Automated efficiency loss analysis by luminescence image reconstruction using generative adversarial networks

Identifying solar cell efficiency shortfalls in production lines is crucial to troubleshoot and optimize manufacturing processes. With the adoption of luminescence imaging as a key end-of-line characterization tool, a wealth of information is available to evaluate cell performance and classify defects, suitable for user input-free deep-learning analysis. We propose an automated reconstruction method, based on state-of-the-art generative adversarial networks, to remove defective regions in luminescence images. The reconstructed and original images are compared to estimate the efficiency loss. The method is validated on intentionally damaged cells by reconstructing defect-free images and then predicting the efficiency loss. The method can differentiate between different types of defects and pinpoint the defects that lead to the highest efficiency shortfall, enabling manufacturers to troubleshoot production lines in a fast and cost-effective manner. The proposed approach unlocks the potential of luminescence imaging as an effective end-of-line characterization tool

Are Drivers of Root-Associated Fungal Community Structure Context Specific?

The composition and structure of plant-root-associated fungal communities are determined by local abiotic and biotic conditions. However, the relative influence and identity of relationships to abiotic and biotic factors may differ across environmental and ecological contexts, and fungal functional groups. Thus, understanding which aspects of root-associated fungal community ecology generalise across contexts is the first step towards a more predictive framework. We investigated how the relative importance of biotic and abiotic factors scale across environmental and ecological contexts using high-throughput sequencing (ca. 55 M Illumina metabarcoding sequences) of >260 plant-root-associated fungal communities from six UK salt marshes across two geographic regions (South-East and North-West England) in winter and summer. Levels of root-associated fungal diversity were comparable with forests and temperate grasslands, quadrupling previous estimates of salt-marsh fungal diversity. Whilst abiotic variables were generally most important, a range of site- and spatial scale-specific abiotic and biotic drivers of diversity and community composition were observed. Consequently, predictive models of diversity trained on one site, extrapolated poorly to others. Fungal taxa from the same functional groups responded similarly to the specific drivers of diversity and composition. Thus site, spatial scale and functional group are key factors that, if accounted for, may lead to a more predictive understanding of fungal community ecology

Belowground DNA-based techniques: untangling the network of plant root interactions

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What Goes in Must Come out: Testing for Biases in Molecular Analysis of Arbuscular Mycorrhizal Fungal Communities

Arbuscular mycorrhizal (AM) fungi are widely distributed microbes that form obligate symbioses with the majority of terrestrial plants, altering nutrient transfers between soils and plants, thereby profoundly affecting plant growth and ecosystem properties. Molecular methods are commonly used in the study of AM fungal communities. However, the biases associated with PCR amplification of these organisms and their ability to be utilized quantitatively has never been fully tested. We used Terminal Restriction Fragment Length Polymorphism (TRFLP) analysis to characterise artificial community templates containing known quantities of defined AM fungal genotypes. This was compared to a parallel in silico analysis that predicted the results of this experiment in the absence of bias. The data suggest that when used quantitatively the TRFLP protocol tested is a powerful, repeatable method for AM fungal community analysis. However, we suggest some limitations to its use for population-level analyses. We found no evidence of PCR bias, supporting the quantitative use of other PCR-based methods for the study of AM fungi such as next generation amplicon sequencing. This finding greatly improves our confidence in methods that quantitatively examine AM fungal communities, providing a greater understanding of the ecology of these important fungi

<i>amoA</i> Gene Abundances and Nitrification Potential Rates Suggest that Benthic Ammonia-Oxidizing Bacteria and Not Archaea Dominate N Cycling in the Colne Estuary, United Kingdom

ABSTRACT Nitrification, mediated by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), is important in global nitrogen cycling. In estuaries where gradients of salinity and ammonia concentrations occur, there may be differential selections for ammonia-oxidizer populations. The aim of this study was to examine the activity, abundance, and diversity of AOA and AOB in surface oxic sediments of a highly nutrified estuary that exhibits gradients of salinity and ammonium. AOB and AOA communities were investigated by measuring ammonia monooxygenase ( amoA ) gene abundance and nitrification potentials both spatially and temporally. Nitrification potentials differed along the estuary and over time, with the greatest nitrification potentials occurring mid-estuary (8.2 μmol N grams dry weight [gdw] −1 day −1 in June, increasing to 37.4 μmol N gdw −1 day −1 in January). At the estuary head, the nitrification potential was 4.3 μmol N gdw −1 day −1 in June, increasing to 11.7 μmol N gdw −1 day −1 in January. At the estuary head and mouth, nitrification potentials fluctuated throughout the year. AOB amoA gene abundances were significantly greater (by 100-fold) than those of AOA both spatially and temporally. Nitrosomonas spp. were detected along the estuary by denaturing gradient gel electrophoresis (DGGE) band sequence analysis. In conclusion, AOB dominated over AOA in the estuarine sediments, with the ratio of AOB/AOA amoA gene abundance increasing from the upper (freshwater) to lower (marine) regions of the Colne estuary. These findings suggest that in this nutrified estuary, AOB (possibly Nitrosomonas spp.) were of major significance in nitrification. </jats:p

Mineralization and nitrification: Archaea dominate ammonia-oxidising communities in grassland soils

In grasslands, N mineralization and nitrification are important processes and are controlled by several factors, including the in situ microbial community composition. Nitrification involves ammonia oxidising archaea (AOA) and bacteria (AOB) and although AOA and AOB co-exist in soils, they respond differently to environmental characteristics and there is evidence of AOA/AOB niche differentiation. Here, we investigated temporal variation in N mineralization and nitrification rates, together with bacterial, archaeal and ammonia-oxidiser communities in grassland soils, on different geologies: clay, Greensand and Chalk. Across geologies, N mineralization and nitrification rates were slower in the autumn than the rest of the year. Turnover times for soil ammonium pools were <24 h, whilst several days for nitrate. In clay soils, bacterial, archaeal, AOA, and AOB communities were clearly distinct from those in Chalk and Greensand soils. Spatially and temporally, AOA were more abundant than AOB. Notably, Nitrososphaera were predominant, comprising 37.4% of archaeal communities, with the vast majority of AOA found in Chalk and Greensand soils. AOA abundance positively correlated with nitrate concentration, whereas AOB abundance correlated with ammonium and nitrite concentrations, suggesting that these N compounds may be potential drivers for AOA/AOB niche differentiation in these grassland soils

Shifts in the source and composition of dissolved organic matter in Southwest Greenland lakes along a regional hydro-climatic gradient

Dissolved organic matter (DOM) concentration and quality were examined from Arctic lakes located in three clusters across south-west (SW) Greenland, covering the regional climatic gradient: cool, wet coastal zone; dry inland interior; and cool, dry ice-marginal areas. We hypothesized that differences in mean annual precipitation between sites would result in a reduced hydrological connectivity between lakes and their catchments and that this concentrates degraded DOM. The DOM in the inland lake group was characterized by a lower aromaticity and molecular weight, a low soil-like fluorescence, and carbon stable isotope (δ 13 C-DOC) values enriched by ~2‰ relative to the coastal group. DOC-specific absorbance (SUVA 254 ) and DOC-specific soil-like fluorescence (SUVF C1 ) revealed seasonal and climatic gradients across which DOM exhibited a dynamic we term “pulse-process”: Pulses of DOM exported from soils to lakes during snow and ice melt were followed by pulses of autochthonous DOM inputs (possibly from macrophytes), and their subsequent photochemical and microbial processing. These effects regulated the dynamics of DOM in the inland lakes and suggested that if circumpolar lakes currently situated in cool wetter climatic regimes with strong hydrological connectivity have reduced connectivity under a drier future climate, they may evolve toward an end-point of large stocks of highly degraded DOC, equivalent to the inland lakes in the present study. The regional climatic gradient across SW Greenland and its influence on DOM properties in these lakes provide a model of possible future changes to lake C cycling in high-latitude systems where climatic changes are most pronounced

Next-Generation Global Biomonitoring: Large-scale, Automated Reconstruction of Ecological Networks

We foresee a new global-scale, ecological approach to biomonitoring emerging within the next decade that can detect ecosystem change accurately, cheaply, and generically. Next-generation sequencing of DNA sampled from the Earth's environments would provide data for the relative abundance of operational taxonomic units or ecological functions. Machine-learning methods would then be used to reconstruct the ecological networks of interactions implicit in the raw NGS data. Ultimately, we envision the development of autonomous samplers that would sample nucleic acids and upload NGS sequence data to the cloud for network reconstruction. Large numbers of these samplers, in a global array, would allow sensitive automated biomonitoring of the Earth's major ecosystems at high spatial and temporal resolution, revolutionising our understanding of ecosystem change

‘Why would we not want to keep everybody safe?’ The views of family members of people who use drugs on the implementation of drug consumption rooms in Scotland

BackgroundPeople who use drugs in Scotland are currently experiencing disproportionately high rates of drug-related deaths. Drug consumption rooms (DCRs) are harm reduction services that offer a safe, hygienic environment where pre-obtained drugs can be consumed under supervision. The aim of this research was to explore family member perspectives on DCR implementation in Scotland in order to inform national policy.MethodsScotland-based family members of people who were currently or formerly using drugs were invited to take part in semi-structured interviews to share views on DCRs. An inclusive approach to ‘family’ was taken, and family members were recruited via local and national networks. A convenience sample of 13 family members were recruited and interviews conducted, audio-recorded, transcribed, and analysed thematically using the Structured Framework Technique.ResultsFamily members demonstrated varying levels of understanding regarding the existence, role, and function of DCRs. While some expressed concern that DCRs would not prevent continued drug use, all participants were in favour of DCR implementation due to a belief that DCRs could reduce harm, including saving lives, and facilitate future recovery from drug use. Participants highlighted challenges faced by people who use drugs in accessing treatment/services that could meet their needs. They identified that accessible and welcoming DCRs led by trusting and non-judgemental staff could help to meet unmet needs, including signposting to other services. Family members viewed DCRs as safe environments and highlighted how the existence of DCRs could reduce the constant worry that they had of risk of harm to their loved ones. Finally, family members emphasised the challenge of stigma associated with drug use. They believed that introduction of DCRs would help to reduce stigma and provide a signal that people who use drugs deserve safety and care.ConclusionsReporting the experience and views of family members makes a novel and valuable contribution to ongoing public debates surrounding DCRs. Their views can be used to inform the implementation of DCRs in Scotland but also relate well to the development of wider responses to drug-related harm and reduction of stigma experienced by people who use drugs in Scotland and beyond

Drug Consumption Rooms and Public Health Policy: Perspectives of Scottish Strategic Decision-Makers

There is widespread support for the introduction of Drug Consumption Rooms (DCRs) in Scotland as part of a policy response to record levels of drug-related harm. However, existing legal barriers are made more complex by the division of relevant powers between the UK and Scottish Governments. This paper reports on a national, qualitative study of key decision-makers in both local and national roles across Scotland. It explores views on the political barriers and enablers to the adoption of Drug Consumption Rooms and the potential role of these facilities in the wider treatment system. It also considers approaches to evidence, especially the types of evidence that are considered valuable in supporting decision-making in this area. The study found that Scottish decision-makers are strongly supportive of DCR adoption; however, they remain unclear as to the legal and political mechanisms that would make this possible. They view DCRs as part of a complex treatment and support system rather than a uniquely transformative intervention. They see the case for introduction as sufficient, on the basis of need and available evidence, thus adopting a pragmatic and iterative approach to evidence, in contrast to an appeal to traditional evidence hierarchies more commonly adopted by the UK Government