Spatial Competition and Accumulation of Public Capital

This paper examines the effect of public capital accumulation on private sectors' productivity in a general equilibrium model where a public capital, such as a transportation infrastructure, affects households' disutility of moving. The focus is on indirect channels through which it affects the productivity. The study finds that the accumulation of public capital does not necessarily enhance the productivity of private sectors when there are plenty of initial public capital or the productivity of public sectors is low. However, it also finds that there are cases where public capital accumulation improves social welfare even if it reduces the productivity.

A WAY TO SELL GOODS WITH NETWORK EXTERNALITIES

There are a lot of goods which have network externalities. While the number of players who have such a good is small, they may not get enough utility from the goods. That is, players have an incentive to delay their decision, when they purchase the goods with network externalities. Delay causes negative effects on players' utility, so equilibrium with delay is inefficient. We propose a way to settle this problem using a kind of call option. If we use the way and some conditions are satisfied, all players purchase the good and the delay decreases in equilibriumNetwork externality, strategic delay, coordination game

"Does e-Commerce Always Increase Social Welfare in the Long Run?"

We examine the effect of electronic commerce ("e-commerce") on social welfare, in the framework of conventional spatial competition models. We consider the case where both conventional and electronic retailers coexist in equilibrium. We show that e-commerce does not necessarily increase social welfare in the long run. In particular, when electronic retailers have clear cost advantage over conventional retailers, then the advent of e-commerce is shown to reduce social welfare.

Genomic divergence within non-photosynthetic cyanobacterial endosymbionts in rhopalodiacean diatoms

Organelle acquisitions via endosymbioses with prokaryotes were milestones in the evolution of eukaryotes. Still, quite a few uncertainties have remained for the evolution in the early stage of organellogenesis. In this respect, rhopalodiacean diatoms and their obligate cyanobacterial endosymbionts, called spheroid bodies, are emerging as new models for the study of organellogenesis. The genome for the spheroid body of Epithemia turgida, a rhopalodiacean diatom, has unveiled its unique metabolic nature lacking the photosynthetic ability. Nevertheless, the genome sequence of a spheroid body from a single lineage may not be sufficient to depict the evolution of these cyanobacterium-derived intracellular structures as a whole. Here, we report on the complete genome for the spheroid body of Rhopalodia gibberula, a lineage distinct from E. turgida, of which genome has been fully determined. Overall, features in genome structure and metabolic capacity, including a lack of photosynthetic ability, were highly conserved between the two spheroid bodies. However, our comparative genomic analyses revealed that the genome of the R. gibberula spheroid body exhibits a lower non-synonymous substitution rate and a slower progression of pseudogenisation than those of E. turgida, suggesting that a certain degree of diversity exists amongst the genomes of obligate endosymbionts in unicellular eukaryotes

<ARTICLE>Public Goods Provision under Imperfect Competition

In this paper, we examine the effect of public goods provision on private goods production under imperfect competition in retail market. We focus on public goods such as a transportation infrastructure which affects households' utility. We find that the amount of the public goods which maximizes the private goods production in market equilibrium is equal to the welfare-maximizing amount of the public goods. However, we also find that the equilibrium number of retailers exceeds the optimal number and that the maximized production of the private goods in the market equilibrium is smaller than the private goods production under social optimum. Finally, we propose a policy that attains the welfare-maximizing allocation under market economy

Unique genome evolution in an intracellular N2-fixing symbiont of a rhopalodiacean diatom

Cyanobacteria, the major photosynthetic prokaryotic lineage, are also known as a major nitrogen fixer in nature. N2-fixing cyanobacteria are frequently found in symbioses with various types of eukaryotes and supply fixed nitrogen compounds to their eukaryotic hosts, which congenitally lack N2-fixing abilities. Diatom species belonging to the family Rhopalodiaceae also possess cyanobacterial symbionts called spheroid bodies. Unlike other cyanobacterial N2-fixing symbionts, the spheroid bodies reside in the cytoplasm of the diatoms and are inseparable from their hosts. Recently, the first spheroid body genome from a rhopalodiacean diatom has been completely sequenced. Overall features of the genome sequence showed significant reductive genome evolution resulting in a diminution of metabolic capacity. Notably, despite its cyanobacterial origin, the spheroid body was shown to be truly incapable of photosynthesis implying that the symbiont energetically depends on the host diatom. The comparative genome analysis between the spheroid body and another N2-fixing symbiotic cyanobacterial group corresponding to the UCYN-A phylotypes – both were derived from cyanobacteria closely related to genus Cyanothece – revealed that the two symbionts are on similar, but explicitly distinct tracks of reductive evolution. Intimate symbiotic relationships linked by nitrogen fixation as seen in rhopalodiacean diatoms may help us better understand the evolution and mechanisms of bacterium-eukaryote endosymbioses

The Impact of Nutritional Status and Body Mass Index on Rehabilitation Outcomes in Patients Receiving Home-Based Medical Care

Background: Home-based medical care is expanding rapidly in Japan.Objectives: We aimed to identify the factors associated with outcomes of therapy in patients receiving home-visit rehabilitation.Methods: One hundred twenty-one patients receiving home-based rehabilitation were investigated. Nutritional status was assessed by the Mini Nutritional Assessment Short Form (MNA-SF). The Functional Independence Measure (FIM) was employed to assess the activities of daily living (ADL). The body mass index (BMI), medical history, and orthopedic disease-related pain were also recorded. The primary outcome was the improvement in FIM scores in one year.Results: A total of 19 (17%) patients were malnourished and 58 (48%) were at risk of malnutrition. Malnourished patients had a lower FIM score at initiation than those at risk of malnutrition or with normal nutritional status. Only changes in patients’ BMI and MNA-SF scores over one year were significantly associated with improved FIM scores (p = 0.0079 and p = 0.0049, respectively). No association was noted with the other factors.Conclusions: This is the first report to demonstrate that changes in MNA-SF scores and BMI are significantly associated with rehabilitation outcomes in home-based care. Nutritional management is essential along with rehabilitation to improve ADL in the long-term home care setting