Potentialités agroforestières de Maranthes polyandra (Benth.) Prance au sud-ouest du Burkina Faso

Objectif: Le maintien d’arbres et d’arbustes dans les champs, en association avec les cultures est certes lié à leur utilité alimentaire, médicinale, mais aussi à leurs aptitudes à améliorer la fertilité des sols. Des observations ont révélé une flore ligneuse abondante qui pousse préférentiellement au pied de Maranthes polyandra (Benth.) Prance. Elles ont suscité l’hypothèse que M. polyandra a des propriétés agro-écologiques intéressantes. L’objectif de l’étude est d’évaluer les relations entre M. polyandra et les propriétés physiques et chimiques du sol.Méthodes et résultats: La quantité de litière foliaire sous le houppier de M. polyandra a été collectée et pesée. Des échantillons de sol ont été prélevés sous le houppier et hors du houppier de M. polyandra pour des analyses physico-chimiques. Les mêmes travaux ont été réalisés à titre comparatif avec Vitellaria paradoxa C.F.Gaertn., qui est une espèce agroforestière connue.La quantité moyenne de litière foliaire sous M. polyandra est de 28,82 ± 16,08 kg par individu contre 5,92 ± 3,07 kg pour V. paradoxa. Nous avons trouvé des teneurs significativement plus élevées en carbone total, en azote total, en phosphore total, en potassium total et en somme des bases échangeables sous M. polyandra, comparativement à V. paradoxa. Les paramètres de texture sont significativement meilleurs pour le sol sous houppier de M. polyandra.Conclusion et application des résultats: Ce travail à permis d’étudier les relations entre M. polyandra et les propriétés physiques et chimiques du sol. Il a montré que l’espèce a un potentiel à améliorer la fertilité physique et chimique du sol. Maranthes polyandra pourrait être adoptée comme espèce agroforestière pour améliorer la fertilité du sol. Au Burkina Faso, plus de la moitié des terres sont pauvres en matière organique, en phosphore et en azote. Ces niveaux bas constituent la contrainte majeure pour la production agricole. Ainsi, M. polyandra pourrait être adoptée comme espèce agroforestière pour améliorer la fertilité du sol en plus de son exploitation pour l’alimentation et comme bois d’énergie ; Cela pourrait constituer une raison supplémentaire pour sa conservation.Mots clés: Agroforesterie, Maranthes polyandra, Fertilité du sol, Burkina Faso, Domestication, ConservationEnglish Title: Agroforestry potentials of Maranthes polyandra (Benth.) Prance in the south-west of Burkina FasoEnglish AbstractObjective: Maintaining trees and shrubs in fields in association with crops is linked to their use as food, firewood and pharmacopoeia, but also to their ability to improve physicochemical properties of soils. Observations revealed the presence of many plant species that grow preferentially at the foot of Maranthes polyandra (Benth.) Prance. These observations led to the hypothesis that M. polyandra has interesting agroecological properties. The objective of the study is to assess the relationship between M. polyandra and the physical and chemical properties of soil.Method and Results. The leaf litter under the crown of M. polyandra was collected and weighed. Soil samples were collected under the crown and outside the crown of M. polyandra for physicochemical analyses. The same work was carried out with Vitellaria paradoxa C.F. Gaertn. which is a known agroforestry species.The litter under M. polyandra is 28.82 ± 16.08 kg per individual plant compared to 5.92 ± 3.07 kg for V. paradoxa. Physicochemical analysis of the soil revealed, higher contents of organic carbon, total nitrogen, total phosphorus, total potassium and values in the sum of exchangeable bases under M. polyandra compared withthose obtained under V. paradoxa. These texture parameters are significantly better for the soil under crowns of M. polyandra.Conclusion and application of results: This work studied the relations between M. polyandra and the physical and chemical properties of the soil. It has shown that the species has potential to improve the physical and chemical fertility of the soil. Maranthes polyandra could be adopted as an agroforestry specie to improve soil fertility by its ability to enhance organic matter, phosphorus, nitrogen and potassium of the soils. In Burkina Faso, more than half of the land is poor in organic matter, in phosphorus and in nitrogen. This low levels are the major constraint for agricultural production. Thus, M. polyandra can be used to improve soils fertility in addition to its exploitation as food and firewood. This may be an additional reason for its conservation.Keywords: Agroforestry, Maranthes polyandra, Soil fertility, Burkina Faso,Domestication, Conservatio

The Tactician (extended version): A Seamless, Interactive Tactic Learner and Prover for Coq

We present Tactician, a tactic learner and prover for the Coq Proof Assistant. Tactician helps users make tactical proof decisions while they retain control over the general proof strategy. To this end, Tactician learns from previously written tactic scripts and gives users either suggestions about the next tactic to be executed or altogether takes over the burden of proof synthesis. Tactician's goal is to provide users with a seamless, interactive, and intuitive experience together with robust and adaptive proof automation. In this paper, we give an overview of Tactician from the user's point of view, regarding both day-to-day usage and issues of package dependency management while learning in the large. Finally, we give a peek into Tactician's implementation as a Coq plugin and machine learning platform.Comment: 19 pages, 2 figures. This is an extended version of a paper published in CICM-2020. For the project website, see https://coq-tactician.github.i

Not yet married: The implications of meanings of marriage on youths in Singapore

Journal website: http://yrc.hkfyg.org.hk/</p

Cross-Over between universality classes in a magnetically disordered metallic wire

In this article we present numerical results of conduction in a disordered quasi-1D wire in the possible presence of magnetic impurities. Our analysis leads us to the study of universal properties in different conduction regimes such as the localized and metallic ones. In particular, we analyse the cross-over between universality classes occurring when the strength of magnetic disorder is increased. For this purpose, we use a numerical Landauer approach, and derive the scattering matrix of the wire from electron's Green's function.Comment: Final version, accepted for publication in New Journ. of Physics, 27 pages, 28 figures. Replaces the earlier shorter preprint arXiv:0910.427

Flore, structure et état sanitaire des peuplements ligneux des parcs agroforestiers des forêts de Dindéresso et de Kuinima à l’ouest du Burkina Faso

Les parcs agroforestiers occupent des superficies non négligeables au Burkina Faso. Mais, du fait de la pression foncière, ils subissent des formes d’exploitation qui menacent leur existence dans le moyen terme. Pour une gestion durable des parcs agroforestiers, leur connaissance sur le plan floristique s’impose. C’est ainsi qu’une étude floristique a été menée dans les parcs agroforestiers des forêts classées de Dindéresso et de Kuinima à l’Ouest du Burkina Faso. L’objectif est de contribuer à une meilleure gestion du peuplement ligneux des parcs agroforestiers. Pour ce faire, un inventaire forestier dans des placettes circulaires de 900 m² a été réalisé en vue d’établir la liste floristique, la diversité spécifique et d’apprécier l’état de la régénération et l’état sanitaire des peuplements ligneux. Au total, 27 espèces ligneuses réparties en 14 familles et 27 genres dans les parcs agroforestiers de Dindéresso et 27 espèces ligneuses réparties en 12 familles et 26 genres dans les parcs agroforestiers de Kuinima ont été inventoriées. La diversité spécifique de Shannon-Weaver est faible avec 1,80 bit pour les parcs agroforestiers de Dindéresso et 1,33 bit pour ceux de Kuinima. La régénération est beaucoup plus marquée par l’espèce Vitellaria paradoxa Gaertn.f. suivie de Anacardium occidentaleL. [cult.]. Les taux de régénération sont de l’ordre de 54,12% et 9,41% pour Dindéresso puis 35,64% et 26,60% pour Kuinima respectivement, pour Vitellaria paradoxa et Anacardium occidentale. L’appréciation de l’état sanitaire révèle que 49,85% des pieds de Vitellaria paradoxa inventoriés dans la forêt classée de Kuinima sont parasités. Par contre dans la forêt classée de Dindéresso, le taux de parasitisme des pieds de Vitellaria paradoxa est de 13,37%. Au regard de ces taux de parasitisme, il est plus que nécessaire de développer des stratégies de lutte contre ces plantes parasites. À court et moyen termes si rien n’est fait, ces parasites affecteront considérablement les capacités de cette espèce agroforestière à fournir des biens et services. Agroforestry parks occupy significant areas in Burkina Faso. But, due to land pressure, they are subjected to forms of exploitation which threaten their existence in the medium term. For a sustainable management of agroforestry parks, their flora knowledge is essential. Thus, a floristic study was carried out in the agroforestry parks of the classified forests of Dindéresso and Kuinima in western Burkina Faso. The objective is to contribute to better management of the woody settlement in agroforestry parks. So, a forest inventory in circular plots of 900 m² was carried out in order to establish the floristic list, the specific diversity and to assess the state of regeneration and the state of health of the woody settlement. A total of 27 woody species divided into 14 families and 27 genera in the agroforestry parks of Dindéresso and 27 woody species divided into 12 families and 26 genera in the agroforestry parks of Kuinima were inventoried. The specific diversity of Shannon-Weaver is low with 1.80 bit for the agroforestry parks of Dinderesso and 1.33 bit for those of Kuinima. Regeneration is much more marked by the species Vitellaria paradoxa Gaertn. f. followed by Anacardium occidentale L. [cult.]. The regeneration rates are of the order of 54.12% and 9.41% for Dindéresso, then 35.64% and 26.60% for Kuinima, respectively for Vitellaria paradoxa and Anacardium occidentale. The assessment of the health status reveals that 49.85% of Vitellaria paradoxa plants inventoried in the Kuinima classified forest are parasitized. On the other hand in the classified forest of Dindéresso, the rate of parasitism of the feet of Vitellaria paradoxa is 13.37%. In view of these parasitism rates, it is more than necessary to develop strategies to combat these parasitic plants. In the short to medium term, if left unchecked, these pests will significantly affect the ability of this agroforestry species to provide goods and services

Missing safer sex strategies in HIV Prevention: A call for further research

Despite the efforts of educators, public health officials, and HIV/AIDS prevention experts, condom promotion has failed to stop the HIV epidemic in most of sub- Saharan Africa and most researchers and policy makers have focused on risk reductions for interventions for penetrative sex. We consider another HIV prevention option: female-to-male oral sex (fellatio). Extensive medical evidence indicates that fellatio is roughly as protective against HIV transmission as vaginal sex with a condom, and much safer than unprotected sex, but it is rarely emphasized in HIV prevention curricula. Moreover, available data on the practice of oral sex in Africa suggests that the practice is very rare compared to the practice in the United States. This paper reviews some of the existing evidence on the efficacy and prevalence of oral sex, discusses the potential of this safer sex strategy for mitigating the spread of HIV in Africa, and stresses the need for further research

T3SS-dependent differential modulations of the jasmonic acid pathway in susceptible and resistant genotypes of Malus spp. challenged with Erwinia amylovora

Fire blight is a bacterial disease of Maloideae caused by Erwinia amylovora (Ea). This necrogenic enterobacterium uses a type III secretion system (T3SS) to inject type III effectors into the plant cells to cause disease on its susceptible hosts, including economically important crops like apple and pear. The expressions of marker genes of the salicylic acid (SA) and jasmonic acid (JA) defense regulation pathways were monitored by RT-qPCR in leaves of two apple genotypes, one susceptible and one resistant, challenged with a wild type strain, a T3SS-deficient strain or water. The transcriptional data taken together with hormone level measurements indicated that the SA pathway was similarly induced in both apple genotypes during infection by Ea. On the contrary, the data clearly showed a strong T3SS-dependent down-regulation of the JA pathway in leaves of the susceptible genotype but not in those of the resistant one. Accordingly, methyl-jasmonate treated susceptible plants displayed an increased resistance to Ea. Bacterial mutant analysis indicated that JA manipulation by Ea mainly relies on the type III effector DspA/E. Taken together, our data suggest that the T3SS-dependent down-regulation of the JA pathway is a critical step in the infection process of Malus spp. by Ea

Locally Perturbed Random Walks with Unbounded Jumps

In \cite{SzT}, D. Sz\'asz and A. Telcs have shown that for the diffusively scaled, simple symmetric random walk, weak convergence to the Brownian motion holds even in the case of local impurities if $d \ge 2$. The extension of their result to finite range random walks is straightforward. Here, however, we are interested in the situation when the random walk has unbounded range. Concretely we generalize the statement of \cite{SzT} to unbounded random walks whose jump distribution belongs to the domain of attraction of the normal law. We do this first: for diffusively scaled random walks on $\mathbf Z^d$ $(d \ge 2)$ having finite variance; and second: for random walks with distribution belonging to the non-normal domain of attraction of the normal law. This result can be applied to random walks with tail behavior analogous to that of the infinite horizon Lorentz-process; these, in particular, have infinite variance, and convergence to Brownian motion holds with the superdiffusive $\sqrt{n \log n}$ scaling.Comment: 16 page

Completed cohomology of Shimura curves and a p-adic Jacquet-Langlands correspondence

We study indefinite quaternion algebras over totally real fields F, and give an example of a cohomological construction of p-adic Jacquet-Langlands functoriality using completed cohomology. We also study the (tame) levels of p-adic automorphic forms on these quaternion algebras and give an analogue of Mazur's `level lowering' principle.Comment: Updated version. Contains some minor corrections compared to the published versio