Childhood obesity in the Caribbean.

OBJECTIVE: To determine the prevalence of overweight among school children in Bonaire, an island in the Caribbean, and to obtain clues for prevention of overweight. METHODS: In a cross-sectional school-based study, weight and height were measured in all 4-16-year old children in Bonaire (n = 2148). Body mass index was categorized as defined by the International Obesity Task Force (IOTF). The children were administered a questionnaire pertaining to lifestyle and nutrition. RESULTS: The prevalence of overweight, including obesity, in boys is 24.3%, and 31.9% in girls; obesity is 9.9% and 13.7%, respectively. Approximately half of the children have an unhealthy food pattern. Significantly less overweight (49%) and obese children (45%) are physically active for > 1 hour/day compared to normal weight children (56%). CONCLUSION: The prevalence of overweight and obesity in children in Bonaire is high. Prevention of overweight should focus on stimulating healthy eating habits and more physical activity.

Estimating maize genetic erosion in modernized smallholder agriculture.

Replacement of crop landraces by modern varieties is thought to cause diversity loss. We studied genetic erosion in maize within a model system; modernized smallholder agriculture in southern Mexico. The local seed supply was described through interviews and in situ seed collection. In spite of the dominance of commercial seed, the informal seed system was found to persist. True landraces were rare and most informal seed was derived from modern varieties (creolized). Seed lots were characterized for agronomical traits and molecular markers. We avoided the problem of non-consistent nomenclature by taking individual seed lots as the basis for diversity inference. We defined diversity as the weighted average distance between seed lots. Diversity was calculated for subsets of the seed supply to assess the impact of replacing traditional landraces with any of these subsets. Results were different for molecular markers, ear- and vegetative/flowering traits. Nonetheless, creolized varieties showed low diversity for all traits. These varieties were distinct from traditional landraces and little differentiated from their ancestral stocks. Although adoption of creolized maize into the informal seed system has lowered diversity as compared to traditional landraces, genetic erosion was moderated by the distinct features offered by modern varieties.

Molecular characterization and physical localization of highly repetitive DNA sequences from Brazilian Alstroemeria species.

Highly repetitive DNA sequences were isolated from genomic DNA libraries of Alstroemeria psittacina and A. inodora. Among the repetitive sequences that were isolated, tandem repeats as well as dispersed repeats could be discerned. The tandem repeats belonged to a family of interlinked Sau3A subfragments with sizes varying from 68-127 bp, and constituted a larger HinfI repeat of approximately 400 bp. Southern hybridization showed a similar molecular organization of the tandem repeats in each of the Brazilian Alstroemeria species tested. None of the repeats hybridized with DNA from Chilean Alstroemeria species, which indicates that they are specific for the Brazilian species. In-situ localization studies revealed the tandem repeats to be localized in clusters on the chromosomes of A. inodora and A. psittacina: distal hybridization sites were found on chromosome arms 2PS, 6PL, 7PS, 7PL and 8PL, interstitial sites on chromosome arms 2PL, 3PL, 4PL and 5PL. The applicability of the tandem repeats for cytogenetic analysis of interspecific hybrids and their role in heterochromatin organization are discussed.