Property rights, collective action, and agroforestry

"In this brief, we explore the role that social institutions — specifically property rights and collective action — may play in the developmentment of agroforestry.... In the future, property rights and collective action will play increasingly pivotal roles in defining rights and responsibilities over the externalities of tree management practices. As stakeholders recognize the need for effective management of, for example, the erosion resulting from tree felling or rights to carbon sequestration from tree planting, they will increasingly value and depend on the institutions that protect their property rights." from Text.Property rights ,Tree planting ,Public goods ,Poverty alleviation ,Collective action ,

Field-induced Berezinskii-Kosterlitz-Thouless transition and string-density plateau in the anisotropic triangular antiferromagnetic Ising model

The field-induced Berezinskii-Kosterlitz-Thouless (BKT) transition in the ground state of the triangular antiferromagnetic Ising model is studied by the level-spectroscopy method. We analyze dimensions of operators around the BKT line, and estimate the BKT point $H_{\rm c}\simeq0.5229\pm0.001$, which is followed by a level-consistency check to demonstrate the accuracy of our estimate. Further we investigate the anisotropic case to clarify the stability of the field-induced string-density plateau against an incommensurate liquid state by the density-matrix renormalization-group method.Comment: 4 pages, 4 figure

Superconductivity and antiferromagnetism in the two-dimensional Hubbard model: a variational study

A variational ground state of the repulsive Hubbard model on a square lattice is investigated numerically for an intermediate coupling strength (U = 8t) and for moderate sizes (from 6 x 6 to 10 x 10). Our ansatz is clearly superior to other widely used variational wave functions. The results for order parameters and correlation functions provide new insight for the antiferromagnetic state at half filling as well as strong evidence for a superconducting phase away from half filling.Comment: 4 pages, 4 figure

Women's land rights in the transition to individualized ownership

This study explores the impact of changes in land tenure institutions on women's land rights and the efficiency of tree resource management in Western Ghana. We find that customary land tenure institutions have evolved toward individualized systems to provide incentives to invest in tree planting. However, contrary to the common belief that individualization of land tenure weakens women's land rights, these have been strengthened through inter vivos gifts and the practice of the Intestate Succession Law. Investment in tree planting, in turn, is affected not simply by the level of land tenure security, but also by its expected changes, as tree planting strengthens land tenure security. Cocoa yields are lower on allocated family land and rented land under share tenancy due to distorted work incentives. While men and women are equally likely to plant trees, women obtain lower yields on their cocoa plots, suggesting the presence of gender-specific constraints.Gender ,Gender issues Africa. ,Land tenure Africa. ,Right of property Gender issues Africa. ,Tree planting. ,Crop yields. ,Property rights ,

Benchmark calculation of no-core Monte Carlo shell model in light nuclei

The Monte Carlo shell model is firstly applied to the calculation of the no-core shell model in light nuclei. The results are compared with those of the full configuration interaction. The agreements between them are within a few % at most.Comment: 4 pages, 1 figure, 1 table, Proceedings of the International Symposium on New Faces of Atomic Nuclei, Okinawa, Japan, Nov. 15-17, 201

Taurek, numbers and probabilities

In his paper, “Should the Numbers Count?" John Taurek imagines that we are in a position such that we can either save a group of five people, or we can save one individual, David. We cannot save David and the five. This is because they each require a life-saving drug. However, David needs all of the drug if he is to survive, while the other five need only a fifth each.Typically, people have argued as if there was a choice to be made: either numbers matter, in which case we should save the greater number, or numbers don't matter, but rather there is moral value in giving each person an equal chance of survival, and therefore we should toss a coin. My claim is that we do not have to make a choice in this way. Rather, numbers do matter, but it doesn't follow that we should always save the greater number. And likewise, there is moral value in giving each person an equal chance of survival, but it doesn't follow that we should always toss a coin.In addition, I argue that a similar approach can be applied to situations in which we can save one person or another, but the chances of success are different

Full control of quadruple quantum dot circuit charge states in the single electron regime

We report the realization of an array of four tunnel coupled quantum dots in the single electron regime, which is the first required step toward a scalable solid state spin qubit architecture. We achieve an efficient tunability of the system but also find out that the conditions to realize spin blockade readout are not as straightforwardly obtained as for double and triple quantum dot circuits. We use a simple capacitive model of the series quadruple quantum dots circuit to investigate its complex charge state diagrams and are able to find the most suitable configurations for future Pauli spin blockade measurements. We then experimentally realize the corresponding charge states with a good agreement to our model.Comment: 4 pages, 3 figure