Faso

Distribution by Scientific Domains

Kinds of Faso

  • burkina faso


  • Selected Abstracts


    BURKINA FASO: Cross-border Conflict

    AFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 4 2010
    Article first published online: 4 JUN 2010
    No abstract is available for this article. [source]


    BURKINA FASO: Call for Population Control

    AFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 1 2009
    Article first published online: 9 MAR 200
    No abstract is available for this article. [source]


    The effect of single vegetation elements on wind speed and sediment transport in the Sahelian zone of Burkina Faso

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2007
    J. K. Leenders
    Abstract Soil loss caused by wind erosion is a widespread phenomenon in the Sahelian zone of West Africa. According to Sahelian farmers, scattered vegetation standing in amongst the crop has the potential for a wind erosion control strategy. This study was conducted to study the effect of single vegetation elements on the pattern of average wind speed and sediment transport. This was done by two experiments that were carried out during the rainy seasons of 2002 and 2003 in north Burkina Faso, West Africa. Wind speeds were measured using three sonic anemometers, at a sampling frequency of 16 Hz. Sediment transport was determined by calculating the mass fluxes from 17 MWAC catchers. In this study, a shrub was defined as a vegetation element with branches until ground and a tree as a vegetation element with a distinctive trunk below a canopy. Behind shrubs wind speed near the soil surface was reduced up to approximately seven times the height of the shrub. The observed reduction in wind speed in the area where wind speed was reduced was 15 per cent on average. At the sides of the shrub, wind speed was increased, by on average 6 per cent. As the area of increase in wind speed is one-third of the area of decrease in wind speed, the net effect of a shrub is a reduction in wind speed. A similar pattern was visible for the pattern of sediment transport around a shrub. Downwind of a shrub, sediment transport was diminished up to seven times the height of the shrub. Probably most of this material was trapped by the shrub. Trees showed a local increase of wind around the trunk, which is expected to relate to an increase in sediment transport around the trunk. Mass flux measurements of sediment transport were not made, but visual observations in the field substantiate this. Behind the canopy of a tree, a tree acts similarly to a shrub regarding its effects on average wind speed, but as a tree is generally a larger obstacle than a shrub the extent of this effect is larger than for shrubs. Thus, whereas shrubs are more effective than trees regarding their direct effect on soil loss by trapping sand particles near the soil surface, trees are more effective in affecting soil loss indirectly by reducing the wind speed downwind more effectively than shrubs. Therefore, to reduce soil loss in an area, the presence of both trees and shrubs is crucial. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Grassland communities on a Sahelian peneplain in Burkina Faso

    FEDDES REPERTORIUM, Issue 1-2 2008
    J. V. Müller Dr.
    A detailed phytosociological analysis of grassland communities of a Sahelian peneplain in Burkina Faso (West Africa) is presented. The floristic structure of the vegetation was documented with 113 relevés, which were classified manually and in addition ordinated to characterize main floristic gradients. The topographical situation from high-lying areas of the peneplain with erosion of material to low-lying areas with accumulation of material turned out to be the most important differentiating factor in the data set. All grassland communities are dominated by annual grasses and have large distribution ranges. They colonize sandy-silty, loamy to clayey soils and can be water-saturated or repeatedly inundated during the rainy season, while dry, non-inundated habitats are also colonized. Many grasses are valuable fodder plants and are appreciated by livestock , the peneplain is economically highly important as a grazing ground. Whereas exozoochorous annual species are constantly present companions, perennial herbaceous species are almost completely missing. Stands were grouped into one alliance Panico laeti-Echinochloion colonae and only two phytocoenoses: a rankless Schoenefeldia gracilis -community (with two subcommunities: a typical subcommunity with a large ecological amplitude from sandy-silty to loamy soils, and an Aristida funiculata -subcommunity on sandy, dry, non-inundated soils) and Eragrostietum pilosae. The Eragrostietum pilosae grows in the low-lying areas of the peneplain and connects between communities of seasonally inundated lakes and the grasslands on the upper parts of the pene- plain. Following the topography, the two plant communities form a large transition (zonation complex). It is widespread across the study area and contains the diagnostic species of both plant communities. The plant communities are compared with other Sahelian grass-dominated plant communities, and with plant communities from the Sahara and the (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Grasfluren einer sahelischen Rumpffläche in Burkina Faso In diesem Beitrag wird eine detaillierte pflanzensoziologische Analyse der Grasfluren einer sahelischen Rumpffläche in Burkina Faso (Westafrika) präsentiert. Die floristische Struktur der Vegetation wurde mit 113 pflanzensoziologischen Aufnahmen dokumentiert. Diese wurden zunächst manuell klassifiziert und anschließend einem Ordinationsverfahren unterzogen, um die wichtigsten Gradienten im floristischen Datensatz aufzuzeigen. Die topographische Geländesituation der Rumpffläche, beginnend mit hochgelegenen Bereichen mit Materialaustrag bis in die Niederungen mit Materialeintrag, wurde als wichtigster differenzierender Faktor des floristischen Datensatzes identifiziert. Alle untersuchten Pflanzengesellschaften der Grasfluren haben große Verbreitungsgebiete und werden von annuellen Gräsern dominiert. Sie sind auf sandig-schluffigen, lehmigen bis tonigen Böden zu finden. Sie können in der Regenzeit entweder wassergesättigt oder wiederholt überflutet sein. Die Grasfluren sind auch auf trockenen, nicht überfluteten Standorten nachgewiesen. Viele der Grasarten sind vom Weidevieh geschätzte Futterpflanzen , die Rumpffläche dient als wirtschaftlich bedeutendes Weideland. Exozoochore, einjährige Arten sind hochstet als Begleiter vorhanden. Hingegen fehlen mehrjährige, krautige Arten fast vollständig. Die Bestände konnten einem pflanzensoziologischen Verband Panico laeti-Echinochloion colonae und zwei Pflanzengesellschaften zugeordnet werden. Die ranglose Schoenefeldia gracilis -Gesellschaft kommt in zwei Untereinheiten vor: eine typische Untereinheit mit breiter ökologischer Amplitude von sandig-schluffigen bis lehmigen Böden, und eine Aristida funiculata Untereinheit auf trockenen, sandigen, nicht überfluteten Böden. Das Eragrostietum pilosae kommt in den tiefliegenden Bereichen Sudanian zone. A close floristic relationship of Sahelian grassland communities with Saharan vegetation could be shown. der Rumpffläche vor und vermittelt zwischen den Pflanzengesellschaften temporärer Seen und den Grasfluren der hochgelegenen Bereiche der Rumpffläche. Der Geländesituation folgend bilden beide Pflanzengesellschaften einen breiten Übergangsbereich (Zonationskomplex). Dieser Übergangsbereich ist im Untersuchungsgebiet weit verbreitet und enthält diagnostische Arten beider Pflanzengesellschaften. Die beschriebenen Einheiten werden mit anderen grasdominierten Pflanzengesellschaften des Sahels sowie der Sahara und der Sudanzone verglichen. Eine enge floristische Beziehung der sahelischen Grasfluren mit Vegetationseinheiten der Sahara wird aufgezeigt. [source]


    On the trail of the global green bean: methodological considerations in multi-site ethnography

    GLOBAL NETWORKS, Issue 4 2001
    Susanne Freidberg
    The need to demystify and ,ground' globalization has spurred many calls for multi-site fieldwork. This article discusses how such fieldwork was used to examine the contemporary restructuring of fresh food commodity chains between Africa and Europe, at a time of increasing European concerns about food safety and quality. Drawing on convention theory and actor-network theory for conceptual guidance, qualitative fieldwork was conducted at sites of production, import and export in ,anglophone' (Zambia,London) and ,francophone' (Burkina Faso,Paris) commodity chains. The article also discusses the challenges posed by multi-site research, especially in realms where secrecy and deception are standard tools of the trade. [source]


    Importance of soil surface characteristics on water erosion in a small grazed Sahelian catchment

    HYDROLOGICAL PROCESSES, Issue 8 2003
    H. Karambiri
    Abstract This study concerns the problem of water erosion in the Sahel. Surface water and sediment yields (suspended matter and bedload) were monitored for 3 years (1998,2000) at the outlet of a small grazed catchment (1·4 ha) in the northern part of Burkina Faso. The catchment consists of about 64% sandy deposits (DRY soil surface type), which support most of the vegetation, and about 34% of crusted bare soils (ERO soil surface type). The annual solid-matter export is more than 90% suspended sediment, varying between 4·0 and 8·4 t ha,1. The bedload represents less than 10% of soil losses. In a single flood event (10 year return period), the sediment yield can reach 4·2 t ha,1. During the period studied, a small proportion (20 to 32%) of the floods was thus responsible for a large proportion (80%) of the solid transport. Seasonal variation of the suspended-matter content was also observed: high mean values (9 g l,1) in June, decreasing in July and stabilizing in August (between 2 and 4 g l,1). This behaviour may be a consequence of a reorganization of the soil surfaces that have been destroyed by trampling animals during the previous long dry season, vegetation growth (increase in the protecting effect of the herbaceous cover) and, to a lesser extent, particle-supply limitation (exhaustion of dust deposits during July). The particle-size distribution in the suspended matter collected at the catchment outlet is 60% made up of clay: fraction ,2 µ m. The contribution of this clay is maximum when the water rises and its kaolinite/quartz ratio is then close to that of the ERO-type surfaces. This indicates that these surfaces are the main source of clay within the catchment. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    SINE insertion polymorphism on the X chromosome differentiates Anopheles gambiae molecular forms

    INSECT MOLECULAR BIOLOGY, Issue 4 2005
    M. J. Barnes
    Abstract Polymorphic SINE insertions can be useful markers for assessing population structure and differentiation. Maque is a family of SINE elements which, based on bioinformatic analysis, was suggested to have been active recently in Anopheles gambiae, the major vector of malaria. Here, we report the development of polymorphic Maque insertions as population genetic markers in A. gambiae, and the use of these markers to better characterize divergence on the X chromosome between A. gambiae M and S molecular forms in populations from Burkina Faso and Mali. Our data are consistent with the recent activity of Maque. Phylogenetic analysis suggests that at least two recently active lineages may have a role in mediating genome evolution. We found differences in element insertion frequency and sequence between the M and S populations analysed. Significant differentiation was observed between these two groups across a 6 Mb region at the proximal (centromeric) end of the X chromosome. Locus-specific FST values ranged from 0.14 to 1.00 in this region, yet were not significantly different from zero in more distal locations on the X chromosome; the trend was consistent in populations from both geographical locales suggesting that differentiation is not due to local adaptation. Strong differentiation between M and S at the proximal end of the X chromosome, but not outside this region, suggests the action of selection counteracting limited gene flow between these taxa and supports their characterization as incipient species. [source]


    Microsatellite DNA markers reveal genetic differentiation among populations of Glossina palpalis gambiensis collected in the agro-pastoral zone of Sideradougou, Burkina Faso

    INSECT MOLECULAR BIOLOGY, Issue 4 2000
    P. Solano
    Abstract Intraspecific genetic variability of Glossina palpalis gambiensis in the area of Sideradougou, Burkina Faso, was studied using polymorphic microsatellite DNA markers. This genetic study was combined with other epidemiological information on the same tsetse: bloodmeal identification, dissection of tsetse and molecular characterization of the trypanosomes detected. There was significant genetic differentiation among flies caught only a few kilometers apart, within the same riverine habitat. These distinct subpopulations were also differentially infected by trypanosomes. In part of the study area, a Factorial Correspondence Analysis undertaken on the genotypes allowed us to detect a Wahlund effect, suggesting the presence of tsetse originating from different source populations coming from two distinct drainage systems. The apparent structuring of populations of G. palpalis gambiensis is discussed relative to appropriate strategies to control African Trypanosomosis. [source]


    Dermatitis cruris pustulosa et atrophicans , a frequent but poorly understood tropical skin condition , a case report from Burkina Faso

    INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 5 2008
    Guido Bens MD
    Dermatitis cruris pustulosa et atrophicans (DCPA) is a benign inflammatory skin disease of the younger population in the tropics. Although this pustular skin condition of particular topography is frequently seen by dermatologists in tropical countries, its origin remains unknown. We report the case of a young woman with DCPA associated with prurigo nodularis. A bacterial origin has not been demonstrated in this case. Histology showed an intraepidermal neutrophilic pustule with dermal and subcutaneous infiltration by neutrophils and eosinophils forming flame figures. Different pathogenic hypotheses are discussed with special regard to a potential relationship between DCPA and eosinophilic cellulitis. [source]


    Food security problems in sub-Saharan Africa: Operations Research as a tool of analysis

    INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 2 2008
    Caspar Schweigman
    Abstract For many years, the author has been involved in teaching and research in the use of Operations Research as a tool of analysis to study food security problems in sub-Saharan Africa, in particular, grass root problems of poor farmers. The paper presents an introduction to the way Operations Research methods have been applied in case studies and research projects, and discusses in retrospect the author's views on the strengths and limitations of the application of Operations Research. The paper has in particular been written for people who are not familiar with applications of Operations Research in agriculture, and are interested to learn about its potential usefulness in practice. The retrospective part is largely based on food security studies in e.g. Tanzania, Burkina Faso, Bénin, Togo and Eritrea and on participation in several interdisciplinary research programmes in Africa. [source]


    MINERAL: GOLD: Burkina Faso

    AFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 7 2010
    Article first published online: 1 SEP 2010
    No abstract is available for this article. [source]


    Identification of Bacillus spp. from Bikalga, fermented seeds of Hibiscus sabdariffa: phenotypic and genotypic characterization

    JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2008
    L.I.I. Ouoba
    Abstract Aims:, To identify Bacillus spp. responsible of the fermentation of Hibiscus sabdariffa for production of Bikalga, an alkaline fermented food used as a condiment in Burkina Faso. Methods and Results:, Seventy bacteria were isolated from Bikalga produced in different regions of Burkina Faso and identified by phenotyping and genotyping using PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS-PCR), repetitive sequence-based PCR (rep-PCR) and DNA sequencing. The isolates were characterized as motile, rod-shaped, endospore forming, catalase positive, Gram-positive bacteria. ITS-PCR allowed typing mainly at species level. Rep-PCR was more discriminative and allowed a typing at ssp. level. The DNA sequencing combined with the Blast search program and fermentation profiles using API 50CHB system allowed an identification of the bacteria as Bacillus subtilis, B. licheniformis, B. cereus, B. pumilus, B. badius, Brevibacillus bortelensis, B. sphaericus and B. fusiformis. B. subtilis were the predominant bacterium (42) followed by B. licheniformis (16). Conclusions:, Various species and ssp. of Bacillus are involved in fermentation of H. sabdariffa for production of Bikalga. Significance and Impact of the study:, Selection of starter cultures of Bacillus for controlled production of Bikalga, selection of probiotic bacteria. [source]


    Evidence for indigenous selection and distribution of the shea tree, Vitellaria paradoxa, and its potential significance to prevailing parkland savanna tree patterns in sub-Saharan Africa north of the equator

    JOURNAL OF BIOGEOGRAPHY, Issue 10 2003
    S. Maranz
    Abstract Aim, Woody vegetation patterns in African savannas north of the equator are closely connected to human presence, but the distinctions between natural and anthropogenic landscapes have not been clear to many observers. Criteria for identifying savanna landscapes on a continuum of intensity of anthropic impact are explored. Methods, A key savanna tree species, Vitellaria paradoxa (Sapotaceae), was used as model for evaluating anthropic impact. Fruits harvested from tree populations across the species range were analysed for variation in traits valued by indigenous peoples. A simple selection index was used to scale tree populations from a hypothetical wild state to a hypothetical domesticated state. Index values were compared with trait values along climate zone gradients and evaluated in the context of indigenous savanna management practices and historical species distribution reports. Results, Trait values such as fruit size and shape, pulp sweetness, and kernel fat content show a significant influence of temperature and rainfall. At the same time, the mean values of groups of traits vary perpendicular to the general climatic zone gradient. Selection index values between Vitellaria populations vary up to sixfold, with highest values in central Burkina Faso. Comparison of present day Vitellaria distribution with historical range limits show range expansion by human migration. Main conclusions, The prevalence of major economic tree species in the savannas of Africa north of the equator is a strong indicator of human involvement in tree dispersal. This conclusion is supported by paleobotanical evidence and by recent Vitellaria range expansion as a result of human migration. The presence of high mean values of several Vitellaria fruit traits in central Burkina Faso suggests that selection for desired characteristics has occurred. The impact of indigenous savanna peoples on woody species composition and spatial distribution is probably much greater than usually thought and is the result of a deliberate strategy of altering the landscape to provide needed human resources. [source]


    Does designation of protected areas ensure conservation of tree diversity in the Sudanian dry forest of Burkina Faso?

    AFRICAN JOURNAL OF ECOLOGY, Issue 2 2010
    Souleymane Paré
    Abstract The importance of conservation status of the forest (protected versus unprotected) at two sites with differing human population density (high versus low) on the tree diversity of a Sudanian dry forest in Burkina Faso was studied. All woody species were recorded in 127 circular plots (area = 456.16 m2), and density, dominance, frequency, importance value indices and a variety of diversity measures were calculated to assess the species composition, structure and heterogeneity. A total of 69 species, representing 26 families and 52 genera, were found. Combretaceae, Leguminosae subfamily Caesalpinioideae and Rubiaceae were the dominant families. Neither human pressure nor forest conservation status significantly influenced the tree species richness. Stem density and basal area were significantly higher at the site with high population density than otherwise. Fisher's diversity index revealed the unprotected forest at the site with low population density as the most diverse. We identified species with high conservation importance that should be enriched to maintain a viable population size. In conclusion, the current designation of protected areas seems inefficient at ensuring the conservation of tree diversity in the forest reserve. Thus, participatory conservation programme should be initiated. Résumé À deux endroits où la densité de population humaine est différente (forte versus faible), nous avons étudié l'importance du statut de conservation de la forêt (protégée ou non) pour la diversité d'une forêt soudanienne sèche du Burkina Faso. On a enregistré toutes les espèces ligneuses sur 127 parcelles circulaires (superficie = 456,16 m²), et on a calculé la densité, la dominance, les indices de valeurs d'importance value et une variété de mesures de diversité pour évaluer la composition, la structure et l'hétérogénéité des espèces. On a découvert un total de 69 espèces, représentant 26 familles et 52 genres. Les familles dominantes étaient Combretaceae, Leguminosae de la sous-famille Caesalpinioideae, et Rubiaceae. Ni la pression humaine, ni le statut de conservation des forêts n'influençaient significativement la richesse en espèces d'arbres. La densité des troncs et la surface terrière à la base étaient significativement plus élevées sur le site à forte densité de population. L'indice de diversité de Fisher a permis de révéler que la forêt non protégée du site à faible densité de population était la plus diversifiée. Nous avons identifié des espèces de haute valeur de conservation qui devraient être enrichies pour préserver une taille de population viable. En conclusion, la désignation actuelle d'aires protégées semble inefficace pour assurer la conservation de la diversité des arbres dans la réserve forestière. Donc, il faudrait initier un programme de conservation participative. [source]


    Assessment of melliferous plant potentialities in Burkina Faso

    AFRICAN JOURNAL OF ECOLOGY, Issue 4 2009
    Issa Nombré
    First page of article [source]


    Long-term effects of prescribed early fire, grazing and selective tree cutting on seedling populations in the Sudanian savanna of Burkina Faso

    AFRICAN JOURNAL OF ECOLOGY, Issue 1 2009
    Didier Zida
    Abstract Annual early fire, selective tree cutting and exclusion of grazing are currently used as management tools in the Sudanian savanna of Burkina Faso although their long-term effects on seedling recruitment are poorly documented. A factorial experiment involving fire, grazing and cutting, each with two levels, was established in 1992 to study the effects of these management regimes and their interactions on the regeneration of woody species, and examine whether their effects varied temporally. Species richness, density and the morphology of seedlings were assessed in 1997 and 2002, and their relative changes were determined. The change in species richness of multi-stemmed individuals was significantly higher (P = 0.018) on plots that received fire × cutting treatment than the control plots. Significantly more species with single-stem were found on unburnt than on burnt plots (P < 0.001). Grazing tended to reduce the change in total density while fire (P < 0.001) and grazing (P = 0.029) significantly reduced the change in density of single-stemmed individuals. Selective cutting did not affect the total seedling density, but tended to reduce the change in single-stemmed seedling density. Principal component analysis revealed species-specific responses to treatments, particularly the relatively high abundance of lianas compared with other species. Résumé Les feux annuels précoces, la coupe sélective d'arbres et l'exclusion du pâturage sont des moyens actuellement utilisés dans la gestion de la savane soudanienne du Burkina Faso, mais leurs effets à long terme sur le recrutement de jeunes plants sont encore mal documentés. Une expérience factorielle impliquant le feu, le pâturage et la coupe, chacun à deux niveaux, a été mis en place en 1992 pour étudier les effets de ces régimes de gestion et leurs interactions sur la régénération d'espèces ligneuses et pour voir si ces effets variaient de façon temporelle. La richesse spécifique, la densité et la morphologie des jeunes plants furent évaluées en 1997 et en 2002, et l'on a leurs changements relatifs déterminés. Le changement de la richesse spécifique des individus multicoles était significativement plus important (P = 0.018) dans les parcelles qui avaient subi le traitement feu × coupe que dans les parcelles témoins. On a trouvé significativement plus d'espèces à tige unique dans les parcelles non brûlées que dans les parcelles brûlées (P < 0.001). Le pâturage avait tendance à réduire le changement de densité totale alors que le feu (P < 0.001) et le pâturage (P = 0.029) réduisaient significativement le changement de densité des individus à tige unique. La coupe sélective n'affectait pas la densité totale des jeunes plants mais avait tendance à réduire le changement de la densité des plants à tige unique. L'analyse en composantes principales a révélé que les réponses aux différents traitements étaient spécifiques aux espèces, particulièrement l'abondance de lianes, relativement grande par rapport aux autres espèces. [source]


    Periodic spotted patterns in semi-arid vegetation explained by a propagation-inhibition model

    JOURNAL OF ECOLOGY, Issue 4 2001
    P. Couteron
    Summary 1,Vegetation cover regularly punctuated by spots of bare soil is a frequent feature of certain semi-arid African landscapes, which are also characterized by banded vegetation patterns (i.e. tiger bush). 2,The propagation-inhibition (PI) model suggests that a periodic pattern characterized by a dominant wavelength can theoretically establish itself through a Turing-like spatial instability depending only on a trade-off between facilitative and competitive interactions among plants. Under strictly isotropic conditions, spotted and banded patterns are distinct outcomes of a unique process, whereas anisotropy leads to a banded structure. The model predicts that spotted patterns will have a lower dominant wavelength than bands. 3,We test some outcomes of the PI model against vegetation patterns observable in aerial photographs from West Africa. Two sites with rainfall of c. 500,600 mm year,1 were studied: a 525-ha plain in north-west Burkina Faso and a 300-ha plateau in southern Niger. Digitized photographs were subjected to spectral analysis by Fourier transform in order to quantify vegetation patterns in terms of dominant wavelengths and orientations. 4,Spotted vegetation proved highly periodic. The characteristic range of dominant wavelengths (30,50 m) was similar at two sites more than 500 km apart. The PI model suggests that spots may occur as a hexagonal lattice but there is little evidence of such patterning in the field. A dominant wavelength was far quicker to establish in simulations (c. 102,103 years for annual grasses) than a hexagonal symmetry (c. 105 years), and observed patterns are therefore likely to be far from the asymptotic structure. 5,Elongated and smudged spots that locally became flexuous bands have been observed in southern Niger. This pattern that had a dominant wavelength of 50 m but lacked any dominant orientation can be interpreted as a transition from spots to bands under fairly isotropic conditions. 6,The PI model provides a framework for further investigation of patterns in semi-arid vegetation and may be of a broader ecological application. [source]


    Sustainable development and institutional change: evidence from the Tiogo Forest in Burkina Faso,

    JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 8 2007
    Philippe Dulbecco
    Abstract The management of forest resources in developing countries is often inefficient and this is particularly the case when forests are a public good managed by the state. These inefficiencies are generally the result of both externalities and free-riding behaviour. The solution usually considered is to change the property rights structure of the resource, that is, privatisation of forests. It appears, however, that privatisation also has inefficiencies of its own, particularly when it is imposed on local populations. The aim of our contribution is to go beyond the usual state management versus privatisation debate, and to propose instead a property rights structure and related co-ordination scheme which take into account the specific institutional circumstances of the economic setting in which the natural resources are being exploited. The purpose is to suggest solutions based on the need to attain coherence between the external institutional structure and the behaviour of local players. In others words, the challenge is to establish the conditions necessary for an induced,rather than imposed,institutional change. A property rights structure of a resource must consequently be analysed from two perspectives. The first, and more traditional one, sees property rights as an efficient institutional structure of production enabling a reduction in transaction costs. The second proposes to evaluate any given property rights structure from the standpoint of its ability to offer a solution to the issue of an effective link between the legal framework and the behaviour of the players. Our analysis will make use of our knowledge of the forest of Tiogo in Burkina Faso based on a survey organised in 12 riverside villages, and using a sample of 300 households. The case of the Tiogo Forest suggests that institutional change needs to follow an incremental and path-dependent process within which the state is invited to play a major role together with the local communities. Indeed the institutional choices of the Tiogo Forest households indicate that they favour an inclusion of the local population in resource management and co-administration of forestry resources with the state. Such an institutional structure favours a negotiated rather than an imposed scheduling of measures, and seeks a minimum of consensus to ensure the adhesion of actors and users to the new institutional arrangements, whilst limiting the number of bad players. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Practice, power and meaning: frameworks for studying organizational culture in multi-agency rural development projects

    JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 5 2003
    David Lewis
    Culture has received increasing attention in critical development studies, though the notion that there are important cultural differences within and between development organizations has received less consideration. This paper elaborates elements of a framework for studying organizational culture in multi-agency development projects. It draws on selected writings in anthropology and in organizational theory and suggests that these two bodies of literature can be usefully brought together, as well as on insights from ongoing fieldwork in Bangladesh, Burkina Faso and Peru. At the centre of this framework is the analysis of context, practice and power. Where development projects involve multiple organizations (such as donors, government agencies, non-governmental organizations and grassroots groups) an analysis of cultures both within and between organizational actors can help explain important aspects of project performance. The paper argues that organizational culture is constantly being produced within projects, sometimes tending towards integration, often towards fragmentation. This fragmentation, indicative of the range of cultures within development organizations, is an important reason why some projects fail, and why ideas stated in project documents are often not realized, especially in the case of the newer and more contentious objectives such as ,empowerment'. © 2003 John Wiley & Sons, Ltd. [source]


    Analysis of the diversity of the HIV-1 pol gene and drug resistance associated changes among drug-naïve patients in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 10 2009
    Denis M. Tebit
    Abstract A cross-sectional study was undertaken among drug-naïve HIV patients at the University Hospital in Ouagadougou shortly before and after the introduction of large-scale antiretroviral therapy (ART) in Burkina Faso. Baseline clinical and virological data as well as protease (PR) and 5, reverse transcriptase (RT) sequences from 104 HIV infected patients were analyzed. Genotypic classification revealed the following subtypes and recombinant forms: CRF06_cpx, n,=,46 (44.2%); CRF02_AG, n,=,39 (37.5%); subtype A, n,=,4 (3.8%); CRF09_cpx, n,=,2 (1.9%); and unclassified, n,=,13 (12.5%). Bootstrap analysis of CRF02_AG and CRF06_cpx viruses showed that >80% had a similar structure to their respective prototypes. The prevalence of primary drug resistance mutations was 12.5%, all mutations arising in the RT sequences in accordance with the dominance of this drug class in Burkina Faso. The mutations were distributed as follows: NRTI (10.6%): M41L (n,=,2), D67N (n,=,2), K70K/E (n,=,2), L210W (n,=,1), T215S/Y (n,=,2), and K219K/Q (n,=,2); NNRTI (6.1%): K103K/N (n,=,2), Y181C (n,=,2), G190G/A (n,=,1), and P236P/L (n,=,1). Subtype specific secondary polymorphisms such as K20I and M36I in the PR were observed in almost all patients. Drug resistance mutations occurred at similar frequencies (12.8% and 10.8%, respectively) among patients infected with CRF02_AG and CRF06_cpx. Some subtype specific polymorphisms were observed within important HLA epitopes, including B35, B7, and A2 in the RT, and A*6802 in the PR sequences. The observed resistance mutations are most likely to have been transmitted based on the timing of the study but prior undocumented use of ART cannot be excluded. J. Med. Virol. 81:1691,1701, 2009. © 2009 Wiley-Liss, Inc. [source]


    Viral load and physical status of human papillomavirus (HPV) 18 in cervical samples from female sex workers infected with HPV 18 in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 10 2009
    Audrey Damay
    Abstract Viral DNA load and physical status might be predictive of either high-grade cervical lesions or disease progression among women infected by human papillomavirus (HPV) 16, but these virological markers have rarely been studied in HPV 18 infections. The relationships between HPV 18 DNA load, viral genome physical status and cervical squamous intraepithelial lesions were analyzed among female sex workers infected with HPV18 in Burkina Faso. HPV 18 E2 and E6 genes were quantitated by real-time PCR. Among 21 women infected with HPV 18, 67% of whom were HIV-1-seropositive, 11 (52.4%) had a normal cytology, 8 (38.1%) had low-grade squamous intraepithelial lesions, and 2 (9.5%) had high-grade squamous intraepithelial lesions. Total viral load and integrated viral load were higher in women with squamous intraepithelial lesions than in women with normal cytology (P,=,0.01 for both parameters). Total viral load and integrated viral load were higher in HIV-1-seropositive women than in those who were not infected with HIV (P,=,0.01, and P, 0.01, respectively). Total viral load or integrated viral load >1,000,copies/ng of DNA were more frequent in women with squamous intraepithelial lesions than in women with normal cytology (7/10 vs. 1/11; P,=,0.007) and in HIV-1-seropositive women (8/14 vs. 0/7 in HIV-uninfected women; P,=,0.02). Both HPV 18 DNA and integrated DNA loads might represent markers of cervical lesions. Prospective evaluations are needed to establish the value of these parameters to predict high-grade lesion or lesion progression. J. Med. Virol. 81:1786,1791, 2009. © 2009 Wiley-Liss, Inc. [source]


    Effective program against mother-to-child transmission of HIV at Saint Camille Medical Centre in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 7 2007
    J. Simpore
    Abstract The present research was aimed to prevent mother-to-child transmission of HIV; to use RT-PCR in order to detect, 6 months after birth, infected children; and to test the antiretroviral resistance of both children and mothers in order to offer them a suitable therapy. At the Saint Camille Medical Centre, 3,127 pregnant women (aged 15,44 years) accepted to be enrolled in the mother-to-child transmission prevention protocol that envisages: (i) Voluntary Counselling and Testing for all the pregnant women; (ii) Antiretroviral therapy for HIV positive pregnant women and for their newborns; (iii) either powdered milk feeding or short breast-feeding and RT-PCR test for their children; (iv) finally, pol gene sequencing and antiretroviral resistance identifications among HIV positive mothers and children. Among the patients, 227/3,127 HIV seropositive women were found: 221/227 HIV-1, 4/227 HIV-2, and 2/227 mixed HIV infections. The RT-PCR test allowed the detection of 3/213 (1.4%) HIV infected children: 0/109 (0%) from mothers under ARV therapy and 3/104 (2.8%) from mothers treated with Nevirapine. All children had recombinant HIV-1 strain (CRF06_CPX) with: minor PR mutations (M36I, K20I) and RT mutations (R211K). Among them, two twins had Non-Nucleoside Reverse Transcriptase Inhibitor mutation (Y18CY). Both mothers acquired a major PR mutation (V8IV), investigated 6 months after a single-dose of Nevirapine. Prevention by single-dose of Nevirapine reduced significantly mother-to-child transmission of HIV, but caused many mutations and resistance to antiretroviral drugs. Based on present study the antiretroviral therapy protocol, together with the artificial-feeding, might represent the ideal strategy to avoid transmission of HIV from mother-to-child. J. Med. Virol. 79:873,879, 2007. © 2007 Wiley-Liss, Inc. [source]


    Viral load and genomic integration of HPV 16 in cervical samples from HIV-1-infected and uninfected women in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 6 2007
    Marie-Noelle Didelot Rousseau
    Abstract The relationships between human papillomavirus type 16 (HPV 16) viral load, HPV 16 integration status, human immunodeficiency virus type 1 (HIV-1) status, and cervical cytology were studied among women enrolled in a cohort of female sex workers in Burkina Faso. The study focused on 24 HPV 16-infected women. The HPV 16 viral load in cervical samples was determined by real-time PCR. Integration ratio was estimated as the ratio between E2 and E6 genes DNA copy numbers. Integrated HPV16 viral load was defined as the product of HPV 16 viral load by the integration ratio. High HPV 16 viral load and high integration ratio were more frequent among women with squamous intraepithelial lesions compared with women with normal cytology (33% vs. 11%, and 33% vs. 0%, respectively), and among women with high-grade squamous intraepithelial lesions compared with women without high-grade squamous intraepithelial lesions (50% vs. 17%, and 50% vs. 11%, respectively). High HPV 16 DNA load, but not high integration ratio, was also more frequent among HIV-1-positive women (39% vs. 9%; and 23% vs. 18%, respectively). The absence of statistical significance of these differences might be explained by the small study sample size. High-integrated HPV 16 DNA load was significantly associated with the presence of high-grade squamous intraepithelial lesions (50% vs. 5%, P,=,0.03) in univariate and multivariate analysis (adjusted odds-ratio: 19.05; 95% confidence interval (CI), 1.11,328.3, P,=,0.03), but not with HIV-1 or other high-risk HPV types (HR-HPV). Integrated HPV 16 DNA load may be considered as a useful marker of high-grade cervical lesions in HPV 16-infected women. J. Med. Virol. 79: 766,770, 2007. © 2007 Wiley-Liss, Inc. [source]


    Characterization of drug-resistance mutations in HIV-1 isolates from non-HAART and HAART treated patients in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 11 2006
    W.M. Nadembega
    Abstract Non-B HIV subtypes have been estimated to account for 88% of HIV infections in the world. These subtypes are particularly relevant in view of the availability of antiretroviral (ARV) drugs, since subtype-specific mutations are associated with drug-resistance in developing countries. Therefore, the pol gene sequences in HIV-1 isolates were examined from the three distinct groups of 39 infected patients from Ouagadougou in Burkina Faso: 17 patients who had not received any antiretroviral therapy (ART); 16 patients received ART, and 6 HIV-infected children, from infected mothers, received a single Nevirapine dose prophylaxis during birth. HIV-1 pol sequencing was successful for 29 samples. As expected, all patients presented the common (non-B subtype) M36I polymorphism and 26/29 (90%) the K20I mutation. Phylogenetic studies showed high predominance of recombinant HIV-1 strains: CRF06_cpx 16/29 (55.17%), CRF02_AG 9/29 (31.03%), A1 2/29 (6.89%), G 1/29 (3.44%), and CRF09_cpx 1/29 (3.44%). Two twins showed, 6 months after birth, a NNRTI-mutation (Y181C/Y). During the same period, the twin mother presented a different NNRTI-mutation (V106I), thus suggesting that the different blood drug concentration may determine a different drug-resistance pathway. Among 17 non-highly active antiretroviral therapy (HAART) patients, 3/17 (17.64%) presented virus with reverse transcriptase (RT) mutations [V118I: 1/17 patients (5.88%), V179E: 2/17 patients (11.76%)]. 10/17 (58.82%) presented virus with minor protease (PR) mutations [L63P: 5/17 patients (29.41%), V77I: 3/17 patients (17.64%), L10I: 2/17 patients (11.76%)]. 4/17 patients did not show any PR and RT mutations (23.52%). Among six HAART-treated patients, 6/6 and 3/6 had M36I and L63LP protease minor subtypes, respectively; and only two (33.33%) presented virus with K103N mutation. The low prevalence of drug-resistant associated mutations in Burkina Faso is encouraging. However, further studies with a larger cohort with a high non-B subtype prevalence are necessary to optimize ART in developing countries. J. Med. Virol. 78:1385,1391, 2006. © 2006 Wiley-Liss, Inc. [source]


    Network of sexual contacts and sexually transmitted HIV infection in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 6 2006
    Vito Latora
    Abstract Two thirds of the people who have been infected by human immunodeficiency virus (HIV) in the world live in Sub-Saharan African countries. The results of a study measuring the degree distribution of the network of sexual contacts in Burkina Faso are described. Such a network is responsible for the spread of sexually transmitted diseases, and in particular of HIV. It has been found that the number of different sexual partners reported by males is a power law distribution with an exponent ,,=,2.9 (0.1). This is consistent with the degree distribution of scale-free networks. On the other hand, the females can be divided into two groups: the prostitutes with an average of 400 different partners per year, and females with a stable partner, having a rapidly decreasing degree distribution. Such a result may have important implications on the control of sexually transmitted diseases and in particular of HIV. Since scale-free networks have no epidemic threshold, a campaign based on prevention and anti-viral treatment of few highly connected nodes can be more successful than any policy based on enlarged but random distribution of the available anti-viral treatments. J. Med. Virol. 78:724,729, 2006. © 2006 Wiley-Liss, Inc. [source]


    Toxoplasma gondii, HCV, and HBV seroprevalence and co-infection among HIV-positive and -negative pregnant women in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 6 2006
    Jacques Simpore
    Abstract Toxoplasma gondii (T. gondii) infections can cause serious complications in HIV-infected pregnant women, leading to miscarriage, stillbirth, birth defects (e.g., mental retardation, blindness, epilepsy etc.) and could favor or enhance the mother-to-child transmission of HCV, HBV, and HIV vertical transmission. From May 20, 2004 to August 3, 2005, 336 18,45 years aged pregnant women, were enrolled for an investigation of the prevalence of serum antibodies against T. gondii, HCV, HBV, and HIV using ELISA. The prevalence of T. gondii, HCV, and HBV in pregnant women was 25.3%, 5.4%, and 9.8%, respectively and the HIV serostatus (61.6%) seems to be associated with greater prevalence rates of both T. gondii (28.5% vs. 20.2%) and HBV (11.6% vs. 7.0%). Without taking into account HIV, only 65.5% (220 of 336) of the women were not infected with these agents. The co-infection rate between HIV-infected and -negative women was different statistically: T. gondii/HBV 0.048 versus 0.015, T. gondii/HCV 0.014 versus 0.008, and HCV/HBV 0.005 versus 0.008, respectively. The elevated co-infection rate in HIV-positive women demonstrated that they are exposed to T. gondii, HCV, and HBV infections prevalently by sexual contact. J. Med. Virol. 78:730,733, 2006. © 2006 Wiley-Liss, Inc. [source]


    Reduction of mother-to-child transmission of HIV at Saint Camille Medical Centre in Burkina Faso

    JOURNAL OF MEDICAL VIROLOGY, Issue 2 2006
    J. Simpore
    Abstract One thousand three hundred and twenty-eight pregnant women with less than 32 weeks of amenorrhea received voluntary counseling and testing at Saint Camille Medical Center from May 1, 2002 to December 30, 2004. Following informed consent and pre-test counseling, HIV screening was performed in 1,202 women. According to the prevention protocol, HIV-positive women received a single dose of Nevirapine (200 mg) during their labor, while their newborn received a single dose of Nevirapine (2 mg/kg) within 72 hr from birth. HIV seroprevalence (11.2%) was higher than in the overall population. One hundred and ninty-three children were born at the end of December 2004; 53 children (27.5%) followed a short breastfeeding protocol for 4 months, while 140 (72.5%) were fed artificially. All the children underwent RT-PCR test for HIV 5,6 months after their birth: 173 (89.6%) were HIV negative whilst 20 children (10.4%) were HIV positive. Out of the 20 positive children 5/53 (9.4%) had received breast milk for 4 months, while the remaining 15/140 (10.7%) had been fed artificially (P,=,0.814). Artificially fed babies (3/140 (2.1%)) and 1/53 (1.9%) of those breast fed for 4 months deceased according to mortality rate of HIV-positive children. This shows that there is no statistically significant difference (P,=,0.648) between the mortality of artificially fed (3/140 or 2.1%) and breast-fed (1/53 or 1.9%) children. Artificially fed children (20/140 (14.3%)) and 5/53 (9.4%) of breast-fed children died within 6,10 months. This figure indicates that there is no significant difference between the mortality rate of artificially and that of breast-fed children (P,=,0.427). Although the HIV prevention program reduced significantly the vertical transmission of HIV at Saint Camille Medical Center, the mortality of artificially fed children was still high due to gastrointestinal diseases. The HIV diagnosis by RT-PCR technique was of great help in the early identification of HIV-infected children. J. Med. Virol. 78:148,152, 2006. © 2005 Wiley-Liss, Inc. [source]


    Phosphate-solubilizing potential of the nematophagous fungus Arthrobotrys oligospora

    JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 2 2006
    Robin Duponnois
    Abstract The nematophagous fungus Arthrobotrys oligospora was tested in vitro and in vivo for its ability to solubilize rock phosphate. Three types of rock phosphate (RP) from Burkina Faso (KRP), Senegal (TRP), and Mali (TIRP) were used at four concentrations for the in-vitro experiment. All three types of RP were solubilized by the fungus. The maximum quantity of P recovered in solution was obtained with TRP, 12.5% for an application of 1 g L,1. The effect of TRP and A. oligospora applied separately or in combination was tested in vivo on the growth of A. holosericea. In a P-deficient soil without addition of RP, P solubilization was increased by addition of A. oligospora. The P uptake by plants growing in soil amended with TRP and inoculated with A. oligospora was significantly higher compared to noninoculated controls, thus demonstrating the ability of the fungus to solubilize additional phosphate from RP in vivo. [source]


    Using farmer knowledge to combat low productive spots in rice fields of a Sahelian irrigation scheme

    LAND DEGRADATION AND DEVELOPMENT, Issue 4 2004
    P. J. A. van Asten
    Abstract In the oldest sections of Burkina Faso's largest irrigation scheme in the Sourou Valley (13°,10,,N, 03°,30,W) rice (Oryza sativa L.) yields dropped from about 5 to 6,t,ha,1 in the early 1990s, shortly after establishment of the scheme, to 2 to 4,t,ha,1 from 1995 onwards. Farmers blamed this yield decline on the appearance of 2 to 20,m diameter low productive spots. According to farmers and field measurements, the low productive spots decreased yields by 25,50 per cent. The low productive spots are caused by Zn deficiency. Low Zn availability is related to the very low DTPA-extractable Zn content of the soil (0·08,0·46,mg,kg,1), the alkaline-calcareous character of the soil, the non-application of Zn fertilizers, and a relatively large P fertilizer dose (21,kg,P,ha,1). Farmers were correct in relating the calcareous nature of the soil to the presence of the low productive spots. They were instrumental in identifying application of decomposed organic resources (e.g. rice straw at 5,t,ha,1) as a short-term solution that increases yields by 1·5 to 2·0,t,ha,1. Application of Zn fertilizer (10,kg,Zn,ha,1) in 29 farmer fields in the 2001 dry season eradicated the low productive spots and increased yields from 3·4 to 6·0,t,ha,1. Although application of Zn fertilizer is strongly recommended, it is not yet available in Burkina Faso. Based on a comparison of fertilizer prices on the world market and the local market, we expect that the use of Zn fertilizers will be highly profitable (cost/value ratio,,,2). Despite the relatively recent introduction of irrigated rice cropping, most farmers showed a good understanding of cropping constraints and possible solutions. Both farmers and researchers mutually benefited from each other's knowledge and observations. Copyright © 2004 John Wiley & Sons, Ltd. [source]


    Rangewide population genetic structure of the African malaria vector Anopheles funestus

    MOLECULAR ECOLOGY, Issue 14 2005
    A. P. MICHEL
    Abstract Anopheles funestus is a primary vector of malaria in Africa south of the Sahara. We assessed its rangewide population genetic structure based on samples from 11 countries, using 10 physically mapped microsatellite loci, two per autosome arm and the X (N = 548), and 834 bp of the mitochondrial ND5 gene (N = 470). On the basis of microsatellite allele frequencies, we found three subdivisions: eastern (coastal Tanzania, Malawi, Mozambique and Madagascar), western (Burkina Faso, Mali, Nigeria and western Kenya), and central (Gabon, coastal Angola). A. funestus from the southwest of Uganda had affinities to all three subdivisions. Mitochondrial DNA (mtDNA) corroborated this structure, although mtDNA gene trees showed less resolution. The eastern subdivision had significantly lower diversity, similar to the pattern found in the codistributed malaria vector Anopheles gambiae. This suggests that both species have responded to common geographic and/or climatic constraints. The western division showed signatures of population expansion encompassing Kenya west of the Rift Valley through Burkina Faso and Mali. This pattern also bears similarity to A. gambiae, and may reflect a common response to expanding human populations following the development of agriculture. Due to the presumed recent population expansion, the correlation between genetic and geographic distance was weak. Mitochondrial DNA revealed further cryptic subdivision in A. funestus, not detected in the nuclear genome. Mozambique and Madagascar samples contained two mtDNA lineages, designated clade I and clade II, that were separated by two fixed differences and an average of 2% divergence, which implies that they have evolved independently for ,1 million years. Clade I was found in all 11 locations, whereas clade II was sampled only on Madagascar and Mozambique. We suggest that the latter clade may represent mtDNA capture by A. funestus, resulting from historical gene flow either among previously isolated and divergent populations or with a related species. [source]