Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers

We present a review of the interplay between the evolution of circumstellar disks and the formation of planets, both from the perspective of theoretical models and dedicated observations. Based on this, we identify and discuss fundamental questions concerning the formation and evolution of circumstellar disks and planets which can be addressed in the near future with optical and infrared long-baseline interferometers. Furthermore, the importance of complementary observations with long-baseline (sub)millimeter interferometers and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics Review"; The final publication is available at http://www.springerlink.co

The History, Relevance, and Applications of the Periodic System in Geochemistry

Geochemistry is a discipline in the earth sciences concerned with understanding the chemistry of the Earth and what that chemistry tells us about the processes that control the formation and evolution of Earth materials and the planet itself. The periodic table and the periodic system, as developed by Mendeleev and others in the nineteenth century, are as important in geochemistry as in other areas of chemistry. In fact, systemisation of the myriad of observations that geochemists make is perhaps even more important in this branch of chemistry, given the huge variability in the nature of Earth materials – from the Fe-rich core, through the silicate-dominated mantle and crust, to the volatile-rich ocean and atmosphere. This systemisation started in the eighteenth century, when geochemistry did not yet exist as a separate pursuit in itself. Mineralogy, one of the disciplines that eventually became geochemistry, was central to the discovery of the elements, and nineteenth-century mineralogists played a key role in this endeavour. Early “geochemists” continued this systemisation effort into the twentieth century, particularly highlighted in the career of V.M. Goldschmidt. The focus of the modern discipline of geochemistry has moved well beyond classification, in order to invert the information held in the properties of elements across the periodic table and their distribution across Earth and planetary materials, to learn about the physicochemical processes that shaped the Earth and other planets, on all scales. We illustrate this approach with key examples, those rooted in the patterns inherent in the periodic law as well as those that exploit concepts that only became familiar after Mendeleev, such as stable and radiogenic isotopes

A random phase II study of mitoxantrone and cisplatin in patients with hepatocellular carcinoma: An ECOG study

Of 86 patients entered in an Eastern Cooperative Oncology Group (ECOG) random Phase II study of mitoxantrone (DHAD) and cisplatin (DDP) in primary liver cancer, 69 were eligible. Nine of the 13 ineligible patients were excluded after a pathology review. Sixty‐one percent of the patients were North American, and 39% were South African. The most common severe or the worst toxicity on DHAD was hematologic; and to DDP, hematologic and vomiting. Of the 69 eligible patients, 21 experienced severe, life‐threatening or fatal toxic reactions. Two patients treated with DDP had partial responses. With a 95% confidence interval, the true response rate to DHAD was less than 8%, and to DDP, less than 17%. The median survival time was 14 weeks on both drugs. Assuming a proportional hazards model, factors that are significantly associated with survival are patient performance status, the presence of the symptoms, raised bilirubin and hepatomegaly, and clinical evidence of cirrhosis. Any differences between survival rates for South African and North American patients were largely explainable by these factors. Copyright © 1987 American Cancer Societ