Abdou Moumouni University

About: Abdou Moumouni University is a education organization based out in Niamey, Niamey, Niger. It is known for research contribution in the topics: Population & Agriculture. The organization has 796 authors who have published 808 publications receiving 17478 citations. The organization is also known as: University of Niamey & Abdou Moumouni Dioffo University.

Oviposition and Development of Bruchidius atrolineatus (Pic) and Callosobruchus maculatus (F.) (Coleopterae: Bruchidae) in Vigna unguiculata (Walp) Cultures in Niger

Abstract: Bruchidius atrolineatus (Pic) is present in crops of Vigna unguiculata towards the end of the dry season at the beginning of September when pods start to form. Females lay many eggs on most available green pods. However, this oviposition behaviour results in an important egg mortality. During September, pods gradually reach maturity whilst new pods are formed. Females therefore have at their disposal a growing number of differently mature pods. Confronted with such a situation, B. atrolineatus females show an opportunist behaviour and lay most of their eggs on the most abundant stage, i.e. the most easily discovered stage (ripening green pods in mid-September or dry pods towards the end of September). However, they also lay eggs on other phenological stages no matter how abundant they are. B. atrolineatus females therefore show a certain behavioural plasticity enabling them to reproduce on all stages of pods whose maturity, chemistry and texture may differ. Larvae can develop either in maturing or dry seeds. The number of eggs laid from mid September is lower and lower whatever the phenological stage attacked. This decrease would be due to a reduction of the first generation adult bruchids and of the reproductive potential of females. Callosobruchus maculatus appears in crops at the same time as B. atrolineatus, but oviposits preferentially on dry pods. Eggs are observed during the whole period of study, but the numbers laid are always low. With the increase in pod number, eggs are dispersed among the different substrates available. However, the average number of eggs laid on the pods remains constant. Despite the high mortality due to the oviposition behaviour of B. atrolineatus and to other factors (impact of hymenopterous parasitoids), these two bruchids cause important losses to seeds of V. unguiculata. Control methods against these pests should be envisaged.in the field before harvesting.

Screening of Tropical Medicinal Plants for Molluscicidal, Larvicidal, Fungicidal and Cytotoxic Activities and Brine Shrimp Toxicity

Abstract: Crude Extracts Of 36 Medicinal Plants Collected In Africa and South America Were Tested For Their Molluscicidal (Biomphalaria Glabrata), Larvicidal (Aedes Aegypti), Fungicidal (Cladosporium Cu-Cumerinum) and Cytotoxic (Against 2 Human Colon Carcinoma Cell Lines) Activities, As Well As For Brine Shrimp Toxicity (Artemia Salina). Members Of The Annonaceae, Guttiferae and Leguminosae Are Shown To Contain Compounds Highly Active In These 5 Bioassays. Three Of The Species Tested Stand Out For Their Marked Activity In Only One Bioassay: Rogeria Adenophylla and Sesamum Indicum (Pe-Daliaceae) Demonstrate Potent Larvicidal Activity and Adenium Obesum (Apocynaceae) Exhibits Very Strong Cytotoxicity.

Differences between banded thickets (tiger bush) at two sites in West Africa.

Abstract: . This paper deals with the influence of edaphic conditions on the spatial structure of banded thickets or tiger bush (brousse tigree). It is based on two sites in West Africa, with similar climatic conditions but located on contrasting substrates. The spatial structure was described with standardized characteristics including thicket spacing, thicket/inter-thicket contrast, upslope/downslope asymmetry and species zonation throughout the vegetation band. Recruitment and senescence features of woody stands were emphasized in order to understand current dynamics. Data were collected on transects oriented perpendicular to the contours and so to the thickets as well. A standardized analytical procedure was applied to data from both sites to ensure consistent and thorough delineation of thickets. The overall periodicity of thickets, the woody flora and the dominant species Combretum micranthum were similar at the two sites. However, thicket spacing, thicket/inter-thicket contrast and upslope/downslope floristic asymmetry of the thickets were higher in the less favourable site. Also seedlings were less abundant, with a greater dependence on pre-existing thickets. Not all banded vegetation systems show sharp contrasts and are strongly asymmetric, since such characteristics are likely to be reinforced by adverse environmental conditions. As a consequence, current dynamics may be more diverse than expected. Quantified inter-site comparisons can greatly help to classify African banded vegetation systems and to discuss potential dynamic outcomes.

The Brans–Dicke–Rastall theory

Abstract: We formulate a theory combining the principles of scalar–tensor gravity and Rastall’s proposal of a violation of the usual conservation laws. We obtain a scalar–tensor theory with two parameters $$\omega $$ and $$\lambda $$ , the latter quantifying the violation of the usual conservation laws ( $$\lambda = 1$$ corresponding to the General Relativity limit). The only exact spherically symmetric solution is that of Robinson–Bertotti besides the Schwarzschild solution. A PPN analysis reveals that General Relativity results are reproduced when $$\lambda = 0$$ . The cosmological case displays a possibility of deceleration/acceleration or acceleration/deceleration transitions during the matter dominated phase depending on the values of the free parameters.