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221.
There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H(2) production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted. 相似文献
222.
Andrew Chin Fergus John Molloy Darren Cameron Jon C. Day Jessica Cramp Karin Leeann Gerhardt Michelle R. Heupel Mark Read Colin A. Simpfendorfer 《Conservation biology》2023,37(1):e13917
Marine protected areas (MPAs) are key tools in addressing the global decline of sharks and rays, and marine parks and shark sanctuaries of various configurations have been established to conserve shark populations. However, assessments of their efficacy are compromised by inconsistent terminology, lack of standardized approaches to assess how MPAs contribute to shark and ray conservation, and ambiguity about how to integrate movement data in assessment processes. We devised a conceptual framework to standardize key terms (e.g., protection, contribution, potential impact, risk, threat) and used the concept of portfolio risk to identify key attributes of sharks and rays (assets), the threats they face (portfolio risk), and the specific role of MPAs in risk mitigation (insurance). Movement data can be integrated into the process by informing risk exposure and mitigation through MPAs. The framework is operationalized by posing 8 key questions that prompt practitioners to consider the assessment scope, MPA type and purpose, range of existing and potential threats, species biology and ecology, and management and operational contexts. Ultimately, MPA contributions to shark and ray conservation differ according to a complex set of human and natural factors and interactions that should be carefully considered in MPA design, implementation, and evaluation. 相似文献
223.
Trijntje van der Velde-Koerts Sam Margerison Nicolas Breysse Jason Lutze Karin Mahieu Hermine Reich 《Journal of environmental science and health. Part. B》2018,53(6):366-379
ABSTRACTIn 2015 a scientific workshop was held in Geneva, where updating the four equations for estimating the short-term dietary exposure (International Estimated Short Term Intake, IESTI) to pesticides was suggested. The impact of these proposed changes on the exposure was studied by using residue data and large portion consumption data from Codex and Australia. For the Codex data, the exposure increased by a median factor of 2.5 per commodity when changing to the proposed IESTI equations. The increase in exposure was highest for bulked and blended food commodities (case 3 equations), followed by medium-sized food commodities (case 2a equations) and small- and large-sized food commodities (case 1 and case 2b equations). For the Australian data, out of 184 maximum residue limit (MRL) large portion combinations showing acute exposures below the acute reference dose (ARfD) with the current IESTI equations, 23 exceeded the ARfD with the proposed IESTI equations (12%). The percentage exceeding the ARfD was higher for the Australian MRL large portion combinations (12% of 184) than for those of Codex (1.3% of 8,366). However, the percentage MRL loss in the Australian dataset may not be representative of all pesticide MRLs since it concerns six pesticides only, specifically selected to elucidate the potential effects of the use of the proposed IESTI equations. For the Codex data, the increase in exposure using the proposed equations resulted in a small increased loss of 2.6% of the 1,110 MRLs estimated by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR): 1.4% of the MRLs were already not acceptable with the current equations, 4.0% of the MRLs were not acceptable with the newly proposed equations. Our study revealed that case 3 commodities may be impacted more by the proposed changes than other commodities. This substantiates one of the conclusions of the Geneva workshop to gather information on bulking and blending practices in order to refine MRL setting and dietary risk assessment for case 3 commodities where possible. 相似文献
224.
Barrueto Andrea Karin Merz Jürg Hodel Elias Eckert Sandra 《Regional Environmental Change》2018,18(3):859-871
Regional Environmental Change - Global climate models predict temperature rises and changes in precipitation regimes that will shift regional climate zones and influence the viability of... 相似文献
225.
Marcussen H Joergensen K Holm PE Brocca D Simmons RW Dalsgaard A 《Environmental monitoring and assessment》2008,139(1-3):77-91
Extensive aquatic or semi-aquatic production of water spinach (Ipomoea aquatica Forssk.) for human consumption takes place in Southeast Asia. The aim of this study was to assess the concentrations of 38
elements in soil and water spinach cultivated under different degrees of wastewater exposure in Hanoi, Vietnam. The results
showed no effect of wastewater use on the overall element concentrations in soil and water spinach. Mean soil concentrations
for selected potentially toxic elements at the studied field sites had the following ranges 9.11–18.7 As, 0.333–0.667 Cd,
10.8–14.5 Co, 68–122 Cr, 34.0–62.1 Cu, 29.9–52.8 Ni, 32.5–67.4 Pb, 0.578–0.765 Tl and 99–189 Zn mg kg−1 dry weight (d.w.). In all samples Cd, Pb and Zn soil concentrations were below the Vietnamese Guideline Values (TCVN 7209-2002)
for agricultural soils whereas As and Cu exceeded the guideline values. Maximum site element concentrations in water spinach
were 0.139 As, 0.032 Cd, 0.135 Cr, 2.01 Cu, 39.1 Fe, 57.3 Mn, 0.16 Ni, 0.189 Pb and 6.01 Zn mg kg−1 fresh weight (f.w.). The site and soil content of organic carbon were found to have high influence on the water spinach element
concentrations whereas soil pH and the total soil element concentrations were of less importance. The estimated average daily
intake of As, Cd, Cu, Fe, Pb and Zn for adult Vietnamese consumers amounts to <11% of the maximum tolerable intake proposed
by FAO/WHO for each element. It is assessed that the occurrence of the investigated elements in water spinach will pose low
health risk for the consumers. 相似文献
226.
Satisfaction of communities living close to forests with forest management authorities is essential for ensuring continued
support for conservation efforts. However, more often than not, community satisfaction is not systematically elicited, analyzed,
and incorporated in conservation decisions. This study attempts to elicit levels of community satisfaction with three management
approaches of Kakamega forest in Kenya and analyze factors influencing them. Three distinct management approaches are applied
by three different authorities: an incentive-based approach of the Forest Department (FD), a protectionist approach of the
Kenya Wildlife Service (KWS), and a quasi-private incentive-based approach of Quakers Church Mission (QCM). Data was obtained
from a random sample of about 360 households living within a 10-km radius around the forest margin. The protectionist approach
was ranked highest overall for its performance in forest management. Results indicate that households are influenced by different
factors in their ranking of management approaches. Educated households and those located far from market centers are likely
to be dissatisfied with all the three management approaches. The location of the households from the forest margin influences
negatively the satisfaction with the protectionist approach, whereas land size, a proxy for durable assets, has a similar
effect on the private incentive based approach of the QCM. In conclusion, this article indicates a number of policy implications
that can enable the different authorities and their management approaches to gain approval of the local communities. 相似文献
227.
A database of global agricultural primary production has been constructed and used to estimate its energy content. The portion
of crops available for food and biofuel after postharvest losses was evaluated. The basic conditions for agriculture and plant
growth were studied, to ensure sustainable scenarios regarding use of residues. The available energy contents for the world
and EU27 was found to be 7,200–9,300 and 430 TWh, respectively, to be compared with food requirements of 7,100 and 530 TWh.
Clearly, very little, or nothing, remains for biofuel from agricultural primary crops. However, by using residues and bioorganic
waste, it was found that biofuel production could theoretically replace one-fourth of the global consumption of fossil fuels
for transport. The expansion potential for global agriculture is limited by availability of land, water, and energy. A future
decrease in supply of fossil energy and ongoing land degradation will thus cause difficulties for increased biofuel production
from agriculture. 相似文献
228.
A multi-scaled model for biodiversity conservation in forests was introduced in Sweden 30 years ago, which makes it a pioneer
example of an integrated ecosystem approach. Trees are set aside for biodiversity purposes at multiple scale levels varying
from individual trees to areas of thousands of hectares, with landowner responsibility at the lowest level and with increasing
state involvement at higher levels. Ecological theory supports the multi-scaled approach, and retention efforts at every harvest
occasion stimulate landowners’ interest in conservation. We argue that the model has large advantages but that in a future
with intensified forestry and global warming, development based on more progressive thinking is necessary to maintain and
increase biodiversity. Suggestions for the future include joint planning for several forest owners, consideration of cost-effectiveness,
accepting opportunistic work models, adjusting retention levels to stand and landscape composition, introduction of temporary
reserves, creation of “receiver habitats” for species escaping climate change, and protection of young forests. 相似文献
229.
Karin Löfstrand Anna Malmvärn Peter Haglund Anders Bignert Åke Bergman Lillemor Asplund 《Environmental science and pollution research international》2010,17(8):1460-1468
Introduction
Naturally occurring hydroxylated polybrominated diphenyl ethers (OH-PBDEs), their methoxylated counterparts (MeO-PBDEs), and polybrominated dibenzo-p-dioxins (PBDDs), together with their potential precursors polybrominated phenols (PBPs) and polybrominated anisoles (PBAs), were analyzed in blue mussels (Mytilus edulis) gathered along the east coast (bordering the Baltic Sea) and west coast of Sweden (bordering the North Sea). Brown algae (Dictyosiphon foenicolaceus) and cyanobacteria (Nodularia spumigena) from the Baltic Sea, considered to be among the primary producers of these compounds, were also analyzed for comparison. 相似文献230.
Maurice C Gustavsson B Ragnvaldsson D Rydvall B Berglind R Haglund P Johnson T Leffler P Luthbom K von Heijne P 《Ambio》2007,36(6):502-511
Investigations of polluted brownfield sites and sample analyses are expensive, and the resulting data are often of poor quality. Efforts are needed, therefore, to improve the methods used in investigations of brownfield sites to both reduce costs and improve the quality of the results. One approach that could be useful for both of these purposes is the triad strategy, developed by the US Environmental Protection Agency, in which managing uncertainty is a central feature. In the investigations reported here, a field study was conducted to identify possible ways in which uncertainties could be managed in practice. One example considered involves optimizing the uncertainty by adjusting the sizes of samples and the efforts expended in analytical work according to the specific aims of the project. In addition, the potential utility of several toxicity assessment methods for screening sites was evaluated. As well as presenting the results of these assessments, in this contribution we discuss ways in which a flexible work strategy and screening methods inspired of the triad philosophy could be incorporated into the Swedish approach to remediate brownfield sites. A tiered approach taking advantage of field and screening methods is proposed to assess brownfield sites focusing on the response and acceptable uncertainty that are required for the task. 相似文献