32 research outputs found
Microsatellites and agronomic traits for assessing genetic relationships among 18 New Rice for Africa (NERICA) varieties
The Africa Rice Center (WARDA) has developed several interspecific rice varieties by crossing the high yielding Asian rice (Oryza sativa subsp. japonica) with the locally adapted African rice (Oryza glaberrima). Eighteen varieties were named with the prefix NERICA (New Rice for Africa) but theirgenetic difference and patterns of relationship is largely unknown. A total of 102 polymorphic microsatellite markers were used to genotype 18 NERICAs. A subset of seven NERICAs (NERICA 1 to 7) was further characterized for 10 agronomic traits. The microsatellites data revealed no genetic difference between NERICA 8 and 9. The absence of genetic distance and identical SSR haplotype distribution (banding pattern) observed between NERICAs 8 and 9 is highly likely to be due to lack molecular difference at the DNA level but the possibility for seed admixture remains to be explored. This study, however, revealed the presence of a wide range of genetic differences among all other NERICAs, with the highest being between NERICA 6 and 17. Cluster and principal component analyses of the SSR data revealed distinct separation of NERICA 1 to 7 from NERICA 8 to 18. The possible reasons for such separation and the implications for breeding programs are discusse
Molecular profiling of an interspecific rice population derived from a cross between WAB 56-104 (Oryza sativa) and CG 14 (Oryza glaberrima)
NERICA rices are interspecific inbred progeny derived from crosses between Oryza sativa x O. glaberrima. In this study, we evaluated 70 BC2 interspecific lines, developed by crossing a tropicaljaponica variety (WAB 56-104) as the recurrent parent to an O. glaberrima variety (CG 14) as the donor parent, followed by the use of anther culture to derive doubled haploids (DH) (26 lines) or eightgenerations of inbreeding to fix the lines (44 lines). Seven of these BC2 derived inbred lines have been released as NERICA 1 - NERICA 7. This study examined the relative contribution of each parent and theextent of genetic differences among these 70 sister lines using 130 well-distributed microsatellite markers which cover 1725 cM of the rice genome. The average proportion of O. sativa recurrent parentgenome was 87.4% (1,508 cM), while the observed average proportion of O. glaberrima donor genome was 6.3% (108 cM). Non-parental alleles were detected in 83% of the lines and contributed an average of38 cM per line (~2.2% of genomic DNA). Lines that had undergone eight generations of inbreeding in the field contained significantly more non-parental alleles (av. 2.7%) compared to the DH lines (av. 1.3%)that were developed from BC2 anthers. Using both cluster and principal component analyses, two major groups were detected in these materials. The NERICA varieties (NERICA 1 to 7) clustered in one group while the remaining 63 lines clustered in another group, suggesting that the second group may offer significant opportunities for further selection and variety development
Molecular profiling of interspecific lowland rice populations derived from IR64 (Oryza sativa) and Tog5681 (Oryza glaberrima)
Several lowland NERICAs (New Rice for Africa) were derived from crosses between IR64 (an Oryza sativa subsp. indica variety) and Tog5681 (an Oryza glaberrima variety) that possess useful traitsadapted to lowland conditions in West Africa. The proportion of parental genomic contribution and extent of genetic differences among these sister lines is unknown at the molecular level. The objectivesin this study were therefore to determine, with 60 SSR markers that cover 1162 cM of the rice genome, the frequency and magnitude of deviations from the expected parental contributions among 21 BC2F10,17 BC3 F8 and 10 BC4F8 lines and determine patterns of their genetic relationships. The estimated average O. glaberrima genome coverage was 7.2% (83.5 cM) at BC2F10, 8.5% (99.3 cM) at BC3F8 and 8.1%(93.8 cM) at BC4F8 lines. The O. sativa parent accounted for 73.2% (851.3 cM) at BC2F10, 82.6% (959.5 cM) at BC3F8 and 78.2% (908.6 cM) at BC3F8. Non-parental alleles were detected at all 3 backcross generations but the frequency of such alleles at BC2 (8.8%) was twice that of BC3F8 (3.4%) and nine times that of BC4F8 (0.9%). Both cluster and principal component analyses revealed two major groups irrespective of the level of backcross generations and the proportion of parental genome contribution
Point-of-Care Ultrasound for Tuberculosis Management in Sub-Saharan Africa-A Balanced SWOT Analysis.
Point-of-care ultrasound (POCUS) is an increasingly accessible skill, allowing for the decentralization of its use to non-specialist healthcare workers to guide routine clinical decision making. The advent of ultrasound-on-a-chip has transformed the technology into a portable mobile health device. Due to its high sensitivity to detect small consolidations, pleural effusions and sub pleural nodules, POCUS has recently been proposed as a sputum-free likely triage tool for tuberculosis (TB). To make an objective assessment of the potential and limitations of POCUS in routine TB management, we present a Strengths, Weaknesses, Opportunities & Threats (SWOT) analysis based on a review of the relevant literature and focusing on Sub-Saharan Africa (SSA). We idenitified numerous strengths and opportunities of POCUS for TB management e.g.; accessible, affordable, easy to use & maintain, expedited diagnosis, extra-pulmonary TB detection, safer pleural/pericardial puncture, use in children/pregnant women/PLHIV, targeted screening of TB contacts, monitoring TB sequelae, and creating AI decision support. Weaknesses and external threats such as operator dependency, lack of visualization of central lung pathology, poor specificity, lack of impact assessments and data from Sub-Saharan Africa must be taken into consideration to ensure that the potential of the technology can be fully realized in research as in practice
Rice bran supplementation modulates growth, microbiota and metabolome in weaning infants: a clinical trial in Nicaragua and Mali
Rice bran supplementation provides nutrients, prebiotics and phytochemicals that enhance gut immunity, reduce enteric pathogens and diarrhea, and warrants attention for improvement of environmental enteric dysfunction (EED) in children. EED is a subclinical condition associated with stunting due to impaired nutrient absorption. This study investigated the effects of rice bran supplementation on weight for age and length for age z-scores (WAZ, LAZ), EED stool biomarkers, as well as microbiota and metabolome signatures in weaning infants from 6 to 12 months old that reside in Nicaragua and Mali. Healthy infants were randomized to a control (no intervention) or a rice bran group that received daily supplementation with increasing doses at each month (1–5 g/day). Stool microbiota were characterized using 16S rDNA amplicon sequencing. Stool metabolomes were analyzed using ultra-high-performance liquid-chromatography tandem mass-spectrometry. Statistical comparisons were completed at 6, 8, and 12 months of age. Daily consumption of rice bran was safe and feasible to support changes in LAZ from 6–8 and 8–12 months of age in Nicaragua and Mali infants when compared to control. WAZ was significantly improved only for Mali infants at 8 and 12 months. Mali and Nicaraguan infants showed major differences in the overall gut microbiota and metabolome composition and structure at baseline, and thus each country cohort demonstrated distinct microbial and metabolite profile responses to rice bran supplementation when compared to control. Rice bran is a practical dietary intervention strategy that merits development in rice-growing regions that have a high prevalence of growth stunting due to malnutrition and diarrheal diseases. Rice is grown as a staple food, and the bran is used as animal feed or wasted in many low- and middle-income countries where EED and stunting is prevalent
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Using a community-based definition of poverty for targeting poor households for premium subsidies in the context of a community health insurance in Burkina Faso
Background: One of the biggest challenges in subsidizing premiums of poor households for community health insurance is the identification and selection of these households. Generally, poverty assessments in developing countries are based on monetary terms. The household is regarded as poor if its income or consumption is lower than a predefined poverty cut-off. These measures fail to recognize the multi-dimensional character of poverty, ignoring community members? perception and understanding of poverty, leaving them voiceless and powerless in the identification process. Realizing this, the steering committee of Nouna's health insurance devised a method to involve community members to better define `perceived? poverty, using this as a key element for the poor selection. The community-identified poor were then used to effectively target premium subsidies for the insurance scheme.
Methods: The study was conducted in the Nouna's Health District located in northwest Burkina Faso. Participants in each village were selected to take part in focus-group discussions (FGD) organized in 41 villages and 7 sectors of Nouna's town to discuss criteria and perceptions of poverty. The discussions were audio recorded, transcribed and analyzed in French using the software NVivo 9.
Results: From the FGD on poverty and the subjective definitions and perceptions of the community members, we found that poverty was mainly seen as scarcity of basic needs, vulnerability, deprivation of capacities, powerlessness, voicelessness, indecent living conditions, and absence of social capital and community networks for support in times of need. Criteria and poverty groups as described by community members can be used to identify poor who can then be targeted for subsidies.
Conclusion: Policies targeting the poorest require the establishment of effective selection strategies. These policies are well-conditioned by proper identification of the poor people. Community perceptions and criteria of poverty are grounded in reality, to better appreciate the issue. It is crucial to take these perceptions into account in undertaking community development actions which target the poor. For most community-based health insurance schemes with limited financial resources, using a community-based definition of poverty in the targeting of the poorest might be a less costly alternative
Molecular profiling of an interspecific rice population derived from a cross between WAB 56-104 (Oryza sativa) and CG 14 (Oryza glaberrima)
NERICA rices are interspecific inbred progeny derived from crosses between Oryza sativa Ă— O. glaberrima. In this study, we evaluated 70 BC2 interspecific lines, developed by crossing a tropical japonica variety (WAB 56-104) as the recurrent parent to an O. glaberrima variety (CG 14) as the donor parent, followed by the use of anther culture to derive doubled haploids (DH) (26 lines) or eight generations of inbreeding to fix the lines (44 lines). Seven of these BC2 derived inbred lines have been released as NERICA 1-NERICA 7. This study examined the relative contribution of each parent and the extent of genetic differences among these 70 sister lines using 130 well-distributed microsatellite markers which cover 1725 cM of the rice genome. The average proportion of O. sativa recurrent parent genome was 87.4% (1,508 cM), while the observed average proportion of O. glaberrima donor genome was 6.3% (108 cM). Non-parental alleles were detected in 83% of the lines and contributed an average of 38 cM per line (~2.2% of genomic DNA). Lines that had undergone eight generations of inbreeding in the field contained significantly more non-parental alleles (av. 2.7%) compared to the DH lines (av. 1.3%) that were developed from BC2 anthers. Using both cluster and principal component analyses, two major groups were detected in these materials. The NERICA varieties (NERICA 1 to 7) clustered in one group while the remaining 63 lines clustered in another group, suggesting that the second group may offer significant opportunities for further selection and variety development
Molecular profiling of an interspecific rice population derived from a cross between WAB 56-104 (Oryza sativa) and CG 14 (Oryza glaberrima)
Establishment of actinorhizal symbiosis in response to ethylene, salicylic acid, and jasmonate
Phytohormones play a crucial role in regulating plant developmental processes. Among them, ethylene and jasmonate are known to be involved in plant defense responses to a wide range of biotic stresses as their levels increase with pathogen infection. In addition, these two phytohormones have been shown to inhibit plant nodulation in legumes. Here, exogenous salicylic acid (SA), jasmonate acid (JA), and ethephon (ET) were applied to the root system of Casuarina glauca plants before Frankia inoculation, in order to analyze their effects on the establishment of actinorhizal symbiosis. This protocol further describes how to identify putative ortholog genes involved in ethylene and jasmonate biosynthesis and/or signaling pathways in plant, using the Arabidopsis Information Resource (TAIR), Legume Information System (LIS), and Genevestigator databases. The expression of these genes in response to the bacterium Frankia was analyzed using the gene atlas for Casuarina-Frankia symbiosis (SESAM web site)