Dextran Sodium Sulfate (DSS) Induces Colitis in Mice by Forming Nano-Lipocomplexes with Medium-Chain-Length Fatty Acids in the Colon

Inflammatory bowel diseases (IBDs), primarily ulcerative colitis and Crohn's disease, are inflammatory disorders caused by multiple factors. Research on IBD has often used the dextran sodium sulfate (DSS)-induced colitis mouse model. DSS induces in vivo but not in vitro intestinal inflammation. In addition, no DSS-associated molecule (free glucose, sodium sulfate solution, free dextran) induces in vitro or in vivo intestinal inflammation. We find that DSS but not dextran associated molecules established linkages with medium-chain-length fatty acids (MCFAs), such as dodecanoate, that are present in the colonic lumen. DSS complexed to MCFAs forms nanometer-sized vesicles ∼200 nm in diameter that can fuse with colonocyte membranes. The arrival of nanometer-sized DSS/MCFA vesicles in the cytoplasm may activate intestinal inflammatory signaling pathways. We also show that the inflammatory activity of DSS is mediated by the dextran moieties. The deleterious effect of DSS is localized principally in the distal colon, therefore it will be important to chemically modify DSS to develop materials beneficial to the colon without affecting colon-targeting specificity

Fort Fordyce : the Eastern Cape's hidden gem

As part of plant taxonomy training, second-year Botany students at Rhodes University are sent on a weekend field trip to learn plant collection and identification. In 2015, the second-years visited Fort Fordyce Nature Reserve (NR) near the towns of Fort Beaufort and Adelaide in the Eastern Cape.http://www.botanicalsociety.org.za/Plant Scienc

Vortices in Saturn's Northern Hemisphere (2008-2015) observed by Cassini ISS

We use observations from the Imaging Science Subsystem on Cassini to create maps of Saturn's Northern Hemisphere (NH) from 2008 to 2015, a time period including a seasonal transition (i.e., spring equinox in 2009) and the 2010 giant storm. The processed maps are used to investigate vortices in the NH during the period of 2008–2015. All recorded vortices have diameters (east‐west) smaller than 6000 km except for the largest vortex that developed from the 2010 giant storm. The largest vortex decreased its diameter from ~11,000 km in 2011 to ~5000 km in 2015, and its average diameter is ~6500 km during the period of 2011–2015. The largest vortex lasts at least 4 years, which is much longer than the lifetimes of most vortices (less than 1 year). The largest vortex drifts to north, which can be explained by the beta drift effect. The number of vortices displays varying behaviors in the meridional direction, in which the 2010 giant storm significantly affects the generation and development of vortices in the middle latitudes (25–45°N). In the higher latitudes (45–90°N), the number of vortices also displays strong temporal variations. The solar flux and the internal heat do not directly contribute to the vortex activities, leaving the temporal variations of vortices in the higher latitudes (45–90°N) unexplained

Vortices in Saturn's Northern Hemisphere (2008-2015) observed by Cassini ISS

We use observations from the Imaging Science Subsystem on Cassini to create maps of Saturn's Northern Hemisphere (NH) from 2008 to 2015, a time period including a seasonal transition (i.e., spring equinox in 2009) and the 2010 giant storm. The processed maps are used to investigate vortices in the NH during the period of 2008–2015. All recorded vortices have diameters (east‐west) smaller than 6000 km except for the largest vortex that developed from the 2010 giant storm. The largest vortex decreased its diameter from ~11,000 km in 2011 to ~5000 km in 2015, and its average diameter is ~6500 km during the period of 2011–2015. The largest vortex lasts at least 4 years, which is much longer than the lifetimes of most vortices (less than 1 year). The largest vortex drifts to north, which can be explained by the beta drift effect. The number of vortices displays varying behaviors in the meridional direction, in which the 2010 giant storm significantly affects the generation and development of vortices in the middle latitudes (25–45°N). In the higher latitudes (45–90°N), the number of vortices also displays strong temporal variations. The solar flux and the internal heat do not directly contribute to the vortex activities, leaving the temporal variations of vortices in the higher latitudes (45–90°N) unexplained

Discovery of common and rare genetic risk variants for colorectal cancer.

To further dissect the genetic architecture of colorectal cancer (CRC), we performed whole-genome sequencing of 1,439 cases and 720 controls, imputed discovered sequence variants and Haplotype Reference Consortium panel variants into genome-wide association study data, and tested for association in 34,869 cases and 29,051 controls. Findings were followed up in an additional 23,262 cases and 38,296 controls. We discovered a strongly protective 0.3% frequency variant signal at CHD1. In a combined meta-analysis of 125,478 individuals, we identified 40 new independent signals at P < 5 × 10-8, bringing the number of known independent signals for CRC to ~100. New signals implicate lower-frequency variants, Krüppel-like factors, Hedgehog signaling, Hippo-YAP signaling, long noncoding RNAs and somatic drivers, and support a role for immune function. Heritability analyses suggest that CRC risk is highly polygenic, and larger, more comprehensive studies enabling rare variant analysis will improve understanding of biology underlying this risk and influence personalized screening strategies and drug development.Goncalo R Abecasis has received compensation from 23andMe and Helix. He is currently an employee of Regeneron Pharmaceuticals. Heather Hampel performs collaborative research with Ambry Genetics, InVitae Genetics, and Myriad Genetic Laboratories, Inc., is on the scientific advisory board for InVitae Genetics and Genome Medical, and has stock in Genome Medical. Rachel Pearlman has participated in collaborative funded research with Myriad Genetics Laboratories and Invitae Genetics but has no financial competitive interest

REDUCING FOOD SPOILAGE AND WASTE THROUGH EVIDENCE-BASED STRATEGIES FROM PRODUCTION TO CONSUMPTION

275 pagesMicrobial spoilage is challenge for a range of food industries and is also a major contributor to global food waste. In order to prevent and reduce microbial food spoilage, evidence-based strategies must be implemented throughout supply chains. To this end, the studies presented here contribute to (i) methods for monitoring spoilage microorganisms, (ii) improved understanding of sources and mechanisms of transmission of microorganisms into food, and (iii) potential strategies to implement at the various points in food supply chains aimed at preventing and reducing microbial spoilage. While microbial spoilage originating from sources throughout the food chain is an issue for many sectors, the studies presented here focus specifically on dairy and fresh produce. In the area of dairy quality, we provided insights into spore enumeration methods for milk powders and identified a set of methods that captures a wide range of variation in spore count across powders. We also contributed to understanding of routes of transmission of spoilage microorganisms into raw milk; specifically, we found bedding material had a direct influence on levels of spores in unused and used bedding, as well as an indirect association with spore levels in bulk tank raw milk through used bedding spore levels. Furthermore, we identified strategies at farm and processing levels for reducing microbial spoilage of dairy products. At the farm-level, we identified specific bedding and farm management practices associated with spores in bedding and bulk tank raw milk. At the processing-level, we identified important quality management practices associated with fluid milk spoilage due to post-pasteurization contamination, including cleaning and sanitation, employee training, and quality testing programs. Preventing microbial spoilage is also challenge for the fresh produce industry, yet relative to dairy, research in the area of microbial spoilage of fresh produce has been limited. Our foundational study of bacterial dynamics on spinach for a supply chain located in Northeast China, from point-of-harvest through shelf life, improved understanding of factors associated with spinach spoilage. Overall, these studies expand our understanding of microbial spoilage of dairy foods and fresh produce and will facilitate implementation evidence-based strategies for preventing and reducing microbial spoilage