Will a rising sea sink some estuarine wetland ecosystems?

Sea-level rise associatedwith climate change presents amajor challenge to plant diversity and ecosystemservice provision in coastal wetlands. In this study,we investigate the effect of sea-level rise on benthos, vegetation, and ecosystem diversity in a tidal wetland in westWales, the UK. Present relationships between plant communities and environmental variableswere investigated through 50 plots atwhich vegetation (species and coverage), hydrological (surface or groundwater depth, conductivity) and soil (matrix chroma, presence or absence ofmottles, organic content, particle size) data were collected. Benthic communities were sampled at intervals along a continuum from saline to freshwater. To ascertain future changes to the wetlands' hydrology, a GIS-based empirical model was developed. Using a LiDAR derived land surface, the relative effect of peat accumulation and rising sea levels were modelled over 200 years to determine how frequently portions of the wetland will be inundated by mean sea level, mean high water spring and mean high water neap conditions. The model takes into account changing extents of peat accumulation as hydrological conditions alter. Model results show that changes to the wetland hydrology will initially be slow. However, changes in frequency and extent of inundation reach a tipping point 125 to 175 years from2010 due to the extremely low slope of the wetland. From then onwards, large portions of the wetland become flooded at every flood tide and saltwater intrusion becomes more common. This will result in a reduction in marsh biodiversity with plant communities switching toward less diverse and occasionally monospecific communities that are more salt tolerant.IS

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Evaluation of Y-12 landfill

The purpose of this project was to provide team members with practical experience in application of Civil Engineering 555, Solid Waste Management principles. Team members chose to evaluate the functional elements of the Oak Ridge Y-12 Plant's (Y-12's) solid waste management system. The following factors contributed to selection of Y-12'system for evaluation: team members' familiarity with the Y-12 system; knowledge that the Y-12 Centralized Sanitary Landfill II was nearing capacity; and presence of the unique issues posed by special national security and potential radioactive contamination considerations. This report was limited to evaluation of the solid waste management system for conventional solid waste; hazardous radioactive, and radioactive mixed waste were not addressed. The report: (1) describes each functional element including waste generation, storage, collection, transport, processing, recovery, and disposal; (2) identifies and evaluates alternatives for each element and (3) identifies system strengths and recommends opportunities for improvement. 34 figs