This experiment was aimed to investigate some changes of ovarian structure in order to confirm the onset of puberty in Thai indigenous gilts. Fifty female animals collected from the North-Eastern area of Thailand were...This experiment was aimed to investigate some changes of ovarian structure in order to confirm the onset of puberty in Thai indigenous gilts. Fifty female animals collected from the North-Eastern area of Thailand were slaughtered in the different age groups as 0, 1, 2, 3, 3.5, 4, 4.5, 5, 5.5 and 6 months of age, respectively （each group = 5 pigs）, for monitoring corpus luteum （CL） occurrence on ovarian surface and some changes of reproductive structure. CL was clearly found for the first time in the 4.5 months age group （P 〈 0.05） which was defined as the first ovulation; nevertheless, group of follicles with 〉 2.0 mm in diameter appeared for the first time in the 3.5 month age group （P 〈 0.05）. For other conformations, size of uterine horns, oviducts or ovaries, including weight of ovaries or whole reproductive tracts, were significantly developed （P 〈 0.05） that was initially taken place in the 3.5 months age group onwards. Thus, it was summarized that the onset of puberty in Thai indigenous gilts, affirmed by CL appearance at the first time, should be happened between 4.0 and 4.5 months of age; however, the development of reproductive structure and follicles to prepare in approaching puberty should be started before 3.5 months of age.展开更多
The ability of 42 Coupled Model Intercomparison Project Phase 5(CMIP5) models in simulating the annual and seasonal temperature and precipitation over China is first examined by using their historical experiments for ...The ability of 42 Coupled Model Intercomparison Project Phase 5(CMIP5) models in simulating the annual and seasonal temperature and precipitation over China is first examined by using their historical experiments for 1986–2005, and then 39 relatively reliable models are chosen to project temperature and precipitation changes against the natural internal variability over the country under the Representative Concentration Pathways(RCP) scenarios in the 21 st century. The result shows the temperature continuing to increase, especially in northern China. The annual warming for 2081–2099 relative to 1986–2005 over the whole of the country is larger than the background variability, with the multimodel median changes under RCP2.6, RCP4.5, RCP6.0, and RCP8.5 being 9.9, 19.3, 22.8, and 35.9 times greater than one standard deviation of internal variability, respectively. The annual precipitation is projected to increase by 6.1%, 9.3%, 9.6%, and 16.2% for 2081–2099 relative to 1986–2005 under RCP2.6, RCP4.5, RCP6.0, and RCP8.5 respectively, while large changes with high model agreement only occur over the northern Tibetan Plateau and Northeast China, which is mainly due to the robust changes in winter and spring under RCP6.0 and RCP8.5.展开更多
Prehistoric human history on the Tibetan Plateau is a hotly debated topic. Archaeological research on the plateau during the past few decades has enormously improved our understanding of the topic and makes it possibl...Prehistoric human history on the Tibetan Plateau is a hotly debated topic. Archaeological research on the plateau during the past few decades has enormously improved our understanding of the topic and makes it possible for us to consider the processes and mechanisms of prehistoric human migration to the region. By reviewing the published archaeological research on the Tibetan Plateau, we propose that the first people on the plateau initially spread into the He-Huang region from the Chinese Loess Plateau, and then moved to the low elevation Northeastern Tibetan Plateau and perhaps subsequently to the entire plateau. This process consisted of four stages.(1) During the climatic amelioration of the Last Deglacial period(15–11.6 ka BP), Upper Paleolithic hunter-gatherers with a developed microlithic technology first spread into the Northeastern Tibetan Plateau.(2) In the early-mid Holocene(11.6–6 ka BP), Epipaleolithic microlithic hunter-gatherers were widely distributed on the northeastern plateau and spread southwards to the interior plateau, possibly with millet agriculture developed in the neighboring low elevation regions.(3) In the mid-late Holocene(6–4 ka BP), Neolithic millet farmers spread into low elevation river valleys in the northeastern and southeastern plateau areas.(4) In the late Holocene(4–2.3 ka BP), Bronze Age barley and wheat farmers further settled on the high elevation regions of the Tibetan Plateau, especially after 3.6 ka BP. Finally, we suggest that all of the reported Paleolithic sites earlier than the LGM on the Tibetan Plateau need further examination.展开更多
文摘This experiment was aimed to investigate some changes of ovarian structure in order to confirm the onset of puberty in Thai indigenous gilts. Fifty female animals collected from the North-Eastern area of Thailand were slaughtered in the different age groups as 0, 1, 2, 3, 3.5, 4, 4.5, 5, 5.5 and 6 months of age, respectively （each group = 5 pigs）, for monitoring corpus luteum （CL） occurrence on ovarian surface and some changes of reproductive structure. CL was clearly found for the first time in the 4.5 months age group （P 〈 0.05） which was defined as the first ovulation; nevertheless, group of follicles with 〉 2.0 mm in diameter appeared for the first time in the 3.5 month age group （P 〈 0.05）. For other conformations, size of uterine horns, oviducts or ovaries, including weight of ovaries or whole reproductive tracts, were significantly developed （P 〈 0.05） that was initially taken place in the 3.5 months age group onwards. Thus, it was summarized that the onset of puberty in Thai indigenous gilts, affirmed by CL appearance at the first time, should be happened between 4.0 and 4.5 months of age; however, the development of reproductive structure and follicles to prepare in approaching puberty should be started before 3.5 months of age.
基金supported by the National Basic Research Program of China(Grant No.2012CB955401)the National Natural Science Foundation of China(Grant No.41375084)
文摘The ability of 42 Coupled Model Intercomparison Project Phase 5(CMIP5) models in simulating the annual and seasonal temperature and precipitation over China is first examined by using their historical experiments for 1986–2005, and then 39 relatively reliable models are chosen to project temperature and precipitation changes against the natural internal variability over the country under the Representative Concentration Pathways(RCP) scenarios in the 21 st century. The result shows the temperature continuing to increase, especially in northern China. The annual warming for 2081–2099 relative to 1986–2005 over the whole of the country is larger than the background variability, with the multimodel median changes under RCP2.6, RCP4.5, RCP6.0, and RCP8.5 being 9.9, 19.3, 22.8, and 35.9 times greater than one standard deviation of internal variability, respectively. The annual precipitation is projected to increase by 6.1%, 9.3%, 9.6%, and 16.2% for 2081–2099 relative to 1986–2005 under RCP2.6, RCP4.5, RCP6.0, and RCP8.5 respectively, while large changes with high model agreement only occur over the northern Tibetan Plateau and Northeast China, which is mainly due to the robust changes in winter and spring under RCP6.0 and RCP8.5.
基金supported by National Natural Science Foundation of China (Grant Nos. 41101087 & 41171168)the Project of Tracing Civilization Origin (Grant No. 2013BAK08B02)Primary Supports for Scientific Research of Lanzhou University (Grant Nos. LZUJBKY-2014-121, LZUJBKY-2016-159, LZUJBKY-2015-K09 & LZUJBKY-2014-120)
文摘Prehistoric human history on the Tibetan Plateau is a hotly debated topic. Archaeological research on the plateau during the past few decades has enormously improved our understanding of the topic and makes it possible for us to consider the processes and mechanisms of prehistoric human migration to the region. By reviewing the published archaeological research on the Tibetan Plateau, we propose that the first people on the plateau initially spread into the He-Huang region from the Chinese Loess Plateau, and then moved to the low elevation Northeastern Tibetan Plateau and perhaps subsequently to the entire plateau. This process consisted of four stages.(1) During the climatic amelioration of the Last Deglacial period(15–11.6 ka BP), Upper Paleolithic hunter-gatherers with a developed microlithic technology first spread into the Northeastern Tibetan Plateau.(2) In the early-mid Holocene(11.6–6 ka BP), Epipaleolithic microlithic hunter-gatherers were widely distributed on the northeastern plateau and spread southwards to the interior plateau, possibly with millet agriculture developed in the neighboring low elevation regions.(3) In the mid-late Holocene(6–4 ka BP), Neolithic millet farmers spread into low elevation river valleys in the northeastern and southeastern plateau areas.(4) In the late Holocene(4–2.3 ka BP), Bronze Age barley and wheat farmers further settled on the high elevation regions of the Tibetan Plateau, especially after 3.6 ka BP. Finally, we suggest that all of the reported Paleolithic sites earlier than the LGM on the Tibetan Plateau need further examination.
