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61.
Hydrothermal vents are rare deep-sea oases that house faunal assemblages with a similar density of life as coral reefs. Only approximately 600 of these hotspots are known worldwide, most only one-third of a football field in size. With advancing development of the deep-sea mining industry, there is an urgent need to protect these unique, insular ecosystems and their specialist endemic faunas. We applied the IUCN (International Union for the Conservation of Nature) Red List criteria to assess the extinction risk of vent-endemic molluscs with varying exposure to potential deep-sea mining. We assessed 31 species from three key areas under different regulatory frameworks in the Indian, West Pacific, and Southern Oceans. Three vent mollusc species were also examined as case studies of different threat contexts (protected or not from potential mining) to explore the interaction of local regulatory frameworks and IUCN Red List category assignment. We found that these assessments were robust even when there was some uncertainty in the total range of individual species, allowing assessment of species that have only recently been named and described. For vent-endemic species, regulatory changes to area-based management can have a greater impact on IUCN Red List assessment outcomes than incorporating additional data about species distributions. Our approach revealed the most useful IUCN Red List criteria for vent-endemic species: criteria B and D2. This approach, combining regulatory framework and distribution, has the potential to rapidly gauge assessment outcomes for species in insular systems worldwide.  相似文献   
62.
Protected areas (PAs) are a frequently used conservation strategy, yet their socioeconomic impacts on local communities remain contentious. A shift toward increased participation by local communities in PA governance seeks to deliver benefits for human well‐being and biodiversity. Although participation is considered critical to the success of PAs, few researchers have investigated individuals’ decisions to participate and what this means for how local people experience the costs and benefits of conservation. We explored who participates in PA governance associations and why; the perceived benefits and costs to participation; and how costs and benefits are distributed within and between communities. Methods included 3 focus groups, 37 interviews, and 217 questionnaire surveys conducted in 3 communities and other stakeholders (e.g., employees of a nongovernmental organization and government officials) in PA governance in Madagascar. Our study design was grounded in the theory of planned behavior (TPB), the most commonly applied behavior model in social psychology. Participation in PA governance was limited by miscommunication and lack of knowledge about who could get involved and how. Respondents perceived limited benefits and high costs and uneven distribution of these within and between communities. Men, poorer households, and people in remote villages reported the highest costs. Our findings illustrate challenges related to comanagement of PAs: understanding the heterogeneous nature of communities; ensuring all households are represented in governance participation; understanding differences in the meaning of forest protection; and targeting interventions to reach households most in need to avoid elite capture.  相似文献   
63.
Ultrasonographic features of a fetus at 18 weeks of gestation suggesting a body stalk anomaly are presented. These included a large abdominal anterior wall defect in apparent continuity with the placenta, severe kyphoscoliosis of the lower spine, the absence of one kidney, and a very short umbilical cord with only one umbilical artery. The amniotic fluid was reduced and the fetus was almost immobile at short-interval ultrasound examinations. The pregnancy was terminated and autopsy of the fetus showed abnormalities compatible with maldevelopment of both cephalic and caudal embryonic folds.  相似文献   
64.
This paper describes a survey of total selenium contents of surface soil samples in Wales. Samples were collected from three areas: over Silurian shales where deficiences in sheep have been reported, in an area severely affected by pollution from lead mining and in an area where black, marine shales outcrop. Selenium levels were low over the Silurian shales but high in the other two areas. Statistical analysis of the data permitted the separating out of a basal range of selenium values low enough to account for the reports of deficiences in sheep. Some selenium values were high enough to suggest the possibility of selenosis in sheep.  相似文献   
65.
Opencast coal mining in England and Wales can cause a wide range of environmental problems which are increasingly public issues due to the planned expansion in output and the impact this may have on agriculture and landscape. Opencast mining is reviewed on a county by county basis to identify the variations in the disturbance caused. A detailed review of restoration techniques and the agricultural quality of the restored land is presented, and the role of Planning Authorities is discussed. Significant variations in the impact of opencast operations are identified, especially in relation to the potential for derelict land reclamation and the grade of agricultural land affected. The latter is generally lower grade 3 and below, although in certain areas operations are entering land of higher agricultural and scenic quality. The quality of restoration, while good, still has scope for improvements, such as reducing soil compaction and the subsequent management of the land by the farmer. The impact on agricultural productivity is difficult to assess, but it appears to be only slight in those cases where recent restoration techniques were used and when lower grade agricultural land is taken.  相似文献   
66.
A study of the extraction, reclamation and after use of flood plain gravel quarries between Bagham and Thannington, south west of Canterbury in Kent, South-east England, was made, based on a review of the literature and field work. The area represents a linear extension of the urban fringe of Canterbury. Gravel production has been the most significant industry in terms of environmental impact over the last thirty years, and the result of such activity has been the creation of an extensive area of lakes and wetland habitats. Present and future gravel production will more than double the existing lakes and wetlands areas. It is suggested that, in terms of land use, this man-made environment is best suited for water-based recreation and that three zones should be recognised for an amenity park, angling and wildlife respectively. Further mineral production between Ashford and Bagham may mean a reappraisal of the proposed water resource use, particularly for wildlife. As a result of this study, attention is drawn to the spatial relationships between recreational demand groups and flood plain location with respect to the urban centre and to each other.  相似文献   
67.
Summary. Larvae of the turnip sawfly, Athalia rosae L. (Hymenoptera: Tenthredinidae), sequester glucosinolates of their host plants, namely members of the Brassicaceae family, in their haemolymph. Therefore, they need to circumvent myrosinase activities of the plant tissue which normally hydrolyse the glucosinolates after plant damage. Effects of varying levels of glucosinolates and myrosinases on the performance of A. rosae were investigated using homozygous lines of Brassica juncea (L.) with either (1) low glucosinolate (lowGS) and low myrosinase (lowMR), (2) high glucosinolate (highGS) and high myrosinase (highMR), or (3) high glucosinolate (highGS) and low myrosinase (lowMR) levels. To insure that the given quantities remained as constant as possible, newly hatched larvae were enclosed on the second-youngest leaf of a plant, and were offered a new plant of comparable physiological age (6-leaf-stage) every day. The performance of A. rosae was little affected by leaf quality. Body masses of eonymphs and adults were on average lowest on the highGS/highMR-line, but these differences were rarely significant. The pupal developmental times of females and males were longest on the highGS/lowMR-line in only one of two replicate experiments. All other performance traits (developmental times of larvae, egg numbers, adult longevity) were not significantly different. Glucosinolates, sequestered by the larvae, are carried through the pupal stage. The glucosinolate concentration measured in adult insects reflected the level of the host plant line, without showing any obvious costs for sequestration. Obviously, A. rosae is highly tolerant to variation in the glucosinolate-myrosinase system of its host. In addition, induced changes of glucosinolate concentrations and myrosinase activities caused by 24 h-feeding of groups of three small larvae were analysed in the second-youngest leaves. In contrast to the patterns most herbivores evoke on Brassicaceae, namely an increase of both glucosinolate concentration and myrosinase activity, we detected a significant decrease of both traits in all three lines where the respective trait was originally high in the plants. Although glucosinolate levels dropped in the highGS lines about 50%, these still contained higher concentrations than the lowGS line. Whereas the activity of soluble myrosinases remained highest in the highMR line, even after a decrease to almost 30% due to feeding, the levels of insoluble myrosinases converged after feeding in lowMR and highMR lines. Levels of the signalling molecule salicylic acid slightly decreased on average after feeding, whereas jasmonic acid was below the detection threshold in almost all samples. The concentration of several molecules varies strongly in plant tissue with age and can change due to induction by herbivore feeding. Therefore, if performance of an insect species is measured on plants with specific traits, the variability in these traits needs to be carefully controlled in experiments.  相似文献   
68.
Summary. Easy bleeding is a phenomenon discovered in some tenthredinid insects which possess a particularly low mechanical resistance of the integument, leading under mechanical stress to haemolymph exudation. It has a defensive effect against ants and wasps through harmful plant compounds which are sequestered in the haemolymph. Here we describe etho-ecological and some chemical aspects of the defence of easy bleeders and specify the range of predators to which easy bleeding might be effective. Beside a high haemolymph deterrence associated with low integument resistance across sawfly species, we also detected toxicity of the haemolymph of some species to workers of the ant Myrmica rubra. The behaviour of easy bleeders is to move slowly and, once disturbed, to become motionless, thereby probably impeding the tendency of a predator to attack. This behaviour had no beneficial effect for easy bleeders when attacked by the predatory bug Podisus maculiventris. Bugs could successfully and without harm prey on sawfly larvae without evoking easy bleeding. For the easy bleeder Athalia rosae, host plants with different secondary metabolite profiles, and, consequently, changes in haemolymph chemistry only slightly affected the feeding behaviour of the bugs. To test the effectiveness of easy bleeding towards a vertebrate predator, easy bleeders were offered to birds, Sturnus vulgaris. The body colouration of the sawfly larvae was of prime importance in determining the predators response when testing birds in a group. It is likely that easy bleeding is a defence strategy directed primarily towards foraging insects with biting-chewing mandibles and that it is much less active towards predatory insects with piercing-sucking mandibles as well as birds. The involvement of chemical and/or physical cues in the strategy is discussed with respect to these types of predators.  相似文献   
69.
Molecular speciation of atmospheric organic matter was investigated during a short summer field campaign performed in a citrus fruit field in northern Corsica(June 2011). Aimedat assessing the performance on the field of newly developed analytical protocols, this work focuses on the molecular composition of both gas and particulate phases and provides an insight into partitioning behavior of the semi-volatile oxygenated fraction. Limonene ozonolysis tracers were specifically searched for, according to gas chromatography–mass spectrometry(GC–MS) data previously recorded for smog chamber experiments. A screening of other oxygenated species present in the field atmosphere was also performed. About sixty polar molecules were positively or tentatively identified in gas and/or particle phases. These molecules comprise a wide range of branched and linear, mono and di-carbonyls(C_3–C7),mono and di-carboxylic acids(C_3–C_18), and compounds bearing up to three functionalities.Among these compounds, some can be specifically attributed to limonene oxidation and others can be related to α- or β-pinene oxidation. This provides an original snapshot of the organic matter composition at a Mediterranean site in summer. Furthermore, for compounds identified and quantified in both gaseous and particulate phases, an experimental gas/particle partitioning coefficient was determined. Several volatile products, which are not expected in the particulate phase assuming thermodynamic equilibrium, were nonetheless present in significant concentrations. Hypotheses are proposed to explain these observations, such as the possible aerosol viscosity that could hinder the theoretical equilibrium to be rapidly reached.  相似文献   
70.
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