Family communication, genetic testing and colonoscopy screening in hereditary non-polyposis colon cancer: a qualitative study

Objective: Genetic testing and colonoscopy is recommended for people with a strong history of colorectal cancer (CRC). However, families must communicate so that all members are aware of the risk. The study aimed to explore the factors influencing family communication about genetic risk and colonoscopy among people with a strong family history of CRC who attended a genetic clinic with a view to having a genetic test for hereditary non-polyposis colon cancer (HNPCC).

Sensory systems and spatial memory in the fruit bat Rousettus aegyptiacus

The megachiropteran fruit bat Rousettus aegyptiacus is able to orient and navigate using both vision and echolocation. These two sensory systems have different environmental constraints however, echolocation being relatively short range when compared with vision. Despite this difference, an experiment testing their memory of a perch location demonstrates that once the location of a perch is learned R. aegyptiacus is not influenced by the movement of local landmark cues in the vicinity of the perch under either light or dark conditions. Thus despite the differing constraints of vision and echolocation, this suggests a place is remembered as a location in space and not by associations with landmarks in the vicinity. A decrease in initial performance when the task was repeated in the dark suggested the possibility that a memory of a location learned using vision does not generalize to echolocation.

Low flow water quality in rivers; septic tank systems and high-resolution phosphorus signals

Rural point sources of phosphorus (P), including septic tank systems, provide a small part of the overall phosphorus budget to surface waters in agricultural catchments but can have a disproportionate impact on the low flow P concentration of receiving rivers. This has particular importance as the discharges are approximately constant into receiving waters and these have restricted dilution capacity during ecologically sensitive summer periods. In this study, a number of identified high impact septic systems were replaced with modern sequential batch reactors in three rural catchments during a monitoring period of 4 years. Sub-hourly P monitoring was conducted using bankside-analysers. Results show that strategic replacement of defective septic tank systems with modern systems and polishing filters decreased the low flow P concentration of one catchment stream by 0.032 mg TP L- 1 (0.018 mg TRP L- 1) over the 4 years. However two of the catchment mitigation efforts were offset by continued new-builds that increased the density of septic systems from 3.4 km- 2 to 4.6 km- 2 and 13.8 km- 2 to 17.2 km- 2 and subsequently increased low flow P concentrations. Future considerations for septic system mitigation should include catchment carrying capacity as well as technology changes.

Occurrence of chromosome- or plasmid-mediated aerobactin iron transport systems and hemolysin production among clonal groups of human invasive strains of Escherichia coli K1

The incidence of the aerobactin system and the genetic location of aerobactin genes were investigated in Escherichia coli K1 neonatal isolates belonging to different clonal groups. A functional aerobactin system was found in all members of the O7 MP3, O1 MP5, O1 MP9, and O18 MP9 clonal groups examined and also in K1 strains having O6, O16, and O75 lipopolysaccharide types, which are less frequently associated with neonatal infections. In contrast, the aerobactin system was not detected in strains from the O18 MP6 clone. The combined results of plasmid and colony hybridization experiments showed that the aerobactin genes were located on the chromosome in the majority (75%) of the aerobactin-producing K1 isolates, the genetic location of the aerobactin genes was closely correlated with the outer membrane protein profile rather than the O lipopolysaccharide type, the K1 strains harboring a chromosome-mediated aerobactin system did not possess colicin V genes, and five of six K1 isolates possessing a plasmid-borne aerobactin system contained colicin V genes which were located on the same plasmids carrying the aerobactin genes. The comparison of hemolysin production with possession of the aerobactin system in virulent clones of E. coli K1 strains showed that all of the aerobactin-producing strains from the O18 MP9 and O7 MP3 clonal groups did not synthesize hemolysin, whereas 11 of 12 aerobactin-nonproducing O18 MP6 isolates were hemolytic. Of the K1 strains examined, 92.5% possessed either the aerobactin system or the ability to produce hemolysin or both.