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The management of climate-resilient grassland systems is important for stable livestock fodder production. In the face of climate change, maintaining productivity while minimizing yield variance of grassland systems is increasingly challenging. To achieve climate-resilient and stable productivity of grasslands, a better understanding of the climatic drivers of long-term trends in yield variance and its dependence on agronomic inputs is required. Based on the Park Grass Experiment at Rothamsted (UK), we report for the first time the long-term trends in yield variance of grassland (1965–2018) in plots given different fertilizer and lime applications, with contrasting productivity and plant species diversity. We implemented a statistical model that allowed yield variance to be determined independently of yield level. Environmental abiotic covariates were included in a novel criss-cross regression approach to determine climatic drivers of yield variance and its dependence on agronomic management. Our findings highlight that sufficient liming and moderate fertilization can reduce yield variance while maintaining productivity and limiting loss of plant species diversity. Plots receiving the highest rate of nitrogen fertilizer or farmyard manure had the highest yield but were also more responsive to environmental variability and had less plant species diversity. We identified the days of water stress from March to October and temperature from July to August as the two main climatic drivers, explaining approximately one-third of the observed yield variance. These drivers helped explain consistent unimodal trends in yield variance—with a peak in approximately 1995, after which variance declined. Here, for the first time, we provide a novel statistical framework and a unique long-term dataset for understanding the trends in yield variance of managed grassland. The application of the criss-cross regression approach in other long-term agro-ecological trials could help identify climatic drivers of production risk and to derive agronomic strategies for improving the climate resilience of cropping systems.

Background The optimal intensity of continuous renal-replacement therapy remains unclear. We conducted a multicenter, randomized trial to compare the effect of this therapy, delivered at two different levels of intensity, on 90-day mortality among critically ill patients with acute kidney injury. Methods We randomly assigned critically ill adults with acute kidney injury to continuous renal-replacement therapy in the form of postdilution continuous venovenous hemodiafiltration with an effluent flow of either 40 ml per kilogram of body weight per hour (higher intensity) or 25 ml per kilogram per hour (lower intensity). The primary outcome measure was death within 90 days after randomization. Results Of the 1508 enrolled patients, 747 were randomly assigned to higher-intensity therapy, and 761 to lower-intensity therapy with continuous venovenous hemodiafiltration. Data on primary outcomes were available for 1464 patients (97.1%): 721 in the higher-intensity group and 743 in the lower-intensity group. The two study groups had similar baseline characteristics and received the study treatment for an average of 6.3 and 5.9 days, respectively (P = 0.35). At 90 days after randomization, 322 deaths had occurred in the higher-intensity group and 332 deaths in the lower-intensity group, for a mortality of 44.7% in each group (odds ratio, 1.00; 95% confidence interval [CI], 0.81 to 1.23; P = 0.99). At 90 days, 6.8% of survivors in the higher-intensity group (27 of 399), as compared with 4.4% of survivors in the lower-intensity group (18 of 411), were still receiving renal-replacement therapy (odds ratio, 1.59; 95% CI, 0.86 to 2.92; P = 0.14). Hypophosphatemia was more common in the higher-intensity group than in the lower-intensity group (65% vs. 54%, P Conclusions In critically ill patients with acute kidney injury, treatment with higher-intensity continuous renal-replacement therapy did not reduce mortality at 90 days. (ClinicalTrials.gov number, NCT00221013.)

Surveys and field experiments showed pasmo to be the most serious disease affecting UK winter linseed in the 1997-98, 1998-99 and 1999-2000 growing seasons. Survey data indicated that pasmo was widespread in England and Scotland, causing extensive loss of leaves and stem and capsule symptoms, on both winter and spring linseed crops. In winter linseed experiments at ADAS Boxworth and Rothamsted, when severe epidemics occurred (1997-98 and 1999-2000), control of pasmo with one or two MBC fungicide sprays increased yield. In experiments when severe pasmo epidemics did not occur (1998-99), fungicide applications did not increase yield. In all three growing seasons, large numbers of air-borne Mycosphaerella linicola ascospores were collected in the summer months. At the time when the winter linseed crop was emerging and becoming established in October/November, there were more air-borne M. linicola ascospores in 1999 than in 1998. April/May rainfall was much greater in 1998 (135 mm) and 2000 (223 mm), when severe pasmo epidemics developed by July, than in 1999 (68 mm) when disease severity in July was less. Regression analyses suggested that yield decreased as percentage area affected by pasmo on leaves or stems in July increased. The formulae relating yield loss to pasmo severity, derived from these experiments, were combined with disease survey data to estimate, retrospectively, the UK national losses from pasmo. Estimated national losses from pasmo on winter linseed, although > 50% of crops were sprayed with fungicide, were approximately 2.9M pound in 1998, 1.6M pound in 1999 and 0.37M pound in 2000 (when the area of winter linseed had decreased greatly). Estimated combined losses on winter and spring linseed were approximately 14.8M pound in 1998, 34.9M pound in 1999 and 11.0M pound in 2000.

Studying the presence and movement of insects is important in biological research for practical purposes regarding control of pests and environmental monitoring. Detection of insects by conventional trapping (e.g. the Rothamsted Insect Survey) and tracking technologies (e.g. the Rothamsted Radar Entomology Unit) have been effective for monitoring and forecasting pest migration but often require significant investment in capital costs and/or staff time. Insect detection using imaging of natural fluorescence (without additional fluorescent dyes) has been considered less, and much of the work on natural fluorescence in the animal world has been on marine organisms. Work on terrestrial arthropods has been more limited and restricted primarily to non-insect arthropods. Very early work on the distribution of fluorescent pigments in butterflies was demonstrated using long wave mercury vapour lamps followed by more work in the 1950s on butterflies, arthropods; including beetles, spiders and millipedes, cockroaches and eggs of Orthoptera. These studies often involved qualitative approaches; dissecting the animals and investigating internal organs and fluids for fluorescence as well as whole body studies. More recent studies have included quantitative work on butterflies and pest insects plus fluorescence studies in damselflies, moths, millipedes, bees and spiders. Fluorescence in juvenile stages is a property used for detection of flies and beetles in food stuffs. The vast majority of insects, however, have not been investigated for fluorescence and even in those taxa that have been studied, e.g. butterflies, the dataset is incomplete. The easiest way to observe fluorescence is to illuminate a subject with a known waveband of light in otherwise darkness and view or record an image via a filter that blocks the wavelength of the illuminating light. Any light viewed or captured at a different wavelength to the illumination, must have been produced by fluorescence. In contrast, some living organisms themselves can produce light or luminescence by internal chemical means. This work aimed to look at the potential of using natural fluorescence to detect and identify insects, particularly pests.