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271.
Conservation policy and practice is increasingly turning towards market-based interventions to reconcile the growing conflicts between environmental conservation and rural livelihood needs. This short introductory paper to the special issue on “market-oriented conservation governance” critically investigates the growing commitment to markets as a means of meeting conservation objectives and livelihood security. We distinguish market oriented conservation from neoliberal conservation and argue for a grounded, empirically rich investigation into the passive and active promotion of markets in conservation landscapes – analysis which pays attention to how and why certain markets are promoted by ENGOs, governments and private sector, as well as how rural people negotiate livelihoods and markets when adjusting to conservation pressures. Such an approach takes seriously how the particularities of place, from local harvests to trans-local trade, shape market-oriented conservation in practice and expose the messiness of such ventures. The range of papers in this special issue show how neither neoliberal nor market-based interventions in conservation are uniform in character, impact and outcome, and that while identifying the patterns and logic behind these processes remains crucial, the basis for understanding how markets inform conservation, must be done by drawing on empirical data that speaks clearly to how actors variously engage the logic of market-driven conservation in terms of their histories and contemporary realities. We argue that doing so makes it possible to understand not only what is ‘new’ about contemporary market-oriented conservation but also its continuities with earlier forms of command and control conservation.  相似文献   
272.
River inputs of nutrients and organic matter impact the biogeochemistry of arctic estuaries and the Arctic Ocean as a whole, yet there is considerable uncertainty about the magnitude of fluvial fluxes at the pan-Arctic scale. Samples from the six largest arctic rivers, with a combined watershed area of 11.3?×?106?km2, have revealed strong seasonal variations in constituent concentrations and fluxes within rivers as well as large differences among the rivers. Specifically, we investigate fluxes of dissolved organic carbon, dissolved organic nitrogen, total dissolved phosphorus, dissolved inorganic nitrogen, nitrate, and silica. This is the first time that seasonal and annual constituent fluxes have been determined using consistent sampling and analytical methods at the pan-Arctic scale and consequently provide the best available estimates for constituent flux from land to the Arctic Ocean and surrounding seas. Given the large inputs of river water to the relatively small Arctic Ocean and the dramatic impacts that climate change is having in the Arctic, it is particularly urgent that we establish the contemporary river fluxes so that we will be able to detect future changes and evaluate the impact of the changes on the biogeochemistry of the receiving coastal and ocean systems.  相似文献   
273.
This study of Durance River terrace morphologies in the lower 200 km of the valley shows that terrace ages, elevations and heights above the river generally all increase upstream. It is based on extensive fieldwork checked against geological maps and memoirs. Subdivision of the valley, based on gorges and former tectonic blockages, is relevant because there are no Durance terraces downstream of Mallemort and there are considerable differences between each reach. For most of the Pleistocene, the river was diverted through the Crau Plains to the sea. Below the Mirabeau gorge, there are a few narrow low and middle terraces. The best terrace development is between Mirabeau and the Sisteron defile. Upstream of that barrier there is glacial dominance. Changes in terrace continuity are illustrated by means of height-range diagrams and their rates of dissection have been quantified approximately, based on cosmic ray exposure age modelling. Climate forcing cannot explain all the changes found. The influence of tectonic activity was found to increase in an upstream direction and also with age on the southwestern flanks of the Alps.  相似文献   
274.
During the third flyby of Mercury by the MESSENGER spacecraft, a dedicated disk-integrated photometric sequence was acquired with the wide-angle multispectral camera to observe Mercury's global photometric behavior in 11 spectral filters over as broad a range of phase angle as possible within the geometric constraints of the flyby. Extraction of disk-integrated measurements from images acquired during this sequence required careful accounting for scattered light and residual background effects. The photometric model fit to these measurements is shown to fit observed radiances at phase angles below 110°, possibly except where both solar incidence and emission angles are high (>70°). The complexity of the scattered light at wavelengths greater than 828 nm contributes to a less accurate photometric correction at these wavelengths. The model is used to correct the global imaging data set acquired at a variety of geometries to a common geometry of incidence angle=30°, emission angle=0°, and phase angle=30°, yielding a relatively seamless mosaic. The results here will be used to correct image mosaics of Mercury acquired in orbit.  相似文献   
275.
This research presents the individual amino acid δ13C values in bone collagen of humans (n = 9) and animals (n = 27) from two prehistoric shell midden sites in Korea. We obtained complete baseline separation of 16 of the 18 amino acids found in bone collagen by using liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). The isotopic results reveal that the humans and animals in the two sites had similar patterns in essential amino acids (EAAs) and non-essential amino acids (NEAAs). The EAA and NEAA δ13C values in humans are intermediate between those in marine and terrestrial animals. However, the threonine δ13C values in humans and animals measured in this study are more highly enriched than those of other amino acids. At both sites, all amino acids in marine animals are 13C-enriched relative to those of the terrestrial animals. The isotopic evidence suggests that the Tongsamdong human had EAAs and NEAAs from marine food resources, while the Nukdo humans mainly had EAAs from terrestrial food resources but obtained NEAAs from both terrestrial and marine resources. The δ13C isotopic differences in amino acids between marine and terrestrial animals were the largest for glycine (NEAA) and histidine (EAA) and the smallest for tyrosine (NEAA) and phenylalanine (EAA). In addition, threonine among the EAAs also had a large difference (∼8‰) in δ13C values between marine and terrestrial animals, and has the potential to be used as an isotopic marker in palaeodietary studies. Threonine δ13C values were used in conjunction with the established Δ13CGlycine-phenylalanine values and produced three distinct dietary groups (terrestrial, omnivorous, and marine). In addition, threonine δ13C values and Δ13CSerine-phenylalanine values were discovered to separate between two dietary groups (terrestrial vs. marine), and these δ13C values may provide a potential new indicator for investigating the distinction between marine and terrestrial protein sources in human diets.  相似文献   
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278.
Recent measurements of the high-energy, omni-directional electron environment by the Galileo spacecraft Energetic Particle Detector (EPD) have been analyzed in the range from 7 to 28 Jupiter radii. 10-min averages of these data between Jupiter orbit insertion in 1995 to the end of the mission have been analyzed to provide estimates of the electron differential fluxes at 1.5, 2, and 11 MeV in the jovian equatorial plane as a function of radial distance. These data provide a long term picture of the variations in the high-energy electron environment over the ∼8 years of the Galileo mission. This paper reviews those measurements and the statistics associated with them for the 8 year period. In general, the data variations are well behaved with variations being within a factor of ∼2 of a median value at a given distance from Jupiter. These results are analyzed in detail and the orbit variations discussed in the context of the overall data set. The results of this analysis of the long-term statistical variations in high-energy electron fluxes are directly applicable to models that estimate the effects of the radiation environment on Jupiter's moons and their atmospheres as they permit estimates of the possible range of radiation effects that might be expected.  相似文献   
279.
280.
Atmospheric CO2 removal is currently receiving serious consideration as a supplement or even alternative to emissions reduction. However the possible consequences of such a strategy for the climate system, and particularly for regional changes to the hydrological cycle, are not well understood. Two idealised general circulation model experiments are described, where CO2 concentrations are steadily increased, then decreased along the same path. Global mean precipitation continues to increase for several decades after CO2 begins to decrease. The mean tropical circulation shows associated changes due to the constraint on the global circulation imposed by precipitation and water vapour. The patterns of precipitation and circulation change also exhibit asymmetries with regard to changes in both CO2 and global mean temperature, but while the lag in global precipitation can be ascribed to different levels of CO2 at the same temperature state, the regional changes cannot. Instead, ocean memory and heat transfer are important here. In particular the equatorial East Pacific continues to warm relative to the West Pacific during CO2 ramp-down, producing an anomalously large equatorial Pacific sea surface temperature gradient and associated rainfall anomalies. The mechanism is likely to be a lag in response to atmospheric forcing between mixed-layer water in the east Pacific and the sub-thermocline water below, due to transport through the ocean circulation. The implication of this study is that a CO2 pathway of increasing then decreasing atmospheric CO2 concentrations may lead us to climate states during CO2 decrease that have not been experienced during the increase.  相似文献   
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