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Dinosaur and other tetrapod tracks are already known from multiple (~25) sites in the Early Cretaceous Hekou Group of Gansu Province. In addition to large sites (e.g. Yanguoxia) which have yielded more than 1500 tracks, small sites are important for verifying the distribution of morphotypes (ichnotaxa) over a wider region. Documentation of five newly-reported sites in the Honggu area supports previous studies which indicate a saurischian dominated (theropod and sauropod) ichnofauna with Asianopodus a common component of many assemblages. Ornithopod tracks also occur in several assemblages probably representing two morphotypes (Caririchium and Ornithopodichnus). One site reveals evidence of a small ornithopod progressing quadrupedally. [ABSTRACT FROM AUTHOR]

The phenomenon characterised by faster growth of the side of trees exposed to sunlight relative to the opposite side is termed plant phototropism. Vertical trunks of silicified wood occur in situ in the Hongliuxia area of Yumen City in north-western Gansu Province, China. A few trunks in the area exhibit well-preserved growth rings. Two petrified stumps reveal positive phototropism values of 279°–293° in the northwest direction. Living plants in Yumen City, Lanzhou City of Gansu Province and Beijing City showed positive phototropism values of 210°–255°±5° in the south-west direction. The evidence from wood phototropism supports clockwise rotation of the North China Block from previous palaeomagnetic studies since the Early Cretaceous. The petrified wood stumps in the Hongliuxia area of Yumen City are associated with 109 Ma strata corresponding to the main stage of the Yanshanian movement. [ABSTRACT FROM AUTHOR]

Sixty-ore SARS coronavirus genomic sequences derived from the early, middle, and late phases of the severe acute respiratory syndrome (SARS) epidemic were analyzed together with two viral sequences from palm civets. Genotypes characteristic of each phase were discovered, and the earliest genotypes were similar to the animal SARS-like coronaviruses. Major deletions were observed in the Orf8 region of the genome, both at the start and the end of the epidemic. The neutral mutation rate of the viral genome was constant but the amino acid substitution rate of the coding sequences slowed during the course of the epidemic. The spike protein showed the strongest initial responses to positive selection pressures, followed by subsequent purifying selection and eventual stabilization. [ABSTRACT FROM AUTHOR]

Quantity is the key factor to ensure the safety and effectiveness of medicines. It is very important to study and determine the traditional measuring units and their quantity values of Tibetan medicine. Based on the literature records of Tibetan medicine and combined with modern experimental verification and investigation research, this study determined the reference, name, and conversion rate of traditional measuring units of Tibetan medicine. Meanwhile, through large sample sampling and repeated quantification of refe-rence of basic units, its weight and volume were clarified. The modern SI volume and weight unit values corresponding to the traditional volume and weight units of Tibetan medicine were deduced, and the correctness, reliability, and practicability of these determination results were demonstrated. This study also put forward some specific suggestions and reference values for formulating the standards of measuring units of weight and volume of Tibetan medicine. It is of great significance in guiding the processing, production, and clinical treatment of Tibetan medicine, and promoting the standardization and standardized development of Tibetan medicine.

Carbon and nitrogen stable isotopic technique has been widely used in research of glassland ecosystems. Here, we summarized studies using carbon and nitrogen stable isotopes in the alpine meadow ecosystem on the Qinghai-Tibet Plateau. Firstly, we reviewed the environmental factors which influenced carbon and nitrogen isotope composition (δ 13 C and δ 15 N) of plants and soils in alpine meadow, such as altitude, moisture, fertilization, grassland degradation, and temperature. The values of plant δ 13 C were positively correlated with altitude, and negatively correlated with atmospheric pressure, grassland degradation and temperature. The relationship between plant δ 13 C and precipitation was non-linear. The values of soil δ 13 C were positively correlated with altitude and grassland degradation. The values of plant δ 15 N were positively correlated with soil moisture and fertilization, and negatively correlated with grassland degradation. Secondly, we reviewed the current application and progresses of 13 C and 15 N in the identification of plant photosynthetic type, water use, nutrient transport along food chain and carbon and nitrogen cycle in the alpine meadow. Finally, we prospected the 13 C and 15 N isotopes application in researches on soil organic carbon and soil respiration in the alpine meadow, transitions of vegetation type, and climate change, soil N 2 O trace, exploration of vegetation degradation, identification of the origin of Tibetan medicine and animal food, etc . 13 C and 15 N isotopes could be widely used and play important roles in researches on the alpine ecosystems.