Lubricated wrinkles: imposed constraints affect the dynamics of wrinkle coarsening

We study the dynamic coarsening of wrinkles in an elastic sheet that is compressed while lying on a thin layer of viscous liquid. When the ends of the sheet are instantaneously brought together by a small distance, viscous resistance initially prevents the sheet from adopting a globally buckled shape. Instead, the sheet accommodates the compression by wrinkling. Previous scaling arguments suggested that a balance between the sheet's bending stiffness and viscous effects lead to a wrinkle wavelength $\lambda$ that increases with time $t$ according to $\lambda\propto t^{1/6}$. We show that taking proper account of the compression constraint leads to a logarithmic correction of this result, $\lambda\propto (t/\log t)^{1/6}$. This correction is significant over experimentally observable time spans, and leads us to reassess previously published experimental data.Comment: 12 pages. Version accepted in Phys. Rev. Fluids (with small correction to bibliography

Spatial price transmission and market integration in Senegal’s groundnut market

The groundnut sector is the largest of Senegal’s agricultural sectors. It has been subject to various degrees of intervention since the country’s independence. Some, including the determination of farm prices by the government have survived the wave of reforms of the 1980s. Groundnut pricing policies have been the source of major transfers from farmers to the groundnut milling industry, which until 2007, was dominated by SONACOS, a publicly owned parastatal. The state was thus a major beneficiary of the transfers. In 2007, the company was privatized and is now privately owned, raising even greater concerns about the distribution of implications of pricing policies for groundnuts. The paper examines the potential ramifications of liberalizing groundnut prices in terms of its impact on prices received by producers and paid by the milling industry. One fundamental question in the analysis is the extent to which local markets would respond to such a move. To answer this question, the paper presents a dynamic model of price formation that uses estimates of spatial integration across local markets to measure the response of local agricultural prices to policy changes. We then apply this model to simulate the impact of liberalizing groundnut prices to allow domestic prices to reflect their international levels. We find that doing so would change prices in the border city of Dakar, which happens to be the central market that determines prices in the local markets of the producing regions of Kaolack and Fatick. We also find that if markets had been fully liberalized when SONACOS was privatized in January 2007, then groundnut prices would have been higher and that the increase in prices would have been passed on almost entirely to producers in Kaolack and, to a lesser extent, to producers in Fatick. Such reforms would have reversed the longstanding discrimination of groundnut farmers. Prices received by farmers in Kaolack over a period of one year would have increased from 352 FCFA/kg to 494 FCFA/kg of shelled groundnuts. For farmers in the Fatick region, prices would increase from 389 FCFA/kg to 474 FCFA/kg.groundnuts, Liberalization, marketing integration, pricing policies, Privatization,

Building capacities for evidence and outcome-based food policy planning and implementation

The Comprehensive Africa Agriculture Development Programme (CAADP) is an Africawide framework for revitalizing agriculture and rural development in order to accelerate economic growth and progress toward poverty reduction and food and nutrition security. This study reviews CAADP and its strategic objectives, key players, implementation modalities, and approach to ensuring evidence and outcome-based policy planning and implementation. The study also lays out CAADP’s common analytical framework at the country level and shares economic modeling results from member countries of the Economic Community of West African States (ECOWAS) in which analysis was conducted to examine agricultural growth and investment options for meeting CAADP growth and expenditure targets and the Millennium Development Goal target of halving poverty. Finally, the paper discusses CAADP’s review and dialogue mechanisms and knowledge support systems that have been put in place to facilitate benchmarking, mutual learning, and capacity strengthening that will improve agricultural policy, program design, and implementation.CAADP, ECOWAS, growth options, MDG 1, Poverty reduction, public expenditure,

The joys or misfortunes of love in the courtly epics of Djado Sékou

Djado Sékou, a professional storyteller, is one of the most celebrated griots in Niger. He has a predilection for everything that deals with the imaginary and dreams. His audience is fond of love stories, which he considers a superior form of literature. Love in the narratives of Djado Sékou, it is a founding and fundamental theme. The theme of love permeates Niger’s courtly epic as the narratives “Labdedjo” by Tinguizi and “Garba Mama” by Djéliba Badjo well exemplify. Djado Sékou is one of the storytellers who have sung the most of love, in particular, the love of men for one woman, Awli Djawando. Along with Lobbo Soga, Takadé Waldé, Fatumata Bidani and Sipti Diembel, Awli Djawando has entered the pantheon of Niger’s celebrated muses. However, if Djado Sékou sings of love, the joy and revival of individuals who experience “dizziness”, it is noteworthy that his songs also often originate from suffering and the misfortunes of love. This essay explores constituting themes Djado Sékou’s narrative repertoire: love stories as fairy tales, ecstasy and loss, metamorphosis of places and names and journeys.&nbsp

ON THE USE OF PRODUCTIVITY-INCREASING TECHNOLOGIES IN SUB-SAHARAN AFRICA: THE CASE OF INLAND VALLEY SWAMP RICE FARMING IN SOUTHERN MALI

There is no improved seed-fertilizer technology available that can generate the needed growth in agricultural production in Sub-Saharan Africa to meet food demand by the rapidly increasing population. This paper identifies factors associated with inland valley swamp rice farmers' decisions to adopt "improved" varieties and/or fertilizer. To achieve this objective, input-specific logistic models were estimated using survey-generated data collected from a random sample of 221 rice plots (one per farmer) selected from a purposive sample of 12 Mali-Sud bas-fond villages during the 1995-96 cropping season. The model estimation results show that the farther the village is from the closest market, the lower the probability to adopt the "improved" variety, increasing the size of the rice plot will decrease this probability, and men are more likely to adopt "improved" varieties than women because men have access to credit through CMDT, and more alternative sources of income to finance input purchases than women. For fertilizer, the use of "improved" varieties, the presence of water control infrastructure, and the village experience in cotton production increase the likelihood that a farmer will apply this input. The significance of the village experience in cotton production and women limited access to credit suggests that one of the constrains to a wider use of modern inputs is the absence of a reliable source of these inputs and/or seasonal credits. The significance of village distance to the closest market and the presence of water control the likelihood of using these inputs suggests that there exits some technological payoff associated with well-functioning markets and road improvements because such investments reduce the effective distance between the farm and the market.Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

CAN AGRICULTURAL PRODUCTION IN THE MARGINAL LANDS CONTRIBUTE TO IMPROVING FOOD SECURITY IN THE SAHELIAN AFRICAN COUNTRIES: AN EVIDENCE FROM THE BAS-FOND RICE PRODUCTION IN MALI

To improve national food security, successive Mali governments have always focused on expanding and intensifying production in the government-managed irrigation schemes (Office du Niger), which account for about 50% of domestic rice production. Because the cost of expanding and rehabilitating those schemes is high, the government is looking for complementary cost-effective ways to achieve this goal. The government could increase domestic rice supply by investing in improving the farmer-managed inland valley swamps. Although the government has paid little attention to those marginal lands, farmers have been growing rice in these areas using traditional technologies. This paper used data from a survey of 334 bas-fond farmers and secondary data to examine the potential contribution that these undeveloped bas-fonds could make to improve food security and rice exports in Mali. The study found that, if fully developed, the bas-fonds and flooded plains could produce more rice than is currently being supplied by the Office du Niger, or imported through commercial imports or food aid. As expected, rice yields in the bas-fonds are lower than in the Office du Niger. However, bas-fonds rice production is both financially profitable and provides a higher return per day of family labor than the competing upland crops (maize, sorghum/millet and cotton). In addition, the estimated domestic resources cost ratios show that, compared to the Office d u Niger, bas-fond rice production represents a better use of domestic resources, both for producing rice for home consumption and for the market.Crop Production/Industries, Food Security and Poverty, Land Economics/Use,

Exploring synergies between health and climate services: Assessing the feasibility of providing climate information to women farmers through health posts in Kaffrine, Senegal

This report details the results of research undertaken in Kaffrine, Senegal in May and June of 2015, which explored the possibility of utilizing rural health posts as a channel of communication of climate information to female farmers. The hypothesis was that since health posts often aim to reach women and other vulnerable populations in rural areas, and because weather events often pose risks to human health, the health posts may have an interest in weather and climate information and may have the means to communicate this information to rural women. A total of 13 key informant interviews exploring this hypothesis were conducted in the Kaffrine region; nine at health posts, and four at other relevant organizations in the region. The interviewees indicated that all weather and climate information that could impact agriculture could also impact human health, and thus all health post staff interviewed expressed interest both in receiving forecasts and in distributing the information they receive. For example, because health posts organize major community health campaigns about malaria just prior to the rainy season each year, they are interested in receiving the forecasted start date of the rainy season, and in communicating this start date to the residents of their region. Many other examples of climate and human health overlap are explored in this report. Most interviewees indicated that they would prefer to receive climate information through email or text messages, and said that they would distribute the forecasts via the same channels that they utilize to distribute health information. These channels include community meetings, door-to-door visits, women’s association meetings, mosque loudspeakers, radio, television, and posters or other publicly displayed written information. All of these channels have a high probability of reaching women and other vulnerable populations in rural areas. This report details additional channels of communication that could be utilized by organizations in cases where the health posts are unable to communicate climate information

Potential for agronomical enhancement of millet yield via Jatropha curcas oilcake fertilizer amendment using placed application technique

This study carried out at the ICRISAT research station of Sadoré in Niger aimed at determining the impact of placed application technique of Jatropha oilcake on millet agronomic parameters. The experimental design was a randomised blocs including five treatments and four replicates. Control was plots without fertilizer while J_100 g, J_200 g, and J_300 gwere plots receiving 100 g , 200 g and 300 g of Jatropha oilcake respectively per seed hole and the plots NPK_6 g were receiving 6 g of NPK (15, 15, 15) per seed hole. ANOVA test was used for data analyses. Only the Control had significantly low number of tillers. At the end of the vegetative period J_300 g has the highest plants. J_300 g induced 196% increase of grain yield compared to the Control. The substitution of NPK (15,15,15) by 100 g, 200 g and 300 g of Jatropha oilcake per seed hole induced 79 - 52.93%, 92 – 72.23% and 152 – 100.65% increase of grain yield respectively compared to the Control in 2009 and 2010. With regard to the grain yield in 2009 and 2010, 100 g of Jatropha cake per seed hole can replace the current 6 g (NPK) per seed hole.Keywords: Jatropha oilcake, NPK (15, 15, 15), millet (H.K.P), placed application, fertilizer, Sadoré –Nige