A biomonitor as a measure of an ecologically-significant fraction of metals in an industrialized harbour

Biomonitors are commonly used to assess levels of bioavailable contaminants in the environment, however the relationships between biomonitor tissue concentrations and ecological effects are rarely assessed. The present study investigated metal contamination within a highly industrialised harbour and ecological effects on sessile invertebrates. The native oyster Saccostrea glomerata was deployed as a biomonitor across twenty-six sites to test for correlations between metal levels in their tissues and the recruitment of hard-substrate invertebrates. Concentrations of lead and copper in oyster tissues were negatively correlated with densities of the dominant barnacle, Amphibalanus variegatus, and positively correlated with densities of the dominant polychaete, Hydroides elegans, and the two native encrusting bryozoans Celloporaria nodulosa and Arachnopusia unicornis. Results suggest that highly localised events drive contaminant availability and that these events pose a significant risk to fauna. Biomonitoring studies may be enhanced by running concurrent ecological surveys.     

A Wind Tunnel Study to Design Large,Open-top Chambers for Whole-tree Pollutant Exposure Experiments

A wind tunnel study was conducted to determine the optimal design features of a large, open-top chamber, as needed for pollution exposure studies on mature trees. An optimally-designed, open-top chamber must minimize the incursion of ambient air through its opening and maintain a uniform treatment concentration throughout the chamber. The design features of interest are the diameter and height of the chamber and the deflection angle and opening size of any frustum that may be mounted on top of a model chamber.

Design specifications depend on the turbulence regime about the chamber, which is influenced by the nature of the surrounding vegetation. Consequently, our investigation was performed on scale-model, open-top chambers in a wind tunnel populated with a model coniferous forest. Turbulence measurements demonstrated the similarity between the turbulence regime of the model and a natural forest. A hydrocarbon tracer was injected into the wind tunnel flow to characterize chamber performance.

The main design features of open-top chambers are the velocity of air exiting through the top and the relationship between the length scale of the turbulence and the diameter of the chamber opening. As exit velocities increase, the proportion of eddies with sufficient force to penetrate into the chamber decrease. Therefore, for equal volumetric air flows, smaller opening sizes increase the exit velocities and reduce the number and extent of ambient air incursions. Almost total exclusion of ambient air is achieved as the exit velocity of the air exceeds the magnitude of one standard deviation of the vertical wind velocity measured at the chamber top. The incursion of ambient air is also reduced when the diameter of the chamber opening is smaller than the characteristic length scale of the turbulence, a measure of mean eddy size.

Frusta deflect air flow over the chamber. Three prototypes, with 30?, 45? and 60-degree angles were tested. A 30-degree frustum slightly improves the performance of the chamber and is more effective in preventing ambient air from entraining into the chamber opening than frusta with either a 45? or 60-degree angle. A flatter frustum allows for a smoother transition in the wind velocity streamline and is less apt to cause wake turbulence, as is the case with steeper frusta.

Knowledge of the turbulence characteristics of plant canopies are readily available in the literature and can aid scientists and engineers in designing the optimal chamber and frusta dimensions for their particular application. Therefore, the empirical approach to chamber design can be avoided, and substantial savings can be realized.     

Injury Severity Score alone predicts mortality when compared to EMS scene time and transport time for motor vehicle trauma patients who arrive alive to hospital

ABSTRACT

Objective: This study aims to identify the association, if any, between prehospital scene time, prehospital transport time, and Injury Severity Score (ISS) with in-hospital mortality.

Methods: A retrospective analysis was performed on patients at least 18 years of age who arrived to the hospital alive via emergency medical services (EMS) after a motor vehicle collision (MVC) between 1992 and 2016. These patients were divided into groups based on minutes spent at the scene and in transport. The ISS of the in-hospital mortalities, as well as the entire patient sample for each time frame, was collected. Patients without documented scene time, transport time, or ISS were excluded.

Results: Four thousand one hundred ninety-four patients were captured when analyzing scene time, though only 3,980 met inclusion criteria. In addition, 4,177 patients were captured when analyzing transport time, though only 3,979 met inclusion criteria. Scene time and transport time were not statistically significant predictors of in-hospital mortality (P = .31 and P = .458, respectively). ISS was found to be a statistically significant predictor of in-hospital mortality (P < .001).

Conclusions: ISS predicts mortality independent of scene time or transport time for patients who arrive to the hospital alive following an MVC at Guthrie Robert Packer Hospital. Limitations of our study include inability to capture prehospital deaths and inability to correlate ISS with prehospital injury severity scores.     

The psychological effects of false-positive results in prenatal screening for fetal abnormality: A prospective study

The purpose of the study was to describe the impact of false-positive results from initial maternal serum alpha-fetoprotein (MS-AFP) screening. The analyses compared two groups of women, those receiving a negative result (n = 346) and those receiving an initial positive result (n = 26), over four time points—prior to testing, immediately after testing, later in pregnancy, and in the post-partum period. Receiving an abnormal result was associated with high levels of anxiety which were reflected in increased worry about the baby's health and a more negative attitude towards the pregnancy and the baby. Women who had an initial abnormal result were offered a variety of further tests. Those women who went on to have amniocentesis were less worried about their baby's health in the third trimester and also less anxious post-partum than those who did not have amniocentesis. In view of the increasing number of screening tests available, it is necessary to establish whether and how these levels of distress can best be reduced.     

Cultivated cells from mid-trimester amniotic fluids. IV. Cell type identification via one and two-dimensional electrophoresis of clonal whole cell homogenates

Clones of cultivated amniotic fluid cells that have distinct morphologic and growth characteristics (F, AF and E-type) were examined by one-dimensional SDS polyacrylamide gel electrophoresis (SDS-PAGE) and by two-dimensional electrophoresis employing isoelectric focusing and SDS-PAGE (IEF-PAGE). No qualitative differences in band pattern were observed in SDS-PAGE between the various amniotic fluid cell types, but consistent quantitative differences in the ratios of four bands of presumed filamentous proteins provided good distinction between amniotic fluid cells and postnatal skin fibroblast-like cells. By adding separation on the basis of electrical charge to that of molecular size (IEF-PAGE), we observed reproducible qualitative differences in the protein spot patterns between F and both AF and E-type amniotic fluid cells. At least eight discrete proteins appear not to be synthesized by prenatal F-type cells in comparison with their isogenic AF and E counterparts under identical culture conditions. The two-dimensional electrophoretic patterns thus confirm that F and AF amniotic cells, in spite of their morphologic and growth kinetic similarities, are developmentally distinct cell types that retain their differentiated states in culture.     

Strong links between metal contamination, habitat modification and estuarine larval fish distributions

Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages.     

Prenatal diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency

A fatal case of medium-chain acyl-coenzyme A dehydrogenase deficiency is described in a patient who presented with hypoglycaemia and a gross non-ketotic dicarboxylic aciduria. Cultured skin fibroblasts released ¹⁴CO₂ from [1–¹⁴C] octanoic acid at half the normal rate. Prenatal diagnosis was undertaken in a subsequent pregnancy in which cultured amniotic fluid cells revealed a marked reduction in octanoate oxidation indicative of an affected fetus. The pregnancy was terminated and the diagnosis was confirmed by enzyme analysis of skin fibroblasts taken from the fetus. The high residual octanoate oxidation by affected fibroblasts together with the absence of any characteristic abnormality of amniotic fluid organic acids are a potential limitation to the reliability of this type of prenatal diagnosis.     

建立组织外植体的共培养模型(in vitro)用于预测内分泌干扰效应(in vivo)：以黑头软口鲦(Pimephales promelas)的下丘脑-垂体-性腺（HPG）轴内分泌干扰作用为例

内分泌干扰物 （Endocrine Disrupting Compounds, EDCs）可以通过干扰下丘脑-垂体-性腺（HPG）轴来影响生殖系统。虽然目前已有筛选内分泌干扰物的体外检测方法,但这些方法在用于体内实验时却有着不稳定的准确性。本文记录了以黑头呆鱼（Pimephales promelas）的下丘脑-垂体-性腺轴与肝（HPG-L）的共培养组织作为组织外植体来模拟体内反应的结果。我们对成年鱼的大脑（下丘脑）,垂体,性腺和肝进行了单独和共同培养的检测来确定可以在体内重复的情况与组合。只有共培养体表现出去甲雄三烯醇酮对于雌二醇,睾酮和卵黄生成素生成趋势的影响。较低的暴露剂量会抑制激素生成,而较高的暴露剂量则会促进激素生成,形成U型作用曲线。这些数据表明下丘脑-垂体-性腺-肝轴的全部组织的共同培养可以作为体内实验与体外实验的连接,从而预测在完整生物体内内分泌系统的扰乱。本实验中以组织为基础的下丘脑-垂体-性腺-肝系统作为一个灵活的体内系统的解构版本得到了更好的实验控制。通过分离、审查和重组需要的组织,我们能够检测到生物系统功能与对于内分泌干扰物反应中的微小变化。
精选自Theresa K. Johnston, Edward Perkins, Duncan C. Ferguson, Donald M. Cropek. Tissue explant co-culture model of the hypothalamic-pituitary-gonadal-liver axis of the fathead minnow (Pimephales promelas) as a predictive tool for endocrine disruption. Environmental Toxicology and Chemistry: Volume 35, Issue 10, pages 2530–2541, October 2016. DOI: 10.1002/etc.3415
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3415/full
     

ON‐FARM WATER CONSERVATION PRACTICES IN SOUTHERN ALBERTA1

ABSTRACT: In southern Alberta, as elsewhere, pressures on limited water supplies are increasing. Not surprisingly, a great deal of attention has been focused on irrigated agriculture, which accounts for the largest share of water consumed in the region. In order to meet broadly accepted water conservation goals, some commentators have suggested that irrigation water use should be metered and that irrigators should be charged based on the amount of water used. An alternative proposal would have water management authorities rely upon the perceived adaptability of irrigators. This paper offers a perspective on the willingness of irrigators to conserve water. Based on a survey of 183 irrigation farmers conducted over the summer and early fall of 1998, we found that irrigators are generally aware of the need to conserve water and soil moisture, and that a variety of water conserving strategies were being employed. Water saving technologies specific to irrigation agriculture were less widely adopted. The findings suggest that there is considerable potential to reduce the amount of water consumed by the irrigation sector through increased efficiency, but that change will be limited if current economic circumstances and institutional arrangements persist.