20 research outputs found
Périodes D’activités et Quelques Aspects du Comportement des Moyens et Grands Mammifères sur Deux îles (Dafidougou et Nakolo) au Nord du Parc National de Taï, Sud-ouest de la Côte d’Ivoire
Les nombreux travaux de recherche sur les mammifères du parc national de Taï se sont intéressés à sa grande partie sud. L’extrême nord du parc constitué d’un ensemble d’îles a rarement été investigué. Le présent travail essai de combler ce manque d’informations en étudiant la diversité des mammifères, leur période d’activité ainsi que quelques aspects de leur comportement sur Nakolo et Dafidougou, deux des 11 îles que constitue cette portion du parc. A cet effet, un total de 20 pièges photographiques a été installé de façon systématique sur ces deux îles. Un total de neuf espèces de mammifères a été identifié dont huit espèces sur l’île Nakolo et cinq sur Dafidougou. Cependant, l’indice de Shannon indique que la richesse en biodiversité de Dafidougou est légèrement supérieure à celle de Nakolo du fait de la grande dominance de la civette d’Afrique (Civettictis civetta) sur l’île Nakolo. Parmi les neuf espèces de mammifères détectées sur ces îles, la majorité est nocturnes, certaines sont diurnes et d’autres cathémérales. Sur le plan comportemental, les mammifères rencontrés se déplacent beaucoup, se nourrissent fréquemment et sont trè peu vigilants surtout sur l’île Dafidougou. Nous en déduisons l’existence désormais d’une quiétude et d’une tranquillité sur ces îles très anthropisées dans un passé récent.
Many research studies on mammals in Taï National Park have focused on its large southern part. The extreme north of the park, made up of a group of islands, has rarely been investigated. This work tries to fill this lack of information by studying the diversity of mammals, their period of activity as well as some aspects of their behavior on Nakolo and Dafidougou, two of the 11 islands that make up this portion of the park. To this end, a total of 20 camera traps have been systematically installed on these two islands. A total of nine species of mammals have been identified, including eight species on Nakolo Island and five on Dafidougou. However, the Shannon index indicates that the biodiversity richness of Dafidougou is slightly higher than that of Nakolo due to the great dominance of the African civet (Civettictis civetta) on Nakolo Island. Among the nine species of mammals detected on these islands, the majority are nocturnal, some are diurnal and others cathemeral. Behaviourally, the mammals encountered move around a lot, feed frequently and are not very vigilant, especially on Dafidougou Island. We deduce from this the existence now of peace and tranquility on these islands which were very anthropized in the recent past
IMPACT OF SOME CLIMATIC AND PHENOLOGICAL PARAMETERS ON THE CALLOGENESIS AND SOMATIC EMBRYOGENESIS VARIATIONS IN COCOA
Callogenesis and somatic embryogenesis (SE) are influenced by several
factors including climate and phenology. To assess such an influence,
the percentage of callogenesis and SE variations depending on five
climatic and two phenological parameters was measured for 2 years.
Staminodes and petals from six hybrids and two clones as controls were
cultured in bulk, onto three distinct calli induction media only
differing in hormonal concentrations. From the results, it emerged that
sole leaves flush does not vary from year to year. Maximal temperature
and flowering level are the most stably linked. Non-linear regression
provides the best R2-values of fitted curves. This shows that the link
among climate, phenology, callogenesis and SE is not linear. In the
first year, in control clones, climatic and phenological parameters
explain 52.80% callogenesis variations, against 31.50% for SE.
Therefore, climate and phenology significantly influence callogenesis,
but not SE. For further industrial production of secondary metabolites
such as butter, theobromin and chocolate aroma from calli, it would be
desirable also to identify the favourable periods for calli production.
Nevertheless, somatic embryos will continue to be produced all the year
irrespective of period.La callogen\ue8se et l\u2019embryogen\ue8se somatique (ES) sont
influenc\ue9s par plusieurs facteurs dont le climat et la
ph\ue9nologie. Pour \ue9valuer une telle influence, le pourcentage
de callogen\ue8se et d\u2019ES expliqu\ue9 par 5 param\ue8tres
climatiques et 2 param\ue8tres ph\ue9nologiques a \ue9t\ue9
mesur\ue9 durant 2 ann\ue9es. Les staminodes et les p\ue9tales
pr\ue9lev\ue9s sur 6 hybrides et 2 clones t\ue9moins ont
\ue9t\ue9 cultiv\ue9s en vrac, sur 3 milieux distincts
d\u2019induction de la callogen\ue8se se diff\ue9renciant par
leurs concentrations hormonales. Il est ressorti des r\ue9sultats que
seul le rythme des pouss\ue9es foliaires ne varie pas
significativement d\u2019une ann\ue9e \ue0 l\u2019autre. La
temp\ue9rature maximale et le niveau de floraison sont les plus
stablement corr\ue9l\ue9s. Le mod\ue8le non lin\ue9aire fournit
les meilleurs coefficients de d\ue9termination R2. Ceci montre que le
lien entre le climat, la ph\ue9nologie, la callogen\ue8se et
l\u2019ES n\u2019est pas lin\ue9aire. La premi\ue8re ann\ue9e
chez les 2 clones t\ue9moins, les param\ue8tres climatiques et
ph\ue9nologiques expliquent 52,80 % des variations de la
callogen\ue8se, contre 31,50 % pour celles d\u2019ES. En
cons\ue9quence, le climat et la ph\ue9nologie influencent
significativement la callogen\ue8se, mais non l\u2019ES. Pour la
production industrielle ult\ue9rieure de m\ue9tabolites secondaires
tels que le beurre, la th\ue9obromine et l\u2019arome de chocolat
\ue0 partir des cals, il serait souhaitable d\u2019identifier
\ue9galement des p\ue9riodes favorables \ue0 la production des
cals. N\ue9anmoins, les embryons somatiques continueront
d\u2019\ueatre produits toute l\u2019ann\ue9e sans tenir compte
de la p\ue9riode
Périodes D’activités et Quelques Aspects du Comportement des Moyens et Grands Mammifères sur Deux îles (Dafidougou et Nakolo) au Nord du Parc National de Taï, Sud-ouest de la Côte d’Ivoire
Les nombreux travaux de recherche sur les mammifères du parc national de Taï se sont intéressés à sa grande partie sud. L’extrême nord du parc constitué d’un ensemble d’îles a rarement été investigué. Le présent travail essai de combler ce manque d’informations en étudiant la diversité des mammifères, leur période d’activité ainsi que quelques aspects de leur comportement sur Nakolo et Dafidougou, deux des 11 îles que constitue cette portion du parc. A cet effet, un total de 20 pièges photographiques a été installé de façon systématique sur ces deux îles. Un total de neuf espèces de mammifères a été identifié dont huit espèces sur l’île Nakolo et cinq sur Dafidougou. Cependant, l’indice de Shannon indique que la richesse en biodiversité de Dafidougou est légèrement supérieure à celle de Nakolo du fait de la grande dominance de la civette d’Afrique (Civettictis civetta) sur l’île Nakolo. Parmi les neuf espèces de mammifères détectées sur ces îles, la majorité est nocturnes, certaines sont diurnes et d’autres cathémérales. Sur le plan comportemental, les mammifères rencontrés se déplacent beaucoup, se nourrissent fréquemment et sont trè peu vigilants surtout sur l’île Dafidougou. Nous en déduisons l’existence désormais d’une quiétude et d’une tranquillité sur ces îles très anthropisées dans un passé récent.
Many research studies on mammals in Taï National Park have focused on its large southern part. The extreme north of the park, made up of a group of islands, has rarely been investigated. This work tries to fill this lack of information by studying the diversity of mammals, their period of activity as well as some aspects of their behavior on Nakolo and Dafidougou, two of the 11 islands that make up this portion of the park. To this end, a total of 20 camera traps have been systematically installed on these two islands. A total of nine species of mammals have been identified, including eight species on Nakolo Island and five on Dafidougou. However, the Shannon index indicates that the biodiversity richness of Dafidougou is slightly higher than that of Nakolo due to the great dominance of the African civet (Civettictis civetta) on Nakolo Island. Among the nine species of mammals detected on these islands, the majority are nocturnal, some are diurnal and others cathemeral. Behaviourally, the mammals encountered move around a lot, feed frequently and are not very vigilant, especially on Dafidougou Island. We deduce from this the existence now of peace and tranquility on these islands which were very anthropized in the recent past
Diversité et Éthologie des Mammifères sur Deux Îles du Nord du Parc National de Taï, Sud-Ouest, Côte d’Ivoire
Les nombreux travaux de recherche sur les mammifères du parc national de Taï se sont intéressés à sa grande partie sud. L’extrême nord du parc constitué d’un ensemble de 11 îles a rarement été investigué. Le présent travail essai de combler ce manque d’informations en étudiant la diversité des mammifères, leur période d’activité ainsi que quelques aspects de leur comportement sur Nakolo et Dafidougou, deux des 11 îles qui n’ont jamais fait l’objet d’aucune recherche. A cet effet, 20 pièges photographiques a été installé de façon systématique sur ces deux îles pour conduire la présente étude. Un total de neuf (09) espèces de mammifères a été identifié dont huit (08) espèces sur l’île Nakolo et cinq (05) sur Dafidougou. Cependant, l’indice de Shannon indique que la richesse en biodiversité de Dafidougou (H’=1,297) est légèrement supérieure à celle de Nakolo (H’=1,209) du fait de la grande dominance de la civette d’Afrique (Civettictis civetta) sur l’île de Nakolo. Parmi les huit (08) espèces de mammifères détectées sur l’île Nakolo, quatre (04) espèces sont nocturnes, trois (03) sont cathémérales et une (01) seule est diurne. Quant à l’île Dafidougou, des cinq (05) espèces rencontrées, trois (03) sont nocturnes, une (01) cathémérale et une (01) autre diurne. Sur le plan comportemental, les mammifères rencontrés se déplacent beaucoup, se nourrissent fréquemment et sont très peu vigilants surtout sur l’île Dafidougou. Nous en déduisons l’existence désormais d’une quiétude et d’une tranquillité sur ces îles très anthropisées dans un passé récent.
Many research studies on mammals in Taï National Park have focused on its large southern part. The extreme north of the park, made up of a set of 11 islands, has rarely been investigated. The present work tries to fill this lack of information by studying the diversity of mammals, their period of activity as well as some aspects of their behaviour on Nakolo and Dafidougou, two of the 11 islands which have never been the subject of no research. For this purpose, 20 camera traps were systematically installed on these two islands to conduct this study. A total of nine (09) species of mammals have been identified including eight (08) species on Nakolo Island and five (05) on Dafidougou. However, the Shannon index indicates that the biodiversity richness of Dafidougou (H'=1.297) is slightly higher than that of Nakolo (H'=1.209) due to the great dominance of the African civet (Civettictis civetta) on the island of Nakolo. Among the eight (08) species of mammals detected on Nakolo Island, four (04) species are nocturnal, three (03) are cathemeral and only one (01) is diurnal. As for Dafidougou Island, of the five (05) species encountered, three (03) are nocturnal, one (01) cathedral and another (01) diurnal. Behaviourally, the mammals encountered move around a lot, feed frequently and are not very vigilant, especially on Dafidougou Island. We deduce from this the existence now of peace and tranquillity on these islands which were very anthropized in the recent past
Towards an optimal design of target for tsetse control: comparisons of novel targets for the control of Palpalis group tsetse
Abstract Background: Tsetse flies of the Palpalis group are the main vectors of sleeping sickness in Africa. Insecticide impregnated targets are one of the most effective tools for control. However, the cost of these devices still represents a constraint to their wider use. The objective was therefore to improve the cost effectiveness of currently used devices
Towards an optimal design of target for tsetse control: comparisons of novel targets for the control of palpalis group tsetse in West Africa
Background: Tsetse flies of the Palpalis group are the main vectors of sleeping sickness in Africa. Insecticide impregnated targets are one of the most effective tools for control. However, the cost of these devices still represents a constraint to their wider use. The objective was therefore to improve the cost effectiveness of currently used devices.
Methodology/Principal Findings: Experiments were performed on three tsetse species, namely Glossina palpalis gambiensis and G. tachinoides in Burkina Faso and G. p. palpalis in Côte d'Ivoire. The 1×1 m2 black blue black target commonly used in W. Africa was used as the standard, and effects of changes in target size, shape, and the use of netting instead of black cloth were measured. Regarding overall target shape, we observed that horizontal targets (i.e. wider than they were high) killed 1.6-5x more G. p. gambiensis and G. tachinoides than vertical ones (i.e. higher than they were wide) (P<0.001). For the three tsetse species including G. p. palpalis, catches were highly correlated with the size of the target. However, beyond the size of 0.75 m, there was no increase in catches. Replacing the black cloth of the target by netting was the most cost efficient for all three species.
Conclusion/Significance: Reducing the size of the current 1*1 m black-blue-black target to horizontal designs of around 50 cm and replacing black cloth by netting will improve cost effectiveness six-fold for both G. p. gambiensis and G. tachinoides. Studying the visual responses of tsetse to different designs of target has allowed us to design more cost-effective devices for the effective control of sleeping sickness and animal trypanosomiasis in Africa
Pharyngeal Carriage of Beta-Haemolytic Streptococcus Species and Seroprevalence of Anti-Streptococcal Antibodies in Children in Bouaké, Côte d’Ivoire
The pharynx of the child may serve as a reservoir of pathogenic bacteria, including
beta-haemolytic group A streptococci (GAS), which can give rise to upper airway infections
and post-streptococcal diseases. The objective of this study was to determine the prevalence
of beta-haemolytic Streptococcus spp. in pharyngeal samples stemming from children aged 3–14 years
in Bouaké, central Côte d’Ivoire. Oropharyngeal throat swabs for microbiological culture and venous
blood samples to determine the seroprevalence of antistreptolysin O antibodies (ASO) were obtained
from 400 children in March 2017. Identification was carried out using conventional bacteriological
methods. Serogrouping was performed with a latex agglutination test, while an immunological
agglutination assay was employed for ASO titres. The mean age of participating children was 9 years
(standard deviation 2.5 years). In total, we detected 190 bacteria in culture, with 109 beta-haemolytic
Streptococcus isolates, resulting in an oropharyngeal carriage rate of 27.2%. Group C streptococci
accounted for 82.6% of all isolates, whereas GAS were rarely found (4.6%). The ASO seroprevalence
was 17.3%. There was no correlation between serology and prevalence of streptococci (p = 0.722).
In conclusion, there is a high pharyngeal carriage rate of non-GAS strains in children from Bouaké,
warranting further investigation
How do tsetse recognise their hosts? The role of shape in the responses of tsetse (Glossina fuscipes and G. palpalis) to artificial hosts
Palpalis-group tsetse, particularly the subspecies of Glossina palpalis and G. fuscipes, are the most important transmitters of human African trypanomiasis (HAT), transmitting .95% of cases. Traps and insecticide-treated targets are used to control tsetse but more cost-effective baits might be developed through a better understanding of the fly’s host-seeking behaviour.Electrocuting grids were used to assess the numbers of G. palpalis palpalis and G. fuscipes quanzensis attracted to and landing on square or oblong targets of black cloth varying in size from 0.01 m2 to 1.0 m2. For both species, increasing the size of a square target from 0.01 m2 (dimensions = 0.1 x 0.1 m) to 1.0 m2 (1.0 x 1.0 m) increased the catch ,4x however the numbers of tsetse killed per unit area of target declined with target size suggesting that the most cost efficient targets are not the largest. For G. f. quanzensis, horizontal oblongs, (1 m wide x 0.5 m high) caught, 1.8x more tsetse than vertical ones (0.5 m wide x 1.0 m high) but the opposite applied for G. p. palpalis. Shape preference was consistent over the range of target sizes. For G. p. palpalis square targets caught as many tsetse as the oblong; while the evidence is less strong the same
appears to apply to G. f. quanzensis. The results suggest that targets used to control G. p. palpalis and G. f. quanzensis should be square, and that the most cost-effective designs, as judged by the numbers of tsetse caught per area of target, are likely to be in the region of 0.25 x 0.25 m2. The preference of G. p. palpalis for vertical oblongs is unique amongst tsetse species, and it is suggested that this response might be related to its anthropophagic behaviour and hence importance as a vector of HAT
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The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses
Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems
IMPACT OF SOME CLIMATIC AND PHENOLOGICAL PARAMETERS ON THE CALLOGENESIS AND SOMATIC EMBRYOGENESIS VARIATIONS IN COCOA
Callogenesis and somatic embryogenesis (SE) are influenced by several
factors including climate and phenology. To assess such an influence,
the percentage of callogenesis and SE variations depending on five
climatic and two phenological parameters was measured for 2 years.
Staminodes and petals from six hybrids and two clones as controls were
cultured in bulk, onto three distinct calli induction media only
differing in hormonal concentrations. From the results, it emerged that
sole leaves flush does not vary from year to year. Maximal temperature
and flowering level are the most stably linked. Non-linear regression
provides the best R2-values of fitted curves. This shows that the link
among climate, phenology, callogenesis and SE is not linear. In the
first year, in control clones, climatic and phenological parameters
explain 52.80% callogenesis variations, against 31.50% for SE.
Therefore, climate and phenology significantly influence callogenesis,
but not SE. For further industrial production of secondary metabolites
such as butter, theobromin and chocolate aroma from calli, it would be
desirable also to identify the favourable periods for calli production.
Nevertheless, somatic embryos will continue to be produced all the year
irrespective of period.La callogenèse et l’embryogenèse somatique (ES) sont
influencés par plusieurs facteurs dont le climat et la
phénologie. Pour évaluer une telle influence, le pourcentage
de callogenèse et d’ES expliqué par 5 paramètres
climatiques et 2 paramètres phénologiques a été
mesuré durant 2 années. Les staminodes et les pétales
prélevés sur 6 hybrides et 2 clones témoins ont
été cultivés en vrac, sur 3 milieux distincts
d’induction de la callogenèse se différenciant par
leurs concentrations hormonales. Il est ressorti des résultats que
seul le rythme des poussées foliaires ne varie pas
significativement d’une année à l’autre. La
température maximale et le niveau de floraison sont les plus
stablement corrélés. Le modèle non linéaire fournit
les meilleurs coefficients de détermination R2. Ceci montre que le
lien entre le climat, la phénologie, la callogenèse et
l’ES n’est pas linéaire. La première année
chez les 2 clones témoins, les paramètres climatiques et
phénologiques expliquent 52,80 % des variations de la
callogenèse, contre 31,50 % pour celles d’ES. En
conséquence, le climat et la phénologie influencent
significativement la callogenèse, mais non l’ES. Pour la
production industrielle ultérieure de métabolites secondaires
tels que le beurre, la théobromine et l’arome de chocolat
à partir des cals, il serait souhaitable d’identifier
également des périodes favorables à la production des
cals. Néanmoins, les embryons somatiques continueront
d’être produits toute l’année sans tenir compte
de la période