Bicycles are a desirable form of transportation for many reasons, including the fact that taking a bicycle is environmentally-friendly, economically cost-effective, a way to keep fit and healthy and, on occasions, an enjoyable social activity. This paper explores the characteristics and commonalities between particular bike-sharing systems in urban areas, with a view to deriving influences on the sustainability of such systems. The empirical study is China and the paper analyses bike-sharing systems in five Chinese cities. China is suffering from the severe negative consequences of high private vehicle usage in large and densely populated cities. Nevertheless a long history of bicycle usage in the country provides great potential for such a green form of travel to be part of public and private transportation.The findings show that bike-sharing systems have varying degrees of success. The configurations which seem the most sustainable consider and integrate elements relating to transport planning, system design and choice of business model. Key conclusions are that those responsible for developing policy and practices in relation to bike-sharing systems need to understand the diverse aspects of value for the stakeholders wishing to engage with such a system. Public bicycle sharing, as a Product Service System, needs to be carefully developed to appreciate the quality and timely interplay between the physical design of the system and the provision of services being offered.

a road traffic safety research center of the ministry of public security, Beijing, china; b school of Geosciences and info-physics, central south University, changsha, china; c cyberGis center for advance Digital and spatial studies, University of illinois at Urbana-champaign, Urbana, il, Usa; d Key laboratory of road and traffic engineering of the ministry of education, tongji University, shanghai, china; e institute of remote sensing and Geographical information systems, peking University, ABSTRACT This article introduces a novel low rank approximation (LRA)-based model to detect the functional regions with the data from about 15 million social media check-in records during a year-long period in Shanghai, China. We identified a series of latent structures, named latent spatio-temporal activity structures. While interpreting these structures, we can obtain a series of underlying associations between the spatial and temporal activity patterns. Moreover, we can not only reproduce the observed data with a lower dimensional representative, but also project spatio-temporal activity patterns in the same coordinate system. With the K-means clustering algorithm, five significant types of clusters that are directly annotated with a combination of temporal activities can be obtained, providing a clear picture of the correlation between the groups of regions and different activities at different times during a day. Besides the commercial and transportation dominant areas, we also detected two kinds of residential areas, the developed residential areas and the developing residential areas. We further interpret the spatial distribution of these clusters using urban form analytics. The results are highly consistent with the government planning in the same periods, indicating that our model is applicable to infer the functional regions from social media check-in data and can benefit a wide range of fields, such as urban planning, public services, and location-based recommender systems.

No abstract

No abstract

In the present study, we report the first successful instance of controlled reproduction in Scatophagus argus, which has recently emerged as a new aquaculture resource. The controlled reproduction process for S. argus was optimized with regard to salinity acclimation. Gonadal maturation was affected by salinity in both sexes. Levels of plasma 17β‐estradiol (E2) and 11‐ketotestosterone (11‐kT) were salinity dependent and increased significantly with the duration of acclimation. Plasma levels of gonadal steroids were higher in fish held at 25‰ salinity. The highest gonadosomatic indices (GSI), 15.1 ± 1.6 in the female and 6.4 ± 1.2 in the male, were also observed at 25‰ salinity. Nevertheless, the optimal salinity for S. argus embryonic development and larval culture was 15‰. Thus, the salinity requirement for gonadal maturation and early development are quite different. The use of advanced reproductive technologies combining salinity acclimation and stimulation of luteinizing hormone‐releasing hormone analog (LHRH‐A2) resulted in a fertilization rate of 83.2%–91.3% and embryonic survival rates of over 90%. Embryos of S. argus at the 2‐cell, blastula, gastrula and pharyngula stages were observed. Most embryos hatched after 21.0 hr of incubation at 28.0 ± 1.0°C. The development of larvae into juveniles was completed at 40–45 days posthatch (dph). In this study, we provide information about the controlled reproduction of S. argus and identify the optimal environmental parameters for S. argus embryonic and larval culture, with the aim of developing reliable reproductive techniques for its mass production.