, and patient admission/discharge). On average, COVID-19 control policies coincided with MRB prevention, including 28.2% [95% uncertainty interval: 2.5%, 60.2%] fewer incident cases of patient MRB colonization. Conversely, surges in COVID-19 caseloads favoured MRB transmission, resulting in a 13.8% [−3.5%, 77.0%] increase in colonization incidence and a 10.4% [0.2%, 46.9%] increase in antibiotic resistance rates in the absence of concomitant COVID-19 control policies. When COVID-19 policy responses and caseload responses were combined, MRB colonization incidence decreased by 24.2% [−7.8%, 59.3%], while resistance rates increased by 2.9% [−5.4%, 23.2%]. Impacts of COVID-19 responses varied across patients and staff and their respective routes of pathogen acquisition. The second set of simulations was tailored to specific hospital wards and nosocomial bacteria (methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase producing Escherichia coli). Consequences of nosocomial SARS-CoV-2 outbreaks were found to be highly context specific, with impacts depending on the specific ward and bacteria evaluated. In particular, SARS-CoV-2 outbreaks significantly impacted patient MRB colonization only in settings with high underlying risk of bacterial transmission. Yet across settings and species, antibiotic resistance burden was reduced in facilities with timelier implementation of effective COVID-19 control policies. Conclusions: Our model suggests that surges in nosocomial SARS-CoV-2 transmission generate selection for the spread of antibiotic-resistant bacteria. Timely implementation of efficient COVID-19 control measures thus has 2-fold benefits, preventing the transmission of both SARS-CoV-2 and MRB, and highlighting antibiotic resistance control as a collateral benefit of pandemic preparedness

Representing crop rotations in life cycle assessment: a review of legume LCA studies

There is an imperative to accurately assess the environmental sustainability of crop system interventions in the context of food security and climate change. Previous studies have indicated that the incorporation of legumes into cereal rotations could reduce overall environmental burdens from cropping systems. However, most LCA studies focus on individual crops and miss environmental consequences of inter-annual crop sequence and nutrient cycling effects. This review investigates state-of-the-art representation of inter-crop rotation effects within legume LCA studies

First-principles modeling of strain in perovskite ferroelectric thin films

We review the role that first-principles calculations have played in understanding the effects of substrate-imposed misfit strain on epitaxially grown perovskite ferroelectric films. We do so by analyzing the case of BaTiO$_3$, complementing our previous publications on this subject with unpublished data to help explain in detail how these calculations are done. We also review similar studies in the literature for other perovskite ferroelectric-film materials.Comment: 14 pages, submitted to Phase Transition

A Neuroanatomical Signature for Schizophrenia Across Different Ethnic Groups

Schizophrenia is a disabling clinical syndrome found across the world. While the incidence and clinical expression of this illness are strongly influenced by ethnic factors, it is unclear whether patients from different ethnicities show distinct brain deficits. In this multicentre study, we used structural Magnetic Resonance Imaging to investigate neuroanatomy in 126 patients with first episode schizophrenia who came from 4 ethnically distinct cohorts (White Caucasians, African-Caribbeans, Japanese, and Chinese). Each patient was individually matched with a healthy control of the same ethnicity, gender, and age (±1 year). We report a reduction in the gray matter volume of the right anterior insula in patients relative to controls (P < .05 corrected); this reduction was detected in all 4 ethnic groups despite differences in psychopathology, exposure to antipsychotic medication and image acquisition sequence. This finding provides evidence for a neuroanatomical signature of schizophrenia expressed above and beyond ethnic variations in incidence and clinical expression. In light of the existing literature, implicating the right anterior insula in bipolar disorder, depression, addiction, obsessive-compulsive disorder, and anxiety, we speculate that the neuroanatomical deficit reported here may represent a transdiagnostic feature of Axis I disorders

Net Zero requires ambitious greenhouse gas emission reductions on beef and sheep farms coordinated with afforestation and other land use change measures

CONTEXT: The UK Climate Change Committee has recommended a 64% reduction in greenhouse gas emissionsfrom the agriculture and land-use sector to meet the 2050 Net Zero target in the UK. However, it is unclear howthis reduction can be achieved at a farm level.OBJECTIVE: Using detailed real farm data and novel modelling approaches, we investigated the managementinterventions and afforestation that would be required to deliver Net Zero within the farm boundary.METHODS: Baseline carbon footprints were calculated for twenty Welsh beef and sheep farms using the Agrecalccarbon calculator, whilst carbon sequestration was estimated using Bangor University’s Carbon FootprintingTool. Scenarios were created to determine the emissions reductions achievable on each farm through implementationof cost-effective mitigation measures. Mitigation measures and their abatement potentials weresourced from the most recent UK Marginal Abatement Cost Curve, which allow emissions to be reduced mostlythrough improvements in efficiency thus maintaining the production of the system. Area footprints werecalculated for production, with and without offset (afforested) areas needed to achieve Net Zero