Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section r...Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section ranging from 450 to 200 mm. The results showed that the measured mean fluxes of CO2, N2O and CH4were (1 180.4 ±308.7), (0.010 ± 0.004) and (-0.039 ± 0.016) mg · m-2/h, respectively. The decrease of the fluxes of CO2, N2O and CH4 follows with that of annual rainfall gradient in the measurement area. Human activities, such as grazing and reclamation are also critical factors to affect the fluxes of these gases from grassland. Daily continuous measurement of CO2, N2O and CH4 fluxes showed a strong diurnal variation with higher emission in the daytime. A good relationship between the fluxes of CO2, N2O, CH4 and temperature was exposed in this study.展开更多
According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Ti...According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept展开更多
The distribution of C<sub>4</sub> plants and the C<sub>4</sub>/C<sub>3</sub> ratio along Northeast China transect （NECT） have been studied. A model to quantify their relation with...The distribution of C<sub>4</sub> plants and the C<sub>4</sub>/C<sub>3</sub> ratio along Northeast China transect （NECT） have been studied. A model to quantify their relation with environmental factors has been set up. The ratio of the number of C<sub>4</sub> plants to that of C<sub>3</sub> plants along NECT shows two low and two high trends from east to west, and their distribution is mainly decided by annual average temperature and precipitation.展开更多
The North East China Transect (NECT) is an exemplary region of landmass running along the line of 43°30′ North Latitude and caught between 112° and 130°30′ East Longtitude, and is being sampled by the...The North East China Transect (NECT) is an exemplary region of landmass running along the line of 43°30′ North Latitude and caught between 112° and 130°30′ East Longtitude, and is being sampled by the International Geosphere-Biosphere Program (IGBP) for today’s study on global change. So far, it has already been listed in the first set of IGBP-sponsored transects, becoming a key theatre and "hot spot" for probing terrestrial ecosystems. In terms of biota, the nearly 1,600-kilometre-long tract is located in a mid-latitude zone, featuring a vegetational transition from a temperate timberland of evergreen coniferous forests and broadleaved deciduous forests to a mild-temperate steppe. According to the norms of biome types, it consists of three subzones: meadow steppe, typical steppe and desert steppe in a continuous east-to-west spatial sequence. There are four ecological stations supported by a great number of permanent samples, long-term plots and an enormous build-up of experimental data along展开更多
Key facts Distinct type of slow-growing ependymoma.Most common tumor of conus/cauda equina/filum terminale.Cysts,hemorrhage common（may cause acute nonaneurysmal SAH）Often presents with back pain,and can be missed if...Key facts Distinct type of slow-growing ependymoma.Most common tumor of conus/cauda equina/filum terminale.Cysts,hemorrhage common（may cause acute nonaneurysmal SAH）Often presents with back pain,and can be missed if scans don＇t include conus!Imaging finding General features Best imaging clue is enhancing cauda equina mass with hemorrhage.展开更多
Pregnancy-associated breast cancer （PABC） is defined as breast cancer occurring anytime during gestation, lactation, or within 1 year after delivery. The incidence is between 1 in 3000 and 1 in 10,000 pregnancies an...Pregnancy-associated breast cancer （PABC） is defined as breast cancer occurring anytime during gestation, lactation, or within 1 year after delivery. The incidence is between 1 in 3000 and 1 in 10,000 pregnancies and comprises about 0.2% to 3.8% of all breast cancers diagnosed in women under the age of 50 years. As women tend to delay childbearing into their third and fourth decades, the incidence of PABC is expected to increase. Here we reported two PABC patients with similar clinic and pathologic characters received chemotherapy before or after termination of pregnancy respectively, and found that the former got pathologic complete response. Based on the phenomena and the fact that endocrine hormones may have chemosensiUzation role in cancer chemotherapy, which is called hormonosensitizing chemotherapy （HSCT）, endocrinosensitizing chemotherapy （ESCT） or neoendocrinochemotherapy （NECT）, suggestion is proposed that chemotherapy should be taken before or immediately after termination for PABC, especially for the patients who prefer to artificial abortion, which may possibly acquire improved chemotherapeutic effect.展开更多
利用1 km、4 km和8 km 3种空间分辨率的NOAA/AVHRR数字影像,对中国NECT样带西部地区进行了土地覆盖分类及其景观特征的比较研究。重点比较了几种空间分辨率遥感数据分类结果边界的一致性和空间差异,以及影像所记录的景观格局的差异。为...利用1 km、4 km和8 km 3种空间分辨率的NOAA/AVHRR数字影像,对中国NECT样带西部地区进行了土地覆盖分类及其景观特征的比较研究。重点比较了几种空间分辨率遥感数据分类结果边界的一致性和空间差异,以及影像所记录的景观格局的差异。为进一步在不同尺度上研究景观变化过程以及尺度转换研究奠定了基础。研究表明:3种空间分辨率的遥感影像所反映的区域土地覆盖的宏观空间格局是一致的,但类型的边界、每一类型斑块的形状和数量均产生较大的差异;经过对反映景观空间结构的4种指标(分维数、破碎度、多样性、优势度)的比较显示出随着遥感影像空间分辨率的变化,影像所反映的景观结构发生了较大的变化。其中,各覆盖类型的分维数表现出最大差异,表征着空间分辨率的变化对斑块复杂程度的影响最大。展开更多
文摘Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section ranging from 450 to 200 mm. The results showed that the measured mean fluxes of CO2, N2O and CH4were (1 180.4 ±308.7), (0.010 ± 0.004) and (-0.039 ± 0.016) mg · m-2/h, respectively. The decrease of the fluxes of CO2, N2O and CH4 follows with that of annual rainfall gradient in the measurement area. Human activities, such as grazing and reclamation are also critical factors to affect the fluxes of these gases from grassland. Daily continuous measurement of CO2, N2O and CH4 fluxes showed a strong diurnal variation with higher emission in the daytime. A good relationship between the fluxes of CO2, N2O, CH4 and temperature was exposed in this study.
文摘According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept
文摘The distribution of C<sub>4</sub> plants and the C<sub>4</sub>/C<sub>3</sub> ratio along Northeast China transect （NECT） have been studied. A model to quantify their relation with environmental factors has been set up. The ratio of the number of C<sub>4</sub> plants to that of C<sub>3</sub> plants along NECT shows two low and two high trends from east to west, and their distribution is mainly decided by annual average temperature and precipitation.
基金This research work is jointly subsidied by two research projects entitled"A Predictive Study on the Changing Trend of Life-supporting Environment in China Over the Next 20-50 YearsA Modeling Research on the Responses of China's Terrestrial Ecosys
文摘The North East China Transect (NECT) is an exemplary region of landmass running along the line of 43°30′ North Latitude and caught between 112° and 130°30′ East Longtitude, and is being sampled by the International Geosphere-Biosphere Program (IGBP) for today’s study on global change. So far, it has already been listed in the first set of IGBP-sponsored transects, becoming a key theatre and "hot spot" for probing terrestrial ecosystems. In terms of biota, the nearly 1,600-kilometre-long tract is located in a mid-latitude zone, featuring a vegetational transition from a temperate timberland of evergreen coniferous forests and broadleaved deciduous forests to a mild-temperate steppe. According to the norms of biome types, it consists of three subzones: meadow steppe, typical steppe and desert steppe in a continuous east-to-west spatial sequence. There are four ecological stations supported by a great number of permanent samples, long-term plots and an enormous build-up of experimental data along
文摘Key facts Distinct type of slow-growing ependymoma.Most common tumor of conus/cauda equina/filum terminale.Cysts,hemorrhage common（may cause acute nonaneurysmal SAH）Often presents with back pain,and can be missed if scans don＇t include conus!Imaging finding General features Best imaging clue is enhancing cauda equina mass with hemorrhage.
文摘Pregnancy-associated breast cancer （PABC） is defined as breast cancer occurring anytime during gestation, lactation, or within 1 year after delivery. The incidence is between 1 in 3000 and 1 in 10,000 pregnancies and comprises about 0.2% to 3.8% of all breast cancers diagnosed in women under the age of 50 years. As women tend to delay childbearing into their third and fourth decades, the incidence of PABC is expected to increase. Here we reported two PABC patients with similar clinic and pathologic characters received chemotherapy before or after termination of pregnancy respectively, and found that the former got pathologic complete response. Based on the phenomena and the fact that endocrine hormones may have chemosensiUzation role in cancer chemotherapy, which is called hormonosensitizing chemotherapy （HSCT）, endocrinosensitizing chemotherapy （ESCT） or neoendocrinochemotherapy （NECT）, suggestion is proposed that chemotherapy should be taken before or immediately after termination for PABC, especially for the patients who prefer to artificial abortion, which may possibly acquire improved chemotherapeutic effect.
文摘利用1 km、4 km和8 km 3种空间分辨率的NOAA/AVHRR数字影像,对中国NECT样带西部地区进行了土地覆盖分类及其景观特征的比较研究。重点比较了几种空间分辨率遥感数据分类结果边界的一致性和空间差异,以及影像所记录的景观格局的差异。为进一步在不同尺度上研究景观变化过程以及尺度转换研究奠定了基础。研究表明:3种空间分辨率的遥感影像所反映的区域土地覆盖的宏观空间格局是一致的,但类型的边界、每一类型斑块的形状和数量均产生较大的差异;经过对反映景观空间结构的4种指标(分维数、破碎度、多样性、优势度)的比较显示出随着遥感影像空间分辨率的变化,影像所反映的景观结构发生了较大的变化。其中,各覆盖类型的分维数表现出最大差异,表征着空间分辨率的变化对斑块复杂程度的影响最大。
