The Possibility of a Green Revolution in Sub-Saharan Africa: Evidence from Kenya

It is widely believed that a Green Revolution similar to the one achieved in Asia is impossible in Sub-Saharan Africa. Although grain yields have been stagnant in this region, there are some signs of the intensification of farming systems in the face of growing population pressure on limited land resources. In this paper we focus on the new farming system based on the use of manure produced by dairy cows, which may be termed an “Organic Green Revolution.†Using the farm household data collected from Kenya, this paper demonstrates that the Organic Green Revolution has a potential of doubling maize yields in highlands of Kenya.Green Revolution, Agricultural Revolution, Organic Green Revolution, dairy cows, manure, chemical fertilizer, maize yield, International Development,

Novel Extrapolation Method in the Monte Carlo Shell Model

We propose an extrapolation method utilizing energy variance in the Monte Carlo shell model in order to estimate the energy eigenvalue and observables accurately. We derive a formula for the energy variance with deformed Slater determinants, which enables us to calculate the energy variance efficiently. The feasibility of the method is demonstrated for the full $pf$-shell calculation of $^{56}$Ni, and the applicability of the method to a system beyond current limit of exact diagonalization is shown for the $pf$+$g_{9/2}$-shell calculation of $^{64}$Ge.Comment: 4 pages, 4figure

Neutrino Nucleus Reactions based on New Shell Model Hamiltonians

A new shell model Hamiltonian for p-shell nuclei which properly takes into account important roles of spin-isospin interactions is used to obtain cross sections of neutrino-^12C reactions induced by decay-at-rest (DAR) neutrinos as well as supernona neutrinos. Branching ratios to various decay channels are calculated by the Hauser-Feshbach theory. Neutrino-^4He reactions are also investigated by using recent shell model Hamiltonians. The reaction cross sections are found to be enhanced for both ^12C and ^4He compared with previous calculations. As an interesting consequence of this, a possible enhancement of the production yields of light elements, ^7Li and ^11B, during supernova explosions is pointed out.Comment: 11 pages, 14 eps-figures, to be published in Physical Review C (in press

Efficient computation of Hamiltonian matrix elements between non-orthogonal Slater determinants

We present an efficient numerical method for computing Hamiltonian matrix elements between non-orthogonal Slater determinants, focusing on the most time-consuming component of the calculation that involves a sparse array. In the usual case where many matrix elements should be calculated, this computation can be transformed into a multiplication of dense matrices. It is demonstrated that the present method based on the matrix-matrix multiplication attains $\sim$80% of the theoretical peak performance measured on systems equipped with modern microprocessors, a factor of 5-10 better than the normal method using indirectly indexed arrays to treat a sparse array. The reason for such different performances is discussed from the viewpoint of memory access.Comment: 8 pages, 3 figure