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Salinity variations can be considered as a potential source of information for orientation in the marine environment. To
use this kind of environmental information marine animals must be able to detect these salinity differences. Therefore we
determined salinity-difference thresholds of two harbour seals for the discrimination of seawater solutions as a function
of the salinity level (15–35‰) and compared them with the thresholds of human subjects. Whereas in humans thresholds increased
with increasing salinity level, thresholds of seals decreased with increasing salinity level. Both seals achieved best sensitivity
at 30‰ salinity, where they detected a salinity difference ≤4%. These data indicate that the ability of seals to detect salinity
differences of seawater is well tuned to the natural occurrence of this environmental information. Their high gustatory resolving
power for differences in seawater salinity is suggested to meet the basic requirements for chemosensory orientation of seals
in the marine habitat.
Received: 10 February 2000 / Accepted in revised form: 19 September 2000 相似文献
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Barbara ZanuttighAuthor vitae 《Environmental Science & Policy》2011,14(7):845-863
Coastal areas are vital economic hubs in terms of settlement, industry, agriculture, trade and tourism to mention some key sectors. There are already many coastal problems including erosion, flood risk and long-term habitat deterioration. As economies continue to develop the asset base at risk will grow, while accelerating climate change will increase the likelihood of damaging extreme events, as well as accelerate habitat decline. Existing coastal management and defence approaches are not well tuned to these challenges as they assume a static situation.THESEUS project is developing a systematic approach to delivering both a low-risk coast for human use and healthy habitats for evolving coastal zones subject to multiple change factors. The project examines innovative mitigation and adaptation technologies and integrate the best of these technical measures in a strategic policy context through overarching guidelines. THESEUS activities are carried out within a multidisciplinary framework using 8 study sites across Europe, with specific attention to the most vulnerable coastal environments such as deltas, estuaries and wetlands, where many large cities and industrial areas are located.This paper describes THESEUS approach, and specifically: the Source-Pathway-Receptor-Consquence model for coastal risk assessment; the engineering, social, economic and ecological mitigation measures under analysis; the participatory approach with end users and coastal authorities for the selection and identification of the appropriate defence strategy to be planned in sudy sites. 相似文献
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Due to both natural and anthropogenic forces, the south west part of the Ganges-Brahmaputra coastal area is facing diverse problems such as waterlogging, salinity, and loss of biodiversity. In order to address these challenges, local people have identified ‘tidal river management (TRM)’ as a comprehensive approach for sustainably managing this part of the Ganges-Brahmaputra Basin. However, due to institutional limitations, mismanagement and social conflicts, application of the TRM approach is not straightforward. In order to identify existing implementation barriers and to effectively apply the TRM approach, a transdisciplinary approach is examined for its potential to inform the re-shaping of TRM governing values and actions. It is argued that a thorough application of a transdisciplinary framework is essential, supported by the active involvement of key agencies and local stakeholders. The proposed transdisciplinary framework can potentially be applied to TRM projects for solving waterlogging and associated problems in order to achieve greater sustainability of the area. 相似文献
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The footprint of human activities within Antarctica is increasing, making it essential to consider whether current conservation/protection of environmental and scientific values is adequate. The Antarctic protected area network has developed largely without any clear strategy, despite scientific attempts to promote protection of representative habitats. Many Antarctic Specially Protected Area (ASPA) Management Plans do not state clearly if conservation or science is the priority objective. This is problematic as science and conservation may have conflicting management requirements, i.e. visitation may benefit science, but harm conservation values. We examined recent estimated mean annual levels of visitation to ASPAs. On average, ASPAs protecting scientific research interests were visited twice as often as ASPAs conserving Antarctic habitat and biological communities. However, ASPAs protecting both science and conserving habitat were visited three times as often as ASPAs conserving habitat alone. Examination of visitation data showed that the proportion of visitors entering ASPAs for science, environmental management and/or education and tourism purposes, did not reflect the primary reason for designation, i.e. for science and/or conservation. One third of APSAs designated since the Environmental Protocol entered into force (1998) did not describe clearly the main reason for designation. Policy makers should consider (i) for all Management Plans stating unambiguously the reason an area has ASPA designation, e.g. either to protect habitat/environmental values or scientific research, in accordance with adopted guidance, (ii) designating new protected areas where visitation is kept to an absolute minimum to ensure the long-term conservation of Antarctic species and habitats without local human impacts (possibly located far from areas of human activity), and (iii) encouraging the use of zoning in ASPAs to help facilitate the current and future requirements of different scientific disciplines. 相似文献
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B.M. Smyth B.P. Ó Gallachóir N.E. Korres J.D. Murphy 《Journal of Cleaner Production》2010,18(16-17):1671-1685
The deployment of biofuels is significantly affected by policy in energy and agriculture. In the energy arena, concerns regarding the sustainability of biofuel systems and their impact on food prices led to a set of sustainability criteria in EU Directive 2009/28/EC on Renewable Energy. In addition, the 10% biofuels target by 2020 was replaced with a 10% renewable energy in transport target. This allows the share of renewable electricity used by electric vehicles to contribute to the mix in achieving the 2020 target. Furthermore, only biofuel systems that effect a 60% reduction in greenhouse gas emissions by 2020 compared with the fuel they replace are allowed to contribute to meeting the target. In the agricultural arena, cross-compliance (which is part of EU Common Agricultural Policy) dictates the allowable ratio of grassland to total agricultural land, and has a significant impact on which biofuels may be supported. This paper outlines the impact of these policy areas and their implications for the production and use of biofuels in terms of the 2020 target for 10% renewable transport energy, focusing on Ireland. The policies effectively impose constraints on many conventional energy crop biofuels and reinforce the merits of using biomethane, a gaseous biofuel. The analysis shows that Ireland can potentially satisfy 15% of renewable energy in transport by 2020 (allowing for double credit for biofuels from residues and ligno-cellulosic materials, as per Directive 2009/28/EC) through the use of indigenous biofuels: grass biomethane, waste and residue derived biofuels, electric vehicles and rapeseed biodiesel. 相似文献
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China, as the world’s largest emitter, intends to achieve the peaking of carbon dioxide (CO2) emissions around 2030 and to make best efforts to peak early to mitigate global change. Under this strategy, a dynamic, recursive computable general equilibrium (CGE) model is used to analyze the economy, energy, and environment impact of CO2 emission reduction policy based on 17 scenarios in China: carbon tax, emission trading scheme (ETS), and the mixed policy in different price level, in order to find out which kind of emission reduction strategy is more feasible. The results show that CO2 emission in 2030 will be reduced with the implementation of tax, ETS and mixed policy, by 10–13 %, 12–14 %, and 18–28 %, respectively. From 2016 to 2030, China can reduce 18,338–24,156 Mt CO2 through the implementation of mixed policy. Furthermore, relative to single policy, mixed policy has stronger effects on primary energy consumption cut, by 738–1124 Mtoe or 18–28 %, which will make CO2 emissions reach a peak before 2030 and the peak emission is not greater than 12 billion tons which is in line with the reduction demand in China. Thus, the mixed policy is the most effective strategy so that mixed policy is recommended to parties included in Annex I in United Nations Framework Convention on Climate Change Kyoto Protocol and other countries with large potential of emission reduction, while ETS is suggested to countries with low carbon emissions per capita which can balance economic development and CO2 mitigation. 相似文献
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Alan J. Bond Cláudia V. Viegas Christianne Coelho de Souza Reinisch Coelho Paulo Maurício Selig 《Journal of Cleaner Production》2010,18(1):6-13
Environmental Impact Assessment (EIA) was originally tailored for restructuring rules and values regarding environmental protection, through interdisciplinary work. EIA has developed as a tool for decision-making for the implementation of projects which potentially pose significant environmental impacts. This paper reviews the sustainability and interdisciplinarity assumptions inherent in EIA. It illustrates through a case study of a proposed landfill extension in Rio Grande do Sul, Brazil, that these principles can arise more from informal knowledge processes than from legal ones. It can be shown that interdisciplinarity is often misunderstood as multidisciplinarity or simple knowledge clustering, and sustainability has no common definition amongst EIA practitioners, but that there predominates an understanding which delivers weak sustainability, driven primarily by social and economic goals. The conclusion is that EIA cannot achieve the original vision set out in the world's first legislation adopted in 1970 unless a learning-organization approach is taken whereby: the critical role of informal knowledge is recognized; informal knowledge is properly managed by EIA teams to engender a common understanding of sustainable development goals; interdisciplinary and transdisciplinary working practices are adopted. 相似文献
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This paper describes experiments on the locomotor activity rhythm of queens of the ant species Camponotus compressus, which were performed to investigate the consequences of mating on circadian clocks. Locomotor activity rhythm of virgin and mated queens was monitored individually under constant conditions of the laboratory. The locomotor activity rhythm of virgin queens entrained to a 24 h (12:12 h) laboratory light/dark (LD) cycle and free-ran under constant dim red light (RR) with a free-running period () of approximately 24 h. The locomotor activity of the mated queens on the other hand was arrhythmic during the period when they were laying eggs, and robust rhythmicity appeared soon after the egg-laying phase was over. The of the locomotor activity rhythm of mated queens was significantly greater than that of virgin queens. These results are contrary to the commonly held belief that the role of circadian clocks in ant queens ceases after mating flights, thus suggesting that circadian clocks of ant queens are adaptively plastic and display activity patterns, perhaps depending on their physiological state and tasks in the colony. 相似文献
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The opportunities and limitations of electrically driven mobility are currently widely discussed in public debates on vehicles and future transport. E-mobility has by and large been communicated in the context of sustainable mobility and its central idea is an urban e-car. Questioning the hype for this technology, this paper presents the development of the hegemonic discourse of e-mobility focusing on the actors involved. The study is based on a media analysis of selected German print media. The various phases of the e-mobility discourse were reconstructed by the detailed study of thematic focuses brought about by various actors such as politicians, electric supply companies and traditional automotive industry, and by the temporal distribution of the articles dealing with e-mobility. In addition the actor configuration is clarified by reference to the statements of the actors in the articles. The phases in the e-mobility discourse can be explained by a certain constellation of actors and how they manage to enforce their claims and interests. While the government plays a prominent role in the current development of the e-mobility discourse, the change of the automobile industry's common position towards the electric vehicle and the rising interests of the power supply industry also play an important role. Finally, the paper reveals the internal and external driving forces of the e-mobility discourse and evaluates whether it is promoted in a sustainable way. 相似文献
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Arsenobetaine and thio-arsenic species in marine macroalgae and herbivorous animals: Accumulated through trophic transfer or produced in situ? 总被引:1,自引:0,他引:1
Arsenobetaine(AB) and thio-arsenoribosides were measured in common macroalgae species(8 phaeophyta, 4 rhodophyta and 2 chlorphyta), along the Australian south east coast line. As well, arsenic species profiles were measured for two common marine herbivores, the sea urchin Centrostephanus rodgersii and the fish Odax cyanomelas that graze on these macroalgae to understand if trophic transfer of these species would account for their presence in marine herbivores. AB was found in seven of the fourteen macroalgae species investigated but does not contributed significantly to any of the macroalgae arsenic content(0.01-1.2 μg/g). AB was found in only two of the brown macroalgae and all the red and green macroalgae(with the exception of Corallina officinalis). Thio-arsenic species were found sporadically, but not in high concentrations in any of the macroalgae investigated.AB present in macroalgae is likely to be associated with epiphytic organisms while thio-arsenoribosides are likely to be produced by decaying parts of damaged macroalgae.A laboratory feeding experiment in which the herbivorous gastropod, Austrocochlea constricta, was fed macroalgae containing thio-arsenoribosides for a 24 hr period every three days showed that these are readily accumulated over a short period. Thio-arsenoribosides in herbivores are therefore probably obtained through trophic transfer. Some AB is also obtained through trophic transfer; however, the presence of trimethylated arsonioribosides,a hypothesized precursor of AB formation in herbivores, suggests that some AB is produced within herbivores from the transformation of arsenoribosides accumulated from their diet. 相似文献
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Marcello M. Veiga Denise Nunes Bern Klein Janis A. Shandro P. Colon Velasquez Rodolfo N. Sousa 《Journal of Cleaner Production》2009,17(15):1373-1381
Artisanal small-scale gold miners (ASM) occasionally employ whole ore amalgamation by adding mercury into ball mills to recover gold. In this process, 25–30% of the mercury added is lost to the environment. It is also inefficient less than 30% of gold is recovered. Amalgamation, followed by cyanidation, has been observed at many artisanal mining sites. This combination poses additional environmental and health consequences. Tests with ore samples from Talawaan, North Sulawesi, Indonesia indicate the possibility of replacing mercury by cyanidation in the ball mill, reaching gold extraction of 93% in 6 h of leaching. The gold in the Indonesian ore sample is fine and less than 8% of gold recovery was obtained with gravity concentration of the ore ground 80% below 0.25 mm, which is a reasonably fine grain size for artisanal gold operations. Replacing mercury addition with cyanidation in ball mills was implemented in one artisanal gold mining operation in Portovelo, Ecuador, achieving 95% of gold extraction in 8 h of mill leaching. This technique demonstrated a drastic improvement in gold recovery. It was found to be a simple, inexpensive technique well accepted by local miners. The results from laboratory and field tests are promising; however a thorough investigation into the socio-economic and environmental aspects of this presented alternative must be conducted prior to introduction. 相似文献
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Waterborne exposure to human viruses through contact with sewage-contaminated water environments can result in infections associated with a wide range of illnesses. Gastrointestinal symptoms are the most commonly encountered manifestations of waterborne viral illness. Respiratory diseases, neurological diseases and paralysis can also occur. Whether viral infections resulting in health outcomes like cancer might also be transmitted by the waterborne route is unknown. Recently, viruses belonging to two oncogenic groups—Human Papillomaviruses (HPVs) and Human Polyomaviruses (HPyVs)—have been detected in urban sewages worldwide. The latter have also been identified in other water environments. HPVs are epitheliotropic viruses responsible for several diseases of skin and mucosae, from common warts to squamous intraepithelial lesions that can either heal or progress to invasive carcinoma of the cervix, vulva, vagina, penis, anus or oropharynx. Human PyVs infect different tissues and organs, causing infections that are usually subclinical in immunocompetent individuals but can be serious in immunocompromised hosts. These pathogens belong to a family of DNA tumour viruses. Merkel cell polyomavirus, a HPyV identified in recent years, has attracted much attention due to its link with a rare and aggressive form of human cancer. Merkel cell carcinoma, the incidence of which has tripled over the past two decades. JC polyomavirus and BK polyomavirus are also potentially oncogenic. The observed abundance and wide dissemination of HPVs and HPyVs in water environments strongly suggest the need to shed light on the fate of these viruses in water environments and to elucidate their potential for waterborne transmission. Such information is essential for the improvement of wastewater management programs in terms of both sewage treatment and water quality surveillance. 相似文献
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Maciej A. Pszczolkowski Kevin Durden Juleah Marquis Sonny B. Ramaswamy John J. Brown 《Die Naturwissenschaften》2009,96(5):621-624
Neonate larvae of codling moth, Cydia pomonella (L.), modify their behavior in the presence of saccharin, monosodium glutamate (MSG), or L(+)-2-amino-4-phosphonobutyric
acid (L-AP4) by commencing their feeding earlier. Previously published pharmacological analysis demonstrated that phagostimulatory
effects of MSG and L-AP4 (which elicit umami taste sensation in humans) are reversed by adenylate cyclase activator and phosphodiesterase
inhibitor. In this study, by measuring the time needed to start ingestion of foliage treated with mixtures of phagostimulants
and signal transduction modulators, we show that phagostimulatory effects of l-aspartate (the third hallmark umami substance) are also abolished by both adenylate cyclase activator and phosphodiesterase
inhibitor, but not by phospholipase C inhibitor. However, stimulatory effects of hemicalcium saccharin were affected only
by phospholipase C inhibitor. The results suggest that codling moth neonates use different transduction pathways for perception
of hemicalcium saccharin and umami. 相似文献
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Uncertainty,complexity and controversy in dolphin threat management: A role for post-normal science?
Managing fishing threats to populations of endemic, threatened Hector’s and Māui dolphins around New Zealand is a complex and controversial issue, underpinned by uncertain scientific knowledge. As such, it can be argued that it falls into the realm of post-normal science, which advocates transparency about uncertainties and stakeholder peer review of knowledge feeding into decision-making. This paper focuses on selected examples of modelling and risk assessment research relating to Hector’s and Māui dolphin threat management. It explores how knowledge is developed, shared and utilised by decision-makers, finding that uncertain scientific knowledge may be shared in ways that make it appear more certain, with some of the subjectivities involved in knowledge production hidden from view. Interviews with stakeholders illustrate how some stakeholders are aware of the subjectivities involved when uncertain knowledge underpins decision-making, so a lack of transparency may be leading to erosion of social trust in decisions made. This in turn can lead to a lack of support for dolphin conservation measures from key stakeholders such as the commercial fishing industry. The paper concludes that while moves towards increasing transparency and stakeholder involvement are apparent, a deeper embrace of post-normal science approaches to knowledge production and dissemination would contribute to effective dolphin threat management in New Zealand. 相似文献
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Gwynne DT 《Die Naturwissenschaften》2002,89(3):125-127
Secondary copulatory structures are well-known in male dragonflies and spiders. Here I report a secondary copulatory organ in female ground weta, Hemiandrus pallitarsis (Ensifera, Orthoptera - crickets and allies). The organ, located on the underside of the abdomen, appears to secure the male's genitalia during the transfer of a spermatophylax nuptial meal to this location, an area quite separate from the female's primary copulatory structures, where the sperm ampulla is attached. 相似文献