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OALib Journal期刊

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Submergence Tolerance in Irrigated and Rainfed Lowland Rice Varieties: Agro-Morphological Basis for Rice Genetic Improvement in Southern Benin  [PDF]
Magloire Oteyami, Espérance Codjia, Clement Agbangla, Leonard Ahoton, Carline Santos, David Montcho, Antoine Missihoun
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104304
Abstract:
Objective: The study was carried out, on the rice perimeter of Southern Benin, to evaluate the response of irrigated and lowland rice varieties to the complete and partial submergence using agro-morphological traits. Method: Thus, 15 rice varieties were submerged in the field during 60 days according to split plot experimental design with two factors and three replications. Agro-morphological parameters such as plant height, number of tillers, the distance of internodes and the number of internodes were measured respectively at 13 days and 45 days. After harvest, some traits such as length, width and thickness of grains, panicle length, number of primary and secondary branches, the average number of empty grains and full grains per panicle and 1000-grain weight were recorded. Results: Very highly significant (P ≤ 0.0001) differences were identified between agro morphological parameters according to the type of submergence while the factor type of immersion has significant influence on the number of internodes at 45 days after transplanting (P ≤ 0.01). The submergence was not significant effect on tillering and length of internodes. Conclusion: The plant height, the weight of thousand grains and the average number of empty grains per panicle constitute key aspects and have been essential for evaluating tolerance to submergence in Benin.
Utilisation des espèces sauvages australiennes Gossypium sturtianum J.H. Willis et G. australe F. Muell. pour l'amélioration du cotonnier cultivé G. hirsutum L
Ahoton, L.
Tropicultura , 2003,
Abstract: Use of the Wild Australian Species Gossypium sturtianum J. H. Willis and G. australe F. Muell to Improve G. hirsutum L. Huit variétés de niébé améliorées et une locale (témoin) ont été testées en champ pendant trois ans en vue d'évaluer leur performance à produire à la fois des graines et du fourrage. Les résultats obtenus montrent que les taux de germination et de croissance étaient élevés (80%) pour toutes les variétés étudiées. Les moyennes de rendement étaient respectivement de 1262 à 3598 kg/ha pour la production de fourrage sec et de 528 à 1149 kg/ha pour la production de graines. Les variétés IAR 4/48/15-1, IAR 72 et TVU 12349 ont produit la plus grande quantité de feuilles vertes (> 50%) au stade de la récolte de graines durant la saison sèche tandis que les variétés IAR 4/48/15-1, IAR 7/180-4-5 et TVU 12349 ont produit le plus grand nombre de gousses par plant. Le poids de 100 graines le plus élevé a été produit par la variété IT89KD-288 et la variété témoin (Kananado). Le pourcentage moyen de la matière protéique variait de 15,2 à 21,6%.Une faible corrélation a été observée entre les rendements en graines, les rendements en fourrage et le rapport gousses/plant. Pour l'augmentation du revenu des fermiers, les variétés TVU 12349, IT89KD-288, IAR 7/180-4-12 et IAR 4/48/15-1 s'avèrent les plus performantes pour ces paramètres étudiés et sont à recommander dans un système de production intégré.
Floral Biology and Hybridization Potential of Nine Accessions of Physic Nut Jatropha curcas L. originating from Three Continents
Ahoton, LE.,Quenum, F.
Tropicultura , 2012,
Abstract: Jatropha curcas is a shrub which has an important economic and medicinal role in tropical and subtropical zones of the world. The oil of its kernels can serve as fuel feedstock to produce diesel, indicating its potential as a renewable source of energy. In an attempt to introduce new variation into cultivated Jatropha curcas, a program of intraspecific hybridization with several ecotypes originating from Africa, Asia and America was undertaken. Field studies were performed over three years 2009, 2010 and 2011. Before achieving hybridization, the floral ratio and the breeding system of physic nut were studied in Southern Benin ecological conditions. Significant differences (P< 0.05) were observed between the analysed ecotypes regarding the number of female flowers. This study has also confirmed that the breeding system of Jatropha curcas is essentially outcrossing and that foraging insects are the main pollination actors of female flowers. New intraspecific hybrid combinations were produced involving nine accessions. Crosses results varied according to the origin and the direction of the hybridization. Crosses between accessions of J. curcas originating from Africa and Asia gave hybrids without difficulty. The data obtained confirm that apomixis might play a major role in J. curcas a reproductive biology. Considering the high number of female flowers per inflorescence produced by the accession from Ecuador, and the large genetic distance existing between this accession and those from Africa and Asia, it should constitute a valuable genetic stock for the development of F1 hybrids with local ecotypes of J. curcas. However, the use of growth regulators might be necessary to improve the hybridization success rate when it is used as female parent.
Propagation of Black Plum (Vitex donania Sweet) Using Stem and Root Cuttings in the Ecological Conditions of South-Benin
Sanoussi, A.,Ahoton, LE.,Odjo, T.
Tropicultura , 2012,
Abstract: The black plum is a multi-purpose tree well known to the rural and urban populations of tropical Africa. Its uses are well documented, but its regeneration possibilities have not yet been studied, despite the importance of this species. The objective of this study is to ensure that this tree can be propagated from other organs instead of seeds. In order to achieve this, a trial propagation, using stem and root cuttings, was conducted on two types of substrate: topsoil at the planting site (sand mixed with poultry manure) and soil taken from undergrowth at the forest research station in Pobe, which focuses on the oil palm tree. The trial was based on a randomised complete block, two factors and four treatments. The results show that it is possible to propagate black plum trees from stem cuttings (46.62% of developed cuttings) but especially from root cuttings (96.25% of developed cuttings). The compared treatments significantly influenced the recovery rate of the cuttings. The first leaf produced by the stem cuttings is multi-lobed (3-5 lobes), while that produced by root cuttings is generally single-lobed. One year after transplanting, the substrate (2/3 sand and 1/3 chicken manure in volume) produced the best plant growth from cuttings.
On Valuing Constant Maturity Swap Spread Derivatives  [PDF]
Leonard Tchuindjo
Journal of Mathematical Finance (JMF) , 2012, DOI: 10.4236/jmf.2012.22020
Abstract: Motivated by statistical tests on historical data that confirm the normal distribution assumption on the spreads between major constant maturity swap (CMS) indexes, we propose an easy-to-implement two-factor model for valuing CMS spread link instruments, in which each forward CMS spread rate is modeled as a Gaussian process under its relevant measure, and is related to the lognormal martingale process of a corresponding maturity forward LIBOR rate through a Brownian motion. An illustrating example is provided. Closed-form solutions for CMS spread options are derived.
Seeds'germination of Four Traditionnal Leafy Vegetables in Benin (LFT)
Etèka, CA.,Ahohuendo, BC.,Ahoton, LE.,Dabadé, SD.
Tropicultura , 2010,
Abstract: Many African traditional leafy vegetables such as Acmella uliginosa, Ceratotheca sesamoides, Justicia tenella and Sesamum radiatum have been under domestication in the rural areas. Experiments were conducted in Benin to test the germination ability of their seeds. The seeds were subjected to 4 treatments and seeds without treatment served as control. The experimental design was a completely randomized block with 3 replications. With a germination rate above 80%, seeds of J. tenella did not demonstrate seed dormancy. Similarly, the germination rate of A. uliginosa seeds without pappus was above 85% unlike the seeds with pappus whose germination rate was 15%. The germination of the seeds of S. radiatum and C. sesamoides was very low (< 15%). However, the seeds of S. radiatum with low water content (8.77%) and immersed in water for 24 hours gave the best germination rate (50%), whereas under the same conditions with C. sesamoides no germination was observed. The seeds of C. sesamoides and S. radiatum were dormant. Meanwhile, to ensure better germination of A. uliginosa, the pappus must be removed from its seeds.
The Influence of Team Demographic Composition on Individual Helping Behavior  [PDF]
Igor Kotlyar, Leonard Karakowsky
Psychology (PSYCH) , 2012, DOI: 10.4236/psych.2012.312152
Abstract: The aim of our laboratory study was to examine how the demographic composition (in terms of gender and culture) of work teams can influence levels of helping behavior demonstrated among group members. Participants included 216 university students from undergraduate business programs in two large North American universities (108 men, 108 women) who were randomly assigned to small groups for the purpose of engaging in business case discussions. Discussions were videotaped in order to observe helping behavior among individuals. Our findings indicated that the numerical minority member (measured in terms of gender or ethnicity) was less likely to engage in the helping activity. These findings suggest that the effects of numerical minority status are not confined to task-performance related behaviors like participation and emergent leadership, but also influence behaviors that involve how members relate to one and other, and whether they engage in helping behavior.
What Is the Natural Weight of the Current Old?  [PDF]
Damien Gaumont, Daniel Leonard
Theoretical Economics Letters (TEL) , 2013, DOI: 10.4236/tel.2013.35043
Abstract: We consider a simple overlapping generations model with an externality à la Arrow-Romer [1,2] and a government with fiscal powers. If it wishes to maximize a criterion depending on the lifelong utility of agents, is there a natural weight for the utility of the current old? We show in a simple example that this weight depends on the specific features of the model, in particular the length of the horizon, and cannot be chosen arbitrarily. Our result has a neat economic interpretation [2].
Mass Density Distributions in Spiral Galaxies  [PDF]
Robert Leonard Bish
World Journal of Mechanics (WJM) , 2014, DOI: 10.4236/wjm.2014.45016
Abstract:

The purpose of this paper is to show, on the basis of Newtonian mechanics (in Euclidean space), that the core disks of spiral galaxies (the central disks in galactic cores that are perpendicular to the axes of rotation) rotate in the same fashion as a phonograph turntable, if the mass densities in the cores of such galaxies remain uniform. On the basis of the hypothesis of uniform mass density in the core, it is then shown that the density of mass in the shell (the entire domain outside of the core) must remain inversely proportional to the square of radial distance from the axis of rotation and that the angular velocity in the shell annulus (annulus in the shell that contains the spiral forms) is inversely proportional to radial distance, or that the circumferential velocity on the shell disk is independent of radial distance from the core axis. The equation of motion for the shell disk is then obtained and it is concluded that the spiral shaped lanes are not trajectories. But it is shown that any bar-shaped feature crossing the shell annulus and core disk, collinear with the core centre, will become distorted, due to the above angular velocity distribution in the shell disk, assuming the form of two, symmetrically disposed, Archimedean spirals, while the portion of the bar inside the core remains undistorted and merely rotates.

A Brief Overview of How Male Medicine Co-Opted the Midwife’s Role in the Birth Process  [PDF]
Leonard F. Vernon
Open Journal of Nursing (OJN) , 2015, DOI: 10.4236/ojn.2015.59079
Abstract: The term medicalization has been defined as the process by which non-medical issues come to be defined and treated as medical problems. There are no better examples of this than pregnancy and childbirth. Prior to the intervention of physicians and hospitals, most females delivered unassisted or assisted by a relative or a midwife who usually had no formal education. As long as this remained the practice, pregnancy could not become a medical procedure. Through systematic changes, discussed in detail herein, this primarily female-oriented event involving family and amateur aids would come to be dominated by males who were the sole legally authorized providers of obstetrical care [1]. The increasing cultural authority of medicine facilitated the transfer of home delivery to hospital delivery and changed normal birth into a surgical procedure. This paper will examine the history of obstetrics and how a profession comes to redefine a normal life event as a disease state.
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