Spatial variation in female fertility related to interactions with flower consumers and pathogens in a forest metapopulation ofPrimula sieboldii

Antagonistic biological interactions with flower consumers and pathogens may influence reproductive success of flowering plants, affecting population dynamics and natural selection for floral traits. However, ecological and evolutionary consequences of the interactions may depend on both spatial and temporal patterns of the interactions. In a forest metapopulation ofPrimula sieboldii E. Morren, an endangered clonal plant species, we measured between-subpopulation patterns of seed sets and interactions with an influential flower consumer, a rove beetle,Eusphalerum bosatsu Watanabe, and a specific smut fungal pathogen,Urocystis tranzschelina (Lavrov) Zundel (Ustilaginales), for three years. Mean female fertility (seed set per flower) for individual subpopulations fluctuated moderately among years but was highly variable within each year among the five subpopulations studied. In two subpopulations, the impact ofEusphalerum beetle, was sufficiently large to result in almost complete failure in seed production over eight years including the three study and five previous preliminary observation years. In the two other subpopulations, seed set failure was caused by infection by the smut fungus. Infected capsules which constitute 10–30% of the capsules produced in the subpopulations were filled with ustilospores instead of seeds. In the subpopulation that escaped flower damage byEusphalerum beetles and smut fungal infection, seed sets of both pin and thrum flowers were much higher than in the other subpopulations. The spatial restriction of individual antagonistic agents to a part of subpopulations suggest that dispersal of the agents, as well as the mode of spatial subdivision of the plant population would be important for determining the overall effects of antagonistic interactions on plant performances at the metapopulation level.     

Production planning and inventory control in a company manufacturing PC parts: A case study

In this paper, we present a case study on the production planning and inventory system in a company manufacturing personal computer (PC) parts. In the case study, the targets are specified for developing a system for production planning and inventory control. The current state of the company is analysed for clarifying the points necessary to achieve the targets. Also, a system based on the analysis is proposed and its effects are estimated.     

The Complex Road to Happiness: The Influence of Human Development, a Healthy Environment and a Free Press

Happiness is considered one of the goals of individuals and nations. Thus, many interdisciplinary efforts have attempted to determine the factors that lead to happiness. However, most of these efforts have ignored some important but less tangible factors, such as having a free press and a healthy environment. In this study, we argue that press freedom—a measure of social capital—along with human and built capital, and natural capital, predicts levels of life satisfaction across nations. Using data from 161 countries, our study provides empirical support to our theoretical model that forms of capital do not influence life satisfaction separately but are actually situated in a web of interrelationships. This is consistent with the assumptions that the road to happiness is not direct. It is a complex path where different forms of capital influence one another before leading to a happy life.     

Coalitionally strategy-proof rules in allotment economies with homogeneous indivisible goods

We consider the allotment problem of homogeneous indivisible goods among agents with single-peaked and risk-averse von Neumann–Morgenstern expected utility functions. We establish that a rule satisfies coalitional strategy-proofness, same-sideness, and strong symmetry if and only if it is the uniform probabilistic rule. By constructing an example, we show that if same-sideness is replaced by respect for unanimity, this statement does not hold even with the additional requirements of no-envy, anonymity, at most binary, peaks-onlyness and continuity. We would like to thank the associate editor and two anonymous referees whose comments and suggestions significantly improve this paper. We are also grateful to Masaki Aoyagi, Kazuhiko Hashimoto, Hervé Moulin, Hiroo Sasaki, Koji Takamiya, William Thomson, Takuma Wakayama as well as other participants at the Eighth International Meeting of the Society for Social Choice and Welfare in Istanbul, the 2006 Autumn Annual Meeting of the Japanese Economic Association in Osaka, and Yokohama National University Seminar of Economic Theory for their helpful comments. We acknowledge financial supports from the Japan Society for the Promotion of Science via the Research Fellowship for Young Scientist (Hatsumi) and the Grant-in-Aid for Scientific Research (Serizawa).