Constructions and classifications of projective Poisson varieties.

This paper is intended both as an introduction to the algebraic geometry of holomorphic Poisson brackets, and as a survey of results on the classification of projective Poisson manifolds that have been obtained in the past 20 years. It is based on the lecture series delivered by the author at the Poisson 2016 Summer School in Geneva. The paper begins with a detailed treatment of Poisson surfaces, including adjunction, ruled surfaces and blowups, and leading to a statement of the full birational classification.

Cost-effectiveness of cimetidine maintenance therapy in chronic gastric and duodenal ulcer.

The effects of cimetidine maintenance therapy on the socioeconomic life of patients with peptic ulcers in the 3 years after healing and the extent to which treatment was cost-effective were studied. Three hundred eleven patients with healed ulcers (184 gastric, 127 duodenal) were studied for periods of up to 3 years; 261 patients (152 gastric ulcer, 109 duodenal ulcer) completed the 3-year follow-up. Cimetidine (400 mg at night) was compared with placebo in a double-blind, randomized prospective study.

Comparison of human ZFY and ZFX transcripts.

ZFY is a candidate for the primary sex-determining gene (TDF, testis-determining factor) on the human Y chromosome. We have isolated cDNA clones of ZFY and its homologue on the X chromosome, ZFX. The transcripts of these genes are very similar to each other and encode predicted proteins of equal size.

The MIC2 gene product: epitope mapping and structural prediction analysis define an integral membrane protein.

The MIC2 locus is located in the pseudoautosomal (pairing) region of human X and Y chromosomes (Goodfellow et al., Science 234, 740-743, 1986). Despite extensive molecular analysis of MIC2 (see Darling et al.

The pseudoautosomal boundary in man is defined by an Alu repeat sequence inserted on the Y chromosome.

The Y chromosome, which in man determines the male sex, is composed of two functionally distinct regions. The pseudoautosomal region is shared between the X and Y chromosome and is probably required for the correct segregation of the sex chromosomes during male meiosis. The second region includes the sex-determining gene(s), the presence of which is necessary for the development of testes.