Genetic diversity and population structure of Eleutheronema rhadinum in the East and South China Seas revealed in mitochondrial COI sequences

Eleutheronema rhadinum is a potential commercial fisheries species and is subject to intense exploitation in China. Knowledge on the population structure of E. rhadinum in Chinese coastal waters, which is important for sustainable exploitation and proper resource management, is lacking. In the present study, the genetic diversity and population structure of E. rhadinum were evaluated using a 564-base pair fragment of the mitochondrial cytochrome c oxidase subunit I （COl） gene. A total of 76 specimens were collected from three localities around the East （Qidong and Zhoushan） and South China Seas （Zhuhai）. Among these individuals, nine polymorphic sites were detected and 1 l distinct haplotypes were defined. High levels ofhaplotype diversity （h=0.759i0.035） and low levels of nucleotide diversity （re=0.001 98i0.003 26） were observed in these populations, Hierarchical analysis of molecular variance （AMOVA） indicated that 96.72% of the genetic variation occurred within the populations, whereas 3.28% occurred among populations. No significant genealogical branches or clusters were recognized on the neighbor-joining tree. Intra-group variation among populations was significant （~0~t=0.032 85, P〈0.01）. These results suggest that E. rhadinum populations in the East and South China Seas have developed divergent genetic structures. Tests of neutral evolution and mismatch distribution suggest that E. rhadinum may have experienced a population expansion. The present study provides basic information for the conservation and sustainable exploitation of this species.     

Sensitive Ion‐Flotation Separation of Ag(I) Traces Using 2‐(2‐Methoxyphenyl)benzimidazole before Flame Atomic Absorption Spectrometric Determination in Water

A sensitive, reliable, and environmentally friendly method for simple separation and preconcentration of Ag(I) traces in aqueous samples is presented prior to their flame atomic absorption spectrometric determinations. At pH 7.0, Ag(I) was separated with 2‐(2‐methoxyphenyl)benzimidazole (MPBI) as a new complexing agent and floated after adding sodium dodecyl sulfate (SDS) as a foaming reagent. The floated layer was then dissolved in proper amount of concentrated nitric acid in methanol and introduced to the flame atomic absorption spectrometer (FAAS). The effects of pH, concentration of MPBI, type and amount of surfactant as the floating agent, type and amount of eluting agent, and influence of foreign ions on the recovery of the analyte ion were investigated. Also, using a nonlinear curve fitting method, the formation constant of 1.62 × 10⁶ was obtained for Ag(I)–MPBI complex. The analytical curve was linear in the range of 1.8 × 10^?7–1.7 × 10^?6 mol/L for determination of Ag(I). The relative standard deviation (RSD; N = 10) corresponding to 0.7 × 10^?6 mol/L of Ag(I), the limit of detection (10 blanks), and the enrichment factor were obtained as 1.7%, 2.9 × 10^?8 mol/L, and 43.0, respectively. The proposed procedure was then applied successfully for determination of silver ions in different water samples.     

Genetic difference of Chinese horseshoe crab (Tachypleus tridentatus) in southeast coast of China based on mitochondrial COI gene analysis

Population genetic structure and historical demography of Chinese horseshoe crab (T. tridentatus) along southeast coast of China were inferred from the sequence data of mitochondrial cytochrome c oxidase subunit I (COI) fragment. The sequence analysis for 964 bp COI fragment was conducted in 28 individuals collected from five localities: Ninghai in Zhejiang Province, Meizhou and Zhangpu in Fujian Province, Beihai of Guangxi Zhuang Autonomous Region and Danzhou of Hainan Province. Sequence variation was relatively low with a total of seven transitions observed. In all localities, Haplotype H3 was the dominant type observed among eight haplotypes defined previously, and was at the center of radiation in Median-Joining network. The prolonged star-like network suggests a signature of population expansions. The level of diversity was low in total, with haplotype diversity (H_d) being equal to 0.765 and nucleotide diversity (π) being equal to 0.001 18, respectively. The genetic structure analysis revealed the significant genetic difference between Ninghai and Danzhou populations. Both mismatch distribution analysis and Fu's F_s test provided consistent inference of historic population expansion. The low genetic diversity of horseshoe crab observed along China coast indicated that urgent measures should be taken to protect this rare marine animal.     

基于软件接收机的BDS/MEMS IMU深组合导航性能分析

针对BDS/MEMS IMU深组合导航全物理实验难度较大的问题,提出一种基于软件接收机的BDS/MEMS深组合导航系统仿真分析方法。给出BDS软件接收机结构,介绍深组合导航系统结构设计及滤波算法,最后基于仿真数据进行验证。结果表明,在高动态条件下,就BDS/MEMS IMU导航系统而言,其深组合的导航精度较紧组合有较大提高,位置误差小于1 m,速度误差小于0.01 m/s。     

锦屏一级电站地下厂房岩锚梁载荷试验研究

详细介绍了锦屏一级水电站工程地下厂房岩锚梁试验过程、安全监测方法及结果。试验结果表明,岩锚梁锚杆应力、接缝开度、围岩变形及锚索荷载变化主要由围岩二次应力调整引起的,试验荷载引起的增量远远小于各监测物理量,岩锚梁大多数锚杆承受拉应力,C锚杆的应力增量比A、B锚杆的应力增量反应更敏感;锚杆应力增量随着埋深增加迅速减小,岩锚梁荷载试验全过程中各监测物理量变化均小于设计控制标准值。建议在围岩变形较大的条件下,岩锚梁的设计、施工应考虑围岩和岩锚梁共同作用的影响     

Genesis of Tertiary Magnetite–Apatite Deposits,Southeast of Zanjan,Iran

Magnetite–apatite deposits in the Alborz volcano–plutonic belt, southeast Zanjan, in Iran, have blade, lenzoid, and vein forms, which extend in an E‐W direction. There are many magnetite–apatite veins and veinlets in this region, and some of them are economically important, such as Zaker, Morvarid, Sorkheh–Dizaj, and Aliabad. The sizes of the vein orebodies vary between 2 and 16 m in width, 10–100 m in length, and 5–40 m in depth. Microscopic examination of thin sections and polishes indicate that they are composed of magnetite and apatite, with minor amounts of goethite, hematite, actinolite, quartz, muscovite–illite, talc, dolomite, and calcite. The geochemistry and mineralogy of the granitic host rock reveals that it is calc‐alkaline and I‐type. Field observations, mineral paragenesis, the composition of the orebodies, and the composition of the fluid inclusions in the apatite minerals with low salinity (less than 20 wt.% NaCl equivalent) indicate that these magnetite veins were hydrothermally generated at about 200–430°C and are not related to silica–iron oxide immiscibility, as are the major Precambrian magnetite deposits in central Iran.     

Cercis siliquastrum Tree Leaves as an Efficient Adsorbent for Removal of Ag(I): Response Surface Optimization and Characterization of Biosorption

The Cercis siliquastrum tree leaves are introduced as a low cost biosorbent for removal of Ag(I) from aqueous solution in a batch system. FT‐IR, XRD analysis, and potentiometric titration illustrate that the adsorption took place and the acidic functional group (carboxyl) of the sorbent was involved in the biosorption process. In addition, it was observed that the pH beyond pH_pzc 4.4 is favorable for the removal procedure. The effect of operating variables such as initial pH, temperature, initial metal ion concentration, and sorbent mass on the Ag(I) biosorption was analyzed using response surface methodology (RSM). The proposed quadratic model resulting from the central composite design approach (CCD) fitted very well to the experimental data. The optimum condition obtained with RSM was an initial concentration of Ag(I) of 85 mg L^?1, pH = 6.3 and sorbent mass 0.19 g. The applicability of different kinetic and isotherm models for current biosorption process was evaluated. The isotherm, kinetic, and thermodynamic studies showed the details of sorbate‐sorbent behavior. The competitive effect of alkaline and alkaline earth metal ions during the loading of Ag(I) was also considered.     

Water Supply Maps for the Western Front (Belgium and Northern France) Developed by British,German and American Military Geologists during World War I: Pioneering Studies in Hydrogeology from Trench Warfare

Abstract

Innovations for the British Army during World War I included use of a military geologist to compile 'water supply' maps and to guide well drilling. Between June 1915 and November 1918, W. B. R. King served as a staff lieutenant at General Headquarters of the British Expeditionary Force deployed on the Western Front. He pioneered British development of water supply maps for parts of Belgium and northern France, in several different styles and at scales of 1 : 100 000, 1 : 250 000 and 1 : 40 000. These assisted planning for advances into enemy-occupied territory or the development of water supply infrastructure within the region held ultimately by five British armies: in total about 1,500,000 men with some 500,000 horses and mules, each man/animal requiring on average 10 gallons (45 L) per day of potable water. The maps guided emplacement of over 470 military boreholes to supply drinking water to British forces, especially in provinces underlain by Cretaceous Chalk: Picardy and Artois. German forces also made use of military geologists at the Front, but in much greater number: up to about 300 in total. Water supply tasks were given high priority, and German water supply maps were finally standardized like other medium scale German geotechnical maps at 1 : 25 000. Six geologists were deployed with the American Expeditionary Force late in the war, and for their sector of the Front compiled at least two water supply maps at 1 : 80 000, and 11 at 1 : 50 000 that were supported by explanatory reports. Wartime imperatives thus generated expertise in hydrogeology that became available for civilian use post-war, and laid the foundation for further military development during World War II.     

Mapping for history: the influence of the 7th Field Survey Company’s 1917 operation maps on the historiography of the 3rd Battle of Gaza

ABSTRACT

During Palestine Campaign of World War I, the British Army’s Egyptian Expeditionary Force produced a series of operation maps to track and control the progress of their offensive into Palestine. These maps demonstrated innovation in both their form and function, and they have been referenced and reproduced by both map scholars and military historians ever since. Leaning on J.B. Harley and Matthew Edney’s ideas about critical map history, this essay provides a critical examination of these operation maps to illuminate the sociocultural context of their creation and examines the maps’ influence over the broader historiography of the Palestine Campaign. In doing so it highlights the interdisciplinary value of critical map histories.