A new method to calculate monthly CO emissions using MOPITT satellite data

A new method is developed to calculate monthly CO emission data using MOZART modeled and MOPITT observed CO data in 2004. New CO emission data were obtained with budget analysis of the processes controlling CO concentration such as surface emission, transport, chemical transform and dry deposition. MOPITT data were used to constrain the model simulation. New CO emission data agree well with Horowitz’s emissions in the spatial distributions. Horowitz’s emissions are found to underes- timate CO emissions significantly in the industrial areas of Asia and North America, where high CO emissions are mainly due to the anthropogenic activities. New CO emissions can better reflect the more recent CO actual emissions than Horowitz’s.     

DNA methylation status of H19 and Xist genes in lungs of somatic cell nuclear transfer bovines

In somatic cell nuclear transfer （SCNT） technologies, the donor cell＇s nuclei need to be epigenetically reprogrsmmed for embryonic development. The incomplete reprogramming of donor cell nuclei has been Implicated as s primary reason for the low efficiency of SCNT. DNA methylstion is s major epigenetic modification of the genome that regulates crucial aspects of genome function, including establishment of genomic imprinting. In order to make sure whether the DNA methylstion reprogramming is efficient in SCNT animals, we analyzed the DNA methylstion status of two imprinting genes, H19 and Xist, in lungs of deceased SCNT bovines that died within 48 h of birth using bisulfite sequencing analysis. Our findings demonstrated that cloned bovines showed significantly lower DNA methylstion of H19 than controls （P〈0.05）, and three tested CpGs sites （1, 2, 3） exhibited unmethylstion in one cloned bovine （9C3）; however, Xist showed similar DNA methylation levels between clones and controis, and both showed hypermethylstion （96.11% and 86.67%）.     

大断面合金钢连铸坯洁净度的研究与控制

本文主要是针对45#、40Cr、20CrMnTiH等钢种大断面铸坯夹杂问题导致了在轧制Φ120圆钢时出现低倍夹杂以及顶锻裂纹缺陷提出的,为此我们从连铸设备、保护渣、保护浇注等方面进行了分析,采取了相关的措施,取得了良好的效果。     

Diets, eco-environments and seasonal variations recorded in the oxygen and carbon isotopic compositions of mammal tooth enamel from the Shunshanji site, Sihong County, Jiangsu Province, China

The carbon and oxygen isotopic compositions of the tooth enamel of mammals, including deer, wild pigs, buffaloes and domesticated pigs from the Shunshanji site, Sihong County, Jiangsu Province, China, were analyzed to reconstruct the mammals’ ecoenvironments and diets, and to evaluate seasonal variations in the study area. Carbon isotopic compositions of buck samples revealed that the deer ate completely C₃ plants and the environments they inhabited were relatively open and that wild pigs ate primarily C₃ plants. Oxygen isotopic compositions indicated that the body sources of these two mammals were different, i.e. the deer and pigs lived in different niches within a relatively similar ecosystem. Modern domesticated pigs were isotopically more positive than the ancient wild pigs in carbon δ ¹³C values, suggesting the former ingested more C₃ plants relative to the latter. Although the δ ¹⁸O data showed modern domesticated and ancient pigs had similar oxygen isotope compositions, their water sources were different. The carbon and oxygen isotopic patterns of premolar microsamples of ancient and modern buffaloes indicated that the plants ingested by the ancient buffalo varied with seasonal shifts, but plants ingested by the modern buffalo were relatively constant. The eco-environment of the modern buffalo was more open, warmer and drier than eco-environment of the ancient buffalo, which may be the result of the deforestation and other human activities. Ancient and modern seasonal changes were clearly recorded in the isotopic patterns and the seasonal variation amplitudes of the ancient and modern eco-environments were similar.     

Carbon and nitrogen stable isotope analyses of mammal bone fossils from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River,China

Based on AMS ¹⁴C dating data, carbon and nitrogen isotope analyses were conducted on mammal bone collagen of deer, cattle and pigs from the Zhongba site in the Three Gorges Reservoir region of the Yangtze River. These analyses were conducted to reconstruct palaeodiets of mammals, palaeoecology, palaeoenviroment and previous human activities in the study area. Results show that the collagen loss of bone did not change the in vivo isotopic composition of carbon and nitrogen stable isotopes, and most of the bone fossils were well preserved. The bone collagen of samples from deer had a mean δ¹³C of -23.1‰ and a mean δ¹⁵N of 4.7‰, suggesting that deer subsisted in a closed habitat and fed on branches and leaves. The bone collagen of cattle had a mean δ¹³C of –19.6‰ and a mean δ¹⁵N of 5.2‰, which indicates that cattle subsisted in an open habitat and fed on grasses and stems. The δ¹³C values show that both deer and cattle fed on C₃ plants and lived in the same ecosystem, but the t-test results show that deer δ¹³C and δ¹⁵N values were both more negative than those of cattle, indicating that they inhabited different niches. The δ¹³C and δ¹⁵N values of cattle partially overlapped those of deer, suggesting some competition in diets between them. The t-tests show that the δ¹³C and δ¹⁵N values of pigs were more positive than those of cattle and deer, which signifies that pigs occupied a higher trophic level compared to cattle and deer. The wide range of pig δ¹³C values demonstrates that pig trading had been taking place from early Neolithic Age to late Bronze Age. There were no significant differences in deer δ¹³C and δ¹⁵N values among different archaeological periods, making it clear that climatic, ecological and environmental conditions were kept relatively stable from 2200 to 4200 a BP. This stability may have been responsible for the extensive and complete cultural layers at the Zhongba site. The minimum number of samples required to estimate the mean δ¹³C values of deer, pigs and cattle are 8, 73 and 16, respectively, and for mean δ¹⁵N values of deer, pigs and cattle, the minimum numbers are 4, 5 and 6, respectively.     

Methoxy n-fatty acids in surface soils from the Gongga and Kunlun Mountains: Ecological implications

GC-MS characteristics of surface soil samples from the eastern and northern Tibetan Plateau provide tentative identification of 8(–14)-Methoxy hexadecanoic acid (iME-16:0) and 9(–17)-methoxy octadecanoic acid (iME-18:0). Sixty surface soil samples were collected from the eastern slope of Gongga Mountain, at elevations ranging from ~1230 to 4500 m (eastern Tibetan Plateau), and from the northern slope of West Kunlun Mountains, ranging from ~1300 to 5500 m (northern Tibetan Plateau). This study also analyzed the methoxy n-fatty acids (MFAs) of Gongga Mountain tree leaves from six common living species, at the elevation of 2900–4200 m. MFAs dominate these samples, with more centrally located methoxy groups eluting earlier than those with methoxy groups located closer to the end of the main carbon chain. MFAs occur prominently in most of the Gongga Mountain soil samples (and from six tree samples) from dominantly coniferous and deciduous broadleaved forests. Other than in two narrow vegetation zones between 4000–4350 m and 2900–3300 m, no MFAs were found in 19 Kunlun Mountains soil samples from areas covered mainly with montane desert and alpine desert steppe vegetation. Based on the inventory of plants and soils from which MFAs have been isolated, we conclude that the MFAs most probably originate from specific woody plants. If we can exclude some particular grasses as sources, MFAs may be specific woody plants-derived biomarkers; thus they would serve as an important additional proxy for comprehensive and precise ecological reconstructions.