Microbial carbon use efficiency: accounting for population, community, and ecosystem-scale controls over the fate of metabolized organic matter

Microbial carbon use efficiency (CUE) is a critical regulator of soil organic matter dynamics and terrestrial carbon fluxes, with strong implications for soil biogeochemistry models. While ecologists increasingly appreciate the importance of CUE, its core concepts remain ambiguous: terminology is inconsistent and confusing, methods capture variable temporal and spatial scales, and the significance of many fundamental drivers remains inconclusive. Here we outline the processes underlying microbial efficiency and propose a conceptual framework that structures the definition of CUE according to increasingly broad temporal and spatial drivers where (1) CUEP reflects population-scale carbon use efficiency of microbes governed by species-specific metabolic and thermodynamic constraints, (2) CUEC defines community-scale microbial efficiency as gross biomass production per unit substrate taken up over short time scales, largely excluding recycling of microbial necromass and exudates, and (3) CUEE reflects the ecosystem-scale efficiency of net microbial biomass production (growth) per unit substrate taken up as iterative breakdown and recycling of microbial products occurs. CUEE integrates all internal and extracellular constraints on CUE and hence embodies an ecosystem perspective that fully captures all drivers of microbial biomass synthesis and decay. These three definitions are distinct yet complementary, capturing the capacity for carbon storage in microbial biomass across different ecological scales. By unifying the existing concepts and terminology underlying microbial efficiency, our framework enhances data interpretation and theoretical advances

The regional cost gap of the Japanese local telecommunications service

The focus of the Japanese local telecommunications policy is shifting towards solving the problem of the digital divide that accompanies the spread of high-speed and broadband services. The article estimates a translog cost function of two outputs - the standard telephone service and the leased circuit service - and measures the regional gap of those stand-alone costs and incremental costs. The main point we make is that the cost gap for the leased circuit service is larger than that for the standard telephone service among the 11 Nippon Telegraph and Telephone (NTT) regional offices. Copyright RSAI 2005.

Exploring the Determinants of Internet Usage in Nigeria: A Micro-spatial Approach

Part 6: ICT and Gender Equality and DevelopmentInternational audienceThe dearth of Information Communication Technology (ICT) infrastructure in the Sub-Saharan Africa region underscores the argument that the spread of broadband infrastructure can foster internet adoption in the region. Consequently, the aim of this paper is to present results on the determinants of internet adoption in a sub-Saharan African country. Drawing on a dataset of households in Nigeria, this study presents findings on the demographic, socio-economic and infrastructure factors that predict internet usage in Nigeria. The novelty of our analysis stems from a unique dataset constructed by matching geo-referenced information from an inventory of network equipment to a nationally representative street-level survey of over 20,000 Nigerians, by far one of the largest technology adoption surveys in sub-Saharan Africa to date within the information systems literature. The results are discussed and concluding remarks highlighting next steps are made

An econometric analysis of mobile services growth across regions of India

Diffusion processes, Gompertz model, Mobile services, Techno-economic modeling, Competition,

Transport infrastructure and regional economic growth: evidence from China

Transport infrastructure, Economic growth, Regional disparity, China,