Species diversity is presently declining and homogenizing globally due to human land use changes and climate change effects. However, the causes of these declines are difficult to determine due to complex ecological interactions. Lepidopterans are a diverse and ecologically important group of insects that are declining in Britain and other parts of Europe. Long-term monitoring data made
available in 2003 showed that 66% of observed species declined over the course of 35 years, however, it is not known what effect species losses has on ecosystem stability. Here, we assess long-term moth diversity dynamics in relation to climatic shifts over 20 years, and investigate the importance of stability in maintaining and conserving ecological communities. From 1993 to 2014, moth species data and abundances were recorded over 7,390 trapping nights. Overall, 376 species were recorded over 20-years, identifying seasonal
and annual trends in species richness strongly associated with oscillations in temperature. Long-term stability, measured using meanrank shifts and temporal variability, was indicative of significant positive associations between species diversity and temperature. Using rank shift analyses we were able to not only assess community stability dynamics, but also the individual species dynamics and their contribution to community diversity over time. We also noted eneralist feeders were more associated with maintaining diverse species communities subjected to oscillating climatic conditions compared to specialist taxa. Overall, our study shows the benefit of utilizing community-based stability assessments to distill population level information from complex datasets, highlighting the need for long-term monitoring at the community level to explore impacts of environmental change on ecosystem function.

Chaos generation in a discrete-mode (DM) laser subject to optical feedback is
experimentally explored. The results show that a DM laser with only optical feedback can produce flat broadband chaos under an optimized feedback ratio. The effect of the laser bias current on the bandwidth and flatness of chaos is also investigated. It shows that the higher bias current, the better the flatness that can be obtained at the optimal feedback ratio.

Hydrogen can serve as an electron donor for chemolithotrophic acidophiles, especially in the deep terrestrial subsurface and geothermal ecosystems. Nevertheless, the current knowledge of hydrogen utilization by mesophilic acidophiles is minimal. A multi-omics analysis was applied on Acidithiobacillus ferrooxidans growing on hydrogen, and a respiratory model was proposed. In the model, [NiFe] hydrogenases oxidize hydrogen to two protons and two electrons. The electrons are used to reduce membrane-soluble ubiquinone to ubiquinol. Genetically associated iron-sulfur proteins mediate electron relay from the hydrogenases to the ubiquinone pool. Under aerobic conditions, reduced ubiquinol transfers electrons to either cytochrome aa₃ oxidase via cytochrome bc₁ complex and cytochrome c₄ or the alternate directly to cytochrome bd oxidase, resulting in proton efflux and reduction of oxygen. Under anaerobic conditions, reduced ubiquinol transfers electrons to outer membrane cytochrome c (ferrireductase) via cytochrome bc₁ complex and a cascade of electron transporters (cytochrome c₄, cytochrome c₅₅₂, rusticyanin, and high potential iron-sulfur protein), resulting in proton efflux and reduction of ferric iron. The proton gradient generated by hydrogen oxidation maintains the membrane potential and allows the generation of ATP and NADH. These results further clarify the role of extremophiles in biogeochemical processes and their impact on the composition of the deep terrestrial subsurface.

This article explores the experiences and discourses of precarious work and welfare from the perspectives of young people who are unemployed or in precarious employment, and frontline staff broadly involved in welfare practices. The narratives of unemployed young people and frontline workers, within an area of Wales, offer a snapshot of work and welfare from 2015; with young people a ‘litmus paper’ of the landscape and frontline workers as street-level bureaucrats (Lipsky, 2010). The main findings discussed here are that any work and work schemes are regarded as an appropriate solution for the ‘problem’ of unemployment by both young people and frontline workers, who valorise work and denigrate welfare. Young people compete for, and frontline workers encourage, unpaid and paid labour market participation, whether stable employment is forthcoming or not, and focus on individualising effort and hard work. This is not new, discipline by welfare stigma and the elevation of work has guided workers both now and historically, and a deliberate commodification of labour with work schemes and ‘work first’ approaches, alongside welfare sanctions ensure individuals labour for profit (Daguerre and Etherington, 2014; Grover, 2012). Drawing on the concepts of ‘governmentality’ (Foucault, 1994a) this article argues that the problematizing of the unemployed, and centrality of work and the work ethic, has contributed to young people, particularly those without financial resources, to become a resilient self-governing and effortful reserve army of labour, shaped through discursive practices.

The outwelling paradigm argues that mangrove and saltmarsh wetlands export much excess production to downstream marine systems. However, outwelling is difficult to quantify and currently 40–50% of fixed carbon is unaccounted for. Some carbon is thought outwelled through mobile fauna, including fish, which visit and feed on mangrove produce during tidal inundation or early life stages before moving offshore, yet this pathway for carbon outwelling has never been quantified. We studied faunal carbon outwelling in three arid mangroves, where sharp isotopic gradients across the boundary between mangroves and down-stream systems permitted spatial differentiation of source of carbon in animal tissue. Stable isotope analysis (C, N, S) revealed 22–56% of the tissue of tidally migrating fauna was mangrove derived. Estimated consumption rates showed that 1.4% (38 kg C ha−1 yr−1) of annual mangrove litter production was directly consumed by migratory fauna, with <1% potentially exported. We predict that the amount of faunally-outwelled carbon is likely to be highly correlated with biomass of migratory fauna. While this may vary globally, the measured migratory fauna biomass in these arid mangroves was within the range of observations for mangroves across diverse biogeographic ranges and environmental settings. Hence, this study provides a generalized prediction of the relatively weak contribution of faunal migration to carbon outwelling from mangroves and the current proposition, that the unaccounted-for 40–50% of mangrove C is exported as dissolved inorganic carbon, remains plausible.