Genetic impact of the Prestige oil spill in wild populations of a poor dispersal marine snail from intertidal rocky shores

In November 2002, the sinking of the Prestige cargo ship produced an oil spill of 60,000 tons that affected many areas along the Galician coast (in the northwest of Spain). In a number of rocky shore sites, most organisms (particularly marine mollusks) were nearly extinct at a local scale. We tested whether the local bottleneck/extinction that occurred in affected localities caused any detectable reduction of the genetic diversity in the marine snail Littorina saxatilis, an ovoviviparous rocky shore model species characterized by a low dispersal ability, high population density, and wide distribution range. We compared the level of genetic variation and population differentiation between affected (polluted) and control sites located in seven geographical areas (three sites per area, one impacted and two controls, and two replicates per site) one and a half years after the spill. The analysis included molecular marker variation (microsatellite and AFLP loci) and quantitative trait genetic variation for shell variables in embryos extracted from pregnant females. Our results indicate that the affected populations did not show a significant overall reduction in genetic diversity when compared to the controls, suggesting that the species is highly resistant to losing genetic variability as a consequence of a local short-term pollution process in spite of its low dispersal ability and direct development. However, some genetic effects were detected in the polluted populations, particularly for quantitative shell traits and AFLPs, consistent with local adaptations resulting from the fuel contamination.     

A new solution to the lagrange's case of the three‐body problem

The motion of three particles, interacting by gravitational forces, is studied in a new coordinate system given by the principal axes of inertia, as determined by Euler angles, and using the inertia principal moments and an auxiliar angle as coordinates. The solution to the particular Lagrange case of the three‐body problem is reviewed and solved in these new coordinates. This revised version was published online in July 2006 with corrections to the Cover Date.     

库车前陆褶皱冲断带中段第三系盐枕构造

本文旨在探讨库车前陆褶皱冲断带盐枕构造的类型、分布、成因机制及其与油气聚集的关系。通过地震反射剖面的解释和石油地质条件综合分析,认为库车前陆褶皱冲断带由北而南依次发育残留盐枕、非稳态盐枕和稳态盐枕等 3类盐枕构造,沿克拉苏构造带和西秋立塔克构造带呈长条形带状分布,其成因受重力滑动、重力扩展、区域挤压和塑性流动作用的联合控制。从盐枕构造的演化序列和分布特征看,该区盐枕构造的主要特点表现为:北部盐枕形成较早,稳定性差,出现残留盐枕,盐枕规模较小;南部盐枕形成较晚,稳定性较强,形态相对完整,规模较大。库车前陆褶皱冲断带盐枕构造与油气聚集密切相关,伴随盐枕构造的形成,发育大量盐相关油气圈闭构造,沿盐枕构造成带状分布,同时盐枕构造巨厚的盐岩层为油气聚集提供了良好的封闭条件。     

1995年云南孟连西7.3级地震前震序列特征及其与主震的关系

在分析１９９５年云南孟连西７３级地震的前震序列时,发现跟踪最大前震６２级的余震序列中,有一组较大震级的地震呈现出随时间的增长不断线性递增的特点,这种特点在云南其他震例中也曾多次出现过。利用修正的大森公式ｎ（ｔ）＝ｋ／（ｔ＋ｃ）ｐ拟合该序列,在获得的参数重新构造的频度－线性化时间坐标中,这一组地震显示出与海城前震序列随时间变化震级出现非线性增强的共同特征。采用表征物质加速应变而失稳的方程ｄ（∑Ｍ０１／２）／ｄｔ＝ｃ／（ｔｍ－ｔ）ｎ,对孟连西前震序列多方面进行跟踪定量分析,预测主震的发生时间平均比实发时间仅推迟２６ｍｉｎ,震级相差０１７级。     

Correction to: Observational Investigation of the Statistical Properties of Surface-Layer Turbulence in a Suburban Area of São Paulo,Brazil: Objective Analysis of Scaling-Parameter Accuracy and Uncertainties

Boundary-Layer Meteorology -     

(U–Th)/He dating of fluorite: application to the La Azul fluorspar deposit in the Taxco mining district, Mexico

The (U–Th)/He dating method was applied to fluorite of the La Azul fluorspar deposit, Taxco mining district, Mexico. Ages of ten U-rich (4–94 g/g) samples range from 30 to 33 Ma (mean 32±2 Ma, 1). This age range is interpreted as the time of primary fluorite precipitation and is close to the K/Ar age of sericite from a small fluorspar deposit (Los Tréboles) in the same area, and the K/Ar age of the nearby volcanic succession, which is thought to be the main source of fluorine in both deposits. This age is also in concordance with the very few published ages of epithermal deposits in southern Mexico. The dating of fluorite by other methods, particularly for young samples, is a difficult task. We believe that the (U–Th)/He method, which has been applied before to thermochronological studies of apatite, zircon, titanite and hematite, can be used as a tool for direct dating of fluorite with microgram per gram levels of uranium and thorium.Editorial handling: B. Lehmann     

Salt-related structural styles of Kuqa foreland fold belt,northern Tarim basin

It is indicated that the salt beds have a bearingupon the hydrocarbon accumulation more than 80%discovered oil-gas reserves of the world[1]. The saltbeds can change the occurrence of overlying horizons,forming various structural traps[2,3]. The salt bed itselfis the most effective caprocks. The deposits ofhigh-saliniferous environment may have favorablepetroleum-generating conditions[4]. The salt beds withlow specific thermal conductivity may result in highergeothermal gradient of sub-salt str…     

Solving positioning problems with minimal data

GPS Solutions - Global and local positioning systems (LPS) make use of nonlinear equations systems to calculate coordinates of unknown points. There exist several methods, such as Sturmfels’...     

The heat goes on—changes in indices of hot extremes in Poland

Theoretical and Applied Climatology - On the basis of temperature observations at 60 meteorological stations in Poland, changes in the indices associated with the presence of extremely high air...