Modeling and Assessing Variability in Energy Consumption During the Use Stage of Online Multimedia Services

In this study, we use an improved, more accurate model to analyze the energy footprint of content downloaded from a major online newspaper by means of various combinations of user devices and access networks. Our results indicate that previous analyses based on average figures for laptops or desktop personal computers predict national and global energy consumption values that are unrealistically high. Additionally, we identify the components that contribute most of the total energy consumption during the use stage of the life cycle of digital services. We find that, depending on the type of user device and access network employed, the data center where the news content originates consumes between 4% and 48% of the total energy consumption when news articles are read and between 2% and 11% when video content is viewed. Similarly, we find that user devices consume between 7% and 90% and 0.7% and 78% for articles and video content, respectively, depending on the type of user device and access network that is employed. Though increasing awareness of the energy consumption by data centers is justified, an analysis of our results shows that for individual users of the online newspaper we studied, energy use by user devices and the third‐generation (3G) mobile network are usually bigger contributors to the service footprint than the datacenters. Analysis of our results also shows that data transfer of video content has a significant energy use on the 3G mobile network, but less so elsewhere. Hence, a strategy of reducing the resolution of video would reduce the energy footprint for individual users who are using mobile devices to access content by the 3G network.     

Energy Use in Sales and Distribution via E-Commerce and Conventional Retail: A Case Study of the Japanese Book Sector

Energy use associated with sales and distribution via business-to-consumer (B2C) e-commerce versus conventional retail is analyzed for the Japanese book sector. Results indicate that e-commerce uses considerably more energy per book than conventional retail in dense urban areas, because of additional packaging. In suburban and rural areas, the energy consumption of the two systems is nearly equal because the relative efficiency of courier services compared to personal automobile transport balances out the impact of additional packaging. The main reason e-commerce does not save energy, even in rural areas, is because of the multipurpose use of automobiles; e-commerce does consume less energy in the case of single-purpose shopping trips by automobile. Overall consumption at the national level is nearly the same: 5.6 mega-joules (MJ) per book for e-commerce and 5.2 MJ per book for traditional retail. Although this difference is smaller than the uncertainty in the result, the structure of energy use for the two systems is quite distinct, which suggests reprioritization of energy-efficiency strategies. Important factors influencing the energy efficiency of B2C e-commerce include packaging, loading factors of courier trucks, number of trips per delivery, and residential energy consumption.     

Cloning,expression and cellular localization of the Doublesex gene in the water flea, Daphnia carinata, during different developmental stages

In this study, one of Doublesex genes from the common freshwater cladoceran Daphnia carinata, designated DapcaDsx1, was cloned using primers based on homologous sequences and rapid amplification of cDNA ends (RACE). qPCR was employed to quantify differences in DapcaDsx1 expression between the different sexual phases, with expression levels being higher in sexual females. The role of DapcaDsx1 in the reproductive transformation was further investigated in parthenogenetic-phase females and sexual-phase females using whole-mount in situ hybridization. This cellular localization study showed specific expression of DapcaDsx1 in the thoracic segments, second antenna and part of the ventral carapace. Higher expression levels were exhibited in sexual females compared to parthenogenetic females. This suggests that the DapcaDsx1 gene plays significant roles in switching modes of reproduction and during sexual differentiation.