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821.
Kelly Jarod C. Dai Qiang Wang Michael 《Mitigation and Adaptation Strategies for Global Change》2020,25(3):495-495
Mitigation and Adaptation Strategies for Global Change - The article Globally regional life cycle analysis of automotive lithium-ion nickel manganese cobalt batteries written by Jarod C. Kelly,... 相似文献
822.
Economic effects of CO2 fertilization of crops: transforming changes in yield into changes in supply 总被引:1,自引:0,他引:1
Increasing concentrations of atmospheric carbon dioxide CO2 have a beneficial effect on crop production that would tend to offset some of the economic losses that might be generated in some areas by the climatic effects of atmospheric CO2 and other greenhouse gases. Previous estimates of the economic benefits of CO2 fertilization on world crop production, however, were based on the assumption that percent changes in supply are equal to percent changes in yield. This assumption is not valid, however, because it confounds changes in supply with changes in quantity supplied. This error leads to an overestimation of the real economic benefits of CO2 fertilization by 61–166%. The effects of CO2 fertilization on crop production, therefore, will reduce some of the potential damages caused by the climatic impacts of greenhouse gases, but by significantly less than that indicated in earlier research. 相似文献
823.
The gastropods Lepetodrilus fucensis and Depressigyra globulus are abundant faunal components of animal communities at deep-sea hydrothermal vents along the Juan de Fuca Ridge in the NE
Pacific. The population structure and recruitment pattern of both species were studied using modal decomposition of length–frequency
distributions. Gastropod populations were collected from Axial Volcano and Endeavour Segment in 2002 and 2003. Polymodal size–frequency
distributions, particularly at Axial Volcano vent sites, suggest a discontinuous recruitment pattern for D. globulus. In contrast, there were no distinct peaks visible in the distributions of L. fucensis, suggesting a continuous recruitment pattern for this species. For both species, distributions were positively skewed towards
the smaller length–classes, implying post-settlement mortality is high. However, variations in growth, due to short- and long-term
variability in environmental conditions in the hydrothermal vent habitat, as well as biological interactions, may also be
influencing the distribution and abundance of subsequent life-history stages. Using maximum shell lengths from populations
of known ages, the growth rate of L. fucensis was estimated as 9.6 μm day−1, indicating adulthood would be reached in ∼1 year. Our results suggest that, despite occupying the same habitat, abundance
and population structure are regulated by different biotic and abiotic processes in L. fucensis and D. globulus. 相似文献
824.
Julie K. Desjardins Kelly A. Stiver John L. Fitzpatrick Nicole Milligan Glen J. Van Der Kraak Sigal Balshine 《Behavioral ecology and sociobiology》2008,62(5):785-794
Among taxonomically widespread cooperatively breeding vertebrates, those with non-breeding helpers-at-the-nest provide an
excellent opportunity to understand the proximate mechanisms underlying care and allocare. In this study, we examined androgen
levels in relation to care behavior in a cooperatively breeding cichlid fish, Neolamprologus pulcher, from Lake Tanganyika. We concentrated on androgens, as these hormones have been linked to the defense behavior, and the
defense of young is a common form of parental care in fishes. N. pulcher dominant female breeders performed the most care and also displayed the highest levels of plasma testosterone (T) compared
with other individuals within the social group. We also found that dominant male breeders provided a similar amount of care
as did the subordinate helpers, but breeding males had the highest levels of 11-ketotestosterone (11KT), an important androgen
in fish. Breeders had higher levels of both androgens (T and 11KT) compared to helpers. There was a weak but significant positive correlation between T levels and the frequency of
care regardless of sex and status. Our results suggest that androgens may promote defense of young and are in contrast to
the commonly reported trade-off between androgen and parental care. 相似文献
825.
Edwards G. C. Dias G. M. Thurtell G. W. Kidd G. E. Roulet N. T. Kelly C. A. Rudd J. W. M. Moore A. Halfpenny-Mitchell L. 《Water, Air, & Soil Pollution: Focus》2001,1(5-6):447-454
Methane emissions were measured from a bog andlake in the Experimental Lakes Area in Northern Ontario in 1992and 1993, prior to and following flooding. Bog fluxes were smallin 1992 (0.27 mg m-2 d-1) but increased 5-fold in 1993 afterflooding. Over the bog, there was a diel cycle of nighttimeemission and daytime uptake in 1992 in contrast to constantemission in 1993. Lake emissions decreased after flooding butwere much greater than bog emissions in both years (average = 7.3 mg m-2 d-1). Seasonally, the bog flux was correlated withground temperatures after flooding. In 1992, lake fluxes werecorrelated with air temperature on a daily basis. In contrast,seasonal lake fluxes were correlated with water and sedimenttemperatures in 1992, but only with sediment temperatures in1993. These results are explained with respect to the effects offlooding on lake and bog dynamics. 相似文献
826.
827.
This paper has studied the environmental deterioration due to copper mining in Malanjkhand at Central-east India. No data
is available on environmental degradation at the studied site although geological aspects are well studied. Mine drainage
from the mines is definitively toxic. The site is also undergoing various stages of acid mine drainage (AMD) particularly
from the heap leaching sites and the tailing area. AMD impacted water steam and sediment were also analysed. Results show
substantial level of contamination of almost all segments of environment. Presence of elevated level of other heavy metal
viz. Au, Ag, Pb, Cr, Cd, Fe, Cu and base metals like Na, K in AMD impacted water and sediments is due to metal leaching effect
of AMD. Bio monitoring with the help of benthic macro invertebrates and metal accumulation in plants was also carried to know
the impact of the toxic drainage. Results prove a very significant impact on the environmental health. 相似文献
828.
The pattern of the spatial variation in arsenic concentration in groundwater of Bangladesh is usually needed for the planning of safe drinking water. Often a model-based prediction is required for this purpose. In this paper, we fit a Bayesian hierarchical geostatistical model by utilizing data from the project, ‘Groundwater studies of arsenic concentration in Bangladesh’ conducted by the British Geological Survey and the Department of Public Health Engineering of Bangladesh. We also develop a predictive model for arsenic concentration at different levels of well-depth using the same approach. The resulting predictive model has been cross-validated by appropriate statistical tools. Finally, we obtained reliable spatially continuous predictive maps and predictive probability maps showing the areas with high probability of arsenic concentration for different levels of well-depth. Results indicate that our model fits the data well and captures a substantial amount of spatial variation. Moreover, well-depth is found to have a significant contribution in explaining the observed variation in arsenic concentration. The predictive maps that have been produced are observed to be different for various levels of well-depths and are expected to be helpful to the policy makers in preparing proper regional planning for safe drinking water. 相似文献
829.
Transport phases of four metals of geochemical and water quality importance were investigated in rivers around Jamshedpur. The metals iron, manganese, zinc and copper were partitioned into dissolved, adsorbed and or ion exchangeable, solid organic, oxide coating and crystalline phases applying filtration for the dissolved phase and a chemical fractionation scheme for the particulates. Iron and copper were transported mainly in the particulate phases at all sites, while manganese and zinc were found in the dissolved phase up to a hundred percent depending on the pH of water sample and pollution at the site concerned. Except copper more than 75 percent of all other three metals occurred in transport modes thought to be available to aqueous and biotic interactions. Copper was in available phases from 50 to 70 percent. The significance of metal partitioning as a factor in controlling metal availability and toxicity to biota is discussed. 相似文献
830.
Su Sponaugle Kristen D. Walter Kelly L. Denit Joel K. Llopiz Robert K. Cowen 《Marine Biology》2010,157(4):839-849
Atlantic blue marlin (Makaira nigricans) and sailfish (Istiophorus platypterus) larvae were collected from 10 monthly cruises (June–October 2003 and 2004) across the Straits of Florida to test (1) whether
growth differed between the more productive western region near the Florida shelf, and the less productive eastern region
toward the Bahamas, and (2) whether growth was related to prey consumption. Examination of larval sagittal otoliths revealed
that instantaneous growth and daily growth during the first 2–3 weeks of life did not vary significantly between the two regions
for either species. However, recent growth during the last two full days prior to collection was greater in the west for blue
marlin larvae. Recent growth of blue marlin larvae <9 mm SL (primarily zooplanktivorous) was significantly related to prey
composition (faster growth when higher proportions of Farranula copepods were consumed). Western larvae grew faster and had higher proportions of Farranula in their guts. Trends for sailfish larvae were not significant. In both species, comparison of early growth between <9 and ≥9 mm
SL size groups indicated that growth trajectories diverged around 5–8 mm SL, the time when billfish larvae become capable
of piscivory. Significantly faster growth of larger (older) larvae suggests that mortality was selective for fast growers
and that the transition to piscivory may be a critical point in the early life of billfish. 相似文献