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Food trade connects distant places of food production to places of consumption. Through traded food, associated environmental impacts are also displaced as the consumer benefits from the product without incurring the externalities of production. Taking U.S. rice as an example, we discuss the sustainability implications of rewiring U.S. rice production and trade for reducing the impacts of irrigation (water and energy) and transportation greenhouse gas (GHG) emissions. We model a series of robust optimization scenarios that re-arrange the origin of trade and therefore the production to target virtual water use and GHG emission reductions. For the baseline case, virtual water trade amounts to 35 billion m3, and embodied irrigation and transportation GHG emissions amount to 6 billion kg CO2-equivalent and 0.7 billion kg CO2-equivalent, respectively. Rewiring consistently achieves better results compared to the baseline even in the presence of uncertainty. However, our findings reveal strikingly sobering national-level savings in optimizing the water use (2%) and GHG emissions (14%) with tradeoffs in other impacts. To achieve these results, all rice-producing states undergo changes, with the state of Mississippi completely stopping production. California’s unique ability to produce medium-grain rice at a large scale makes it indispensable for current rice production and hence a major constraint for rewiring rice production. The findings of this work reveal the inflexibility of our food system in balancing the food–energy–water nexus tradeoffs through restructuring trade.

Gram-positive streptococci are non-motile, chain-forming bacteria commonly found in the normal oral and bowel flora of warm-blooded animals. Over the past decade, a proteomic approach combining 2-DE and MS has been used to systematically map the cellular, surface-associated and secreted proteins of human pathogenic streptococcal species. The public availability of complete streptococcal genomic sequences and the amalgamation of proteomic, genomic and bioinformatic technologies have recently facilitated the identification of novel streptococcal vaccine candidate antigens and therapeutic agents. The objective of this review is to examine the constituents of the streptococcal cell wall and secreted proteome, the mechanisms of transport of surface and secreted proteins, and describe the current methodologies employed for the identification of novel surface-displayed proteins and potential vaccine antigens.

Serum opacity factor (SOF) is a unique multifunctional virulence determinant expressed at the surface of Streptococcus pyogenes and has been shown to elicit protective immunity against GAS infection in a murine challenge model. SOF consists of two distinct domains with different binding capacities: an N-terminal domain that binds apolipoprotein AI and a C-terminal repeat domain that binds fibronectin and fibrinogen. The capacity of SOF to opacify serum by disrupting the structure of high density lipoproteins may preclude its use as a vaccine antigen in humans. This study generated mutant forms of recombinant SOF with reduced (100-fold) or abrogated opacity factor (OF) activity, for use as vaccine antigens. However, alterations introduced into the N-terminal SOF peptide (SOFFn) by mutagenesis to abrogate OF activity, abolish the capacity of SOF to protect against lethal systemic S. pyogenes challenge in a murine model. Mutant forms of purified SOFFn peptide were also used to assess the contribution of OF activity to the pathogenic processes of cell adhesion and cell invasion. Using latex beads coated with full-length SOF, SOFFn peptide, or a peptide encompassing the C-terminal repeats (FnBD), we demonstrate that adhesion to HEp-2 cells is mediated by both SOFFn and FnBD. The HEp-2 cell binding displayed by the N-terminal SOFFn peptide is independent of OF activity. We demonstrate that while the N terminus of SOF does not directly mediate intracellular uptake by epithelial cells, this domain enhances epithelial cell uptake mediated by full-length SOF, in comparison to the FnBD alone.

Serum opacity factor (SOF) is a bifunctional cell surface protein expressed by 40-50% of group A streptococcal (GAS) strains comprised of a C-terminal domain that binds fibronectin and an N-terminal domain that mediates opacification of mammalian sera. The sof gene was recently discovered to be co-transcribed in a two-gene operon with a gene encoding another fibronectin-binding protein, sfbX. We compared the ability of a SOF(+) wild-type (WT) serotype M49 GAS strain and isogenic mutants lacking SOF or SfbX to invade cultured HEp-2 human pharyngeal epithelial cells. Elimination of SOF led to a significant decrease in HEp-2 intracellular invasion while loss of SfbX had minimal effect. The hypoinvasive phenotype of the SOF(-) mutant could be restored upon complementation with the sof gene on a plasmid vector, and heterologous expression of sof49 in M1 GAS or Lactococcus lactis conferred marked increases in HEp-2 cell invasion. Studies using a mutant sof49 gene lacking the fibronectinbinding domain indicated that the N-terminal opacification domain of SOF contributes to HEp-2 invasion independent of the C-terminal fibronectin binding domain, findings corroborated by observations that a purified SOF N-terminal peptide could promote latex bead adherence to HEp- 2 cells and inhibit GAS invasion of HEp-2 cells in a dose-dependent manner. Finally, the first in vivo studies to employ a single gene allelic replacement mutant of SOF demonstrate that this protein contributes to GAS virulence in a murine model of necrotizing skin infection.

Streptococcus pyogenes (Group A streptococcus) interacts with host fibronectin via a number of distinct surface components. The streptococcal serum opacity factor (SOF) is a cell-surface protein of S. pyogenes which causes opalescence of human serum and mediates bacterial binding to fibronectin. In this study, hexahistidyl-tagged fusion proteins encompassing full-length SOF, and domains of SOF encompassing opacity factor activity and fibronectin-binding regions, were used in the characterization of the Aboriginal immune response to SOF. Anti-SOF serum IgG responses were found to be significantly higher (P>0.0001) in Aboriginal adults and children when compared to a non-Aboriginal adult group. The Aboriginal immune response against the fibronectin-binding region of SOF was significantly reduced when compared to the response against the whole SOF protein and N-terminal domains examined in this study (P>0.001). This pattern of immune response was also observed in rabbits immunized with recombinant SOF. Comparison of the deduced amino acid sequence of SOF from a number of common Australian isolates with other SOF sequences revealed that the N-terminus of SOF exhibits sequence similarity values ranging from 42.9% to 96.5%. The C-terminus containing the fibronectin-binding domain and membrane-spanning regions was more highly conserved, exhibiting sequence similarity values ranging from 84.6% to 100% within the fibronectin-binding repeats. These data suggest that the immune response against SOF is directed toward the variable N-terminus of the SOF protein. Phylogenetic analysis indicated that the sof genes of S. pyogenes do not exhibit geographical variation.

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The book is in three parts, parts 1 and 2 providing regional descriptions of the deposits of the two cratons and part 3 discussing the distribution of the deposits in space and time. For some regions, such as the Anabar shield, a complete description of deposits was precluded by lack of knowledge and only the general features of ore genesis in certain blocks and zones are presented. There are deposit and subject indexes and a list of 483 references. Individual chapters discuss the Kola terrain, Karelia terrain, Belomorian belt, Ladoga belt, Ukrainian shield, Voronezh crystalline massif, platform cover of the East European craton, major features of the geological structure and metallogeny of the Anabar shield, the Aldan terrain, Olyokma terrain, Batomga terrain, Dzhugdzhur-Stanovoy terrain, Pre-Sayan inlier, Angara-Kan inlier, Khamar-Daban and Pre-Olkhon inliers of SW Pre-Baikal, Yenisey fold belt, Baikal-Patom fold belt, tectonic evolution and metallogeny of the platform cover of the Siberian craton, evolutionary patterns of mineral deposits in Precambrian terrains, and the classification of Precambrian mineral deposit types., The book is in three parts, parts 1 and 2 providing regional descriptions of the deposits of the two cratons and part 3 discussing the distribution of the deposits in space and time. For some regions, such as the Anabar shield, a complete description of deposits was precluded by lack of knowledge and only the general features of ore genesis in certain blocks and zones are presented. There are deposit and subject indexes and a list of 483 references. Individual chapters discuss the Kola terrain, Karelia terrain, Belomorian belt, Ladoga belt, Ukrainian shield, Voronezh crystalline massif, platform cover of the East European craton, major features of the geological structure and metallogeny of the Anabar shield, the Aldan terrain, Olyokma terrain, Batomga terrain, Dzhugdzhur-Stanovoy terrain, Pre-Sayan inlier, Angara-Kan inlier, Khamar-Daban and Pre-Olkhon inliers of SW Pre-Baikal, Yenisey fold belt, Baikal-Patom fold belt, tectonic evolution and metallogeny of the platform cover of the Siberian craton, evolutionary patterns of mineral deposits in Precambrian terrains, and the classification of Precambrian mineral deposit types.