Identification of mega-environments and rice genotypes for general and specific adaptation to saline and alkaline stresses in India.

In the present study, a total of 53 promising salt-tolerant genotypes were tested across 18 salt-affected diverse locations for three years. An attempt was made to identify ideal test locations and mega-environments using GGE biplot analysis. The CSSRI sodic environment was the most discriminating location in individual years as well as over the years and could be used to screen out unstable and salt-sensitive genotypes. Genotypes CSR36, CSR-2K-219, and CSR-2K-262 were found ideal across years. Overall, Genotypes CSR-2K-219, CSR-2K-262, and CSR-2K-242 were found superior and stable among all genotypes with higher mean yields. Different sets of genotypes emerged as winners in saline soils but not in sodic soils; however, Genotype CSR-2K-262 was the only genotype that was best under both saline and alkaline environments over the years. The lack of repeatable associations among locations and repeatable mega-environment groupings indicated the complexity of soil salinity. Hence, a multi-location and multi-year evaluation is indispensable for evaluating the test sites as well as identifying genotypes with consistently specific and wider adaptation to particular agro-climatic zones. The genotypes identified in the present study could be used for commercial cultivation across edaphically challenged areas for sustainable production.

A comparison of the National Center for Health Statistics and new World Health Organization growth references for school-age children and adolescents with the use of data from 11 low-income countries.

BACKGROUND: In 2007 new World Health Organization (WHO) growth references for children aged 5-19 y were introduced to replace the National Center for Health Statistics (NCHS) references. OBJECTIVE: This study aimed to compare the prevalence of stunting, wasting, and thinness estimated by the NCHS and WHO growth references. DESIGN: NCHS and WHO height-for-age z scores were calculated with the use of cross-sectional data from 20,605 schoolchildren aged 5-17 y in 11 low-income countries. The differences in the percentage of stunted children were estimated for each year of age and sex. The z scores of body mass index-for-age and weight-for-height were calculated with the use of the WHO and NCHS references, respectively, to compare differences in the prevalence of thinness and wasting. RESULTS: No systematic differences in mean z scores of height-for-age were observed between the WHO and NCHS growth references. However, z scores of height-for-age varied by sex and age, particularly during early adolescence. In children for whom weight-for-height could be calculated, the estimated prevalence of thinness (WHO reference) was consistently higher than the prevalence of wasting (NCHS reference) by as much as 9% in girls and 18% in boys. CONCLUSIONS: In undernourished populations, the application of the WHO (2007) references may result in differences in the prevalence of stunting for each sex compared with results shown when the NCHS references are used as well as a higher estimated prevalence of thinness than of wasting. An awareness of these differences is important for comparative studies or the evaluation of programs. For school-age children and adolescents across all ranges of anthropometric status, the same growth references should be applied when such studies are undertaken.

Prevalence of periodontopathogens in a black Brazilian secluded community matched with a black urban population.

OBJECTIVE: To evaluate the prevalence of periodontopathogens according to periodontal profile in a black Brazilian secluded community matched with an urban black population. PARTICIPANTS: A total of 84 subjects were selected, 42 (mean age 25.7 sd 18.0 years) from a secluded community called Santo Antonio do Guapore (SAG) and 42 (mean age 25.4 sd 18.1 years) from an urban area of Sao Paulo State (SPT). METHODS: Participants received clinical examinations as follows: periodontal pocket depth; clinical attachment loss; plaque and gingival indexes. After examination, the secluded population was classified as periodontal health (13), gingivitis (15) or periodontitis (14). Then, 182 urban volunteers were screened and 42 subjects were selected matched for the variables: periodontal diagnosis, age (+/- 2 years) and gender. Samples were taken for microbial analysis. Genomic DNA for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, Tannerella forsythia and Prevotella intermedia was provided by polymerase chain reaction. RESULTS: Except for C. rectus, all pathogens were present in both groups with no statistically significant difference. In particular, C. rectus was more prevalent only in gingivitis subjects from the SPT group (p<0.05). A high frequency of periodontopathogens was related to the severity of periodontal disease. CONCLUSION: In general, the prevalence of the examined periodontopathogens in this study did not differ between a secluded black Brazilian population and an urban black population.