Electrical Resistivity Imaging of Seawater Intrusion into the Monterey Bay Aquifer System

We use electrical resistivity tomography to obtain a 6.8-km electrical resistivity image to a depth of approximately 150 m.b.s.l. along the coast of Monterey Bay. The resulting image is used to determine the subsurface distribution of saltwater- and freshwater-saturated sediments and the geologic controls on fluid distributions in the region. Data acquisition took place over two field seasons in 2011 and 2012. To maximize our ability to image both vertical and horizontal variations in the subsurface, a combination of dipole-dipole, Wenner, Wenner-gamma, and gradient measurements were made, resulting in a large final dataset of approximately 139,000 data points. The resulting resistivity section extends to a depth of 150 m.b.s.l., and is used, in conjunction with the gamma logs from four coastal monitoring wells to identify four dominant lithologic units. From these data, we are able to infer the existence of a contiguous clay layer in the southern portion of our transect, which prevents downward migration of the saltwater observed in the upper 25 m of the subsurface to the underlying freshwater aquifer. The saltwater and brackish water in the northern portion of the transect introduce the potential for seawater intrusion into the hydraulically connected freshwater aquifer to the south, not just from the ocean, but also laterally from north to south.

Survival in patients with primary liver cancer, gallbladder and extrahepatic biliary tract cancer and pancreatic cancer in Europe 1999-2007: Results of EUROCARE-5

BACKGROUND

The EUROCARE study collects and analyses survival data from population-based cancer registries (CRs) in Europe in order to provide data on between-country differences in survival and time trends in survival.

METHODS

This study analyses data on liver cancer, gallbladder and extrahepatic biliary tract cancers ("biliary tract cancers"), and pancreatic cancer diagnosed in 2000-2007 from 88 CRs in 29 countries. Relative survival (RS) was estimated overall, by region, sex, age and period of diagnosis using the complete approach. Time trends in 5-year RS over 1999-2007 were also analysed using the period approach.

RESULTS

The prognosis of the studied cancers was poor. Age-standardised 5-year RS was 12% for liver cancer, 17% for biliary tract cancers and 7% for pancreatic cancer. There were some between-country differences in survival. In general, RS was low in Eastern Europe and high in Central and Southern Europe. For all sites, 5-year RS was similar in men and women and decreased with advancing age. No substantial changes in survival were reported for pancreatic cancer over the period 1999-2007. On average, there was a crude increase in 5-year RS of 3 percentage points between the periods 1999-2001 and 2005-2007 for liver cancer and biliary tract cancers.

CONCLUSIONS

The major changes in imaging techniques over the study period for the diagnosis of the three studied cancers did not result in an improvement in the prognosis of these cancers. In the near future, new innovative treatments might be the best way to improve the prognosis in these cancers.