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A standardized assessment of geographic variation in size at maturity of European lobster (Homarus gammarus L.) in the North East Atlantic
Get PDFThis study collates existing data on physiological maturity of female European Lobster Homarus gammarus across the North East Atlantic, together with new data from Orkney, Wales, and the Isle of Man. Using a standardised methodology, physiological estimates of size at maturity were undertaken using 1,309 lobsters from eleven locations. Size at 50% maturity varied between populations, ranging from 81.3 -94.1mm carapace length. Generalised Additive Models were used to characterise geographic patterns in size at maturity. Optimum monthly sea surface temperature (OPTIMNTH) had a significant and non-linear effect on the probability of being sexually mature at a given size in different populations. This is consistent with a thermal optimum previously demonstrated in absolute growth
Circular wood use can accelerate global decarbonisation but requires cross-sectoral coordination
Get PDFPredominantly linear use of wood curtails the potential climate-change mitigation contribution of forestry value-chains. Using lifecycle assessment, we show that more cascading and especially circular uses of wood can provide immediate and sustained mitigation by reducing demand for virgin wood, which increases forest carbon sequestration and storage, and benefits from substitution for fossil-fuel derived products, reducing net greenhouse gas emissions. By United Kingdom example, the circular approach of recycling medium-density fibreboard delivers 75% more cumulative climate-change mitigation by 2050, compared with business-as-usual. Early mitigation achieved by circular and cascading wood use complements lagged mitigation achieved by afforestation; and in combination these measures could cumulatively mitigate 258.8 million tonnes CO 2e by 2050. Despite the clear benefits of implementing circular economy principles, we identify many functional barriers impeding the structural reorganisation needed for such complex system change, and propose enablers to transform the forestry value-chain into an effective societal change system and lead to coherent action. </p
Tailoring the Direct Current Modulation Response of Electrically Pumped Semiconductor Nano-Laser Arrays
Get PDFSemiconductor nano-lasers have been a topic of interest from the perspective of advancing the capabilities of photonic integration. Nano-lasers are perceived as the means to achieve improved functionality in photonic integrated circuits. The properties and performance of nano-lasers have been examined by means of simulations and laboratory measurements. Nano-lasers lend themselves to integration to form dense arrays in both one and two dimensions. In a recent work, a theoretical treatment was presented for the dynamic behaviour of stand-alone electrically pumped nano-laser arrays. In this work, the response of nano-laser arrays to direct current modulation is examined. As in previous works, attention is given to two prototype array geometries: a linear three-element linear array and an equilateral triangular array. Large one-dimensional arrays can be built by repeating this elementary linear array. Two-dimensional photonic integrated circuits can incorporate the triangular arrays studied here. Such prototypical configurations offer opportunities to tailor the modulation response of the nano-laser arrays. The principal factors which provide that capability are the coupling strengths between lasers in the arrays and the direct modulation parameters. The former are fixed at the design and manufacture stage of the array whilst the latter can be chosen. In addition, the enhancement of the spontaneous emission rate via the so-called Purcell effect in nano-lasers offers a device-specific means for accessing a range of modulation responses. Two-dimensional portraits of the regimes of differing modulation responses offer a convenient means for determining the dynamics that may be accessed by varying the laser drive current. It is shown by these means that a rich variety of modulation responses can be accessed in both linear and triangular arrays
Attenuation of Methane Oxidation by Nitrogen Availability in Arctic Tundra Soils
Get PDFCH4 emission in the Arctic has large uncertainty due to the lack of mechanistic understanding of the processes. CH4 oxidation in Arctic soil plays a critical role in the process, whereby removal of up to 90% of CH4 produced in soils by methanotrophs can occur before it reaches the atmosphere. Previous studies have reported on the importance of rising temperatures in CH4 oxidation, but because the Arctic is typically an N-limited system, fewer studies on the effects of inorganic nitrogen (N) have been reported. However, climate change and an increase of available N caused by anthropogenic activities have recently been reported, which may cause a drastic change in CH4 oxidation in Arctic soils. In this study, we demonstrate that excessive levels of available N in soil cause an increase in net CH4 emissions via the reduction of CH4 oxidation in surface soil in the Arctic tundra. In vitro experiments suggested that N in the form of NO3- is responsible for the decrease in CH4 oxidation via influencing soil bacterial and methanotrophic communities. The findings of our meta-analysis suggest that CH4 oxidation in the boreal biome is more susceptible to the addition of N than in other biomes. We provide evidence that CH4 emissions in Arctic tundra can be enhanced by an increase of available N, with profound implications for modeling CH4 dynamics in Arctic regions.</p
Emotional AI Survey, UK: Aggregate Data, 2022
No full textThis project aimed to quantitatively understand citizens' attitudes to Emotional AI via national surveys (as described in point 6 "Project Description", see above). We developed a demographically representative survey to gauge citizen attitudes to emotion capture technologies in cities in the UK. The survey introduces the overall topic of emotion profiling with the phrase: ‘We would now like to ask your opinion on use of technologies that try to measure and understand emotions (e.g., through computer analysis of social media posts, facial expression, voice, heart rate, gesture, and other data about the body). Closed-ended questions allowed then to explore 10 different use cases (38 questions in total): security, policing, communications, political campaigning, health, transport, education, toys and robots. For each case, positive and negative themes were tested, by grounding each question in an applied use case. In total, nine themes were explored, (although not across all the use cases to minimise survey fatigue)
Environmental DNA biomonitoring in biodiversity hotspots: A case study of fishes of the Okavango Delta
Get PDFThe Okavango Delta is the largest freshwater wetland in southern Africa and a recognized biodiversity hotspot and UNESCO World Heritage Site. The region is extremely rich in floral and faunal diversity, including a fish fauna of ~90 species in 15 families, that also support recreational and subsistence fishing. Anthropogenic pressures and invasive species threaten the unique biodiversity and ecosystem services that the Delta provides, necessitating biomonitoring tools that can provide broad community-level diversity insights. Here, we utilize environmental DNA metabarcoding of aquatic eDNA using the MiFish 12S rRNA primers, to investigate fish communities and also sequenced 211 mtDNA 12S barcodes for 74 species across 36 genera of fishes from the region. Metabarcoding recovered 11 of 15 families, with 40 species detected across 23 genera, representing ~50% of known diversity, with the mtDNA 12S fragment able to delineate all genera (except for the cichlid genera Serranochromis and Pharyngochromis that comprised a single clade) and most species, except for some in the Clarias, Enteromius, Labeo, Lacustricola, and Petrocephalus genera. Generally, abundant and wide-spread taxa such as Clarias spp. and Marcusenius altisambesi, amongst others, were often detected in the surveys, with other species, including Zaireichthys kavangoensis, Schilbe intermedius, and Labeo sp. detected less frequently. Dissolved oxygen, temperature, and dissolved organic solids were positively correlated with community diversity, highlighting the influence of environmental factors in shaping fish communities in the region. Further, there was strong variability in the eDNA signal across only 1000 m, suggesting that future surveys need to consider spatio-temporal aspects of sample collection. Our study highlights the potential of eDNA metabarcoding for surveying aquatic biodiversity in the Okavango Delta, particularly within the context of baseline biodiversity inventories, that underpin conservation and management initiatives. As such, we provide a number of recommendations that can help structure future sampling efforts in the region
Ecological evidence for later dementia diagnosis in areas with higher rates of bilingualism: Evidence from Y Fro Gymraeg in Wales
Get PDFOrganic Carbon Stocks of Great British Saltmarshes
Get PDFCoastal wetlands, such as saltmarshes, are globally widespread and highly effective at capturing and storing 'blue carbon' and have the potential to regulate climate over varying timescales. Yet only Australia and the United States of America have national inventories of organic carbon held within saltmarsh habitats, hindering the development of policies and management strategies to protect and preserve these organic carbon stores. Here we couple a new observational dataset with 4,797 samples from 26 saltmarshes across Great Britain to spatially model organic carbon stored in the soil and the above and belowground biomass of Great British saltmarshes. Using average values derived from the 26 marshes, we deliver first-order estimates of organic carbon stocks across Great Britain's 448 saltmarshes (451.66 km 2 ). The saltmarshes of Great Britain contain 5.20 ± 0.65 Mt of organic carbon, 93% of which is in the soil. On average, the saltmarshes store 11.55 ± 1.56 kg C m -2 with values ranging between 2.24 kg C m -2 and 40.51 kg C m -2 depending on interlinked factors such as geomorphology, organic carbon source, sediment type (mud vs sand), sediment supply, and relative sea level history. These findings affirm that saltmarshes represent the largest intertidal blue carbon store in Great Britian, yet remain an unaccounted for component of the United Kingdom's natural carbon stores.perched marshes are found only in Scotland (Pye and French, 1993;Haynes, 2016), whilst the saltmarshes of Wales are generally situated in small estuaries resulting in 49 marshes of modest size.Table 1. Areal extent of the saltmarshes within the constituent nations of Great Britain (GB), divided into saltmarsh zone following the modified EUNIS classification system (Section 3.7.1). Data were compiled from the latest spatial mapping of saltmarshes (Haynes, 2016; Natural Resources Wales, 2016;Environment Agency, 2023).Zone Area (km 2 ) Nation Number of Saltmarshes High Mid-Low Pioneer Spartina Unclassified Total Proportion of GB Saltmarsh Habitat (%
