Despite great progress in identifying genetic variants that influence human disease, most inherited risk remains unexplained. A more complete understanding requires genome-wide studies that fully examine less common alleles in populations with a wide range of ancestry. To inform the design and interpretation of such studies, we genotyped 1.6 million common single nucleotide polymorphisms (SNPs) in 1,184 reference individuals from 11 global populations, and sequenced ten 100-kilobase regions in 692 of these individuals. This integrated data set of common and rare alleles, called ‘HapMap 3’, includes both SNPs and copy number polymorphisms (CNPs). We characterized population-specific differences among low-frequency variants, measured the improvement in imputation accuracy afforded by the larger reference panel, especially in imputing SNPs with a minor allele frequency of ≤5%, and demonstrated the feasibility of imputing newly discovered CNPs and SNPs. This expanded public resource of genome variants in global populations supports deeper interrogation of genomic variation and its role in human disease, and serves as a step towards a high-resolution map of the landscape of human genetic variation.

In this work we present two new methods for approximating the Kullback-Liebler (KL) divergence between two mixtures of Gaussians. The first method is based on matching between the Gaussian elements of the two Gaussian mixture densities. The second method is based on the unscented transform. The proposed methods are utilized for image retrieval tasks. Continuous probabilistic image modeling based on mixtures of Gaussians together with KL measure for image similarity, can be used for image retrieval tasks with remarkable performance. The efficiency and the performance of the KL approximation methods proposed are demonstrated on both simulated data and real image data sets. The experimental results indicate that our proposed approximations outperform previously suggested methods.

The causal agent of pitch canker disease of pines, Fusarium subglutinans f.sp. pini, is a recent introduction to California. The work presented here demonstrates that this pathogen is seed‐borne in Monterey pine (Pinus radiata). The pathogen was isolated from up to 83% of seeds collected from cones on recently infected branches. Seedling emergence from infested Monterey pine seeds was 9%, compared with 67% for uninfested seeds. The fungus was isolated more frequently from seedlings originating from diseased branches than from symptomless branches. However, more than 50% of seeds from symptomless Monterey pine branches produced symptomless seedlings from which the pathogen was isolated. It is hypothesized that F. s. pini is carried within the seeds, where it may remain dormant until germination. The implications of these findings for the regeneration of native and landscape‐planted Monterey pines, and for the transport of this non‐native pathogen in pine seeds and seedlings to previously uninfested areas, are discussed.

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Summary.We investigated the impact of maternal and fetal variables on cord blood (CB) haemopoietic stem/progenitor cell content. These included maternal age, ethnic origin, parity, ABO and Rhesus D blood group, antenatal haemoglobin, alcohol and cigarette consumption at time of registration, mode of delivery, duration of the first and second stages of labour, gestational age, birth weight, cord pH and cord erythrocyte mean cell volume (MCV). Cord volumes and total nucleated cellularities (TNC) were recorded, the colony assay for granulocyte-macrophage colony-forming-cells (CFU-GM) was used to quantify the progenitor cells and the potential of CFU-GM to produce secondary colonies on replating was used as a measure of progenitor cell quality. We found: (1) significantly greater ( P ¼ 0·04) volumes were collected from babies who weighed у 2·5 kg versus babies with a birth weight < 2·5 kg; (2) significantly greater numbers of mononuclear cells (MNC) from mothers who drank 0-3 units versus those who drank у 4 units of alcohol weekly ( P ¼ 0·03), and in babies with a cord pH р 7·1 v > 7·1 ( P ¼ 0·02); (3) Significantly greater numbers of cord CFU-GM in mothers who drank 0-3 v у 4 units weekly ( P ¼ 0·004) and smokers of у 10 v 0-9 cigarettes daily ( P ¼ 0·02) and in spontaneous vaginal deliveries than assisted vaginal and caesarean deliveries ( P ¼ 0·04), and (4) the potential of CFU-GM to produce secondary colonies was significantly greater in CB derived from Caucasians than from non-Caucasians ( P ¼ 0·02); in assisted vaginal delivery v spontaneous vaginal ( P ¼ 0·02) and in deliveries with prolonged first stage of labour v short first stage of labour ( P ¼ 0·04). We conclude that antenatal and perinatal variables may influence the CB stem/ progenitor cell yield available for transplantation.Keywords: maternal factors, fetal factors, progenitor assays, AUC.Human cord blood (CB) is an alternative source of haemopoietic stem cells for clinical transplantation. Over 500 related and unrelated CB transplants have been undertaken, mostly in children. The availability of CB may shorten the period needed to search for an unrelated donor in the case of recipients who have no sibling donor. Rubinstein et al (1993) found that unrelated cord blood was available at a median of 69 d versus > 2·5 months for bone marrow. More recently, during a search for unrelated CB for 85 high-risk leukaemic patients (Gluckman, personal communication), potential donations were identified for 65/ 85 patients (76%) at a median of 4 d (range 0-586); of these 59 donations fully eligible for transplantation were identified for 34 patients (40%) after a median of 47 d (1-449).The contribution of CB to adult transplantation remains limited due to the restricted number of stem/ progenitor cells available in CB donations (Wagner et al,