305 research outputs found

    Homecoming of Brachiaria: improved hybrids prove useful for African animal agriculture

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    Species of the genus Brachiaria originate primarily from Africa, where they are constituents of natural grasslands. Due to their adaptation to acidic, low-fertility soils, millions of hectares of Brachiaria species have been sown as improved pastures in South and Central America, especially B. brizantha cv. Marandu and B. decumbens cv. Basilisk. Due to B. decumbens' susceptibility to spittlebug insect pests in the Americas, CIAT in Colombia and EMBRAPA in Brazil initiated breeding programs in the 1980s. First cultivars released from CIAT's breeding program, cvs. Mulato and Mulato-II, have also been investigated in African countries. They have been examined for integration in conservation agriculture systems (Madagascar), for drought and acidic soil tolerance (Rwanda) and for intercropping forages in dairy systems (Uganda, Madagascar), among others. Seed sales to African countries suggest that an area of at least 1,000 ha has been sown so far. Largest adoption of cv. Mulato-II is currently happening in eastern Africa, where it is used by over 20,000 farmers as trap plant in the push-pull system for control of maize stem borers and parasitic Striga weed. Cv. Mulato-II's particular advantage is relatively high crude protein content due to greater leafiness and thinner stems than those of traditional Napier grass, resulting in higher nutritive quality. Yet, new pest challenges have emerged requiring further research attention. Though, diverse hybrids are in the pipeline for release, among them such suitable for cut-and-carry systems prevalent in eastern Africa. This paper reviews research, development and incipient adoption of new Brachiaria hybrids in African countries. (Résumé d'auteur

    Exercise training reduces central adiposity and improves metabolic indices in HAART-treated HIV-positive subjects in Rwanda: A randomized controlled trial

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    As HAART becomes more accessible in sub-Saharan Africa, metabolic syndromes, body fat redistribution (BFR), and cardiovascular disease may become more prevalent. We conducted a 6-month, randomized controlled trial to test whether cardiorespiratory exercise training (CET), improves metabolic, body composition and cardiorespiratory fitness parameters in HAART-treated HIV(+) African subjects with BFR. Six months of CET reduced waist circumference (−7.13 ± 4.4 cm, p < 0.0001), WHR (−0.10 ± 0.1, p < 0.0001), sum skinfold thickness (−6.15 ± 8.2 mm, p < 0.0001) and % body fat mass (−1.5 ± 3.3, p < 0.0001) in HIV(+)BFR(+)EXS. Hip circumference was unchanged in non-exercise control groups. CET reduced fasting total cholesterol (−0.03 ± 1.11 mM, p < 0.05), triglycerides (−0.22 ± 0.48 mM, p < 0.05) and glucose levels (−0.21 ± 0.71 mM, p < 0.05) (p < 0.0001). HDL-, LDL-cholesterol and HOMA values were unchanged after CET. Interestingly, HIV(+) subjects randomized to non-exercising groups experienced increases in fasting plasma glucose levels, whereas HIV seronegative controls did not (p < 0.001). Predicted VO(2) peak increased more in the HIV(+)BFR(+)EXS than in all other groups (4.7 ± 3.9 ml/kg/min, p < 0.0001). Exercise training positively modulated body composition and metabolic profiles, and improved cardiorespiratory fitness in HAART-treated HIV(+) Africans. These beneficial adaptations imply that exercise training is a safe, inexpensive, practical, and effective treatment for evolving metabolic and cardiovascular syndromes associated with HIV and HAART exposure in resource-limited sub-Saharan countries, where treatment is improving, morbidity and mortality rates are declining, but where minimal resources are available to manage HIV- and HAART-associated cardiovascular and metabolic syndromes

    Homecoming of Brachiaria: Improved hybrids prove useful for African animal agriculture

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    Species of the genus Brachiaria originate primarily from Africa, where they are constituents of natural grasslands. Due to their adaptation to acidic, low-fertility soils, millions of hectares of Brachiaria species have been sown as improved pastures in South and Central America, especially B. brizantha cv. Marandu and B. decumbens cv. Basilisk. Due to B. decumbens' susceptibility to spittlebug insect pests in the Americas, CIAT in Colombia and EMBRAPA in Brazil initiated breeding programmes in the 1980s. First cultivars released from CIAT's breeding programme – cvs. Mulato and Mulato-II – have also been investigated in African countries. They have been examined for integration in conservation agriculture systems (Madagascar), for drought and acidic soil tolerance (Rwanda) and for intercropping forages in dairy systems (Uganda, Madagascar), among others. Seed sales to African countries suggest that an area of at least 1,000 ha has been sown so far. The largest adoption of cv. Mulato-II is currently happening in eastern Africa, where it is used by over 20,000 farmers as a trap plant in the push-pull system for control of maize stem borers and parasitic Striga weed. Cv. Mulato-II's particular advantage is its relatively high crude protein content due to greater leafiness and thinner stems than those of traditional Napier grass, resulting in higher nutritive quality. Yet new pest challenges have emerged, requiring further research attention. Diverse hybrids are in the pipeline for release, among them those that are suitable for cut-and-carry systems which are prevalent in eastern Africa. This paper reviews research, development and incipient adoption of new Brachiaria hybrids in African countries. (Résumé d'auteur

    Prevalence of Kidney Disease in HIV-Infected and Uninfected Rwandan Women

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    Background: In the United States, HIV-related kidney disease disproportionately affects individuals of African descent; however, there are few estimates of kidney disease prevalence in Africa. We evaluated the prevalence of kidney disease among HIV-infected and uninfected Rwandan women. Methods: The Rwandan Women's Interassociation Study and Assessment prospectively enrolled 936 women. Associations with estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m2^2 and proteinuria were assessed in separate logistic regression models. Results: Among 891 non-pregnant women with available data, 2.4% had an eGFR<60 mL/min/1.73 m2^2 (calculated by the Modification of Diet in Renal Disease equation, MDRD eGFR) and 8.7% had proteinuria \ge1+. The prevalence of decreased eGFR varied markedly depending on the estimating method used, with the highest prevalence by Cockcroft-Gault. Regardless of the method used to estimate GFR, the proportion with decreased eGFR or proteinuria did not differ significantly between HIV-infected and -uninfected women in unadjusted analysis. After adjusting for age and blood pressure, HIV infection was associated with significantly higher odds of decreased MDRD eGFR but not proteinuria. Conclusion: In a well-characterized cohort of Rwandan women, HIV infection was associated with decreased MDRD eGFR. The prevalence of decreased eGFR among HIV-infected women in our study was lower than that previously reported in African-Americans and in other Central and East African HIV populations, although there was substantial variability depending on the equation used to estimate GFR. Future studies are needed to optimize GFR estimates and to determine the impact of antiretroviral therapy on kidney disease in this population

    Weight evolution in HIV-1 infected women in Rwanda after stavudine substitution due to lipoatrophy: comparison of zidovudine with tenofovir/abacavir.

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    This cohort study was conducted amongst female patients manifesting lipoatrophy while receiving stavudine-containing first-line antiretroviral treatment regimens at two urban health centres in Rwanda. The objectives were to assess weight evolution after stavudine substitution and to describe any significant difference in weight evolution when zidovudine or tenofovir/abacavir was used for substitution. All adult patients on stavudine-containing first-line regimens who developed lipoatrophy (diagnosed using a lipodystrophy case definition study-based questionnaire) and whose treatment regimen was changed were included (n=114). In the most severe cases stavudine was replaced with tenofovir or abacavir (n=39), and in the remainder with zidovudine (n=75). For patients changed to zidovudine a progressive weight loss was seen, while those on tenofovir/abacavir showed a progressive weight increase from six months. The between-group difference in weight evolution was significant from nine months (difference at 12 months: 2.3kg, P=0.02). These differences were confirmed by follow-up lipoatrophy scores. In multivariate analysis, substitution with tenofovir/abacavir remained significantly associated with weight gain. This is the first study in Africa assessing weight gain as a proxy for recovery after stavudine substitution due to lipoatrophy, providing supporting evidence that tenofovir/abacavir is superior to zidovudine. The weight loss with zidovudine might justify earlier substitution and access to better alternatives like tenofovir/abacavir

    Nutritional Characterisation of Introduced Improved \u3ci\u3eBrachiaria\u3c/i\u3e Grasses in Rwanda

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    A study aimed at characterising nutritive value of introduced Brachiaria grasses in Rwanda was conducted. Four Brachiaria grasses including, Brachiaria decumbens cv. Basilisk, Brachiaria brizantha cv. MG4, Brachiaria brizantha cv. Piata and Brachiaria cv. Cayman with Panicum coloratum as control were planted in two contrasting environments of low rainfall in Kirehe district and acidic soils in Nyamagabe district. The experiment was set in a randomized complete block design (RCBD) with four replications and the treatments were harvested after 60 days and 90 days. Data collected were dry matter (DM), crude proteins (CP), organic matter (OM), cellulose, neutral detergent fibre (NDF), acid detergent fibre (ADF) and ash content. Also, in vitro gas production was used to estimate metabolisable energy (ME), organic matter digestibility (OMD) and kinetic parameters. The results showed that the DM, CP, NDF, ADF, OM, Cellulose and ash were significant difference (P\u3c 0.05) among improved Brachiaria grasses and increased from 60 to 90 days of harvest except CP which declined with harvesting time. There was significant difference (P\u3e 0.05) among Brachiaria grasses for ME and OMD. Quickly degradable fraction (A) and slowly degradable fraction (B) did differ significantly (P\u3e 0.05) but rate of degradation (C) varied among species and with harvesting time. Time required producing half of the gas volume (T1/2) declined as grasses matured. All improved Brachiaria grasses had better nutritional attributes than Panicum coloratum. Grasses planted in the low rain-fall had high nutritive values compared to those planted in acid soil prone areas of Rwanda. Nevertheless, the results suggested that improved Brachiaria grass could be an alternative forage for dairy farmers in both contrasting environments
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