The changes of microbial biomass carbon (MBC) and nitrogen (MBN) and microbial community in the topsoil of the abandoned agricultural land on the semi-arid Loess Plateau in China during the natural succession were eva...The changes of microbial biomass carbon (MBC) and nitrogen (MBN) and microbial community in the topsoil of the abandoned agricultural land on the semi-arid Loess Plateau in China during the natural succession were evaluated to understand the relationship between microbial community and soil properties. MBC and MBN were measured using fumigation extraction, and microbial community was analyzed by the method of fatty acid methyl ester (FAME). The contents of organic C, total N, MBC, MBN, total FAME, fungal FAME, bacterial FAME and Gram-negative bacterial FAME at the natural succession sites were higher than those of the agricultural land, but lower than those of the natural vegetation sites. The MBC, MBN and total FAME were closely correlated with organic C and total N. Furthermore, organic C and total N were found to be positively correlated with fungal FAME, bacterial FAME, fungal/bacterial and Gram-negative bacterial FAME. Natural succession would be useful for improving soil microbial properties and might be an important alternative for sustaining soil quality on the semi-arid Loess Plateau in China.展开更多
目的分析广西壮族自治区边境城区和村镇的越南籍女性性工作者(female sex workers,FSWs)人口学特征、高危性行为特征及性病感染情况,为进一步制定有关干预措施和策略提供依据。方法以广西壮族自治区边境城市越南籍FSWs为研究对象,采用...目的分析广西壮族自治区边境城区和村镇的越南籍女性性工作者(female sex workers,FSWs)人口学特征、高危性行为特征及性病感染情况,为进一步制定有关干预措施和策略提供依据。方法以广西壮族自治区边境城市越南籍FSWs为研究对象,采用问卷调查收集人口学、高危性行为特征等信息;采集其静脉血样检测人类免疫缺陷病毒(human immunodeficiency virus,HIV)、梅毒螺旋体(treponema pallidum,TP)和丙型肝炎病毒(hepatitis C virus,HCV)感染情况,并比较城乡越南籍FSWs性病感染及相关高危性行为特征。结果本研究共纳入越南籍FSWs 746人,其中城区和村镇越南籍FSWs分别为453人和293人。城区和村镇越南籍FSWs的HIV感染率分别为3.31%和1.71%(χ^(2)=1.756,P>0.05),TP感染率分别为6.62%和1.71%(χ^(2)=9.616,P<0.05),HCV感染率分别为1.55%和0.68%(χ^(2)=0.505,P>0.05)。城区越南籍FSWs最近一次商业性行为安全套使用率低于村镇越南籍(χ^(2)=5.596,P<0.05)。多因素logistic分析显示,与村镇越南籍FSWs相比,城区越南籍FSWs本次本地工作时间更长(OR=5.84,95%CI:2.60~13.15),在一个场所工作时长更短(OR=2.32,95%CI:1.04~5.18),最近一个月接客数更多(OR=1.91,95%CI:1.26~2.91),服务的客人年龄更大(OR=2.91,95%CI:1.22~6.95),平均每次商业性交易收费更多(OR=10.37,95%CI:3.29~35.08)。结论广西壮族自治区边境城市城区越南籍FSWs性病(HIV、TP、HCV)感染率高于村镇越南籍FSWs,发生性传播相关高危行为的频率也较高,当地有关部门需针对其行为特征制定针对性干预措施,以有效降低性病的流行。展开更多
基金Supported by the National Natural Science Foundation of China (Nos.50639070-4 and 30671666)the National Major Program on Pollution Control and Management of Water Body (No.2008ZX07104-003-03)
文摘The changes of microbial biomass carbon (MBC) and nitrogen (MBN) and microbial community in the topsoil of the abandoned agricultural land on the semi-arid Loess Plateau in China during the natural succession were evaluated to understand the relationship between microbial community and soil properties. MBC and MBN were measured using fumigation extraction, and microbial community was analyzed by the method of fatty acid methyl ester (FAME). The contents of organic C, total N, MBC, MBN, total FAME, fungal FAME, bacterial FAME and Gram-negative bacterial FAME at the natural succession sites were higher than those of the agricultural land, but lower than those of the natural vegetation sites. The MBC, MBN and total FAME were closely correlated with organic C and total N. Furthermore, organic C and total N were found to be positively correlated with fungal FAME, bacterial FAME, fungal/bacterial and Gram-negative bacterial FAME. Natural succession would be useful for improving soil microbial properties and might be an important alternative for sustaining soil quality on the semi-arid Loess Plateau in China.
文摘目的分析广西壮族自治区边境城区和村镇的越南籍女性性工作者(female sex workers,FSWs)人口学特征、高危性行为特征及性病感染情况,为进一步制定有关干预措施和策略提供依据。方法以广西壮族自治区边境城市越南籍FSWs为研究对象,采用问卷调查收集人口学、高危性行为特征等信息;采集其静脉血样检测人类免疫缺陷病毒(human immunodeficiency virus,HIV)、梅毒螺旋体(treponema pallidum,TP)和丙型肝炎病毒(hepatitis C virus,HCV)感染情况,并比较城乡越南籍FSWs性病感染及相关高危性行为特征。结果本研究共纳入越南籍FSWs 746人,其中城区和村镇越南籍FSWs分别为453人和293人。城区和村镇越南籍FSWs的HIV感染率分别为3.31%和1.71%(χ^(2)=1.756,P>0.05),TP感染率分别为6.62%和1.71%(χ^(2)=9.616,P<0.05),HCV感染率分别为1.55%和0.68%(χ^(2)=0.505,P>0.05)。城区越南籍FSWs最近一次商业性行为安全套使用率低于村镇越南籍(χ^(2)=5.596,P<0.05)。多因素logistic分析显示,与村镇越南籍FSWs相比,城区越南籍FSWs本次本地工作时间更长(OR=5.84,95%CI:2.60~13.15),在一个场所工作时长更短(OR=2.32,95%CI:1.04~5.18),最近一个月接客数更多(OR=1.91,95%CI:1.26~2.91),服务的客人年龄更大(OR=2.91,95%CI:1.22~6.95),平均每次商业性交易收费更多(OR=10.37,95%CI:3.29~35.08)。结论广西壮族自治区边境城市城区越南籍FSWs性病(HIV、TP、HCV)感染率高于村镇越南籍FSWs,发生性传播相关高危行为的频率也较高,当地有关部门需针对其行为特征制定针对性干预措施,以有效降低性病的流行。
