Improving soil quality and upland rice yield in northern Benin with no-tillage, rice straw mulch and nitrogen fertilization

Management practices that simultaneously improve soil properties and yield are crucial to sustain high crop production and minimize detrimental impact on the environment. The objective of this study was to determine the influence of tillage, rice straw mulch and nitrogen fertilization on soil quality and upland rice yield in northern Benin, West Africa. The 2-year (2014-2015) field experiment was conducted with two tillage systems (no-tillage, and manual tillage), two rice straw managements (no rice straw, and rice straw mulch at 3 Mg ha-1) and three nitrogen fertilizer levels (no nitrogen, moderate level of nitrogen: 60 kg ha-1, and high level of nitrogen: 120 kg ha-1). Rice yield was not significantly different as a function of tillage systems. On the contrary, rice yield significantly increased with application of rice straw mulch and nitrogen fertilizer. The highest response of rice yield to nitrogen fertilizer addition was obtained for 60 kg N ha-1 in combination with 3 Mg ha-1 of rice straw for the two tillage systems. Soil moisture and soil microbial carbon were higher under no-tillage, rice straw mulch and nitrogen fertilizer. No-tillage combined with rice straw mulch and 60 kg N ha-1 could be used by smallholder farmers to improve soil quality and achieve higher grain yield in upland rice fields in northern Benin. (Résumé d'auteur

Experimental Investigation of a Lift Augmented Ground Effect Platform

This experimental study investigated the feasibility of applying the concept of a skirtless hovercraft into the production of an operational vehicle. A 0.255 m diameter prototype was designed, built and tested. An air bearing table was used as a testing platform, virtually eliminating the influence of friction and providing one degree of freedom for the experiments. Static tests were performed at various heights and craft configurations, providing a wide range of data for comparison. Lift, torque and efficiency were measured and calculated for each setting. Pressure and velocity information was also collected at specific points around the craft when operating at different heights above ground. The results indicate a significant increase in total lift and efficiency when operating the model at close to the ground heights, in ground effect, compared to the lift produced by the propeller and motor alone. Even more significant changes were found when comparing the in ground effect results with the out of ground effect values of lift and efficiency. The study also investigated the use of Coanda nozzles on the peripheral region of the craft, and found them to be less efficient than straight nozzles with similar size and flow rates. Comparisons between the experimental results and previous computational fluid dynamic analysis are also made and presented in this study

Syndrome inflammatoire chez les schizophrènes toxicomanes

La schizophrénie est une maladie mentale grave qui présente une comorbidité fréquente avec la toxicomanie et avec divers troubles immunitaires. Une méta-analyse réalisée récemment dans notre laboratoire a montré une augmentation d’IL-6 (une cytokine pro-inflammatoire), du récepteur soluble d’IL-2 (un marqueur d’activation du système immunitaire), et d’IL-1RA (une cytokine anti-inflammatoire) dans la schizophrénie, suggérant l’existence d’un syndrome inflammatoire dans cette maladie. La toxicomanie aussi est associée au dérèglement du réseau des cytokines inflammatoires, mais les effets dépendent du type de drogues et ils sont parfois diamétralement opposés. On dispose encore de peu d’informations sur le statut immunitaire et inflammatoire des patients qui ont un double diagnostic de schizophrénie et de toxicomanie. Le but de ce travail était d’explorer l’existence d’un état inflammatoire systémique chez les patients schizophrènes et toxicomanes, et l’influence du traitement avec un médicament antipsychotique atypique, la quétiapine. Les objectifs spécifiques étaient : 1) Mesurer les concentrations plasmatiques des cytokines inflammatoires chez les schizophrènes et toxicomanes avant, pendant et après traitement avec la quétiapine ; et 2) Faire des études de corrélations entre les taux de cytokines, les symptômes cliniques, et la consommation de drogues. Les résultats montrent que comparativement aux contrôles normaux, les patients avec un double diagnostic présentent une augmentation d’IL-6, d’IL-1RA, du sIL-2R et d’IL-8 avant traitement à la quétiapine. Les augmentations des concentrations plasmatiques d’IL-1RA sont particulièrement importantes chez les patients avec double diagnostic, si on les compare à celles publiées chez les schizophrènes sans toxicomanie. Le traitement à la quétiapine n’influence pas les concentrations plasmatiques de ces cytokines, sauf sIL-2R qui augmente davantage au cours du traitement. Des corrélations positives de puissance modérée sont retrouvées entre IL-6 et dépression, IL-6 et alcool, IL-1RA et cognition, IL-8 et dépression, IL-8 et alcool, sIL-2R et cannabis. Notre étude révèle que la réponse inflammatoire est activée chez les schizophrènes et toxicomanes. De plus, la toxicomanie semble jouer un rôle facilitant ou potentialisateur dans les augmentations des taux circulants d’IL-1RA. Les études en cours sur différentes populations de schizophrènes avec ou sans toxicomanie, et chez des toxicomanes non schizophrènes permettront de préciser le rôle des différentes drogues d’abus dans le syndrome inflammatoire chez les schizophrènes, ainsi que les implications de ce syndrome sur le plan clinique et thérapeutique.Schizophrenia is a psychosis which presents a frequent comorbidity with substance use disorders (SUD) and with various immune alterations. Using meta-analysis, we have demonstrated previously establishment of an inflammatory syndrome in schizophrenia patients, illustrated by elevated circulating levels of IL-6 (a pro-inflammatory cytokine), sIL-2R (marker of immune activation) and IL-1RA (an anti-inflammatory cytokine). SUD is also associated with dysregulation of inflammatory cytokines, but the effects may depend on the type of substance of abuse. The goal of this project was: 1) To measure plasma concentrations of inflammatory cytokines in schizophrenia patients with comorbid SUD, before, during and after treatment with an atypical antipsychotic, quetiapine; and 2) To perform correlation studies between plasma concentrations of inflammatory cytokines and clinical symptoms, including positive and negative symptoms, cognition, depression and substance use. Relative to normal controls, patients with a dual diagnosis showed increased plasma concentrations of IL-6, IL-1RA, sIL-2R, and IL-8 at baseline, IL-1RA increases being the most important. Quetiapine treatment did not influence plasma cytokine concentrations, except sIL-2R which increased further. Moderate positive correlations were found between IL-6 and depression, IL-6 and alcohol, IL-1RA and cognition, IL-8 and depression, IL-8 and alcohol and between sIL-2R and cannabis. This study demonstrates that the immune and inflammatory response is activated in schizophrenia patients with comorbid SUD. Furthermore, SUD may play a facilitating or potentiating role in the increases in peripheral levels of IL-1RA. Ongoing studies in different patient populations with schizophrenia with or without SUD, and patients with SUD alone will help elucidate the role of different substances of abuse in the inflammatory syndrome in schizophrenia, as well as the clinical and therapeutic relevance of this syndrome

Impact of Rising International Market Prices of Rice on Welfare and Poverty in Senegal

This study assessed the impact of rising international market prices of rice on real household income and poverty in Senegal. Net benefit ratio indicator developed by Deaton (1989) to assess the impact of a change in the international rice price on household welfare were used in the analysis. The data came from the second poverty monitoring survey in Senegal. Using two indicators: (i) per capita spending and (ii) expenditure per adult equivalent, the results showed that rising international rice prices negatively affect real income and poverty. This negative effect were more pronounced in urban areas and in areas with high rice consumption. Poverty also increased by 3.5% when the first indicator was used. However, it increased by 4.25% when the second indicator was used. Statistics showed that 37% of the richest households consume rice compared to 7% of the poorest households. In addition, urban households allocate 25% of their budget to rice consumption, compared to 24.4% for rural households. To reduce Senegal’s vulnerability, governments need to take steps to limit the country’s dependence on rice imports. Therefore, it would be essential to invest more in the production and consumption of local rice

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Impact of Climate Change on Cereal Yield and Production in the Sahel: Case of Burkina Faso

Climate change is one of the biggest challenges of the 21st century. It affects all countries in the world, especially Sahelian countries in Africa. This paper aimed at evaluating the impact of climate change on cereal yield in Burkina Faso. The ordinary least squares (OLS) was applied to time-series data from 1991 to 2016 collected on the World Bank website. The results have shown that temperature adversely affects yield and cereal production, while precipitation has positive effect. An increase in rainfall of 1 millimetre would increase cereal production by 385 tons in the long term and 252 tons in the short term. In the same, an increase in rainfall of 1 millimetre would increase agricultural yield by 9 kg per hectare in the long term. However, in the short term, an increase in temperatures of 1ºC would result in a decrease in cereal production and agricultural yield of 134748 tons and 72 kg per hectare, respectively. However, in the long term, a rise in temperatures of 1ºC would result in a decrease in cereal production and cereal yield of 154 634 tons and 1074 kg per hectare, respectively. Besides, the results indicate that the emission of carbon dioxide (CO2) has no significant effect on yield and cereal production. Implementing effective adaptation strategies, such as access to improved seed, introduce smart agriculture in the system of cereal in Burkina Faso and increasing irrigation infrastructure could reduce the cereal production's vulnerability to climate shocks

Bandolerismo, patriotismo y etnicidad poscolonial : los "morochucos" de Cangallo, Ayacucho en las guerras de Independencia, 1814-1824

Entre 1814 y 1823, la planicie principalmente ganadera que se extiende sobre el norte del partido de Cangallo y el extremo sur del de Huamanga, en la intendencia de Huamanga, presenció una serie de actos de rebeldía de la población local quechuahablante —conocida desde entonces por el sobrenombre de “morochucos”— contra las autoridades coloniales. Por su constancia patriótica, los morochucos recibieron, durante las campañas finales de la independencia y en la década inicial de vida republicana, el sobreseimiento de sus tributos al Estado, reconocimientos simbólicos oficiales y una cuota de participación en las estructuras de poder del Estado expresada en funciones militares como la represión del levantamiento de los campesinos de Huanta en 1827. La presente tesis estudia estos episodios tradicionalmente romantizados más que documentados y analizados e intenta ofrecer un contexto social, económico y cultural en que estos hechos puedan ser interpretados.Tesi

Contribution of Radio Musical Broadcasting to National Development in Nigeria: A Media Practitioners and Audience-Based Survey in Delta State, Nigeria

Music is an essential feature of most broadcasting programmes, and research indicates that the appropriate use of music by broadcasting organisations could actuate significant national renaissance and promote development efforts. This study examines the contributions of radio musical broadcasting to national development efforts as perceived by two distinct cohorts comprising media practitioners and media audiences. Anchored on the Uses and Gratification Theory, the study utilises the survey research method and multisampling technique to recruit 500 study participants in two major cities in Delta State. The outcome of the study shows that there is a high level of exposure to radio musical broadcasting on national development-related issues among the two cohorts, and such broadcasting content is widely perceived to contribute to national development efforts in Nigeria by serving as a platform for nationalists to preach the principles of justice, equality, unity, national integration, freedom, democracy, and genuine social change in Nigeria. However, the study also found a significant discrepancy in the rating of the benefits arising from music broadcast between the two cohorts with the media practitioners group tending to overrate the influence of music broadcasting on national development. The study recommends that radio broadcasting stations should regularly conduct audience surveys to understand the actual influence of their content on the audience to ensure better programming

Taux de change du Naira et croissance économique au Bénin : Évidence empirique

L’objet de cette étude est d’évaluer les effets de l’évolution du taux de change officiel du Naira sur la croissance économique au Bénin en utilisant des données annuelles sur la période 1990-2020. Pour ce faire, nous avons établi un modèle de la croissance économique qui prend en compte la tendance du taux de change réel du Naira nigérian au franc de la Communauté Financière Africaine (CFA) et sa volatilité. Les résultats des estimations économétriques obtenus à partir du modèle empirique ARDL (AutoRegressive Distributed Lag) de cointégration, concluent qu’une amélioration tendancielle du taux de change réel Naira/franc CFA exerce un effet favorable aussi bien direct qu’indirect sur la croissance économique du Bénin, alors qu’une grande volatilité agit en sens inverse

Tillage, Rice Straw Mulch and Nitrogen Fertilization Effects on Upland Rice Yield in Northern Benin

In Benin, upland rice is typically grown under intensive tillage in slash-and-burn systems. Some of the major constraints associated with upland rice production are water deficit, declining soil fertility and rice yield. To explore effective ways to improve rice yield, field experiments were conducted on two upland rice soils (Lixisol and Gleyic Luvisol) in northern Benin, West Africa for two consecutive years. The treatments comprised two tillage systems (no-tillage, and manual tillage), two rice straw managements (no rice straw, and rice straw mulch at 3 Mg ha-1) and three nitrogen fertilizer levels (no nitrogen, moderate level of nitrogen: 60 kg ha-1, and high level of nitrogen: 120 kg ha-1). Phosphorus and potassium fertilizers were applied to be non-limiting at 40 kg P2O5 ha-1 and 40 kg K2O ha-1. Four replications of the twelve treatment combinations were arranged in a randomized complete block design. Soil moisture and soil temperature were measured at 5 cm depth in 6 to 10 days intervals during the growing seasons. At maturity, crop parameters measured included rice grain yield, aboveground biomass, and root biomass. No-tillage with rice straw mulch increased soil moisture and decreased soil temperature. Root biomass, shoot biomass and rice yield significantly increased with rice straw mulch and nitrogen fertilizer application. The highest response of rice yield to nitrogen fertilizer addition was obtained for 60 kg N ha-1 in combination with 3 Mg ha-1 of rice straw for the two tillage systems. No-tillage combined with rice straw mulch and 60 kg N ha-1 could be used by smallholder farmers to improve soil water availability and upland rice yield in northern Benin. Keywords: management practices, soil moisture, soil temperature, upland rice, yield