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971.
Sathaye J.A. Makundi W.R. Andrasko K. Boer R. Ravindranath N.H. Sudha P. Rao S. Lasco R. Pulhin F. Masera O. Ceron A. Ordonez J. Deying X. Zhang X. Zuomin S. 《Mitigation and Adaptation Strategies for Global Change》2001,6(3-4):185-211
This paper summarizes studies of carbon (C) mitigation potential and costs of about 40 forestry options in seven developing countries. Each study uses the same methodological approach – Comprehensive Mitigation Assessment Process (COMAP) – to estimate the above parameters between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios. Coupled with data on a per ha basis on C sequestration or avoidance, and costs and benefits, it allows the estimation of monetary benefit per Mg C, and the total costs and carbon potential. The results show that about half (3.0 Pg C) the cumulative mitigation potential of 6.2 Petagram (Pg) C between 2000 and 2030 in the seven countries (about 200× 106 Mg C yr-1) could be achieved at a negative cost and the remainder at costs ranging up to $100 Mg C-1. About 5 Pg C could be achieved, at a cost less than $20 per Mg C. Negative cost potential indicates that non-carbon revenue is sufficient to offset direct costs of these options. The achievable potential is likely to be smaller, however, due to market, institutional, and sociocultural barriers that can delay or prevent the implementation of the analyzed options. 相似文献
972.
Company J 《Die Naturwissenschaften》2011,98(1):67-78
The titanosaur Lirainosaurus astibiae is the only sauropod species known from the Late Cretaceous of the Iberian Peninsula. Lirainosaurus did not reach a gigantic body size and is one of the smallest sauropods discovered to date. Histological analysis of Lirainosaurus bones, focused on diaphyseal transverse sections of appendicular elements, reveals that Lirainosaurus did not exhibit the osseous microstructure typical for large sauropods, but is comparable with that of the coeval titanosaurs
Alamosaurus sanjuanensis, Ampelosaurus atacis, and Magyarosaurus dacus, and also shares histological traits with other small to medium-sized sauropodomorph dinosaurs. Lirainosaurus limb bones exhibit a laminar fibrolamellar bone microstructure interrupted by growth marks, fully obliterated in adulthood
by intense secondary remodeling processes which tend to replace completely the primary cortex. Lirainosaurus attained smaller sizes than typical sauropods reducing the rate of primary periosteal osteogenesis and developing an extensive
secondary remodeling well before the adult size was reached. Histological organization of Lirainosaurus long bones is more mature than observed in basal neosauropods at similar ontogenetic stage, documenting a case of peramorphosis
by pre-displacement. This heterochronic growth would be a reversal of the accelerated pattern of bone deposition typical for
the sauropod lineage. 相似文献
973.
H. Cuckle N. Wald J. D. Stevenson H. M. May M. A. Ferguson-Smith A. Milford Ward H. M. Barbour K. M. Laurence B. Norgaard-Pedersen 《黑龙江环境通报》1990,10(2):71-77
Data on maternal serum alpha-fetoprotein (AFP) levels at 13–24 weeks' gestation in 46 twin pregnancies with open neural tube defects (22 with anencephaly, 24 with open spina bifida) and 169 unaffected twins were used to estimate the detection and false-positive rates associated with different cut-off levels. Using the conventional cut-off level of 2·5 multiples of the median (MoM) for unaffected singleton pregnancies of the same gestation and laboratory, the detection rate in twins was 99 per cent for anencephaly and 89 per cent for open spina bifida, with a false-positive rate of 30 per cent. Using a 5·0 MoM cut-off level to maintain a similar false-positive rate to that found among singleton pregnancies at 16–18 weeks' gestation (about 3 per cent), the detection rate was 83 per cent for anencephaly and 39 per cent for open spina bifida. Estimates are provided of the odds of having an affected twin pregnancy given a positive AFP result as well as the odds for individual women with a raised AFP level. 相似文献
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977.
Nicolas Nantel-Fortier Ann Letellier Virginie Lachapelle Philippe Fravalo Yvan L’Homme Julie Brassard 《Food and environmental virology》2016,8(4):296-304
Viral contamination along the production chain is a significant concern in both food safety and livestock health. Pigs have been reported to act as a reservoir for zoonotic viruses, sometimes emerging ones, and epidemiological studies have shown direct links between the consumption of uncooked pork offal and cases of hepatitis caused by the hepatitis E virus (HEV) genotype 3 in humans. The presence of HEV in swine herds has been reported, but its dissemination in pork production environments is still unknown. To investigate viral contamination sources in the swine industry, 452 environment and fecal samples, including samples from livestock transportation vehicles, were collected over a period of 11 months from ten farms and one slaughterhouse that together represent a single production network. Hepatitis E virus RNA was detected by nested RT-PCR in 32 samples from both inside and outside farm buildings, on trucks, and, mostly, from fomites collected in the slaughterhouse yard, such as on a utility vehicle. Phylogenetic analysis showed a wide diversity of HEV genotype 3 strains, similar to human and swine strains previously found. According to the results of this study, the movements of trucks and utility vehicles might play an important role in HEV dissemination on a slaughterhouse site and throughout an entire network. 相似文献
978.
Charlotte Anne Nakakaawa Paul O. Vedeld Jens B. Aune 《Mitigation and Adaptation Strategies for Global Change》2011,16(1):25-62
Using a map overlay procedure in a Geographical Information System environment, we quantify and map major land use and land
cover (LULC) change patterns in Uganda period 1990–2005 and determine whether the transitions were random or systematic. The
analysis reveals that the most dominant systematic land use change processes were deforestation (woodland to subsistence farmland—3.32%);
forest degradation (woodland to bushland (4.01%) and grassland (4.08%) and bush/grassland conversion to cropland (5.5%) all
resulting in a net reduction in forests (6.1%). Applying an inductive approach based on logistic regression and trend analyses
of observed changes we analyzed key drivers of LULC change. Significant predictors of forest land use change included protection
status, market access, poverty, slope, soil quality and presence/absence of a stream network. Market access, poverty and population
all decreased the log odds of retaining forests. In addition, poverty also increased the likelihood of degradation. An increase
in slope decreased the likelihood of deforestation. Using the stock change and gain/loss approaches we estimated the change
in forest carbon stocks and emissions from deforestation and forest degradation. Results indicate a negligible increase in
forest carbon stocks (3,260 t C yr-1) in the period 1990–2005 when compared to the emissions due to deforestation and forest
degradation (2.67 million t C yr-1). In light of the dominant forest land use change patterns, the drivers and change in carbon
stocks, we discuss options which could be pursued to implement a future national REDD plus strategy which considers livelihood,
biodiversity and climate change mitigation objectives. 相似文献
979.
Meley M. Araya Ole Hofstad 《Mitigation and Adaptation Strategies for Global Change》2016,21(3):421-443
The paper estimates and compares the level of Reducing Emissions from Deforestation and Degradation (REDD+) payments required to compensate for the opportunity costs (OCs) of stopping the conversion of montane forest and miombo woodlands into cropland in two agro-ecological zones in Morogoro Region in Tanzania. Data collected from 250 households were used for OC estimation. REDD+ payment was estimated as the net present value (NPV) of agricultural rent and forest rent during land clearing, minus net returns from sustainable wood harvest, divided by the corresponding reduction in carbon stock. The median compensation required to protect the current carbon stock in the two vegetation types ranged from USD 1 tCO2e?1 for the montane forest to USD 39 tCO2e?1 for the degraded miombo woodlands, of which up to 70 % and 16 %, respectively, were for compensating OCs from forest rent during land clearing. The figures were significantly higher when the cost of farmers’ own labor was not taken into account in NPV calculations. The results also highlighted that incentives in the form of sustainable harvests could offset up to 55 % of the total median OC to protect the montane forest and up to 45 % to protect the miombo woodlands, depending on the wage rates. The findings suggest that given the possible factors that can potentially affect estimates of REDD+ payments, avoiding deforestation of the montane forest would be feasible under the REDD+ scheme. However, implementation of the policy in villages around the miombo area would require very high compensation levels. 相似文献
980.
Tim Lüddecke Stefan Schulz Sebastian Steinfartz Miguel Vences 《Die Naturwissenschaften》2018,105(9-10):56
Terrestrial salamanders of the genus Salamandra represent one of the most prominent groups of amphibians. They are mainly distributed across Europe but also reach Northern Africa and the Near East. Members of the six currently accepted species have long been known to be poisonous; however, work on their toxins was mostly published in German language, and therefore, many nuances of these studies have remained hidden from the majority of herpetologists and toxinologists. Several Salamandra species are called fire salamanders due to their highly contrasted, black-yellow colouration which probably serves to deter predators, although thorough evidence for aposematism in Salamandra is still lacking. Salamandra skin toxins do not only represent a potent antipredator defence but may also have antimicrobial effects. A better understanding of this dual function of Salamandra skin secretions is of utmost importance in the face of the emergence of a fungal disease causing catastrophic declines of fire salamanders in Central Europe, caused by the fungus Batrachochytrium salamandrivorans. In this review, we summarize the knowledge on Salamandra toxins, providing a list of the compounds so far isolated from their secretion and focusing on the bioactivity of the major compounds in Salamandra secretions, the steroidal alkaloids. We identify priorities for future research, including a screening of co-occurrence of steroidal alkaloids and tetrodotoxins in salamandrids, chemical characterization of already identified novel steroidal compounds, elucidation of the presence and role of peptides and proteins in the secretion, and experimental in vitro and in vivo study of the interactions between bioactive compounds in Salamandra skin secretions and cutaneous fungal and bacterial pathogens. 相似文献