Diffuse water pollution during recent extreme wet-weather in the UK: Environmental damage costs and insight into the future?

Periods of extreme wet-weather elevate agricultural diffuse water pollutant loads and climate projections for the UK suggest wetter winters. Within this context, we monitored nitrate and suspended sediment loss using a field and landscape scale platform in SW England during the recent extreme wet-weather of 2019-2020. We compared the recent extreme wet-weather period to both the climatic baseline (1981-2010) and projected near- (2041-2060) and far- (2071-2090) future climates, using the 95th percentiles of conventional rainfall indices generated for climate scenarios downscaled by the LARS-WG weather generator from the 19 global climate models in the CMIP5 ensemble for the RCP8.5 emission scenario. Finally, we explored relationships between pollutant loss and the rainfall indices. Grassland field-scale monthly average nitrate losses increased from 0.39-1.07 kg ha^-1 (2016-2019) to 0.70-1.35 kg ha^-1 (2019-2020), whereas losses from grassland ploughed up for cereals, increased from 0.63-0.83 kg ha^-1 to 2.34-4.09 kg ha^-1. Nitrate losses at landscape scale increased during the 2019-2020 extreme wet-weather period to 2.04-4.54 kg ha^-1. Field-scale grassland monthly average sediment losses increased from 92-116 kg ha^-1 (2016-2019) to 281-333 kg ha^-1 (2019-2020), whereas corresponding losses from grassland converted to cereal production increased from 63-80 kg ha^-1 to 2124-2146 kg ha^-1. Landscape scale monthly sediment losses increased from 8-37 kg ha^-1 in 2018 to between 15 and 173 kg ha^-1 during the 2019-2020 wet-weather period. 2019-2020 was most representative of the forecast 95th percentiles of >1 mm rainfall for near- and far-future climates and this rainfall index was related to monitored sediment, but not nitrate, loss. The elevated suspended sediment loads generated by the extreme wet-weather of 2019-2020 therefore potentially provide some insight into the responses to the projected >1 mm rainfall extremes under future climates at the study location.

Implications of crop model ensemble size and composition for estimates of adaptation effects and agreement of recommendations

Climate change is expected to severely affect cropping systems and food production in many parts of the world unless local adaptation can ameliorate these impacts. Ensembles of crop simulation models can be useful tools for assessing if proposed adaptation options are capable of achieving target yields, whilst also quantifying the share of uncertainty in the simulated crop impact resulting from the crop models themselves. Although some studies have analysed the influence of ensemble size on model outcomes, the effect of ensemble composition has not yet been properly appraised. Moreover, results and derived recommendations typically rely on averaged ensemble simulation results without accounting sufficiently for the spread of model outcomes. Therefore, we developed an Ensemble Outcome Agreement (EOA) index, which analyses the effect of changes in composition and size of a multi-model ensemble (MME) to evaluate the level of agreement between MME outcomes with respect to a given hypothesis (e.g. that adaptation measures result in positive crop responses). We analysed the recommendations of a previous study performed with an ensemble of 17 crop models and testing 54 adaptation options for rainfed winter wheat (Triticum aestivum L.) at Lleida (NE Spain) under perturbed conditions of temperature, precipitation and atmospheric CO2 concentration. Our results confirmed that most adaptations recommended in the previous study have a positive effect. However, we also showed that some options did not remain recommendable in specific conditions if different ensembles were considered. Using EOA, we were able to identify the adaptation options for which there is high confidence in their effectiveness at enhancing yields, even under severe climate perturbations. These include substituting spring wheat for winter wheat combined with earlier sowing dates and standard or longer duration cultivars, or introducing supplementary irrigation, the latter increasing EOA values in all cases. There is low confidence in recovering yields to baseline levels, although this target could be attained for some adaptation options under moderate climate perturbations. Recommendations derived from such robust results may provide crucial information for stakeholders seeking to implement adaptation measures.

An objective approach to model reduction: Application to the Sirius wheat model

An existing simulation model of wheat growth and development, Sirius, was evaluated through a systematic model reduction procedure. The model was automatically manipulated under software control to replace variables within the model structure with constants, individually and in combination. Predictions of the resultant models were compared to growth analysis observations of total biomass, grain yield, and canopy leaf area derived from 9 trials conducted in the UK and New Zealand under optimal, nitrogen limiting and drought conditions. Model performance in predicting these observations was compared in order to evaluate whether individual model variables contributed positively to the overall prediction. Of the 1 1 1 model variables considered 16 were identified as potentially redundant. Areas of the model where there was evidence of redundancy were: (a) translocation of biomass carbon to grain; (b) nitrogen physiology; (c) adjustment of air temperature for various modelled processes; (d) allowance for diurnal variation in temperature; (e) vernalisation (f) soil nitrogen mineralisation (g) soil surface evaporation. It is not suggested that these are not important processes in real crops, rather, that their representation in the model cannot be justified in the context of the analysis. The approach described is analogous to a detailed model inter-comparison although it would be better described as a model intra-comparison as it is based on the comparison of many simplified forms of the same model. The approach provides automation to increase the efficiency of the evaluation and a systematic means of increasing the rigour of the evaluation.

Adapting wheat in Europe for climate change

Increasing cereal yield is needed to meet the projected increased demand for world food supply of about 70% by 2050. Sirius, a process-based model for wheat, was used to estimate yield potential for wheat ideotypes optimized for future climatic projections for ten wheat growing areas of Europe. It was predicted that the detrimental effect of drought stress on yield would be decreased due to enhanced tailoring of phenology to future weather patterns, and due to genetic improvements in the response of photosynthesis and green leaf duration to water shortage. Yield advances could be made through extending maturation and thereby improve resource capture and partitioning. However the model predicted an increase in frequency of heat stress at meiosis and anthesis. Controlled environment experiments quantify the effects of heat and drought at booting and flowering on grain numbers and potential grain size. A current adaptation of wheat to areas of Europe with hotter and drier summers is a quicker maturation which helps to escape from excessive stress, but results in lower yields. To increase yield potential and to respond to climate change, increased tolerance to heat and drought stress should remain priorities for the genetic improvement of wheat.

Measurements and Monte Carlo calculations of photon energy distributions in MAYAK PA workplaces

Photon energy distributions were measured in different workplaces of the Mayak Production Association (MPA), which was the first plutonium production plant in the former Soviet Union. In situ gamma spectrometry measurements were performed with a portable germanium detector. The spectral stripping method is used for the conversion of the in situ gamma-ray spectra to photon fluence rate energy distribution. This method requires the simulation of the portable germanium detector, which has been performed based on the MCNP code of Los Alamos. Measured photon fluence rate energy distributions were compared with calculated photon energy distributions (with the MCNP code) in two different workplaces: in the first workplace the geometry exposure was known. On the contrary, in the second workplace, as in most workplaces of MPA, the exposure geometry was unknown. The results obtained from the comparison between the experimental and calculated photon fluence rate energy distributions are presented and discussed.

LDL-receptor-related proteins in Wnt signal transduction

The Wnt family of secreted signalling molecules are essential in embryo development and tumour formation. The Frizzled (Fz) family of serpentine receptors function as Wnt receptors, but how Fz proteins transduce signalling is not understood. In Drosophila, arrow phenocopies the wingless (DWnt-1) phenotype, and encodes a transmembrane protein that is homologous to two members of the mammalian low-density lipoprotein receptor (LDLR)-related protein (LRP) family, LRP5 and LRP6 (refs 12-15). Here we report that LRP6 functions as a co-receptor for Wnt signal transduction. In Xenopus embryos, LRP6 activated Wnt-Fz signalling, and induced Wnt responsive genes, dorsal axis duplication and neural crest formation. An LRP6 mutant lacking the carboxyl intracellular domain blocked signalling by Wnt or Wnt-Fz, but not by Dishevelled or beta-catenin, and inhibited neural crest development. The extracellular domain of LRP6 bound Wnt-1 and associated with Fz in a Wnt-dependent manner. Our results indicate that LRP6 may be a component of the Wnt receptor complex.

[Evaluation of the health status of 0-to-4-year-old children in an urban community of Abidjan]

During summer 1985 a survey was realized in an administrative territorial division of Abidjan (2 M. residents) in Ivory Coast. Four thousand households were randomly selected (EPI*/WHO model) including 653 children, from 0 to 4 years old. Mothers were interviewed and children examined. Seventeen per cent of children were below the weight curve standardised for Ivory Coast, 8% had a ratio arm diameter on head diameter lower or level of 0.27 and 54% a ratio between 0.28 and 0.31. Diarrhoea was noted among 10% of children, bronchopneumopathy among 44.7%, rhinitis among 53.6% and otitis 15.4%. The interview of mothers confirmed these results; in addition it appeared that 3% of children have had measles in the preceding month. The diarrhoeas and ORL infections prevalence is linked with the lack of drinking water at home, the IRA prevalence with community habitat; ORL infections are more frequent among children from illiterate mothers. The authors think that an amelioration of this situation is possible only by socio-economic progress for families (the work over lunch generalisation would be already an important progress) and putting the specific accent on measles immunization (the incidence rate of measles didn't changed since 1978 in spite of EPI application).

[Setting-up a system of health statistics collection in a rural environment in the Ivory Coast]

In order to improve the sanitary data collection system from the rural Health Centers, Ivory-Coast has modified it in acting upon the three stages of collection. At the level of rural Health Centers, it has been created, from observations and data collected in a sample of 5 centers, a new classification of diseases including 128 items allowing all male and female nurses to classify 94% of the patients examined. At intermediary level, their monthly reports are collected and checked by the chief Medical Practitioner of the Rural Health Sector, who is responsible for all medicine not pertaining to hospital centers. At central level, computerised data treatment and exploitation make possible national data spreading and back-up during the third month after the writing of their report by the nurse.

[Importance, distribution and main causes of accidents in 1980 in two rural health centers in Ivory Coast. Comparative study (author's transl)]

Everywhere, accidents have got some noteworthy consequential effects on socio-economical growth. In many developing countries, with agricultural economic background and still limited in their preventive and educational health action, the damage is able to impair their development, as much as malnutrition, infections and parasitic diseases. Carried out according to a precise methodology within a programme of research entitled: "Recueil de statistiques sanitaires et choix d'indicateurs de santé en Côte-d'Ivoire", this present study shows that most of usual accidents to children are caused by active or passive shocks, and adults injuries are due to handling sharp and penetrating tools. Burns and injuries caused by animals are noticeably numerous. Concerning road accidents, their incidence rate increases rapidly, even in traditional rural areas. The high frequency of such accidents burden seriously the weak credits budgeted to health formations of rural or sub-urban districts in developing countries. This only observation should incite leaders in putting in this nosologic entity among the significant sanitary priorities of their respective countries. This study enlightens the fact that the main problems of public health must benefit from a well defined epidemiological approach, as accidents do, in order to determine the priority rank and to justify the action to be taken. So, the planners would be able to explore ways and means which could solve at minimum cost the given problems. Primary health cases seem to be particularly adapted to this.