Detection of two major grain yield QTL in bread wheat (Triticum aestivum L.) under heat, drought and high yield potential environments.

A large proportion of the worlds' wheat growing regions suffers water and/or heat stress at some stage during the crop growth cycle. With few exceptions, there has been no utilisation of managed environments to screen mapping populations under repeatable abiotic stress conditions, such as the facilities developed by the International Wheat and Maize Improvement Centre (CIMMYT). Through careful management of irrigation and sowing date over three consecutive seasons, repeatable heat, drought and high yield potential conditions were imposed on the RAC875/Kukri doubled haploid population to identify genetic loci for grain yield, yield components and key morpho-physiological traits under these conditions. Two of the detected quantitative trait loci (QTL) were located on chromosome 3B and had a large effect on canopy temperature and grain yield, accounting for up to 22 % of the variance for these traits. The locus on chromosome arm 3BL was detected under all three treatments but had its largest effect under the heat stress conditions, with the RAC875 allele increasing grain yield by 131 kg ha(-1) (or phenotypically, 7 % of treatment average). Only two of the eight yield QTL detected in the current study (including linkage groups 3A, 3D, 4D 5B and 7A) were previously detected in the RAC875/Kukri doubled haploid population; and there were also different yield components driving grain yield. A number of discussion points are raised to understand differences between the Mexican and southern Australian production environments and explain the lack of correlation between the datasets. The two key QTL detected on chromosome 3B in the present study are candidates for further genetic dissection and development of molecular markers.

Linkage to chromosome 1p36 for attention-deficit/hyperactivity disorder traits in school and home settings.

BACKGROUND: Limited success has been achieved through previous attention-deficit/hyperactivity disorder (ADHD) linkage scans, which were all designed to map genes underlying the dichotomous phenotype. The International Multi-centre ADHD Genetics (IMAGE) project performed a whole genome linkage scan specifically designed to map ADHD quantitative trait loci (QTL). METHODS: A set of 1094 single selected Caucasian ADHD nuclear families was genotyped on a highly accurate and informative single nucleotide polymorphism (SNP) panel. Two quantitative traits measuring the children's symptoms in home and school settings were collected and standardized according to a population sample of 8000 children to reflect the developmental nature and gender prevalence difference of ADHD. Univariate linkage test was performed on both traits and their mean score. RESULTS: A significant common linkage locus was found at chromosome 1p36 with a locus-specific heritability of 5.1% and a genomewide empirical p < .04. Setting-specific suggestive linkage signals were also found: logarithm of odds (LOD) = 2.2 at 9p23 for home trait and LOD = 2.6 at 11q21 for school trait. CONCLUSIONS: These results indicate that given large samples with proper phenotypic measures, searching for ADHD genes with a QTL strategy is an important alternative to using the clinical diagnosis. The fact that our linkage region 1p36 overlaps with the dyslexia QTL DYX8 further suggests it is potentially a pleiotropic locus for ADHD and dyslexia.

Teaching prevention through electives.

The Liaison Committee on Medical Education (LCME) accreditation standards affirm that the medical school curriculum should include elective courses to supplement the required courses and provide opportunities for students to pursue individual academic interests. The breadth of opportunities in preventive medicine and population health is extensive as students seek rotations at health departments, rural and urban community health centers, community agencies, occupational health sites, schools, and abroad. A growing number of students choose to participate in MD/MPH dual-degree programs. This article describes four prototypes that foster student learning in preventive medicine: population health, international health, American Medical Student Association opportunities, and public health degree programs. These four types of electives enable students to participate in the front lines of preventive services through experiential learning in: community and population health both at home and abroad, continuous quality improvement, organization and behavioral change, interprofessional teamwork, and health care policy. For those with particular interests in population health and preventive medicine, an increasing number of medical schools offer dual MD/MPH programs, either in conjunction with schools of public health or in graduate programs in public health.

Conference on the Sustainable Development of Small Island Developing States: year-end update.

PIP: A brief description is given of the background behind the Small Island States Global Conference scheduled for March 1994. Preliminary meetings led to the formation of a draft program of action pertaining to climatic change and sea level increases, natural and environmental disasters, freshwater resources, management of wastes, coastal and marine resources, land and energy resources, tourism and biodiversity resources, regional institutions and technical cooperation, and a variety of other topics. Little agreement was reached on implementation, monitoring, and review among member states, which called for additional meetings. The World Coast Conference, held in November 1993, focused on progressive sustainable development and integrated coastal zone management (ICZM). Participants agreed on the necessity to 1) strengthen state's capabilities for ICZM, 2) identify priorities, 3) set up comprehensive and flexible assessment mechanisms, 4) coordinate activities at all levels, and 5) address longterm concerns. Only two nongovernmental organizations (NGOs) sent reports on donor activities. Host country meetings were held in Barbados in preparation for the planned 1994 Conference and settlement of logistics. CNN will provide television coverage of the Conference and produce documentaries on small island states. General Assembly highlights included summary statements by Belgium, Vanuatu, Maldives, the Caribbean community, Korea, and Australia members. The Barbados Declaration, which is in process and will be adopted in some form at the 1994 Conference, may incorporate elements from the Rio Declaration on Environment and Development. The Ecojournalism workshop scheduled for Jamaica in January 1994 is aiming to instill awareness of the 1994 Conference and small island issues. 157 NGOs have received accreditation for the 1994 Conference, of which 50 are from small island states, 50 from developed countries, and 53 from nonisland developing countries. The NGO Liaison Committee will focus on workshops on special issues, examples of sustainable development such as the Village of Hope, and a showcase of affordable technologies and services in order to achieve more sustainable patterns of development.^ieng