济阳坳陷渤南洼陷古近系沙河街组沉积相

渤海湾盆地济阳坳陷渤南洼陷的主要含油层系为古近系的沙河街组。沙河街期各时段沉积相的展布各具特征，并具清晰的演化序列。沙四早期以发育扇三角洲相为特征，分布于洼陷南部；北部边缘则发育近岸水下扇沉积；东部及西部均存在辫状河三角洲相；中部有盐湖沉积。沙四晚期以盐湖相发育为特征，主要占据湖泊深水部位，其周围依次分布半深湖、浅湖及滨湖亚相。此外，局部见及小型辫状河三角洲沉积。沙三期是辫状河三角洲发育的全盛时期，主要分布于洼陷东南部，物源来自孤岛凸起。这些沉积长期来被认为是浊积岩，近期研究表明它们属辫状河三角洲沉积。辫状河三角洲前缘砂体构成了渤南洼陷最主要的储层成因类型，渤南洼陷绝大部分油气均储存在该类砂体中。沙三期湖泊相沉积也始终发育，且深湖、半深湖亚相发育良好。经过沙三期后的抬升剥蚀和填平补齐作用，沙二期湖盆变浅，以浅湖为主，研究区东南部及西北部均发育面积较大的辫状河三角洲沉积。沙一期发生大规模湖侵，物源区向后退缩，研究区仅存在单一的湖泊相，其中半深湖、深湖亚相占绝对优势。     

The post-terminator ionosphere of Venus

We have modeled the near and post-terminator thermosphere/ionosphere of Venus with a view toward understanding the relative importance of EUV solar fluxes and downward fluxes of atomic ions transported from the dayside in producing the mean ionosphere. We have constructed one-dimensional thermosphere/ionosphere models for high solar activity for seven solar zenith angles (SZAs) in the dusk sector: 90°, 95°, 100°, 105°, 110°, 115° and 125°. For the first 4 SZAs, we determine the optical depths for solar fluxes from 3 Å to 1900 Å by integrating the neutral densities numerically along the slant path through the atmosphere. For SZAs of 90°, 95°, and 100°, we first model the ionospheres produced by absorption of the solar fluxes alone; for 95°, 100°, and 105° SZAs, we then model the ion density profiles that result from both the solar source and from imposing downward fluxes of atomic ions, including O⁺, Ar⁺, C⁺, N⁺, H⁺, and He⁺, at the top of the ionospheric model in the ratios determined for the upward fluxes in a previous study of the morphology of the dayside (60° SZA) Venus ionosphere. For SZAs of 110°, 115° and 125°, which are characterized by shadow heights above about 300 km, the models include only downward fluxes of ions. The magnitudes of the downward ion fluxes are constrained by the requirement that the model O⁺ peak density be equal to the average O⁺ peak density for each SZA bin as measured by the Pioneer Venus Orbiter Ion Mass Spectrometer. We find that the 90° and 95° SZA model ionospheres are robust for the solar source alone, but the O⁺ peak density in the “solar-only” 95° SZA model is somewhat smaller than the average value indicated by the data. A small downward flux of ions is therefore required to reproduce the measured average peak density of O⁺. We find that, on the nightside, the major ion density peaks do not occur at the altitudes of peak production, and diffusion plays a substantial role in determining the ion density profiles. The average downward atomic ion flux for the SZA range of 90–125° is determined to be about 1.2 × 10⁸ cm⁻² s⁻¹.     

Sympatric seagrass shrimp show similar structure and selection along the seashore: a comparison of two cryptic Phycomenes zostericola lineages

Small crustaceans are diverse and abundant in seagrass habitats and provide many ecological services. Further information is needed about their long‐ and short‐term response to habitat fragmentation and loss. Shrimp specimens were sampled from coastal seagrasses: latitudes 9°–27° S (Torres Strait to Moreton Bay, Queensland, Australia) and longitudes 141°–153° E (Weipa to Moreton Bay, Queensland, Australia). The seagrass shrimp Phycomenes zostericola (Caridea: Decapoda) underwent phylogeographic analysis using mitochondrial and nuclear sequence data. Lineage relationships were investigated and two deeply divergent sympatric lineages of P. zostericola were discovered in northern samples. The two lineages display vastly different demographic histories in spite of similar overall phylogeographic patterns. The two lineages appear to be in secondary contact with each other, detailing independent histories of sea level change, long distance colonisation and habitat fragmentation. Their regional structure is evidence that the potential for dispersal is only realised under specific environmental conditions. Nuclear data, used to determine reproductive status between lineages, instead displayed a non‐random latitudinal geographic distribution suggesting directional selection, possibly in response to ocean temperatures. The differences between the two deeply divergent lineages highlight the importance of understanding variability among cryptic taxa and their response to habitat change.     

Effects of DEM resolution and source on soil erosion modelling: a case study using the WEPP model

Digital elevation models (DEMs) vary in resolution and accuracy by the production method. DEMs with different resolutions and accuracies can generate varied topographic and hydrological features, which can in turn affect predictions by soil erosion models, such as the WEPP (Water Erosion Prediction Project) model. This study investigates the effects of DEMs on deriving topographic and hydrological attributes, and on predicting watershed erosion using WEPP v2006.5. Six DEMs at three resolutions from three sources were prepared for two small forested watersheds located in northern Idaho, USA. These DEMs were used to calculate topographic and hydrological parameters that served as inputs to WEPP. The model results of sediment yields and runoffs were compared with field observations. For both watersheds, DEMs with different resolutions and sources generated varied watershed shapes and structures, which in turn led to different extracted hill slope and channel lengths and gradients, and produced substantially different erosion predictions by WEPP.     

Geology and the dark side

The diabolical and supernatural folklore traditions of geology are examined systematically for the first time. The following have all been suggested explanations for fossil remains: Devil's footprints, bones, toenails, fingers, thumbs, buttons, money and ninepins; Hobgoblin's claws; Fairy's fingers, heads, faces, hearts, beads, causeways, saltcellars, bottles, weights, money and loaves; elf arrows; witches’ beads and tongues. Twinned staurolite crystals have been called Fairy crosses.     

Pollutants,human health and the environment – A risk-based approach

Over the last 50 a there has been mounting unease about the risk of synthetic chemicals to human health. Publication of Rachel Carson’s Silent Spring in 1962 catalyzed public concern about chemicals. There is now a vast range of synthetic substances in the environment and their potential cocktail as well as the effects of chronic exposure is of concern. Concerns about pollution are not restricted to toxic chemicals, with radioactivity being an issue that continues to be emotive, and exposure to substances such as particulates has been seen to cause health problems. Improved understanding of chemical risks to the environment and human health suggest that a precautionary approach is adopted, with new approaches demonstrating how nature uses thousands of sustainable, non-toxic processes, which can be copied by industry. Policy has evolved from the prevention of local pollution to the holistic management of environmental quality. Regulation is now increasingly underpinned by risk assessment and responsibility for understanding and managing chemical risk is being transferred progressively to manufacturers and users. There is now an increased emphasis on individual responsibilities which requires a debate about the risks and benefits of chemicals in which all members of society can participate.     

The application of in vitro gastrointestinal extraction to assess oral bioaccessibility of potentially toxic elements from an urban recreational site

The use of in vitro gastrointestinal extraction to assess the oral bioaccessibility of 7 potentially toxic elements (PTEs) from soil derived from an urban recreational site, has been assessed. The pseudo-total concentration of the 7 PTEs was determined using microwave digestion followed by inductively coupled plasma mass spectrometry. The bioaccessible fraction was determined and the data compared to the pseudo-total concentrations to determine % bioaccessibility. A generic quantitative risk assessment (GQRA) was undertaken on the pseudo-total PTE concentration of the site by comparing the values with soil guideline (SGV) or generic assessment criteria (GAC) using the residential land use scenario. Based on the GQRA, concentrations of 3 of the PTEs investigated within the soils could present a potential risk to site users. Consideration of receptor exposure and bioaccessibility data allowed a more considered approach to human-health risk assessment at this site. Although the bioaccessibility data did not significantly alter the sites preliminary designation as contaminated (As and Pb concentrations exceeded the GAC even in the in vitro extracts) bioaccessibility data are clearly an additional tool towards furthering our understanding of human-health risk at contaminated sites and have the potential to act as a pragmatic decision-support tool.     

Monitoring Residual Spatial Patterns using Bayesian Hierarchical Spatial Modelling for Exploring Unknown Risk Factors

This article studies Bayesian hierarchical spatial modelling that monitors the changes of residual spatial pattern (structure) of the outcome variable for exploring unknown risk factors in small‐area analysis. Spatially structured random effects (SRE) and unstructured random effects (URE) terms added to the conventional logistic regression model take into account overdispersion and residual spatial structure, which if unaccounted for could cause incorrect identification of risk factors. Mapping and/or calculating the ratio of random effects that are spatially‐structured monitor the extent of residual spatial structure. The monitoring provides insights into identification of unknown covariates that have similar spatial structures to those of SRE. Adding such covariates to the model has the potential to diminish the residual spatial structure, until possibly all or most of the spatial structure can be explained. Risk factors identified are the added covariates that have statistically significant regression coefficients. We apply the methods to the analysis of domestic burglaries in Cambridgeshire, England. Small‐area analysis of crime where data often display apparent spatial structure would particularly benefit from the methodologies. We discuss the methodologies, their relevancy in our analysis of domestic burglaries, their limitations, and possible paths for future research.     

Comparing Conditions of Labor-Intensive Forestry and Fire Suppression Workers

Since the late 1970s, labor-intensive forest workers in the Pacific Northwest have been mostly Latino. These workers and their Anglo counterparts plant and thin trees, perform other forestry services, and fight wildland fires. Poor job quality has been persistent, especially for Latino workers. We compare working conditions between fire suppression and nonsuppression forest work across Latino and non-Latino populations in Oregon. We find that although both groups share some similar conditions, Latino workers often faced poorer conditions, including disrespectful treatment, uncompensated injuries, risk of being blackballed if they complained, and little opportunity for advancement. However, there were some important job quality improvements for Latinos in fire suppression, including compensation for travel and training. Differences in contracting market structure and federal oversight between fire suppression and other forest work may contribute to improved job quality. This suggests the potential for improving conditions by focusing on improving contracting markets and oversight.