58 research outputs found
Physical losses could partially explain modest carotenoid retention in dried food products from biofortified cassava
Gari, a fermented and dried semolina made from cassava, is one of the most common foods in West Africa. Recently introduced biofortified yellow cassava containing provitamin A carotenoids could help tackle vitamin A deficiency prevalent in those areas. However there are concerns because of the low retention of carotenoids during gari processing compared to other processes (e.g. boiling). The aim of the study was to assess the levels of true retention in transâÎČ-carotene during gari processing and investigate the causes of low retention. Influence of processing step, processor (3 commercial processors) and variety (TMS 01/ 1371; 01/1368 and 01/1412) were assessed. It was shown that low true retention (46% on average) during gari processing may be explained by not only chemical losses (i.e. due to roasting temperature) but also by physical losses (i.e. due to leaching of carotenoids in discarded liquids): true retention in the liquid lost from grating negatively correlated with true retention retained in the mash (R = -0.914). Moreover, true retention followed the same pattern as lost water at the different processing steps (i.e. for the commercial processors). Variety had a significant influence on true retention, carotenoid content, and trans-cis isomerisation but the processor type had little effect. It is the first time that the importance of physical carotenoid losses was demonstrated during processing of biofortified crops
The feasibility of classical biological control of two major cowpea insect pests
Biological control, as a key component of biointensive IPM in cowpea, is evaluated for its practical feasibility. The case study of one of the major insect pests, the bean flower thrips Megalumthrips sjosredti (Trybom) (Thysanoptera, Thripidae), is used to indicate the most important criteria for this evaluation: the nature of the pest and the release habitat, the availability and effectiveness of biological control agents, and the current status of biocontrol against the target pest. Although laxonomic aspects need further consideration, present knowledge suggests a southeast Asian origin for M. sjostedlt. In the savannas of West Africa, cultivated and wild host plants are always available to sustain the feeding and reproduction of the pest throughout the year, while the locally present natural enemies are unable to control its population. A first exploration in search of M. sjostedti and efficient natural enemies, undertaken in Malaysia in November-December 1994, yielded an endophagous larval parasitoid, tentatively identified as Ceranisus menes Walker (Hymenoptera, Eulophidae). This parasitoid was able to parasitize up to 70% of the larvae of the closely related species, M. usilalus, found in flowers of Pueraria phaseoloides, a commonly grown cover crop. In a second, less detailed case study, the biocontrol feasibility for another key pest, the legume pod borer, Marnca vitrata Fabricius (previously M. testuUilis Geyer) (Lepidoptera, Pyralidae). is assessed, using the same criteria. These feasibility studies indicate that (1) both pests might be of foreign origin: (2) the alternative host plant habitat is conducive to the perennial presence of the pests; (3) the indigenous antagonists are not effective in controlling the pests; and (4) potential natural enemies of both pests have been identified in southeast Asia. Additional foreign explorations are needed to substantiate the results of these studies
RĂLE DES NTIC DANS LâADAPTATION AUX CHANGEMENTS CLIMATIQUES PAR LES PRODUCTEURS DE COTON DU CENTRE - BĂNIN
The present study analysed the influence of the ICT use and
socio-economic characteristics of agricultural households on the
adaptation of smallholder farmers to climate change in Benin. A
multinomial choice model, suitable to data from a quantitative survey
on 121 cotton producers selected from 6 villages of central Benin has
been used in this study. Twenty-three adaptation strategies from
cross-sectional studies and refined in the study area through a
qualitative study phase were subjected to analysis. Results indicate
that âlate sowingsâ, and ârepeated sowingâ are
the most effective strategies developed by cotton producers to adapt to
climate variability. Collective practices are also developed as
preventive and curative strategies to situations of delay, scarcity,
abundance of rain and pockets of drought. Itâs about strategies
highly worship and based on âSacrifices to the godsâ,
âcollective prayersâ and âvillage meetings to raise
awareness for the respect of social taboosâ. Several variables
influence the adoption of different adaptation strategies. These
include the producerâs level of education, his age and
correlatively his experience in cotton production, the area of
residence, the way of accessing to land, the area of land used for
cotton cultivation and the number of ICT parks used. All actions whose
purpose is to improve the resilience of African agriculture to climate
change must dwell primarily on strategies for updating sowing dates and
new agricultural calendar based on the disruption of crop seasons.
Government policies and international adaptation programs should focus
on education, facilitating farmersâ access to ICT. Different
interventions should be done according to centered approaches on actors
and production systems.La prĂ©sente Ă©tude a analysĂ© lâinfluence de
lâusage des NTIC et des caractĂ©ristiques socio
Ă©conomiques des mĂ©nages agricoles sur lâadaptation des
petits agriculteurs béninois face aux changements climatiques.
Elle a utilisé un modÚle de choix multinomial adapté aux
donnĂ©es issues dâune enquĂȘte quantitative sur 121
producteurs de coton répartis dans 6 villages du
Centre-BĂ©nin. Vingt trois stratĂ©gies dâadaptation
issues dâĂ©tudes transversales et affinĂ©es dans la zone
dâĂ©tude par une phase dâĂ©tude qualitative ont
fait objet dâanalyse. Les rĂ©sultats indiquent que âles
semis tardifsâ et respectivement les âsemis
rĂ©pĂ©tĂ©sâ sont les stratĂ©gies les plus
dĂ©veloppĂ©es par les producteurs de coton pour sâadapter
à la variabilité climatique. Aussi des pratiques collectives
sont développées en guise de stratégies préventives
et curatives aux situations de retard, de rareté,
dâabondance des pluies, et de poches de sĂ©cheresses. Il
sâagit de stratĂ©gies fortement cultuelles basĂ©es sur
les âSacrifices aux divinitĂ©sâ, âles
priĂšres collectivesâ etâ les assemblĂ©es
villageoises de sensibilisation pour le respect des interdits
sociauxâ. Plusieurs variables influencent lâadoption des
diffĂ©rentes stratĂ©gies dâadaptation. Il sâagit
notamment du niveau dâinstruction du producteur, son Ăąge et
corrélativement son expérience dans la production de coton,
sa zone de rĂ©sidence, son mode dâaccĂšs au foncier, la
superficie de coton quâil cultive et le nombre de parc NTIC dont
il fait usage. Toutes actions ayant pour finalité
dâamĂ©liorer la rĂ©silience de lâagriculture
africaine aux changements climatiques doit sâappesantir en
premier lieu sur les stratĂ©gies dâactualisation des dates de
semis et du nouveau calendrier agricole en fonction de la perturbation
des saisons de cultures. Les politiques gouvernementales et programmes
internationaux dâadaptation doivent se focaliser sur
lâĂ©ducation, la facilitation de lâaccĂšs des
producteurs aux TIC. Les différentes interventions devront se
faire suivant des approches centrées sur les acteurs et sur les
systĂšmes de production
R 4LE DES NTIC DANS L\u2019ADAPTATION AUX CHANGEMENTS CLIMATIQUES PAR LES PRODUCTEURS DE COTON DU CENTRE - B\uc9NIN
The present study analysed the influence of the ICT use and
socio-economic characteristics of agricultural households on the
adaptation of smallholder farmers to climate change in Benin. A
multinomial choice model, suitable to data from a quantitative survey
on 121 cotton producers selected from 6 villages of central Benin has
been used in this study. Twenty-three adaptation strategies from
cross-sectional studies and refined in the study area through a
qualitative study phase were subjected to analysis. Results indicate
that \u2018late sowings\u2019, and \u2018repeated sowing\u2019 are
the most effective strategies developed by cotton producers to adapt to
climate variability. Collective practices are also developed as
preventive and curative strategies to situations of delay, scarcity,
abundance of rain and pockets of drought. It\u2019s about strategies
highly worship and based on \u2018Sacrifices to the gods\u2019,
\u2018collective prayers\u2019 and \u2018village meetings to raise
awareness for the respect of social taboos\u2019. Several variables
influence the adoption of different adaptation strategies. These
include the producer\u2019s level of education, his age and
correlatively his experience in cotton production, the area of
residence, the way of accessing to land, the area of land used for
cotton cultivation and the number of ICT parks used. All actions whose
purpose is to improve the resilience of African agriculture to climate
change must dwell primarily on strategies for updating sowing dates and
new agricultural calendar based on the disruption of crop seasons.
Government policies and international adaptation programs should focus
on education, facilitating farmers\u2019 access to ICT. Different
interventions should be done according to centered approaches on actors
and production systems.La pr\ue9sente \ue9tude a analys\ue9 l\u2019influence de
l\u2019usage des NTIC et des caract\ue9ristiques socio
\ue9conomiques des m\ue9nages agricoles sur l\u2019adaptation des
petits agriculteurs b\ue9ninois face aux changements climatiques.
Elle a utilis\ue9 un mod\ue8le de choix multinomial adapt\ue9 aux
donn\ue9es issues d\u2019une enqu\ueate quantitative sur 121
producteurs de coton r\ue9partis dans 6 villages du
Centre-B\ue9nin. Vingt trois strat\ue9gies d\u2019adaptation
issues d\u2019\ue9tudes transversales et affin\ue9es dans la zone
d\u2019\ue9tude par une phase d\u2019\ue9tude qualitative ont
fait objet d\u2019analyse. Les r\ue9sultats indiquent que \u2018les
semis tardifs\u2019 et respectivement les \u2018semis
r\ue9p\ue9t\ue9s\u2019 sont les strat\ue9gies les plus
d\ue9velopp\ue9es par les producteurs de coton pour s\u2019adapter
\ue0 la variabilit\ue9 climatique. Aussi des pratiques collectives
sont d\ue9velopp\ue9es en guise de strat\ue9gies pr\ue9ventives
et curatives aux situations de retard, de raret\ue9,
d\u2019abondance des pluies, et de poches de s\ue9cheresses. Il
s\u2019agit de strat\ue9gies fortement cultuelles bas\ue9es sur
les \u2018Sacrifices aux divinit\ue9s\u2019, \u2018les
pri\ue8res collectives\u2019 et\u2018 les assembl\ue9es
villageoises de sensibilisation pour le respect des interdits
sociaux\u2019. Plusieurs variables influencent l\u2019adoption des
diff\ue9rentes strat\ue9gies d\u2019adaptation. Il s\u2019agit
notamment du niveau d\u2019instruction du producteur, son \ue2ge et
corr\ue9lativement son exp\ue9rience dans la production de coton,
sa zone de r\ue9sidence, son mode d\u2019acc\ue8s au foncier, la
superficie de coton qu\u2019il cultive et le nombre de parc NTIC dont
il fait usage. Toutes actions ayant pour finalit\ue9
d\u2019am\ue9liorer la r\ue9silience de l\u2019agriculture
africaine aux changements climatiques doit s\u2019appesantir en
premier lieu sur les strat\ue9gies d\u2019actualisation des dates de
semis et du nouveau calendrier agricole en fonction de la perturbation
des saisons de cultures. Les politiques gouvernementales et programmes
internationaux d\u2019adaptation doivent se focaliser sur
l\u2019\ue9ducation, la facilitation de l\u2019acc\ue8s des
producteurs aux TIC. Les diff\ue9rentes interventions devront se
faire suivant des approches centr\ue9es sur les acteurs et sur les
syst\ue8mes de production
Recovery Rate of intestinal parasites using conventional methods in Ibadan, Nigeria
Five different techniques were used to diagnose all the 232 stool specimens that came into the Parasitology Department of University College Hospital, Ibadan for a period of six months. A prevalence of 25.0% was obtained in the study. Brine flotation recovered the highest number of parasites; 40 (69.0%), followed by formol ether concentration; 32 (55.2%), Katokatz recovered a total of 28 (48.3%) parasites, but could not recover any protozoan parasite, stoll technique recovered 22 (37.9%) parasites and wet preparation detected the least number of parasites; 12 (20.7%). There was a significant statistical difference among the techniques (◈ = 13. 63, P = 0.008). None of the methods could detect all the cases observed in the study alone, thus no single technique was satisfactory as none was equally applicable for trophozoites and cysts of protozoa, eggs or larvae of helminths. Brine flotation technique should be added to the routine diagnostic method (wet preparation), since it significantly detects both helminths and protozoa more than any of the other techniques.Nigerian Journal of Health and Biomedical Sciences Vol. 7 (1) 2008 pp. 42-4
Etude des possibilites de contamination des aliments de rues au Benin : Cas de la ville de Cotonou
Foods poisoning due to microbial toxins are widespread throughout the world. These foods poisoning are prevalent in African countries were street alimentation enable 80% of urban populations to feedthemselves easily and at lower price. The street foods constitute a major public health problem because of the multiplicity and the diversity of bacteria they can transport. So, the aim of our study was to assess the microbial quality of some street foods collected among the vendors in Cotonou city. The investigations on the selling sites and the analysis showed that there is perpetual risk of food contamination. Themajority of the vendors (84%) are women, and 78.67 % are illiterates. The microbiological analysis revealed that 77% of pathogenic bacteria were found among the ambulant vendors, 33% among semistationaryvendors and 26 among stationary vendors. All the concerned meals had a high charge of microbes indicating faecal pollution, of staphylococcal, salmonella and some yeast and mildew. However, considering the role of this kind of alimentation in African national economies, it is importantto find strategies leading a sanitary security, by epidemiologic surveillance of diseases transmitted by street foods. Les intoxications alimentaires dues Ă lâingestion de toxines microbiennes sont rĂ©pandues Ă travers le monde. Ces intoxications alimentaires sont trĂšs frĂ©quentes dans les pays africains oĂč lâalimentation de rue permet Ă plus de 80% des populations urbaines de sâalimenter facilement et Ă moindre coĂ»t. Les aliments vendus aux abords des rues de nos villes constituent donc un problĂšme de majeure de santĂ© publique de par la multiplicitĂ© et la diversitĂ© de la flore microbienne quâils vĂ©hiculent. Ainsi, notre Ă©tude a eu pour butdâĂ©tudier les possibilitĂ©s de contamination de quelques aliments de rue prĂ©levĂ©s chez des vendeurs dans la ville de Cotonou au BĂ©nin. Les investigations sur les lieux de vente et les rĂ©sultats dâanalysemicrobiologique ont rĂ©vĂ©lĂ© la prĂ©sence dâun risque perpĂ©tuel de contamination selon les types de distributeurs. La majoritĂ© (84%) des vendeurs Ă©tait des femmes et 78,67% Ă©taient illettrĂ©s. Les analysesmicrobiologiques ont montrĂ© que les aliments qui ne nĂ©cessitent pas de cuisson lors de la prĂ©paration avaient les plus fortes charges microbiennes. Soixante dix sept pour cent (77%) des germes pathogĂšnes ont Ă©tĂ© dĂ©tectĂ©s dans les aliments prĂ©levĂ©s chez les vendeurs ambulants, 33% chez les semi-fixes et 26% chez les Fixes. Tous les plats incriminĂ©s ont des charges microbiennes en flore aĂ©robie mĂ©sophile, indicateurs de pollution fĂ©cale, de staphylocoques et quelques levures et moisissures. Toutefois vu le rĂŽle que joue cette alimentation dans les Ă©conomies nationales de nos pays africains il est important de mettre en place plusieurs stratĂ©gies visant Ă une sĂ©curitĂ© sanitaire par une surveillance Ă©pidĂ©miologique des maladies transmises par les aliments de rue
The Nigerian national blindness and visual impairment survey: Rationale, objectives and detailed methodology.
BACKGROUND: Despite having the largest population in Africa, Nigeria has no accurate population based data to plan and evaluate eye care services. A national survey was undertaken to estimate the prevalence and determine the major causes of blindness and low vision. This paper presents the detailed methodology used during the survey. METHODS: A nationally representative sample of persons aged 40 years and above was selected. Children aged 10-15 years and individuals aged <10 or 16-39 years with visual impairment were also included if they lived in households with an eligible adult. All participants had their height, weight, and blood pressure measured followed by assessment of presenting visual acuity, refractokeratomery, A-scan ultrasonography, visual fields and best corrected visual acuity. Anterior and posterior segments of each eye were examined with a torch and direct ophthalmoscope. Participants with visual acuity of < = 6/12 in one or both eyes underwent detailed examination including applanation tonometry, dilated slit lamp biomicroscopy, lens grading and fundus photography. All those who had undergone cataract surgery were refracted and best corrected vision recorded. Causes of visual impairment by eye and for the individual were determined using a clinical algorithm recommended by the World Health Organization. In addition, 1 in 7 adults also underwent a complete work up as described for those with vision < = 6/12 for constructing a normative data base for Nigerians. DISCUSSION: The field work for the study was completed in 30 months over the period 2005-2007 and covered 305 clusters across the entire country. Concurrently persons 40+ years were examined to form a normative data base. Analysis of the data is currently underway. CONCLUSION: The methodology used was robust and adequate to provide estimates on the prevalence and causes of blindness in Nigeria. The survey would also provide information on barriers to accessing services, quality of life of visually impaired individuals and also provide normative data for Nigerian eyes
Factors that Influence the Rate and Intensity of Adoption of Improved Irrigation Technologies in Alberta, Canada
Experimental huts trial of the efficacy of pyrethroids/piperonyl butoxide (PBO) net treatments for controlling multi-resistant populations of Anopheles funestus s.s. in KpomĂš, Southern Benin
Open Access Journal; Published online: 13 June 2018Background: Insecticides resistance in Anopheles mosquitoes limits Long-Lasting Insecticidal Nets (LLIN) used for malaria control in Africa, especially Benin. This study aimed to evaluate the bio-efficacy of current LLINs in an area where An. funestus s.l. and An. gambiae have developed multi-resistance to insecticides, and to assess in experimental huts the performance of a mixed combination of pyrethroids and piperonyl butoxide (PBO) treated nets on these resistant mosquitoes.
Methods: The study was conducted at KpomĂš, Southern Benin. The bio-efficacy of LLINs against An. funestus and An. gambiae was assessed using the World Health Organization (WHO) cone and tunnel tests. A released/recapture experiment following WHO procedures was conducted to compare the efficacy of conventional LLINs treated with pyrethroids only and LLINs with combinations of pyrethroids and PBO. Prior to huts trials, we confirmed the level of insecticide and PBO residues in tested nets using high performance liquid chromatography (HPLC).
Results: Conventional LLINs (Type 2 and Type 4) have the lowest effect against local multi-resistant An. funestus s.s. and An. coluzzii populations from KpomÚ. Conversely, when LLINs containing mixtures of pyrethroids and PBO (Type 1 and Type 3) were introduced in trial huts, we recorded a greater effect against the two mosquito populations (P < 0.0001). Tunnel test with An. funestus s.s. revealed mortalities of over 80% with this new generation of LLINs (Type 1 and Type 3),while conventional LLINs produced 65.53 ± 8.33% mortalities for Type 2 and 71.25 ±7.92% mortalities for Type 4. Similarly, mortalities ranging from 77 to 87% were recorded with the local populations of An. coluzzii.
Conclusion: This study suggests the reduced efficacy of conventional LLINs (Pyrethroids alone) currently distributed in Benin communities where Anopheles populations have developed multi-insecticide resistance. The new generation nets (pyrethroids+PBO) proved to be more effective on multi-resistant populations of mosquitoes
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