231 research outputs found
Nollywood: Indigenous Culture, Interculturality, and the Transplantation of American Popular Culture onto Postcolonial Nigerian Film and Screen
Nigeria, the Giant of Africa, has three big tribes: Yoruba, Igbo, and Hausa. It was a British colony which was amalgamated in 1914. The country became independent in 1962 and was right away bedeviled by military coups d’états and a bloody civil war (1967-1970). In 1999, the country experienced democratic dispensation. In the 1990s, the Nollywood nascent movie industry—following in the footpath of Hollywood and Bollywood—flourished. The movie industry grew thanks to four factors: Rapid urbanization; the hand-held video camera; the advent of satellite TV; and, the overseas migrations of Nigerians. Local languages are used in these films; however, English is the most prominent, along with Nigerian pidgin broken English. Many themes are treated in these films: tradition and customs, religion, witchcraft and sorcery, satire, urban and rural lives, wealth acquisition, consumerism, etc. I discuss the ways in which American popular culture is adopted in Nigeria and recreated on screen. Nigeria and USA share Federalism, the superlative mode, and gigantism (houses, cars, people, etc.), and many Nigerians attend American universities. In the final analysis, the arguments exposed in this paper highlight the multitude of ways in which Nigerians navigate the treacherous waters of modernity and globalization
Modélisation des liens entre la morphologie urbaine, la génération de polluants et leur concentration dans l'air par l'approche PLS path modelling
Caractéristiques morphologiques et croissance de jeunes plants de Jatropha curcas L.
Une étude sur le développement de jeunes plants de Jatropha curcas (L) provenant de boutures et de semis a été menée dans le Jardin botanique du Département de Biologie végétale de l’Université Cheikh Anta Diop de Dakar en comparant différents paramètres liés à leur croissance et à leur morphologie racinaire. Une culture de boutures et de semis en pots remplis de sol sablo-argileux et disposés en bloc complètement randomisé puis un essai de semis direct sur une parcelle de 100 m2 du même substrat ont été réalisés. Les résultats ont montré que les segments de rameau proches de la tige débourrent mieux (80%) que les segments apicaux (50%). Par ailleurs, aucune différence significative n’a été notée sur la germination entre les graines décortiquées (87%) et les graines non décortiquées (73,3%). Le rapport « longueur racine / longueur tige » est plus élevé chez les boutures que chez les plants issus de semis. Les boutures ont émis des racines adventives dont l’une évolue en pivot avec beaucoup de ramifications tandis que les autres racines disparaissent. Les semis en pot ont présenté un enracinement dense avec plus de ramifications latérales en forme d’échasse que les semis directs dont les ramifications ont, par ailleurs, été superficielles. Les mensurations effectuées sur la partie aérienne ont montré une croissance en diamètre chez les plants issus de semis direct et de semis en pot de 17,5 mm et de 13,08 mm chez les boutures.Mots clés: Semis, bouture, tige, racin
Anisotropic exchange and non-collinear antiferromagnets on a noncentrosymmetric fcc structure as in the half-Heuslers
One of the signatures of the face-centered cubic (fcc) antiferromagnet as a
typical example of a geometrically frustrated system is the large ground state
degeneracy of the classical nearest neighbor and next-nearest neighbor
Heisenberg (isotropic) model on this lattice. In particular, collinear states
are degenerate with non-collinear and non-coplanar ones: this degeneracy is
accidental and is expected to be lifted by anisotropic exchange interactions.
In this work, we derive the most general nearest and next-nearest neighbor
exchange model allowed by the space-group symmetry of the noncentrosymmetric
half-Heusler compounds, which includes three anisotropic terms: the so-called
Kitaev, Gamma and Dzyaloshinskii-Moriya interactions -- most notably, the
latter is allowed by the breaking of inversion symmetry in these materials and
has not been previously been studied in the context of the fcc lattice. We
compute the resulting phase diagram and show how the different terms lift the
ground state degeneracy of the isotropic model, and lay emphasis on finding
regimes where multi-q (non-collinear/non-coplanar) states are selected by
anisotropy. We then discuss the role of quantum fluctuations and the coupling
to a magnetic field in the ground state selection, and show that these effects
can stabilize non-coplanar (triple-q) states. These results suggest that some
half-Heusler antiferromagnets might host rare non-collinear/non-coplanar
orders, which may in turn explain the unusual transport properties detected in
these semimetals.Comment: 20 pages, 10 figures, 4 table
An Index of African Monetary Integration (IAMI)
This study improves the African Regional Integration Index (ARII) proposed by the African Union, the African Development Bank and the United Nations Economic Commission for Africa by providing a theoretical framework and addressing shortcomings related to weighting and aggregation of the indicator. This paper measures monetary integration in the eight African Regional Economic Communities (RECs) by constructing an Index of African Monetary Integration (IAMI). It proposes an Optimal Currency Area as theoretical framework and uses a panel approach to appreciate the dynamics of the index over different periods of time. The findings show that: (i) inflation and finance (trade and mobility) present the highest (lowest) score while ECOWAS is (EAC and IGAD are) the highest (least) performing. (ii) Surprisingly, in most RECs, the highest contributors to wealth creation are not the top performers in regional monetary integration. (iii) The RECs in Africa are characterized by a stable monetary integration which is different from the gradual process usually observed in monetary integration because with the exception of the EAC and UMA, the dynamics of IAMI show a steady trend in the overall index across time. Policy implications are discussed
Effet du chlorure de sodium sur la germination de graines de Ricinus communis L.
Ricinus communis L (ricin) figure parmi les espèces du Programme biocarburant au Sénégal. Sa culture sur des terrains incultes (terres salées) constitue une alternative pour éviter une concurrence sur les terres à vocation agricole. C’est pourquoi le taux de germination (TG) de sept accessions de graines de ricin a été étudié pendant 15 jours sous des concentrations croissantes de NaCl (0; 20; 50; 80; 100; 150 et 200 mM). Les résultats ont montré une large variabilité de tolérance au sel au stade de la germination. Les accessions 3 et 8 ont été très sensibles avec des TG réduits seulement à la concentration 20 mM NaCl. Les accessions 1, 6 et 7 n’ont pas toléré la concentration 50 mM. L’accession 5 n’a toléré que les teneurs < 80 mM. L’accession 4 a germé dans les milieux ≤ 100 mM NaCl. Elle n’a manifesté une perte significative de TG qu’en présence de 150 mM NaCl. Elle a été la moins affectée par l’effet ralentisseur du sel sur la vitesse de germination. Ces résultats permettent de dire que le mode d’action de NaCl sur la germination est de nature osmotique et/ou toxique.Mots clés : Ricin, espèce, biocarburant, tolérance au sel, teneur en sel, Sénégal
Global health care infrastructure and Africa in times of Covid-19: insights for sustainable development and future pandemics
This exploratory study aims to assess Africa’s lagging position in global heath in relation to some health care infrastructure before critically examining the situation of Africa in the light of pressing Covid-19 healthcare infrastructural needs in terms of number of hospital beds, intensive care units (ICU) beds and ventilators per 100 000 people. A comparative analysis is provided to showcase which regions are leading in the health facilities in the world in general and Africa in particular as well as countries that are lagging in the attendant healthcare facilities. Analytical insights are provided to illustrate that the Covid-19 pandemic has revealed how Africa cannot reach most Sustainable Development Goals (SDGs), especially SDG-3 on health and wellbeing. Moreover, corresponding inferences suggest that the continent is unprepared for future pandemics in terms of health facilities
Research productivity: trend and comparative analyses by regions and continents
Using data for the period 2000 to 2019, the aim of this paper is to: (i) profile and compare research publications in regions and continents worldwide namely Africa, Western Europe, Eastern Europe, Northern America, Latin America, the Asiatic region, the Pacific region and the Middle East; (ii) assess factors associated with research productivity and (iii) verify if African countries are closing the deep gap of research production and by extension, detect factors on which to improve and boost the catch-up process. The empirical evidence is based on the Poisson regression model, quantile regression for counts data and panel negative binomial regression. The findings can be summarised as follows: (i) continuous and linear increasing trends in the production of knowledge are noted in developing regions specifically in Africa even if the contribution of the continent to global research is marginal; (ii) in countries with least production, ‘internet users’ is not significant but schooling modulates its effect on research production contrarily to countries in the upper part of the distribution and (iii) in Africa, if the number of schooling years increases by one, the number of documents or published works produced is expected to increase by a factor of 1.147
La genèse d'un foyer de tiques (Rhipicephalus sanguineux, Latreille 1806) vectrices de fièvre boutonneuse méditerranéenne, dans une cité HLM de l'espace suburbain de Marseille : rôle des facteurs sociologiques
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