基于高分辨率遥感影像的北亚热带森林生物量反演

以北亚热带湖北省太子山林场为研究对象,基于高空间分辨率GF-2与SPOT-6卫星影像,提取不同窗口大小下的纹理信息与光谱信息,利用随机森林回归算法,并结合野外实测106块样地的生物量数据,建立不同影像下的太子山林场森林生物量反演模型。结果显示：（1） GF-2和SPOT-6虽然空间分辨率有差异,但是从其不同波段反射率的相关系数（0.75、0.78、0.73、0.61）发现,两种影像的波段反射率具有较高的相关性,说明两者的辐射性能相近;（2）通过分析不同纹理特征对生物量模型的影响,发现均值和对比度纹理参数对生物量反演具有很好的效果。（3）高分辨率的遥感数据在生物量反演中具有较好的表现,且GF-2生物量模型精度（R²=0.88,RMSE=27.11 Mg/hm²）与SPOT-6生物量模型的精度（R²=0.89,RMSE=23.93 Mg/hm²）相近。（4）两种影像对不同森林类型的生物量预测值不存在显著差异,都适合对不同林分类型的生物量进行预测。     

琉璃苣BoD6D载体的构建及转化

运用植物基因工程手段构建琉璃苣BoD6D转化载体,为提高油料作物油份中γ-亚麻酸含量奠定基础。以琉璃苣基因组DNA为模板克隆BoD6D,构建酵母表达载体并转化酿酒酵母,对酵母进行诱导表达,提取脂肪酸后进行甲酯化反应,利用气相色谱分析脂肪酸含量;同时构建植物双元表达载体,经农杆菌介导通过蘸花法转化拟南芥,最后对转基因拟南芥通过抗性筛选及PCR进行鉴定。结果表明,BoD6D编码区不含有内含子,可以直接用于后续的功能研究;成功构建了酿酒酵母表达载体pYES2-BoD6D,气相色谱检测结果表明BoD6D在酵母中能够成功的将亚油酸催化生成γ-亚麻酸;成功构建了植物双元表达载体pBI121-BoD6D,卡那霉素抗性筛选和PCR鉴定结果表明已经成功获得BoD6D的拟南芥转化植株。通过以琉璃苣基因组DNA为模板比较方便的获得有功能的BoD6D用于转基因植物研究。     

Distribution of gamasid mites on small mammals in Yunnan Province, China

An investigation of gamasid mites on the body surface of small mammals was carried out in Yunnan Province of China from 1990 to 2004. The small mammal hosts were captured from 25 counties which represent five geographical subregions, namely Middle Subregion of Hengduan Mountains, Southern Subregion of Hengduan Mountains, Eastern Plateau Subregion of Yunnan, Western Plateau Subregion of Yunnan and Southern Moun- tainous Subregion of Yunnan. The captured 10 803 small mammal hosts belong to nine families, 29 genera and 52 species in four orders （Rodentia, Insectivora, Scandentia and Lagomorpha）. A total of 68 571 gamasid mites were collected from the body surface of the captured small mammal hosts and all the gamasid mites were identified to 10 families, 33 genera and 112 species. This paper lists all the mite species, together with their taxonomic position （genera and families） and their corresponding hosts. Much more mite species were found in the Middle Subregion of Hengduan Mountains than in other geographical subregions. The total individuals of mites and small mammals in the Middle Subregion of Hengduan Mountains are also the most plentiful in the five geographical subregions. Three dominant mite species and three dominant small mammal hosts were determined as the dominant species in the investigated areas of Yunnan Province. The dominant hosts are Rattus flavipectus （which accounts for 34.85% of the total individuals）, Apodemus chevrieri （13.43%） and Rattus norvegicus （10.40%） while the dominant gamasid mite species are Laelaps nuttalli （Hirst, 1915） （27.84%）, Laelaps echidninus （Berlese, 1887） （18.38%） and Laelaps guizhouensis （Gu et Wang, 1981） （14.79%）. The results showed the high species diversity of gamasid mites in Yunnan Province and the uneven distribution feature in different subregions.     

中国天然林保护工程区森林覆盖遥感监测

天然林资源保护工程（天保工程）自1998年开始实施至2020年底结束,标志着我国林业由以木材生产为主向以生态建设为主进行转变,对天然林资源开展定量监测与评估,有助于全面、及时、科学地评价天保工程对森林资源的保护成效。基于公开发布的土地覆盖产品,利用新的遥感数据合成算法构建了森林类型综合提升方法,生产了一套我国天保工程区的森林覆盖产品,对天保工程区1997年至2020年间的森林覆盖情况开展监测与评估。利用中国森林生态系统定位研究网络数据（CFERN）、森林资源规划设计调查数据和地面调查数据进行精度检验,森林类型的分类精度优于90%。分析结果显示,自天保工程实施以来,工程区的森林覆盖度总体呈恢复性增长趋势,森林覆盖从1997年的30.15%增长到2020年的31.74%,净增长1.59%,其中,长江上游地区森林增长量最高,占全工程区森林增长面积的50.97%。研究结果表明我国天保工程区内森林资源得到有效保护和恢复,天保工程实施效果显著。     

23种中草药体外抗菌活性筛选

为研究23种中草药的80%乙醇提取物对4种临床常见致病菌的体外抗菌活性,该研究用琼脂扩散法测定抑菌圈直径,微量肉汤培养基倍比稀释法测定最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal/fungicidal concentration,MBC/MFC)。结果表明:滇龙胆草、金丝梅、溪黄草等16种提取物对金黄色葡萄球菌的MIC/MBC值在0.19～3.12 mg·mL^-1之间,有很强的抑菌活性。头花蓼、淡竹叶、半枝莲等14种提取物对铜绿假单胞菌的MIC/MBC值在1.56～6.25 mg·mL^-1之间,有较强的抑菌活性。除槐角外,其余提取物对大肠埃希菌的MIC/MBC值均在3.12～12.5 mg·mL^-1之间,有较强的抑菌活性。黄藤、藿香提取物对白色念珠菌的MIC/MFC值在0.78～6.25 mg·mL^-1之间,有较强的抑菌活性; 滇龙胆草、金丝梅、水杨梅、苦参、胡椒、赶黄草、荜菝、淡竹叶提取物对白色念珠菌的MIC/MFC值在6.25～12.5 mg·mL^-1之间,也具有一定抑菌活性。因此,所选中草药的抑菌效果均较好,大部分均具有广谱抗菌活性。其中,藿香、黄藤的提取物对白色念珠菌抑菌活性较强,金丝梅、水杨梅、仙鹤草、苦参、赶黄草、溪黄草的提取物对金黄色葡萄球菌抑菌活性很强,这几种中草药可为进一步追踪其活性单体化合物和作用机制提供一定的参考。     

Association between the frequency of class II HLA antigens and the susceptibility to intrauterine infection of hepatitis B virus

Multiple factors determine the susceptibility to intrauterine hepatitis B virus (HBV) infection. These factors include the HBV structure, HBV mutation, HBV DNA level, placental barrier, the immune status of the mother, and the genetic make-ups of the newborn infants. Since HLA system is an integral component of the immune response, we hypothesized that the highly polymorphic HLA genes are the key determinants of intrauterine HBV infection. In this study, we selected newborn infants of HBsAg-positive mothers, and divided the infants into 2 groups: intrauterine infection group and non-intrauterine infection group according to the status whether or not they were infected at birth. Each infected infant was compared with 2 controls from the same birth cohort. HLA-DR allele typing was performed using a PCR-sequence specific primer (PCR-SSP) for 24 subjects with intrauterine infection and 48 controls without infection. We found that, among the fifteen (15) HLA-DR alleles assessed, HLA-DRB1*07 was the one, and the only one, significantly in excess (OR = 6.66, P = 0.004) in the intrauterine infection group compared to the non-intrauterine infection group. Our findings thus suggest that high frequency of HLA class II molecules, e.g. HLA-DRB1*07, is associated with the susceptibility of the infants to intrauterine HBV infection.     

淀粉分支酶3存在于水稻胚乳的淀粉粒之中

对水稻胚乳淀粉颗粒结合的淀粉分支酶进行了研究.酶活性分析表明水稻胚乳中存在着与淀粉颗粒结合的淀粉分支酶.氨基酸测序分析结果表明结合于水稻胚乳淀粉粒的淀粉分支酶是分子量为84 kD的淀粉分支酶3(rice starch branching enzyme 3; RBE3).从开花后5 d到种子成熟,淀粉颗粒结合的RBE3蛋白都保持较为稳定的含量.Northern 分析表明水稻胚乳发育过程中RBE4最先表达而RBE3和RBE1的表达滞后.综合以上研究结果说明RBE3存在于水稻胚乳的淀粉之中是由于RBE3与淀粉葡聚糖链具有较高亲和性而难以和葡聚糖链解离,进而随着淀粉粒的增长而被其包裹.     

Chitosan-DTPA-Gd舌间质磁共振淋巴造影显示兔颈淋巴的研究

目的：探讨磁共振间质淋巴造影剂Chitosan-DTPA-Gd经舌黏膜下注射后,显示颈淋巴的应用价值。方法：选取健康成年纯种新西兰大白兔12只,麻醉并仰卧位固定磁共振平扫,再于每只兔双侧舌缘中后交界处粘膜下各注射0.1 mL造影剂,注射部位按摩30秒,按摩后5、10、15、20、25、30、35、40 min行三维增强磁共振淋巴造影成像,测量增强前后不同时间颈部淋巴结的信号强度（SI）,计算相对应的信号强化率（E%）,采用SPSS软件进行数据的统计学分析。结果：Chitosan-DTPA-Gd于兔双侧舌缘粘膜下注射后很快吸收进入颈部淋巴引流区,淋巴结及淋巴管明显、均匀的强化,血管无显影。颈部淋巴结于注射后15 min信号强度达到峰值,并可保持一段时间,25 min后信号强化率开始明显降低,40分钟后淋巴系统显影与周围组织无差别。结论：间质磁共振淋巴造影剂Chitosan-DTPA-Gd用量小,强化效应明显,能够有效的显示颈部淋巴结形态及淋巴管走形。     

The Protozoan-Metazoan Trophic Link In Pelagic Ecosystems

ABSTRACT The evidence for a qualitatively and quantitatively important trophic link between planktonic Protozoa and higher order metazoan consumers is reviewed. the available data are obtained primarily, but not exclusively, from laboratory studies of calanoid copepod consumers and tintinnid ciliate prey from marine estuarine and nearshore environments. the data indicates that the protozoan-metazoan link is of similar magnitude and importance in the pelagic ecosystems of freshwaters. It is proposed that planktonic Protozoa constitute a high quality, nitrogen-rich food in the diets of their metazoan consumers. Implications of die trophic link to the consumers, prey, and ecosystem are discussed.