幽蚊幼虫对紫外辐射(UVR)的敏感性

在小型温带湖泊中,鱼类的捕食一般调节着幽蚊幼虫的物种结构和丰度.然而,没有鱼类的湖泊间的幽蚊丰度差别也很明显.安大略省萨德伯里的许多无鱼湖泊的湖水清澈透明.这就产生了这样的可能性:这类湖泊中幽蚊丰度低可能归因于紫外辐射(UVR)引起的死亡.为了确定UVR是否影响幽蚊存活率,我们在罗斯罗伊湖(一个几乎没有幽蚊的水清、无鱼的湖泊)4个水深处进行了为期2～4天的6个现场实验.对第3和第4龄虫C.Punctipennis随机进行3种处理:石英(UVR+PAR)控制;OP3聚丙烯酸酯塑料(只是PAR)控制以及无光控制.在UVR+PAR下的生存率大大低于其他的处理方法.在只是PAR下的生存率较高,与无光控制没有什么不同.死亡时间随着孵化深度和幼虫期的增加而增加.这些结果表明,罗斯罗伊湖,也许还有其他的无鱼、水清湖泊中幽蚊种群规模小可能是缘于UVR引起的死亡.     

A rare case of 68,XX triploidy diagnosed by amniocentesis

68,XX triploidy was found in the amniotic fluid cell culture of a 40-year-old patient. Elective termination of the pregnancy revealed a fetus with multiple congenital anomalies. While this case does show some common features with monosomy X, a greater similarity to the triploidy syndrome is observed.     

1971～200O年间安大略省基拉尼公园里的甲壳类浮游动物群落从酸化水体中得到恢复:pH6作为恢复的目标

尽管大气中SO2- 4的沉降减少,地表水的酸度也因此降低,但尚未记录到广泛的生物从酸化中恢复过来.本文通过考察1971～2000年间加拿大安大略省基拉尼公园的46个湖泊甲壳类浮游动物种的丰富度(物种数目)和组成的时间变化趋势,来估计由于水质有了重大改善即pH现在＞6后湖泊中生物的恢复程度,并与其他两组(从未酸化的湖泊和仍然酸化的湖泊[pH＜6])作比较.在这三组湖泊中,物种丰富度的时间趋势无法加以区别,物种丰富度的变化也不能说明恢复的程度.对比之下,在pH值增加到6以上的湖泊中,其浮游动物群落的组成(以物种多度的多变量指数表征)则有所变化,从"损害"状态返回到了中性湖泊的典型状态.在酸性湖泊也记录到浮游动物组成有某些恢复.虽然仍为酸性,这些湖泊的pH水平已经升高.基拉尼省公园里甲壳类浮游动物恢复的程度和速度为北美和欧洲其他酸化地区的将来预示了光明的前景.     

Organochlorine contaminant assessment in great blue herons using traditional and nonlethal monitoring techniques

A nonlethal method is discussed for the evaluation of contaminant concentrations in whole eggs. Concentrations of pentachlorobenzene, hexachlorobenzene, DDE, and the PCB congeners, BZ-60, BZ-118, BZ-138, BZ-180, and BZ-170 were quantified in tissue samples from great blue herons (Ardea herodias). All tissues within whole eggs from two colonies were homogenized together and analysed for these chlorinated contaminants. Contents and chorio-allantoic membranes (CAMs) of additional whole eggs were separated and analysed. Contaminant distributions were determined for the CAM and contents of whole eggs from the same colonies. CAM tissues remaining in hatched eggs were also analysed for comparative purposes. Utilizing the distributions derived for contaminants between CAM and egg contents and the chemical concentrations determined in CAMs from hatched eggs, contaminant burdens in whole eggs were calculated. This process produced concentration estimates that described actual, whole egg burdens of chlorinated contaminants within a factor of 2 (1.03-3.7). Contaminant burdens in eggs from the two colonies were also statistically different for DDE and total PCB concentrations.     

Exploring CCS community acceptance and public participation from a human and social capital perspective

The delay or cancellation of energy infrastructure projects, such as wind farms and nuclear power plants and more recently carbon capture and storage (CCS) because of community resistance and poor public participation processes are well known. Yet, some communities accept these projects with relative ease. The term acceptance implies passivity and as such does not necessarily reflect community approval or support. If acceptance is passive, what are the characteristics of a community in which the acceptance of CCS is achieved with relative ease; and what best-practice public participation processes are most appropriate for it? This paper attempts to answer these questions through a case study of Australia's Otway Project. Qualitative research methods were used to conduct a human and social capital analysis of the Otway community. An assessment of the project's public participation process was made in light of that analysis. The study found that the community needed capacity-building to enable it to become well-informed about CCS; and to help it develop the negotiation skills necessary to have the proponent address its concerns about the project in a timely manner. An assessment of the Otway public participation process found that while it implemented the majority of best practice principles in public participation, it lacked an adherence to three: transparency, fairness and capacity. A mindfulness of all principles of best practice in public participation would have ensured a fairer and more transparent process.     

Variations in Epilimnion Thickness in Small Boreal Shield Lakes: Relationships with Transparency, Weather and Acidification

We used multiple linear regression analysis to investigate relationships between late-summer epilimnion thickness, transparency, lake area, acidity and summer weather conditions in a large ($n = 116$) multi-year data set for 9 small Boreal Shield lakes. Dissolved organic carbon (DOC) was the best individual predictor of late summer epilimnion thickness ($r^{2} = 0.69$). Total chlorophyll~$a$, the number of days between ice-out and late-summer stratification, and lake area collectively explained an additional 14% of the variation in epilimnion thickness. The three attributes of summer weather that we examined, mean daily temperature, mean daily wind speed, and mean daily hours of bright sunshine, did not add to the predictive ability of our regression model. Lake acidity also did not add directly to the predictive ability of the model, likely because DOC concentrations already reflected the effects of pH. Our study supports an increasing body of evidence indicating that the dominant effects of climate change on lake thermal structure in small lakes will be through effects on processes that affect lake transparency.     

Cold comfort: Arctic seabirds find refugia from climate change and potential competition in marginal ice zones and fjords

Climate change alters species distributions by shifting their fundamental niche in space through time. Such effects may be exacerbated by increased inter-specific competition if climate alters species dominance where competitor ranges overlap. This study used census data, telemetry and stable isotopes to examine the population and foraging ecology of a pair of Arctic and temperate congeners across an extensive zone of sympatry in Iceland, where sea temperatures varied substantially. The abundance of Arctic Brünnich’s guillemot Uria lomvia declined with sea temperature. Accessibility of refugia in cold water currents or fjords helped support higher numbers and reduce rates of population decline. Competition with temperate Common guillemots Uria aalge did not affect abundance, but similarities in foraging ecology were sufficient to cause competition when resources are limiting. Continued warming is likely to lead to further declines of Brünnich’s guillemot, with implications for conservation status and ecosystem services.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01650-7.     

Deriving the factor structure of safety climate scales

Since the original formulation of the notion of safety climate, many people have developed safety climate measures and conducted factor analyses to identify distinct dimensions. Typically, these analyses were based on samples of workers in a limited number of workplaces, but since they did not allow for the non-independence of the data, they are incorrect. An appropriate analysis should use a multi-level method. This flaw in the analyses to date may at least partly explain the different factor structures of safety climate reported in the literature.     

The IMPROVE_A temperature protocol for thermal/optical carbon analysis: maintaining consistency with a long-term database

Thermally derived carbon fractions including organic carbon (OC) and elemental carbon (EC) have been reported for the U.S. Interagency Monitoring of PROtected Visual Environments (IMPROVE) network since 1987 and have been found useful in source apportionment studies and to evaluate quartz-fiber filter adsorption of organic vapors. The IMPROVE_A temperature protocol defines temperature plateaus for thermally derived carbon fractions of 140 degrees C for OC1, 280 degrees C for OC2, 480 degrees C for OC3, and 580 degrees C for OC4 in a helium (He) carrier gas and 580 degrees C for EC1, 740 degrees C for EC2, and 840 degrees C for EC3 in a 98% He/2% oxygen (O2) carrier gas. These temperatures differ from those used previously because new hardware used for the IMPROVE thermal/optical reflectance (IMPROVE_TOR) protocol better represents the sample temperature than did the old hardware. A newly developed temperature calibration method demonstrates that these temperatures better represent sample temperatures in the older units used to quantify IMPROVE carbon fractions from 1987 through 2004. Only the thermal fractions are affected by changes in temperature. The OC and EC by TOR are insensitive to the change in temperature protocol, and therefore the long-term consistency of the IMPROVE database is conserved. A method to detect small quantities of O2 in the pure He carrier gas shows that O2 levels above 100 ppmv also affect the comparability of thermal carbon fractions but have little effect on the IMPROVE_TOR split between OC and EC.