A transient rise in tropical sea surface temperature during the Paleocene-Eocene thermal maximum   总被引：1，自引：0，他引：1  

Zachos JC  Wara MW  Bohaty S  Delaney ML  Petrizzo MR  Brill A  Bralower TJ  Premoli-Silva I 《Science (New York, N.Y.)》2003,302(5650):1551-1554

The Paleocene-Eocene Thermal Maximum (PETM) has been attributed to a rapid rise in greenhouse gas levels. If so, warming should have occurred at all latitudes, although amplified toward the poles. Existing records reveal an increase in high-latitude sea surface temperatures (SSTs) (8 degrees to 10 degrees C) and in bottom water temperatures (4 degrees to 5 degrees C). To date, however, the character of the tropical SST response during this event remains unconstrained. Here we address this deficiency by using paired oxygen isotope and minor element (magnesium/calcium) ratios of planktonic foraminifera from a tropical Pacific core to estimate changes in SST. Using mixed-layer foraminifera, we found that the combined proxies imply a 4 degrees to 5 degrees C rise in Pacific SST during the PETM. These results would necessitate a rise in atmospheric pCO2 to levels three to four times as high as those estimated for the late Paleocene.  相似文献   

A wish,a fear and a complaint: understanding the (dis)engagement of forest owners in forest management     

Gloria Domínguez  Margaret Shannon 《European Journal of Forest Research》2011,130(3):435-450

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Post-mortem findings in 54 cases of anesthetic associated death in cats from two spay-neuter programs in New York State     

Gerdin JA  Slater MR  Makolinski KV  Looney AL  Appel LD  Martin NM  McDonough SP 《Journal of Feline Medicine and Surgery》2011,13(12):959-966

Anesthetic-associated death (AAD) in cats is infrequent, but occurs far more frequently than in people. Post-mortem investigations of AAD in cats are uncommon, and results only sporadically published. Here we report the findings in 54 cases of AAD in cats. Significant gross and/or microscopic pre-existing disease, including pulmonary, cardiac, and systemic disease, was detected in 33% of cases. Pulmonary disease was most frequently diagnosed (24% of cases), and included cases of Aelurostrongylus abstrusus infection (9% of cases). Heart disease, including two cases of hypertrophic cardiomyopathy, was less frequent (11% of cases). Four percent died from surgical complications. No?significant gross or microscopic disease was detected in 63% of cases. Additional studies are needed to determine if these findings are representative of AAD in cats in other geographic areas or with access to veterinary care. This study demonstrates that post-mortem investigation of AADs is an important and worthwhile endeavor.  相似文献   

Social and Cultural Impacts of Mercury Pollution on Aboriginal Peoples in Canada     

Wheatley  Margaret A. 《Water, air, and soil pollution》1997,97(1-2):85-90

Among Aboriginal peoples in Canada, mercury pollution has had an impact on social and cultural well being, both at the community level and among individual members within the community, even when there are no provable direct health effects. This paper explores the link between mercury pollution and social and cultural disruption in Canadian Aboriginal communities. It demonstrates how factors such as Aboriginal holistic concepts of environment and health, perceptions, and difficulties in communication can contribute to indirect impacts of mercury pollution on health and well being. It is argued that, given the blood mercury levels among Canadian Aboriginal peoples, social and cultural impacts of mercury pollution present a much greater problem than do the direct clinical effects of exposure.  相似文献   

Density and distribution of the endemic Seram cockatoo Cacatua moluccensis in relation to land use patterns     

Margaret F Kinnaird  Timothy G O'Brien  David Purmiasa 《Biological conservation》2003,109(2):227-235

The endemic Seram cockatoo, Cacatua moluccensis, was placed on Appendix I of CITES in response to declining trade statistics but in the absence of population data. We conducted population surveys and collected data on habitat structure at seven sites on Seram in 1998. Cockatoo densities ranged from 0.93 to 17.25 birds/km² and averaged 7.9 birds/km² across sites. We classified habitat into three types but found that cockatoo densities did not correspond closely to habitat differences across sites. Cockatoo abundance was significantly associated with presence of potential nest trees and strangling figs. Analysis of forest cover and landuse indicates that while most of the island is still covered in lowland forest, only 14% of these forests are protected and almost half the island is classified as logging concession. Conservation recommendations include better information and enforcement of laws protecting Seram cockatoos and resolution of boundary conflicts between parks and logging concessions.  相似文献   

Distribution, status, and conservation needs of Asian elephants (Elephas maximus) in Lampung Province, Sumatra, Indonesia     

Simon Hedges  Martin J. Tyson  Arnold F. Sitompul  Margaret F. Kinnaird  Donny Gunaryadi 《Biological conservation》2005,124(1):35-48

In the mid 1980s, Asian elephant (Elephas maximus) populations were believed to persist in 44 populations on the Indonesian island of Sumatra. Twelve of these populations occurred in Lampung Province, but our surveys revealed that only three were extant in 2002. Causal factors underlying this decline include human population growth, changes in land use, and human-elephant conflict. Nevertheless, our surveys in the Province’s two national parks, Bukit Barisan Selatan and Way Kambas, produced population estimates of 498 (95% CI = [373, 666]) and 180 (95% CI = [144, 225]) elephants, respectively. The estimate for Bukit Barisan Selatan is much larger than previous estimates; the estimate for Way Kambas falls between previous estimates. The third population was much smaller and may not be viable. These are the first estimates for Southeast Asian elephant populations based on rigorous sampling-based methods that satisfied the assumptions of the models used, and they suggest that elephant numbers in these parks are of international importance. While our results suggest that Sumatra’s remaining elephant populations may be larger than expected, they also suggest that the future for these animals is bleak. Human-elephant conflict was reported around all three areas in Lampung and their elephant populations are currently threatened by habitat loss and poaching. Local solutions are possible, but will require much greater commitment by all stakeholders.  相似文献   

Removal of Benzene by the Indoor Plant/Substrate Microcosm and Implications for Air Quality     

Orwell  Ralph L.  Wood  Ronald L.  Tarran  Jane  Torpy  Fraser  Burchett  Margaret D. 《Water, air, and soil pollution》2004,157(1-4):193-207

Water, Air, &; Soil Pollution - The quality of the indoor environment has become a major health consideration, since urban-dwellers spend 80-90% of their time indoors, where air pollution can be...  相似文献   

Soil catenas to estimate ages of movements on normal fault scarps, with an example from the Wasatch fault zone, Utah, USA     

James P. McCalpin  Margaret E. Berry   《CATENA》1996,27(3-4)

Trenches excavated across fault scarps on a 13 ka delta surface at Brigham City, Utah, USA, document four types of soil-catena phenomena. First, the relict summit soil is eroded at the scarp crest, and its components incorporated into the accumulating colluvial wedge at the scarp base. Second, the pre-faulting soil weakens laterally as it is traced scarpward beneath the colluvial wedge from a relict position beyond the scarp toe. Third, soils developed on individual colluvial wedges and on the underlying, pre-faulting surface merge downslope to form a cumulative soil profile at the scarp toeslope. Fourth, soil horizons thicken downslope, probably due to the combined affect of more available moisture, water infiltration, and sediment accumulation.Two soil catenas were used to evaluate the applicability of a continuity approach to paleoearthquake dating, by which percentages of total development time represented by each soil at a fault scarp footslope could be estimated. The continuity approach sets total soil development at the scarp footslope, including any buried pre-faulting soil plus the sum development of all colluvial wedge soils corrected by a slope factor (F), equal to total soil development at the scarp summit. Soil development was characterized by Profile Development Index (PDI) and pedogenic clay parameters, using facies models to estimate parent material values for genetically-different colluvial units, and recognizing inherited soil components in colluvial wedges as parent material properties. The F slope factor, used to correct colluvial wedge soils for development attributable to slope position rather than age, was checked by using a nearby fluvial scarp as an independent control. Our soil data, when compared to independent age estimates, imply that rates of soil development have not been constant over the last 13 ka at Brigham City, but rather were considerably higher than average between 13 ka and 8.3 ka. Higher rates are probably due to a relatively high influx of eolian dust during the late Pleistocene to early Holocene following the lowering of Lake Bonneville, a large paleolake in the western USA. These variable rates of soil development preclude using the continuity approach for paleoearthquake dating at Brigham City. However, promising results showing that generally consistent F factors can be calculated for fault and fluvial scarps leave open the possibility that in areas where soil development rates have been relatively constant over the time period in question, the continuity approach may be a broadly applicable method for paleoearthquake dating.  相似文献   

Residual effects of fungicidal spray programmes on apple trees     

Robert J. W. Byrde  Christopher W. Harper  Margaret E. Holgate  Thomas Hunter 《Pest management science》1973,4(3):327-333

Spraying programmes for apple scab and mildew control sometimes had residual effects for one or even two years. Thus, benomyl (0.025% a.i.) and pyridinitril (0.035% a.i.) drastically reduced the subsequent incidence of cankers caused by Nectria galligena on young wood. Apple scab fruit infection, caused by Venturia inaequalis, was also less on trees on which benomyl had been used in the previous season. In the bark of such trees, toxic residues equivalent to 1 to 4 μg benomyl/g fresh wt. were detected by bioassay 7 months after spraying.  相似文献   

Comparative tolerance of some dicotyledons to pronamide and chlorpropham     

H. A. Roberts  Margaret E. Ricketts 《Pest management science》1973,4(1):83-87

In laboratory tests with 115 species of dicotyledons, the concentration of pronamide in water for 50% inhibition of root elongation ranged from 0.03 to >8 parts/million. With certain exceptions, species within a family responded similarly. Polygonaceae and Caryophyllaceae were the most susceptible and Compositae the most tolerant, as they were also to chlorpropham. There was good correspondence between the test results and the relative susceptibility of species to pre-emergence application in the field.  相似文献