A guided tour of asynchronous cellular automata

Research on asynchronous cellular automata has received a great amount of attention these last years and has turned to a thriving field. We survey the recent research that has been carried out on this topic and present a wide state of the art where computing and modelling issues are both represented.Comment: To appear in the Journal of Cellular Automat

Siglec-F is a novel intestinal M cell marker

Intestinal microfold (M) cells are epithelial cells primarily present on Peyer's patches (PPs) in the small intestine. The ability of M cells to shuttle antigens into the PP for appropriate immune responses makes M cells a target for next-generation oral vaccine delivery. In this regard, discovery of M cell specific receptors are of great interest, which could act as molecular tags for targeted delivery of cargo to M cells. Here, using a monoclonal antibody we generated to the Sialic acid-binding immunoglobulin-like lectin F (Siglec-F), we show that Siglec-F is expressed on mouse M cells in the small intestine. Immunohistochemical analysis of the PP tissue sections shows that Siglec-F is expressed on the surface of the M cell membrane exposed to the intestinal lumen. Anti-Siglec-F antibody injected into the mouse small intestine bound to M-cells, demonstrating the potential to target M cells via Siglec-F

Siglec-7 Mediates Immunomodulation by Colorectal Cancer-Associated Fusobacterium nucleatum ssp. animalis

Fusobacterium nucleatum is involved in the development of colorectal cancer (CRC) through innate immune cell modulation. However, the receptors of the interaction between F. nucleatum ssp. and immune cells remain largely undetermined. Here, we showed that F. nucleatum ssp. animalis interacts with Siglecs (sialic acid–binding immunoglobulin-like lectins) expressed on innate immune cells with highest binding to Siglec-7. Binding to Siglec-7 was also observed using F. nucleatum-derived outer membrane vesicles (OMVs) and lipopolysaccharide (LPS). F. nucleatum and its derived OMVs or LPS induced a pro-inflammatory profile in human monocyte-derived dendritic cells (moDCs) and a tumour associated profile in human monocyte-derived macrophages (moMϕs). Siglec-7 silencing in moDCs or CRISPR-cas9 Siglec-7-depletion of U-937 macrophage cells altered F. nucleatum induced cytokine but not marker expression. The molecular interaction between Siglec-7 and the LPS O-antigen purified from F. nucleatum ssp. animalis was further characterised by saturation transfer difference (STD) NMR spectroscopy, revealing novel ligands for Siglec-7. Together, these data support a new role for Siglec-7 in mediating immune modulation by F. nucleatum strains and their OMVs through recognition of LPS on the bacterial cell surface. This opens a new dimension in our understanding of how F. nucleatum promotes CRC progression through the generation of a pro-inflammatory environment and provides a molecular lead for the development of novel cancer therapeutic approaches targeting F. nucleatum-Siglec-7 interaction

Overview

The part of Africa designated as West Africa is made up of 16 countries— Benin, Burkina Faso, Cape Verde, Côte d’Ivoire, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo. Its land area is about 5 million square kilometers, and its population in 2010 was about 290 million. With the exception of Mauritania, these countries are members of the Economic Community of West African States (ECOWAS). The subregion comprises a diversified agricultural base spread over a wide range of agroecological zones with significant potential for improved agricultural productivity. Agriculture is the major source of livelihood for the majority of West Africans. The agricultural sector employs 60 percent of the active labor force but contributes only 35 percent of gross domestic product (GDP). The disparity between contribution to GDP and share of population means that many West African farmers are very poor, producing close to subsistence levels and facing numerous constraints such as droughts, soil acidity, and nutrientdepleted and degraded soils that impinge on agricultural development. The most important foodcrops grown and consumed in West Africa are cereals— sorghum, millet, maize, and rice; roots and tubers—cassava, sweet potatoes, and yams; and legumes—cowpeas and groundnuts. Major cash crops are cocoa, coffee, and cotton..

Summary and conclusions

Climate variability is a reality that is affecting rural livelihoods in West Africa today and presenting a growing challenge in the region, as in many other parts of the African continent and elsewhere. Climate change will have far-reaching consequences for the poor and marginalized groups among which the majority depend on agriculture for their livelihoods and have a lower capacity to adapt. Weather-related crop failures, fishery collapses, and livestock deaths in addition to losses of property are already causing economic losses and undermining food security in West Africa. This situation is likely to become more desperate and to threaten the survival of the majority of poor farmers as global warming continues. Feeding the increasing populations in a subregion with one of the highest rates of population growth in the world requires radical transformation of a largely underdeveloped agriculture over the next four decades. A major challenge is increasing agricultural production among resource-poor farmers without exacerbating environmental problems and simultaneously coping with climate change..