Environmental Science and Pollution Research - The contamination left by abandoned mines demands sustainable mitigation measures. Hence, the aim of this study was to examine the phytoremediator... 相似文献
This is the third update of research on graduated driver licensing (GDL) and related teenage driver issues. It briefly summarizes research published since or not included in the 2005 update (Hedlund, J., & Compton, R. (2005). Graduated driver licensing research in 2004 and 2005. Journal of Safety Research, 36(2), 109-119.), describes research in progress of which the authors are aware, and announces plans for a symposium on teenage driving and GDL to be held in February 2007. 相似文献
Arthrobacter sp. strain CN2, capable of degrading 4-nitrophenol, was isolated from activated sludge. Degradation of 4-nitrophenol was optimized at pH 7.7, 30?°C, and 0.53% of glucose. Salt tolerance of 4-nitrophenol degradation was as high as 6% (w/v). Several biodegradation intermediates were identified and quantified by high-performance liquid chromatography and mass spectrometry. 4-Nitrocatechol is involved in the degradation of 4-nitrophenol by CN2. Scale-up of 4-nitrophenol degradation was conducted in a bioreactor with different salinity. When the salinity was below 7%, the degradation rate of 4-nitrophenol was above 90% (100 mg L?1, 3 L). 相似文献
Green macroalgal blooms have substantially altered marine community structure and function, specifically by smothering seagrasses and other primary producers that are critical to commercial fisheries and by creating anoxic conditions in enclosed embayments. Bottom-up factors are viewed as the primary drivers of these blooms, but increasing attention has been paid to biotic controls of species composition. In Washington State, USA, blooms are often dominated by Ulva spp. intertidally and Ulvaria obscura subtidally. Factors that could cause this spatial difference were examined, including competition, grazer preferences, salinity, photoacclimation, nutrient requirements, and responses to nutrient enrichment. Ulva specimens grew faster than Ulvaria in intertidal chambers but not significantly faster in subtidal chambers. Ulva was better able to acclimate to a high-light environment and was more tolerant of low salinity than Ulvaria. Ulvaria had higher tissue N content, chlorophyll, chlorophyll b: chlorophyll a, and protein content than Ulva. These differences suggest that nitrogen availability could affect species composition. A suite of five grazers preferred Ulva to Ulvaria in choice experiments. Thus, bottom-up factors allow Ulva to dominate the intertidal zone while resistance to grazers appears to allow Ulvaria to dominate the subtidal zone. While ulvoid algae are in the same functional-form group, they are not functionally redundant. 相似文献
Megalopae of several crab species exhibit active habitat selection when settling. These megalopae usually select structurally
complex habitats which can provide refuge and food. The portunid mud crab, Scylla serrata, is commonly found within the muddy estuaries of the Indo-West Pacific after attaining a carapace width >40 mm. Despite substantial
efforts, the recruitment mechanism of juvenile mud crabs to estuaries is not understood because their megalopae and early
stage crablets (carapace width <30 mm) are rarely found. We used laboratory experiments to determine whether megalopae and
early stage crablets are selective among three estuarine habitats which commonly occur in Queensland, Australia. These animals
were placed in arenas where they had a choice of habitats: seagrass, mud or sand, and arenas where they had no choice. Contrary
to the associations exhibited by other portunid crab megalopae, S. serrata megalopae were not selective among these estuarine habitats, suggesting that they tend not to encounter these habitats, or,
gain no advantage by selecting one over the others. The crablets, however, strongly selected seagrass, suggesting that residing
within seagrass is beneficial to the crablets and likely increases survival. This supports the model that for S. serrata, crablets and not megalopae tend to colonise estuaries, since a selective behaviour has evolved within crablets but not megalopae. 相似文献
Intrauterine fetal demise (IUFD) in one of twins at 12 weeks of gestation was accompanied by markedly elevated maternal serum alpha-fetoprotein (AFP) at 17 and 18 weeks. Amniotic fluid AFP from the healthy surviving twin's sac at 18·5 and 23 weeks was also greatly increased along with a positive acetylcholinesterase (AChE) band. Persistently elevated AFP and positive AChE so long after fetal demise–-6·5 and 11 weeks post IUFD–-has not, to our knowledge, been previously described. In similar cases, high level ultrasound and careful placental examination at birth should be utilized to search for fetal abnormalities or multiple pregnancy with IUFD. 相似文献
We explored the possible future impacts of increased coastal flooding due to sea level rise and the potential adaptation responses
of two urban, environmental justice communities in the metropolitan Boston area of Massachusetts. East Boston is predominantly
a residential area with some industrial and commercial activities, particularly along the coastal fringe. Everett, a city
to the north of Boston, has a diversified industrial and commercial base. While these two communities have similar socioeconomic
characteristics, they differ substantially in the extent to which residents would be impacted by increased coastal flooding.
In East Boston, a large portion of residents would be flooded, while in Everett, it is the commercial/industrial districts
that are primarily vulnerable. Through a series of workshops with residents in each community, we found that the target populations
do not have an adaptation perspective or knowledge of any resources that could assist them in this challenge. Furthermore,
they do not feel included in the planning processes within their communities. However, a common incentive for both communities
was an intense commitment to their communities and an eagerness to learn more and become actively engaged in decisions regarding
climate change adaptation. The lessons that can be applied to other studies include 1) images are powerful tools in communicating
concepts, 2) understanding existing cultural knowledge and values in adaptation planning is essential to the planning process
and 3) engaging local residents at the beginning of the process can create important educational opportunities and develop
trust and consensus that is necessary for moving from concept to implementation. 相似文献
Pyrolysis of waste materials to produce biochar is an excellent and suitable alternative supporting a circular bio-based economy. One of the properties attributed to biochar is the capacity for sorbing organic contaminants, which is determined by its composition and physicochemical characteristics. In this study, the capacity of waste-derived biochar to retain volatile fuel organic compounds (benzene, toluene, ethylbenzene and xylene (BTEX) and fuel oxygenates (FO)) from artificially contaminated water was assessed using batch-based sorption experiments. Additionally, the sorption isotherms were established. The results showed significant differences between BTEX and FO sorption on biochar, being the most hydrophobic and non-polar contaminants those showing the highest retention. Furthermore, the sorption process reflected a multilayer behaviour and a relatively high sorption capacity of the biochar materials. Langmuir and Freundlich models were adequate to describe the experimental results and to detect general differences in the sorption behaviour of volatile fuel organic compounds. It was also observed that the feedstock material and biochar pyrolysis conditions had a significant influence in the sorption process. The highest sorption capacity was found in biochars produced at high temperature (>?400 °C) and thus rich in aromatic C, such as eucalyptus and corn cob biochars. Overall, waste-derived biochar offers a viable alternative to be used in the remediation of volatile fuel organic compounds from water due to its high sorption capacity.