Occurrence, gas/particle partitioning and carcinogenic risk of polycyclic aromatic hydrocarbons and their oxygen and nitrogen containing derivatives in Xi'an, central China

29 parent- and alkyl-polycyclic aromatic hydrocarbons (PAHs), 15 oxygenated-PAHs (OPAHs), 11 nitrated-PAHs (NPAHs) and 4 azaarenes (AZAs) in both the gaseous and particulate phases, as well as the particulate-bound carbon fractions (organic carbon, elemental carbon, char, and soot) in ambient air sampled in March and September 2012 from an urban site in Xi'an, central China were extracted and analyzed. The average concentrations (gaseous+particulate) of 29PAHs, 15OPAHs, 11NPAHs and 4AZAs were 1267.0±307.5, 113.8±46.1, 11.8±4.8 and 26.5±11.8ngm(-3) in March and 784.7±165.1, 67.2±9.8, 9.0±1.5 and 21.6±5.1ngm(-3) in September, respectively. Concentrations of 29PAHs, 15OPAHs and 11NPAHs in particulates were significantly correlated with those of the carbon fractions (OC, EC, char and soot). Both absorption into organic matter in particles and adsorption onto the surface of particles were important for PAHs and OPAHs in both sampling periods, with more absorption occurring in September, while absorption was always the most important process for NPAHs. The total carcinogenic risk of PAHs plus the NPAHs was higher in March. Gaseous compounds, which were not considered in most previous studies, contributed 29 to 44% of the total health risk in March and September, respectively.

Persistence of Artemisia steppe in the Tangra Yumco Basin, west-central Tibet, China: despite or in consequence of Holocene lake-level changes?

The closed Tangra Yumco Basin underwent the strongest Quaternary lake-level changes so far recorded on the Tibetan Plateau. It was hitherto unknown what effect this had on local Holocene vegetation development. A 3.6-m sediment core from a recessional lake terrace at 4,700 m a.s.l., 160 m above the present lake level of Tangra Yumco, was studied to reconstruct Holocene flooding phases (sedimentology and ostracod analyses), vegetation dynamics and human influence (palynology, charcoal and coprophilous fungi analyses). Peat at the base of the profile proves lake level was below 4,700 m a.s.l. during the Pleistocene/Holocene transition. A deep-lake phase started after 11 cal ka BP, but the ostracod record indicates the level was not higher than similar to 4,720 m a.s.l. (180 m above present) and decreased gradually after the early Holocene maximum. Additional sediment ages from the basin suggest recession of Tangra Yumco from the coring site after 2.6 cal ka BP, with a shallow local lake persisting at the site until similar to 1 cal ka BP. The final peat formation indicates drier conditions thereafter. Persistence of Artemisia steppe during the Holocene lake high-stand resembles palynological records from west Tibet that indicate early Holocene aridity, in spite of high lake levels that may have resulted from meltwater input. Yet pollen assemblages indicate humidity closer to that of present potential forest areas near Lhasa, with 500-600 mm annual precipitation. Thus, the early mid-Holocene humidity was sufficient to sustain at least juniper forest, but Artemisia dominance persisted as a consequence of a combination of environmental disturbances such as (1) strong early Holocene climate fluctuations, (2) inundation of habitats suitable for forest, (3) extensive water surfaces that served as barriers to terrestrial diaspore transport from refuge areas, (4) strong erosion that denuded the non-flooded upper slopes and (5) increasing human influence since the late glacial.

Constructing, Creating and Contesting Cityscapes. A Socio-Anthropological Approach to Urban Transformation in Southern Xinjiang, People’s Republic of China

This manuscript is based on a PhD thesis submitted at the Institute of Social Anthropology at the University of Bern in 2014. The dissertation was part of the research project „Xinjiang Uyghur Autonomous Region and Chinese Territoriality. The Development of Infrastructure and Han Migration into the Region“ under the supervision of Prof. Dr. Heinzpeter Znoj and financed by the Swiss National Science Foundation SNSF. Madlen Kobi analyzes the architectural and socio-political transformation of public places and spaces in rapidly urbanizing southern Xinjiang, P.R. China, and in doing so pays particular attention to the cities of Aksu and Kaxgar. As the Xinjiang Uyghur Autonomous Region lies in between China and Central Asia, it is especially characterized by differing political, cultural, and religious influences, and, furthermore, due to its being a multiethnic region, by multiple identities. One might expect cultural and social identities in this area to be negotiated by referring to history, religion, or food. However, they also become visible by the construction and reconstruction, if not demolition, of public places, architectural landmarks, and private residences. Based on ethnographic fieldwork performed in 2011 and 2012, the study explores everyday life in a continuously transforming urban environment shaped by the interaction of the interests of government institutions, investment companies, the middle class, and migrant workers, among many other actors. Here, urban planning, modernization, and renewal form a highly sensitive lens through which the author inspects the tense dynamics of ethnic, religious, and class-based affiliations. She respects varieties and complexities while thoroughly grounding unfolding transformation processes in everyday lived experiences. The study provides vivid insights into how urban places and spaces in this western border region of China are constructed, created, and eventually contested.