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Historic Spatial Patterns of Storm-Driven Compound Events in UK Estuaries
Get PDFCompound estuarine flooding is driven by extreme sea-levels and river discharge occurring concurrently, or in close succession, and threatens low-lying coastal regions worldwide. We hypothesise that these drivers of flooding rarely occur independently and co-operate at sub-daily timescales. This research aimed to identify regions and individual estuaries within Britain susceptible to storm-driven compound events, using 27 tide gauges linked to 126 river gauges covering a 30-year record. Five methods were evaluated, based on daily mean, daily maximum, and instantaneous 15-min discharge data to identify extremes in the river records, with corresponding skew surges identified within a ‘storm window’ based on average hydrograph duration. The durations, relative timings, and overlap of these extreme events were also calculated. Dependence between extreme skew surge and river discharge in Britain displayed a clear east–west split, with gauges on the west coast showing stronger correlations up to 0.33. Interpreting dependence based on correlation alone can be misleading and should be considered alongside number of historic extreme events. The analyses identified 46 gauges, notably the Rivers Lune and Orchy, where there has been the greatest chance and most occurrences of river-sea extremes coinciding, and where these events readily overlapped one another. Our results were sensitive to the analysis method used. Most notably, daily mean discharge underestimated peaks in the record and did not accurately capture likelihood of compound events in 68% of estuaries. This has implications for future flood risk in Britain, whereby studies should capture sub-daily timescale and concurrent sea-fluvial climatology to support long-term flood management plans
Tracing the mineralization rates of C, N and S from cysteine and methionine in a grassland soil: A 14C and 35S dual-labelling study
Get PDFSulphur-containing amino acids (i.e. Cysteine (Cys) and methionine (Met)) constitute an important proportion of the soil organic sulphur. However, detailed information regarding the microbial transformation of Cys and Met at a molecular level remain poorly characterized. To trace the fate of carbon (C) and sulphur (S) derived from Cys and Met in an agricultural grassland soil, a14C and 35S dual-isotopic labelling approach was adopted. We also investigated whether their mineralization was affected by manipulating C (added as glucose), nitrogen (N), phosphorus (P) and S (added as NH4NO3, KH2PO4 and K2SO4) availability in soil solution. Our results showed that over a 7-day incubation period, 67.2–89.2% of the 14C derived from Cys and Met was respired as 14CO2, 2.7–19.5% had been immobilized in the soil microbial biomass; while the recovery of 35S in soil solution ranged from 6.4 to 9.9%, with the reminder retained in the soil microbial biomass. Overall, our results indicated that soil microbial communities possess a high capacity to utilize Cys and Met. Furthermore, using the 14C and 35S dual-labelling technique, we found that C and S derived from Cys and Met were microbially mineralized and immobilized at different rates, indicating that the cycles of these two elements were temporally decoupled at the molecular level. The addition of glucose-C increased 14CO2 respiration from Cys and Met after 7 d, while in comparison inorganic N, P and S addition had less effect on 14C and 35S partitioning
Leadership under the shadow of the future: Intelligence and strategy choice in infinitely repeated games
Get PDFClimate tracking by freshwater fishes suggests that fish diversity in temperate lakes may be increasingly threatened by climate warming
Get PDFAimMany freshwater fishes are migrating poleward to more thermally suitable habitats in response to warming climates. In this study, we aimed to identify which freshwater fishes are most sensitive to climatic changes and asked: (i) how fast are lakes warming? (ii) how fast are fishes moving? and (iii) are freshwater fishes tracking climate?LocationOntario, Canada.MethodsWe assembled a database containing time series data on climate and species occurrence data from 10,732 lakes between 1986 and 2017. We calculated the rate of lake warming and climate velocity for these lakes. Climate velocities were compared with biotic velocities, specifically the rate at which the northernmost extent of each species shifted north.ResultsLakes in Ontario warmed by 0.2°C decade−1 on average, at a climate velocity of 9.4 km decade−1 between 1986 and 2017. In response, some freshwater fishes have shifted their northern range boundaries with considerable interspecific variation ranging from species moving southwards at a rate of −58.9 km decade−1 to species ranges moving northwards at a rate of 83.6 km decade−1 over the same time period. More freshwater fish species are moving into northern lakes in Ontario than those being lost. Generally, predators are moving their range edges northwards, whereas prey fishes are being lost from northern lakes.Main ConclusionsThe concurrent loss of cooler refugia, combined with antagonistic competitive and predatory interactions with the range expanding species, has resulted in many commercially important predators moving their range edges northwards, whereas prey species have contracted their northern range edge boundaries. Trophic partitioning of range shifts highlights a previously undocumented observation of the loss of freshwater fishes from lower trophic levels in response to climate-driven migrations.<br/
The IN-FAKT study protocol: INvestigating the experiences and management of individuals with FAiling Kidney Transplants
Get PDFBackground: In the UK 1500 kidney transplants fail each year. 2% of living-donor transplants and 5% of deceased-donor transplants fail within a year of transplantation. Many decisions need to be made when a kidney transplant fails, including whether the transplant should be removed, and which immunosuppression medication should be stopped. There is limited evidence on which to base these decisions. We do not understand how decisions are made in the absence of good evidence, and there is national variation in practice. Aims: The overall aim is to develop a theory of patient and clinician transplant failure behaviours and decisions that will inform the design of a Randomised Controlled Trial (RCT) to evaluate treatments to optimise the management of transplant failure and improve outcomes for patients and their families. Methods: In a UK setting, we will develop a Constructivist Grounded theory using in-depth interviews with people over 18 years who are or have experienced kidney transplant failure, their families/close friends, and renal healthcare professional. Iterative purposive sampling of patients from different hospitals will be undertaken to achieve diversity with respect to age, sex, ethnicity, socioeconomic position, transplant type, and cause of transplant failure. Subsequent sampling will be theoretical, to test and develop hypotheses and theories being constructed. The sample size will be determined by reaching theoretical theme saturation with an anticipated minimum of 25–30 patients, 25–30 family members/close friends and 10–15 renal healthcare professionals. The research team will take a reflexive approach to make any influences or potential biases transparent. This knowledge will be used to develop the programme theory and design an RCT to evaluate treatments delivered at the right time in a patient’s journey, to improve experiences and outcomes for people with failing kidney transplants
A New Value Proposition for Uganda’s Maize Stover to Manufacture Moulded Pulp Packaging Material for Fruits and Vegetables
Get PDFPost harvest losses of fresh produce, including fruits and vegetables, have continued to be high in Uganda. This realization has triggered numerous efforts to address this issue. One proposition is to utilize maize stover to produce sustainable moulded pulp bio-based packaging as a possible replacement for single plastics packaging. Maize stover is considered a burden to farmers to dispose after harvesting leading to its wastage. The objectives of this study were; to ascertain the current ways in which maize stover is utilized by farmers, the major packaging materials they use, and the determinants of demand for the quantity of packaging materials that farmers use. A total of 200 smallholder maize farmers from Kamuli district were interviewed. Findings show that a good percentage of farmers destroy the stover through burning, some farmers plough it back to replenish the lost soil nutrients, while others use it as livestock fodder. Polypropylene and polyethylene packaging materials are the most used and preferred packages due to availability, and affordability. The covariates that determine the demand for the number of packages purchased annually were; quantity of maize marketed, distance to the market, funds spent on marketing, and annual income. To increase the demand for maize stover packaging materials formal education, regular training, access to capital and formation of farmer groups are recommended.<br/
