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1.
Climate change is likely to adversely affect many countries throughout the world, but the responses of different countries to this threat vary widely. Attempts to explain the differences in countries’ mitigative policies have been largely deficient. This study seeks to assess the degree to which vulnerability may improve the level of explanation of adopted mitigation policies, studying over 90 countries between 1990 and 2011. Vulnerability is defined to be comprised of two basic factors: impacts (expected damages due to climate change) and adaptive capacity (the ability to adjust to these damages). As there may be a gap between declared and implemented policies, these components of mitigation policy are examined separately. In addition, other variables which mediate between these ‘extreme ends’ of mitigation policies are tested.The effect of vulnerability on climate change mitigation policies is examined by multiple regressions, incorporating a wide range of control variables. The results indicate that climate impacts do not affect mitigation policies. Adaptive capacity has a positive effect on the level of declared policy, but this effect becomes insignificant once implemented policy is examined. However, other tests suggest a possible transition from declarations to actions by high adaptive capacity countries. This finding suggests that high adaptive capacity countries do not view mitigation and adaptation as substitutes. Further analyses indicate that the insignificancy of impacts is caused by the uncertainty in their assessment. 相似文献
2.
Ada Alamaru Yossi Loya Eran Brokovich Ruth Yam Aldo Shemesh 《Geochimica et cosmochimica acta》2009,73(18):5333-5342
We examined the utilization of carbon and nitrogen in two common Red Sea coral species (Stylophora pistillata and Favia favus), differing in colony morphology and polyp size, along a depth gradient down to 60 m. We describe the changes in C/N ratios and in the stable isotope composition of carbon and nitrogen of coral’s tissue and algal symbionts. We also measured the carbon isotopic composition of the lipid fraction extracted from both coral tissue and algal symbionts in order to reveal the changes in the carbon source utilized by the host coral for lipid synthesis.The results show that for both species, δ13C decreases by 7–8‰ in animal tissue, algal symbionts and in the lipid fractions as depth increases. However, in contrast to previous reports, the difference between δ13C values of coral tissue and algal symbionts does not increase with depth. δ15N values of coral tissue and algal symbionts in both species do not correlate with depth suggesting that the heterotrophic capacity of these corals does not increase with depth. δ13C values of tissue lipids were depleted by an average of 3.5‰ compared to δ13C of the entire tissue at all depths. δ13C values of algal lipids were depleted by an average of 2‰ compared to δ13C of the entire zooxanthellae at all depths, indicating high efficiency of carbon recycling between the two symbiotic partners along the entire gradient. The depletion of lipids is attributed to the fractionation mechanism during lipid synthesis. In addition, for both species, δ13C values of algal lipids were enriched compared with δ13C of tissue lipids. In S. pistillata, the difference between δ13C values of tissue lipids and algal lipids increased linearly with depth, indicating a change in the sources of carbon utilized by the coral for lipid synthesis below 20 m from an autotrophic to a heterotrophic source. However, in F. favus, this average difference was 4 times larger compared to shallow S. pistillata and was constant along the entire depth gradient, suggesting that F. favus uses heterotrophically-acquired carbon for lipid synthesis regardless of depth. Overall, F. favus exhibited enriched δ13C and δ15N values compared to S. pistillata along the entire gradient. We attribute these differences to both morphological differences (i.e. colony morphology, tissue thickness and polyp size) between the two species and to a higher heterotrophy/autotrophy ratio in F. favus at all depths. The C/N ratio in S. pistillata tissue decreased with increasing water depth whereas in F. favus it remained constant. This reflects a higher heterotrophic capacity in the large polyped F. favus, at all depths. 相似文献
3.
Neal Jackson Eran O. Ofek Masamune Oguri 《Monthly notices of the Royal Astronomical Society》2009,398(3):1423-1427
We present observations of a new double-image gravitational lens system, ULAS J082016.1+081216, of image separation 2.3 arcsec and high (∼6) flux ratio. The system is selected from the Sloan Digital Sky Survey (SDSS) spectroscopic quasar list using new high-quality images from the UKIRT (United Kingdom Infrared Telescope) Deep Sky Survey (UKIDSS). The lensed quasar has a source redshift of 2.024, and we identify the lens galaxy as a faint red object of redshift 0.803 ± 0.001 . Three other objects from the UKIDSS survey, selected in the same way, were found not to be lens systems. Together with the earlier lens found using this method, the SDSS–UKIDSS lenses have the potential to significantly increase the number of quasar lenses found in SDSS, to extend the survey to higher flux ratios and lower separations, and to give greater completeness which is important for statistical purposes. 相似文献
4.
Natural Hazards - Collapse of residential buildings is the major cause of death during earthquakes. Seismic retrofitting of residential buildings is a cost-effective way to reduce injury and death.... 相似文献
5.
A. S. Drofa V. G. Eran’kov V. N. Ivanov A. G. Shilin G. F. Iskevich 《Izvestiya Atmospheric and Oceanic Physics》2013,49(3):298-306
The results of experimental investigations into the action of polydispersion salt powders on model cloud media are presented. The results of experiments show a considerable positive effect of the modification of convective clouds by salt powders in order to obtain additional precipitation. The introduction of polydispersion salt powder into a forming cloud medium leads to the appearance of large cloud droplets and to the droplet-spectrum broadening. This result is a positive factor for the stimulation of coagulation processes and further precipitation formation. No “overseeding” phenomenon (when, instead of the enlargement of droplets, their sizes decrease and the concentration of cloud droplets increases) is observed at rather high mass concentrations of the introduced powder. 相似文献
6.
Yu. A. Izrael V. M. Zakharov N. N. Petrov A. G. Ryaboshapko V. N. Ivanov A. V. Savchenko Yu. V. Andreev V. G. Eran’kov Yu. A. Puzov B. G. Danilyan V. P. Kulyapin V. A. Gulevskii 《Russian Meteorology and Hydrology》2009,34(10):635-638
The paper describes the results of the field experiment on studying solar radiation transmission in the visible wavelength range through model aerosol media formed in the lower troposphere with the help of generators installed aboard helicopters. The refractive index and the average size of the aerosol particles formed are close to those characteristic of the natural stratospheric aerosol. The composition of the equipment complex used to control aerosol optical and microphysical aerosol parameters is considered. The measurement results are in satisfactory agreement with the results of theoretical and experimental studies in simulation chambers. 相似文献
7.
Zoltn Vci Carl B. Agee Christopher D. K. Herd Erin Walton Oliver Tschauner Karen Ziegler Vitali B. Prakapenka Eran Greenberg Sylvia Monique‐Thomas 《Meteoritics & planetary science》2020,55(5):1011-1030
Hydrous alteration of olivine macrocrysts in a Martian olivine phyric basalt, NWA 10416, and a terrestrial basalt from southern Colorado are examined using SEM, EPMA, TEM, and µXRD techniques. The olivines in the meteorite contain linear nanotubes of hydrous material, amorphous areas, and fluid dissolution textures quite distinct from alteration identified in other Martian meteorites. Instead, they bear resemblance to terrestrial deuteric alteration features. The presence of the hydrous alteration phase Mg‐laihunite within the olivines has been confirmed by µXRD analysis. The cores of the olivines in both Martian and terrestrial samples are overgrown by unaltered rims whose compositions match those of a separate population of groundmass olivines, suggesting that the core olivines are xenocrysts whose alteration preceded crystallization of the groundmass. The terrestrial sample is linked to deep crustal metasomatism and the “ignimbrite flare‐up” of the Oligocene epoch. The comparison of the two samples suggests the existence of an analogous relatively water‐rich magmatic reservoir on Mars. 相似文献
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Tsevi Mazeh David W. Latham Elad Goldberg Guillermo Torres Robert P. Stefanik Todd J. Henry † Shay Zucker Orly Gnat Eran O. Ofek 《Monthly notices of the Royal Astronomical Society》2001,325(1):343-357
We present a radial velocity study of the triple-lined system Gliese 644 and derive spectroscopic elements for the inner and outer orbits with periods of 2.965 5 and 627 d. We also utilize old visual data, as well as modern speckle and adaptive optics observations, to derive a new astrometric solution for the outer orbit. These two orbits together allow us to derive masses for each of the three components in the system: M A =0.410±0.028 (6.9 per cent), M Ba =0.336±0.016 (4.7 per cent), and M Bb =0.304±0.014 (4.7 per cent) M⊙ . We suggest that the relative inclination of the two orbits is very small. Our individual masses and spectroscopic light ratios for the three M stars in the Gliese 644 system provide three points for the mass–luminosity relation near the bottom of the main sequence, where the relation is poorly determined. These three points agree well with theoretical models for solar metallicity and an age of 5 Gyr. Our radial velocities for Gliese 643 and vB 8, two common proper motion companions of Gliese 644, support the interpretation that all five M stars are moving together in a physically bound group. We discuss possible scenarios for the formation and evolution of this configuration, such as the formation of all five stars in a sequence of fragmentation events leading directly to the hierarchical configuration now observed, versus formation in a small N cluster with subsequent dynamical evolution into the present hierarchical configuration. 相似文献
10.
Issues posed by global environmental change can be viewed as the problem of the commons on a larger geographic scale. A framework for analysing how geographic scale affects governments' ability to manage environmental problems is suggested here. It is based on interactions between four dimensions: production-consumption relationships; distribution of the benefits and costs of various activities; level of administrative control; and spatial scale of individuals' attachment to place. Global environmental problems can be viewed as a case where benefits from polluting activities are spatially concentrated relative to costs. The difficulty in addressing such problems stems from the discrepancy in geographic scale between adverse impacts and level of administrative control. The possibility of adapting institutional structures to match the scale of the problems is examined, in light of the increasing spatial scale of production-consumption relationships in the post-industrial world and the growing demand for local control across the globe. The geographic scale of ideological attachment to place is identified as an important variable in determining the ability to respond to large-scale environmental problems. 相似文献