Enterotoxigenic Escherichia coli and Vibrio cholerae Diarrhea, Bangladesh, 2004

Flooding in Dhaka in July 2004 caused epidemics of diarrhea. Enterotoxigenic Escherichia coli (ETEC) was almost as prevalent as Vibrio cholerae O1 in diarrheal stools. ETEC that produced heat-stable enterotoxin alone was most prevalent, and 78% of strains had colonization factors. Like V. cholerae O1, ETEC can cause epidemic diarrhea

Flexible modelling of spatial variation in agricultural field trials with the R package INLA

The objective of this paper was to fit different established spatial models for analysing agricultural field trials using the open-source R package INLA. Spatial variation is common in field trials, and accounting for it increases the accuracy of estimated genetic effects. However, this is still hindered by the lack of available software implementations. We compare some established spatial models and show possibilities for flexible modelling with respect to field trial design and joint modelling over multiple years and locations. We use a Bayesian framework and for statistical inference the integrated nested Laplace approximations (INLA) implemented in the R package INLA. The spatial models we use are the well-known independent row and column effects, separable first-order autoregressive ( AR1⊗AR1 ) models and a Gaussian random field (Matérn) model that is approximated via the stochastic partial differential equation approach. The Matérn model can accommodate flexible field trial designs and yields interpretable parameters. We test the models in a simulation study imitating a wheat breeding programme with different levels of spatial variation, with and without genome-wide markers and with combining data over two locations, modelling spatial and genetic effects jointly. The results show comparable predictive performance for both the AR1⊗AR1 and the Matérn models. We also present an example of fitting the models to a real wheat breeding data and simulated tree breeding data with the Nelder wheel design to show the flexibility of the Matérn model and the R package INLA

Actions of Calcium on Smooth Muscle a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72185/1/j.1749-6632.1988.tb33358.x.pd

Twenty-three unsolved problems in hydrology (UPH) – a community perspective

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focussed on process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come

Comparative Proteomics of Enterotoxigenic <i>Escherichia coli</i> Reveals Differences in Surface Protein Production and Similarities in Metabolism

Enterotoxigenic <i>Escherichia coli</i> (ETEC) infections are an important cause of diarrhea among young children living in low- and middle-income countries and visiting travelers. The development of effective vaccines is complicated by substantial genomic diversity that exists among ETEC isolates. To investigate how ETEC genomic variation is reflected at expressed proteome level, we applied label-free quantitative proteomics to seven human ETEC strains representing five epidemiologically important lineages. We further determined the proteome profile of the nonpathogenic <i>E. coli</i> B strain BL21­(DE3) to discriminate features specific for ETEC. The analysis yielded a data set of 2893 proteins, of which 1729 were present in all strains. Each ETEC strain produced on average 27 plasmid- or chromosomally-encoded proteins with known or putative connections to virulence, and a number of strain-specific proteins associated with the biosynthesis of surface antigens. Statistical comparison of protein levels between the ETEC strains and BL21­(DE3) revealed several proteins with considerably increased levels only in BL21­(DE3) including enzymes of arginine biosynthesis and metabolism of melibiose, galactitol, and gluconate. ETEC strains displayed consistently increased levels of proteins that were functional in iron acquisition, maltose metabolism, and acid resistance. The latter results suggest that specific metabolic functions might be shared among ETEC isolates

Comparative Proteomics of Enterotoxigenic <i>Escherichia coli</i> Reveals Differences in Surface Protein Production and Similarities in Metabolism

Enterotoxigenic <i>Escherichia coli</i> (ETEC) infections are an important cause of diarrhea among young children living in low- and middle-income countries and visiting travelers. The development of effective vaccines is complicated by substantial genomic diversity that exists among ETEC isolates. To investigate how ETEC genomic variation is reflected at expressed proteome level, we applied label-free quantitative proteomics to seven human ETEC strains representing five epidemiologically important lineages. We further determined the proteome profile of the nonpathogenic <i>E. coli</i> B strain BL21­(DE3) to discriminate features specific for ETEC. The analysis yielded a data set of 2893 proteins, of which 1729 were present in all strains. Each ETEC strain produced on average 27 plasmid- or chromosomally-encoded proteins with known or putative connections to virulence, and a number of strain-specific proteins associated with the biosynthesis of surface antigens. Statistical comparison of protein levels between the ETEC strains and BL21­(DE3) revealed several proteins with considerably increased levels only in BL21­(DE3) including enzymes of arginine biosynthesis and metabolism of melibiose, galactitol, and gluconate. ETEC strains displayed consistently increased levels of proteins that were functional in iron acquisition, maltose metabolism, and acid resistance. The latter results suggest that specific metabolic functions might be shared among ETEC isolates

Seismic Characteristics of Large-Scale Sandstone Intrusions in the Paleogene of the South Viking Graben, UK and Norwegian North Sea

Post-depositional remobilization and injection of sand can significantly change the geometry of deepwater clastic reservoirs. Features associated with these processes are particularly well developed in the lower Paleogene of the South Viking Graben of the UK and Norwegian North Sea. Seismic scale sandstone intrusions can be grouped in two classes. Class 1 comprises low-angle (20-40 degrees) tabular sandstone intrusions emanating from steep-sided in situ sand bodies within the Balder Formation. The intrusions may be 5-30+m thick and crosscut 120-250+m of compacted stratigraphic section. They terminate at an unconformity at the top of the Frigg interval where they may have extruded onto the palaeo-seafloor. Class 2 comprises conical sandstone intrusions that emanate some 50-300+m upward from distinct apexes located 400-700+m above the nearest depositional sand body. The conical intrusions may have been sourced from underlying sand bodies by clastic blow out pipes. Both types of intrusions seem to adopt their particular geometry independently of (but occasionally exploiting) polygonal faults within the encasing mudstones. Sandstone intrusions may be highly porous and permeable and are thus important both as reservoirs and as plumbing within thick mudstone sequences.</p

Sandstone intrusions:Detection and significance for exploration and production

Early recognition of sandstone intrusions is a key factor in maximising exploration and production success of the Paleogene deepwater sandstone reservoirs of the northern North Sea. Discordant sandstone intrusions are readily detected in cores, image logs and high quality seismic data by cross-cutting relations with the encasing shales. Many examples of 'ratty' sands seen in borehole logs and 'artefacts' or 'channel margins' seen in seismic data have later proven to be sandstone intrusions, with significant implications for exploration and production. The effects of sand remobilisation and injection include increased connectivity between reservoir compartments, thief sands caused by brecciation and injection into the seal, and large-scale modifications of reservoir geometry, in particular top reservoir. Detailed case studies from the North Sea Paleogene and pilot studies including various other deepwater clastic successions indicate that sandstone intrusions could prove to be an important factor in the development of some highly prolific deepwater provinces such as the West African Atlantic margin. Early recognition of sandstone intrusions in such areas is important for optimal development planning. It requires that the appropriate borehole and seismic data are acquired, and that sandstone intrusions are incorporated in the interpreter's mindset.</p