Climate change and national crop wild relative conservation planning

Climate change is likely to be one of the most important factors affecting our future food security. To mitigate negative impacts, we will require our crops to be more genetically diverse. Such diversity is available in crop wild relatives (CWRs), the wild taxa relatively closely related to crops and from which diverse traits can be transferred to the crop. Conservation of such genetic resources resides within the nation where they are found; therefore, national-level conservation recommendations are fundamental to global food security. We investigate the potential impact of climate change on CWR richness in Norway. The consequences of a 1.5 and 3.0 °C temperature rise were studied for the years 2030, 2050, 2070, 2080 and then compared to the present climate. The results indicate a pattern of shifting CWR richness from the south to the north, with increases in taxa turnover and in the numbers of threatened taxa. Recommendations for in situ and ex situ conservation actions over the short and long term for the priority CWRs in Norway are presented. The methods and recommendations developed here can be applied within other nations and at regional and global levels to improve the effectiveness of conservation actions and help ensure global food security.     

Environmental change in the Sahel: reconciling contrasting evidence and interpretations

The Sahel has been the object of intensive international research since the drought of the early 1970s. A considerable part of the research has focused on environmental change in general and land degradation, land cover change and climate change in particular. Rich and diverse insights from many different scientific disciplines about these three domains have been put forward. One intriguing feature is that an agreement on the overall trends of environmental change does not appear to emerge: questions such as whether the Sahel is greening, cropland is encroaching on rangelands, drought persists remain contested in the scientific literature, and arguments are supported by contrasting empirical evidence. The paper explores the generic reasons behind this situation in a systematic manner. We distinguish between divergences in interpretations emerging from (1) conceptualizations, definitions and choice of indicators, (2) biases, for example, related to selection of study sites, methodological choices, measurement accuracy, perceptions among interlocutors, and selection of temporal and spatial scales of analysis. The analysis of the root causes for different interpretations suggests that differences in findings could often be considered as complementary insights rather than mutually exclusive. This will have implications for the ways in which scientific results can be expected to support regional environmental policies and contribute to knowledge production.     

Echoes from the Past: A Healthy Baltic Sea Requires More Effort

Integrated sediment multiproxy studies and modeling were used to reconstruct past changes in the Baltic Sea ecosystem. Results of natural changes over the past 6000 years in the Baltic Sea ecosystem suggest that forecasted climate warming might enhance environmental problems of the Baltic Sea. Integrated modeling and sediment proxy studies reveal increased sea surface temperatures and expanded seafloor anoxia (in deep basins) during earlier natural warm climate phases, such as the Medieval Climate Anomaly. Under future IPCC scenarios of global warming, there is likely no improvement of bottom water conditions in the Baltic Sea. Thus, the measures already designed to produce a healthier Baltic Sea are insufficient in the long term. The interactions between climate change and anthropogenic impacts on the Baltic Sea should be considered in management, implementation of policy strategies in the Baltic Sea environmental issues, and adaptation to future climate change.     

Amniotic fluid acetylcholinesterase in the prenatal diagnosis of open neural tube defects and abdominal wall defects: A comparison of gel electrophoresis and a monoclonal antibody immunoassay

Stored amniotic fluid samples collected in Oxford and East Birmingham as part of the Collaborative Acetylcholinesterase Study were assayed for the presence of acetylcholinesterase (AChE) using a monoclonal antibody (4F19) enzyme antigen immunoassay. These results were compared with the results of a gel AChE which had been performed earlier. A total of 5689 samples from singleton pregnancies were analysed (including 36 with anencephaly, 77 with open spina bifida and 17 with anterior abdominal wall defects). The gel test yielded detection rates of 97% for anencephaly, 99% for open spina bifida and 94% for abdominal wall defects; the false positive rate (excluding pregnancies associated with serious abnormalities, miscarriages and intrauterine deaths) was 0·24%. The monoclonal test yielded similar results; using appropriate cut-off values to allow for differences in acetylcholinesterase levels in blood stained and clear samples, a similar false-positive rate of 0·22% was associated with detection rates of 97%, 95 % and 71 % respectively for the three types of defect. Although the detection rates and the false positive rate were slightly higher for the gel test, a result that might be explained by a decrease in AChE activity caused by storage of the samples, the monoclonal test has the advantages of requiring less interpretative expertise, it can be performed on a larger number of samples a day and it is not affected by contamination with fetal calf serum.     

Occurrence,prevalence and seasonality of neoplasia in the marine mussel Mytilus edulis from three sites in Denmark

The occurrence, prevalence, seasonality and possible etiology of a neoplastic disorder in natural populations of the mussel Mytilus edulis from three sites in Denmark were studied, comprising monthly sampling of 300 mussels per sample from each site during one year (October 1983 to September 1984). Neoplasia occurred at all three sites. Statistical analysis indicated that there were significant differences in the monthly prevalences of the disorder between the three sites and within each site. At two sites the prevalences were found to be seasonally related. Cytologically, the neoplasia exhibited malignant characteristics. Electron microscopy showed that the neoplastic cells were extremely pleomorphic, with large irregular nuclei. Large (approximately 200 nm diam) virus-like particles were associated with the nuclei.     

Alpha-fetoprotein and acetylcholinesterase activity in first-and early second-trimester amniotic fluid

Normal ranges of amniotic fluid alpha-fetoprotein (AFP) and acetylcholinesterase activity (AChE) are described for gestational weeks 11–14 using rocket gel immunoelectrophoresis for AFP quantitation and a monoclonal antibody (4F19) enzyme antigen immunoassay for AChE activity measurement. The normal ranges were established by the examination of 281 amniotic fluid samples from 281 normal pregnancies. AFP was found to increase from a median level of 14.0 MIU/1 at 11 weeks to a maximum at 13 weeks (median=18.0 MIU/l) (P<0.05), thereafter falling (not significant). No AChE test result exceeded 4.8 nkat/l. In addition, AFP and AChE values for three cases of fetal malformation, identified by the biochemical analyses of amniotic fluid, are given. These cases included two fetuses with a neural tube defect and one fetus with an abdominal wall defect. Amniocentesis was performed at 10, 11, and 14 weeks, respectively. The AFP and AChE values were all high.     

Early prenatal diagnosis of the fragile site AT Xq27.3 associated with Martin-Bell syndrome

Early prenatal diagnosis of the fragile X was attempted in 44 pregnancies, including one twin pregnancy at risk of Martin-Bell (MB) syndrome. The sex ratio was 24M:21F. The fragile site was reproducibly demonstrated in cultured chorionic villus (CV) cells in eight male and five female fetuses. Six of the male and three of the female fetuses were terminated. Simultaneous RFLP analysis provided confirmative data with flanking DNA markers in 3 of 13 analysed cases. Recombination and/or non-informativeness at available distal and/or proximal loci were found in nine cases. In one male fetus, discordance between the haplotype and cyto-genetics (fragile-X-negative) suggested the presence of a normal male transmitter, a double meiotic cross-over within the region, or a false-negative cytogenetic diagnosis. However, discordance between prenatal and post-termination/postnatal cytogenetic findings was not observed in this series. The use of excess thymidine for induction of the fragile X in cultured CV cells provided in the majority of cases a safe and rapid method for cytogenetic diagnosis, with options for early induced termination in fragile-X-positive pregnancies, for simultaneous RFLP analysis, and for subsequent second-trimester analysis of fetal blood in complicated cases.     

Atmospheric methylchloride (CH3Cl)

A global time series of atmospheric methylchloride (CH₃Cl) concentrations is reported showing the variability with latitude and season. Springtime concentrations of CH₃Cl at 45°N latitude are 7.5%±3.5% higher than during other seasons. Lowest concentrations were generally observed during fall. CH₃Cl was found to be more abundant by about 6% (±5% NH, ±3% SH) in the tropical regions of both hemispheres. No significant difference in the burdens of CH₃Cl was observed between the two hemispheres. Based on these data the ratio of the average hydroxyl radical (HO) concentration over the southern hemisphere to that over the northern hemisphere was estimated to be 1.3 or less.