No abstract

Tibetan permafrost largely formed during the late Pleistocene glacial period and shrank in the Holocene Thermal Maximum period. Quantifying the impacts of paleoclimatic extremes on soil carbon stock can shed light on the vulnerability of permafrost carbon in the future. Here, we synthesize data from 1114 sites across the Tibetan permafrost region to report that paleoclimate is more important than modern climate in shaping current permafrost carbon distribution, and its importance increases with soil depth, mainly through forming the soilʼs physiochemical properties. We derive a new estimate of modern soil carbon stock to 3 m depth by including the paleoclimate effects, and find that the stock ($${\mathrm{36}}{\mathrm{.6}}_{{\mathrm{ - 2}}{\mathrm{.4}}}^{{\mathrm{ + 2}}.3}$$ 36 .6 -2 .4 +2 . 3 PgC) is triple that predicted by ecosystem models (11.5 ± 4.2 s.e.m PgC), which use pre-industrial climate to initialize the soil carbon pool. The discrepancy highlights the urgent need to incorporate paleoclimate information into model initialization for simulating permafrost soil carbon stocks.

Urban sprawl is a worldwide phenomenon happening particularly in rapidly developing regions. A study on the spatiotemporal characteristics of urban sprawl and urban pattern is useful for the sustainable management of land management and urban land planning. The present research explores the spatiotemporal dynamics of urban sprawl in the context of a rapid urbanization process in a booming economic region of southern China from 1979 to 2005. Three urban sprawl types are distinguished by analyzing overlaid urban area maps of two adjacent study years which originated from the interpretation of remote sensed images and vector land use maps. Landscape metrics are used to analyze the spatiotemporal pattern of urban sprawl for each study period. Study results show that urban areas have expanded dramatically, and the spatiotemporal landscape pattern configured by the three sprawl types changed obviously. The different sprawl type patterns in five study periods have transformed significantly, with their proportions altered both in terms of quantity and of location. The present research proves that urban sprawl quantification and pattern analysis can provide a clear perspective of the urbanization process during a long time period. Particularly, the present study on urban sprawl and sprawl patterns can be used by land use and urban planners.

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Methadone maintenance treatment (MMT) was first piloted in April 2004 in Yunnan, China, to reduce HIV transmission. This study aimed to examine public support for MMT and was based on cross-sectional data collected in March-April 2006 on a random sample of 411 police staff, medical/health professionals, community members, and drug users. Multivariate logistic regressions were used to analyze the data. The support was the strongest amongst the police and medical professionals but the lowest in drug users. A considerable proportion of the respondents viewed MMT as contradictory to China's drug control policies and this factor was negatively associated with support for MMT. Dissemination of more accurate knowledge and the resolution of these conflicts are urgently needed to increase the public support for MMT.

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The pioneered construction of monodisperse hollow and multihollow Jørgensen–Hayashi‐functionalized microspheres with a well‐defined spherical morphology, high surface area, and large pore volume were developed by initial dispersion copolymerization of the Jørgensen–Hayashi organocatalyst with acrylamide and styrene monomers cross‐linked by p‐divinylbenzene and ethylene glycol dimethacrylate, respectively, on the surface of poly(styrene/acrylic acid) (PS) microspheres to form core–shell structures, followed by removal of the PS core by etching in organic solvents. The as‐prepared hollow and multihollow microspheres were able to achieve better mass transfer in a complex heterogeneous asymmetric three‐component/triple cascade reaction and provided the products in good yields (31–61 %) with excellent stereoselectivities (80:20–93:7 dr, >99 % ee).

In recent years, it has been important to objectively evaluate the degree of regional ecological security with regard to resource depletion and to analyse influential factors to assess sustainable development. This paper tries to assess ecological security in Chongqing while investigating the main influencing factors. Calculations of the consumption footprint, production footprint and ecological capacity for Chongqing from 1996 to 2007 based on an ecological footprint approach were carried out. An ecological security index was also calculated from these results and factors influencing security were analysed using factor analysis. Both the consumption and production footprints present an upward trend, contrary to the gradually decreasing trend of ecological capacity. In addition, the ecological security index shows that Chongqing has deteriorated from a level of less risk to that of risk. Factor analysis suggests that the deterioration of ecological security could primarily be ascribed to socioeconomic factors and industrialisation. With socio-economic development and industrialisation, appropriate measures must be taken to improve the ecosystem in Chongqing so as to achieve sustainable development. The limitations of the methodology are also discussed and areas that require further research are presented.