Archaeal community structure in sediments from a seamount in the Mariana Volcanic Arc

Seamounts are subsurface mountains in the ocean. Examination of the abundance and distribution of Archaea in seamount ecosystems may provide a better understanding of their ecological functions. Most studies of marine archaeal assemblages in seamount area have focused on hydrothermal vents or ferromanganese crusts. We investigated the archaeal communities from a seamount of the Mariana Volcanic Arc, in the tropical western Pacific Ocean by using high-throughput sequencing. Thaumarchaeota was dominant in the sediments of all sample stations. Community diversity and species richness were greatest at stations near the top of the seamount, and lowest at the deepest station. One sample station on the steep southeast slope that faced the Yap-Mariana trench had a unique composition of Archaea. In summary, depth has an important influence on archaeal community structure, and the geographic properties and sediment characteristics may explain the unique distribution patterns of Archaea in this seamount. This study provides a foundation for future research on Archaea in seamounts.     

Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

1 INTRODUCTION Magnetotactic bacteria are able to respond and orient along the direction of terrestrial or artificial magnetic field, a behavior referred to as magneto- taxis. In the majority of magnetotactic bacteria, the magnetosomes are 25–120 nm in d…     

COSMIC及其在气象领域的应用

COSMIC是利用现代遥感技术、通信技术和计算机技术解决当今地球科学重大问题的地球科学卫星探测系统。作为GPS／MET的后续计划，主要是为了进行气象与气候研究、气候监测、太空天气和大地测量等研究。COSMIC计划于2003年之前发射8颗低轨卫星，8颗卫星每天可进行4000次GPS观测。本文介绍COSMIC系统组成及COSMIC数据应用。     

气象卫星亚像元火点面积和亮温估算方法

该文给出了利用极轨气象卫星AVHRR多个红外通道资料在不同火点强度条件下估算亚像元火点面积和温度的方法，包括利用牛顿迭代法求解不同红外波段（如:中红外3.7 μm通道和热红外11 μm通道，或短波红外1.6 μm通道和热红外11 μm通道）混合像元表达式建立的二元非线性方程组, 得到亚像元火点面积和温度；通过建立亚像元火点面积和温度与11 μm混合像元亮温增量和11 μm与12 μm混合像元亮温增量差异的关系，以查表方式获得对于相同红外波段不同通道（如11 μm和12 μm通道）亚像元火点面积和温度估算值。     

利用遥感技术进行毛家庄滑坡调查和稳定性分析

本文介绍了利用遥感技术对毛家在滑坡所作的调查和稳定性分析。毛家在滑坡为一特大型老滑坡。从卫星图像上可看出，滑坡正好处在渭河主干断裂带内。从航空像片上可清楚地圈定出滑坡的范围，并能发现一系列表明滑坡复活的迹象。从对影响滑坡的几个因素进行的分析判断，该滑坡有再次滑动的可能。     

Genomic analysis of a pure culture of magnetotactic bacterium Terasakiella sp. SH-1

Journal of Oceanology and Limnology - Magnetotactic bacteria(MTB) display magnetotaxis ability because of biomineralization of intracellular nanometer-sized, membrane-bound organelles termed...     

How light affect the magnetotactic behavior and reproduction of ellipsoidal multicellular magnetoglobules?

Journal of Oceanology and Limnology - Magnetotactic bacteria (MTB) synthesize intracellular magnetic organelles, magnetosomes, which consist of magnetic crystals that are enveloped in a membrane....     

Observations on a magnetotactic bacteria-grazing ciliate in sediment from the intertidal zone of Huiquan Bay,China

Journal of Oceanology and Limnology - Magnetotactic bacteria(MTB) are a group of prokaryotes having the ability to orient and swim along geomagnetic fi eld lines because they contain intracellular...     

综合物化探方法在明光市柳树庄地区金铜多金属矿勘查中的应用研究

明光市柳树庄地区位于华北、扬子两大构造单元的交接部位,郯庐断裂带的中段东侧。区内及周边的金铜矿化点较多,有良好的成矿背景和地质条件。为在研究区寻找金铜多金属矿,该文开展了深层土壤地球化学、激电中梯、磁法及可控源音频大地电磁法(CSAMT)测量工作。根据物探高低阻接触带、化探带状异常,推测出3条NW向断层(编号为F1、F2、F3),圈定3处找矿靶区(编号为Ⅰ、Ⅱ、Ⅲ)。靶区Ⅰ为中高阻高极化和正磁异常特征,经钻孔ZK301验证,物探异常主要为黄铁矿化、黄铜矿化引起,未见金矿(化)体。靶区Ⅱ、Ⅲ金元素异常特征明显且异常成带状沿区内主要控矿构造线展布,存在金(铜)矿点,可能为今后的工作重心。综合地质和物化探成果认为,研究区下一步找矿应以寻找可能的成矿构造为突破口。     

荣成月湖潮间带单细胞趋磁细菌的多样性研究

Marine magnetotactic bacteria were collected from the intertidal sediments of Yuehu Lake(China), where their abundance reached 103–104 ind./cm3. Diverse morphotypes of magnetotactic bacteria were observed, including cocci and oval, vibrio-, spirillum-, rod-, elliptical-, handle- and bar-shaped forms. The magnetococci were the most abundant, and had flagella arranged in parallel within a bundle. The majority of magnetosomes were arranged in one, two or multiple chains, although irregular arrangements were also evident. All the results of high-resolution transmission electron microscopy(HRTEM) analysis show that magnetosome crystals were composed of Fe3O4, and their morphology was specific to particular cell morphotypes. By the 16 S r RNA gene sequence analysis, we found fourteen operational taxonomic units(OTUs) which were related to magnetotactic bacteria. Among these, thirteen belonged to the Alphaproteobacteria and one to the Gammaproteobacteria.Compared with known axenic and uncultured marine magnetotactic bacteria, the 16 S r RNA gene sequences of most magnetotactic bacteria collected from the Yuehu Lake exhibited sequence identities ranging from 90.1% to96.2%(97%). The results indicate that microbial communities containing previously unidentified magnetotactic bacteria occur in the Yuehu Lake.