Designing Strategies to Support a Transformation of Agriculture in Ethiopia

The paper consists of three parts. The first part of the paper is a review of agricultural performance in Ethiopia over the past forty years. The second part diagnoses agricultural system performance and food security problems in Ethiopia and discusses some tentative practical strategies for promoting an agricultural transformation, and with it, increased productivity, income growth, and food security over the long run. The third part describes the general approach to promoting an agricultural transformation and food security for Ethiopia. It is conceptual and procedural. It draws from the lessons of economic history and theory applied to the current situation in Ethiopia.food security, food policy, Ethiopia, Farm Management, Food Security and Poverty, Q18,

Radiative impact of mineral dust on monsoon precipitation variability over West Africa

The radiative forcing of dust and its impact on precipitation over the West Africa monsoon (WAM) region is simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem). During the monsoon season, dust is a dominant contributor to aerosol optical depth (AOD) over West Africa. In the control simulation, on 24-h domain average, dust has a cooling effect (−6.11 W m⁻²) at the surface, a warming effect (6.94 W m⁻²) in the atmosphere, and a relatively small TOA forcing (0.83 W m⁻²). Dust modifies the surface energy budget and atmospheric diabatic heating. As a result, atmospheric stability is increased in the daytime and reduced in the nighttime, leading to a reduction of late afternoon precipitation by up to 0.14 mm/h (25%) and an increase of nocturnal and early morning precipitation by up to 0.04 mm/h (45%) over the WAM region. Dust-induced reduction of diurnal precipitation variation improves the simulated diurnal cycle of precipitation when compared to measurements. However, daily precipitation is only changed by a relatively small amount (−0.17 mm/day or −4%). The dust-induced change of WAM precipitation is not sensitive to interannual monsoon variability. On the other hand, sensitivity simulations with weaker to stronger absorbing dust (in order to represent the uncertainty in dust solar absorptivity) show that, at the lower atmosphere, dust longwave warming effect in the nighttime surpasses its shortwave cooling effect in the daytime; this leads to a less stable atmosphere associated with more convective precipitation in the nighttime. As a result, the dust-induced change of daily WAM precipitation varies from a significant reduction of −0.52 mm/day (−12%, weaker absorbing dust) to a small increase of 0.03 mm/day (1%, stronger absorbing dust). This variation originates from the competition between dust impact on daytime and nighttime precipitation, which depends on dust shortwave absorption. Dust reduces the diurnal variation of precipitation regardless of its absorptivity, but more reduction is associated with stronger absorbing dust

Water lifting technologies for smallholder farmers provide opportunities for sustainable intensification

United States Agency for International Developmen

Solid Oxide Fuel Cell design and Application of Formal Methods

The design of solid oxide fuel cells has inherent conflicts and compromises due to the mechanical and electrochemical requirements. The design objective is to reduce the fabrication cost of cell components while maintaining high efficiency and reliability. Solid oxide fuel cells have yet to go through a lot of research and development stage before they can be commercialised to replace conventional power generating devices. The cost associated with manufacturing of cells and stack has proved to be prohibitively high at this stage of the development. To overcome this, a cost effective manufacturing process and associated design was needed. Taguchi method of experimentation was employed to this end. Design Function Deployment (DFD) methodology was used to compare and develop previous conceptual designs and a new combined design is proposed. Mathematical models were developed to include, fluid flow pattern across the manifold, electrochemical reactions within the cell, and stress profile across the cell and stack. The results were used in conjunction with correlation chains to establish an optimal design. A new roof for the DFD main chart is proposed to incorporate mathematical models into the design process and arrive at a mathematically optimised solution

The multispecific thyroid hormone transporter OATP1C1 mediates cell-specific sulforhodamine 101-labeling of hippocampal astrocytes

Sulforhodamine 101 (SR101) is widely used for astrocyte identification, though the labeling mechanism remains unknown and the efficacy of labeling in different brain regions is heterogeneous. By combining region-specific isolation of astrocytes followed by transcriptome analysis, two-photon excitation microscopy, and mouse genetics, we identified the thyroid hormone transporter OATP1C1 as the SR101-uptake transporter in hippocampus and cortex. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00429-013-0645-0) contains supplementary material, which is available to authorized users

A stochastic framework for modeling the population dynamics of convective clouds

A stochastic prognostic framework for modeling the population dynamics of convective clouds and representing them in climate models is proposed. The framework follows the non-equilibrium statistical mechanical approach to constructing a master equation for representing the evolution of the number of convective cells of a specific size and their associated cloud-base mass flux, given a large-scale forcing. In this framework, referred to as STOchastic framework for Modeling Population dynamics of convective clouds (STOMP), the evolution of convective cell size is predicted from three key characteristics of convective cells: (i) the probability of growth, (ii) the probability of decay, and (iii) the cloud-base mass flux. STOMP models are constructed and evaluated against CPOL radar observations at Darwin and convection permitting model (CPM) simulations. Multiple models are constructed under various assumptions regarding these three key parameters and the realisms of these models are evaluated. It is shown that in a model where convective plumes prefer to aggregate spatially and the cloud-base mass flux is a non-linear function of convective cell area, then the mass flux manifests a recharge-discharge behavior under steady forcing. Such a model also produces observed behavior of convective cell populations and CPM simulated cloud-base mass flux variability under diurnally varying forcing. In addition to its use in developing understanding of convection processes and the controls on convective cell size distributions, this modeling framework is also designed to be capable of serving as a non-equilibrium closure formulations for spectral mass flux parameterizations