The rise and demise of the Glanville fritillary on the Isle of Wight

The Glanville fritillary is one of Britain’s rarest breeding butterflies, and is predominantly restricted to the south coast of the Isle of Wight. Populations have been monitored annually at a high proportion of known sites by counting the number of larval ‘webs’ during spring since 1996. In this paper, we present population time series for eight core sites. Populations have been observed to fluctuate considerably over the last 18 years, with a high degree of synchrony between sites. Recently, numbers of larval webs have shown a severe decline, with simultaneous extinctions occurring across many former strongholds. We combine our web count data with counts of adult butterflies from five sites of the UK Butterfly Monitoring Scheme. Together, these data suggest that the Glanville fritillary is threatened by extinction on the Isle of Wight, and that the total area used for breeding is likely no more than a few km2. The results flag up the need for a national census of remaining populations and further research to understand causes of decline, so that a conservation recovery plan can be developed

Olive oil, diet and colorectal cancer: an ecological study and a hypothesis

STUDY OBJECTIVES—Colorectal cancer (CRC) is a common cancer in many western countries and is probably caused in part by dietary factors. Southern European countries have lower incidence rates of CRC than many other western countries. It was postulated that, because olive oil is thought to influence bile salt secretion patterns in rats, it may influence the occurrence of CRC. The purpose of this study was to compare national levels of dietary factors, with particular reference to olive oil, with national differences in CRC incidence.
DESIGN—Ecological study using existing international databases. Incidence rates for CRC, food supply data, and olive oil consumption data were extracted from published sources, combined, and analysed to calculate the correlations between CRC and 10 dietary factors. Associations were then explored using stepwise multiple regression.
SETTING—28 countries from four continents.
MAIN RESULTS—76% of the intercountry variation in CRC incidence rates was explained by three significant dietary factors—meat, fish and olive oil—in combination. Meat and fish were positively associated, and olive oil was negatively associated, with CRC incidence.
CONCLUSION—Olive oil may have a protective effect on the development of CRC. The proposed hypothesis is that olive oil may influence secondary bile acid patterns in the colon that, in turn, might influence polyamine metabolism in colonic enterocytes in ways that reduce progression from normal mucosa to adenoma and carcinoma.


Keywords: olive oil; colorectal carcinoma; diamine oxidase; die