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211.
Paul Beier Patricia Sutcliffe Jan Hjort Daniel P. Faith Robert L. Pressey Fabio Albuquerque 《Conservation biology》2015,29(3):668-679
Because conservation planners typically lack data on where species occur, environmental surrogates—including geophysical settings and climate types—have been used to prioritize sites within a planning area. We reviewed 622 evaluations of the effectiveness of abiotic surrogates in representing species in 19 study areas. Sites selected using abiotic surrogates represented more species than an equal number of randomly selected sites in 43% of tests (55% for plants) and on average improved on random selection of sites by about 8% (21% for plants). Environmental diversity (ED) (42% median improvement on random selection) and biotically informed clusters showed promising results and merit additional testing. We suggest 4 ways to improve performance of abiotic surrogates. First, analysts should consider a broad spectrum of candidate variables to define surrogates, including rarely used variables related to geographic separation, distance from coast, hydrology, and within‐site abiotic diversity. Second, abiotic surrogates should be defined at fine thematic resolution. Third, sites (the landscape units prioritized within a planning area) should be small enough to ensure that surrogates reflect species’ environments and to produce prioritizations that match the spatial resolution of conservation decisions. Fourth, if species inventories are available for some planning units, planners should define surrogates based on the abiotic variables that most influence species turnover in the planning area. Although species inventories increase the cost of using abiotic surrogates, a modest number of inventories could provide the data needed to select variables and evaluate surrogates. Additional tests of nonclimate abiotic surrogates are needed to evaluate the utility of conserving nature's stage as a strategy for conservation planning in the face of climate change. 相似文献
212.
213.
Microprobe studies of aluminum accumulation in association with human central nervous system disease
The neurofibrillary tangle, first described by Alzheimer in 1907, along with the senile plaque, represent the two principle neuropathologic lesions identified in the brains of patients with Alzheimer's disease. Aluminum salts inoculated into the central nervous system of certain experimental animals induces neurofilamentous lesions which are similar, but not identical to the neurofibrillary tangles seen in Alzheimer's disease. Although some reports provide evidence of increased amounts of aluminum in the brains of Alzheimer's disease victims, such bulk analysis studies have been difficult to replicate. Over the past several years we have approached this problem using a variety of microprobe techniques in order to determine the distribution of trace elements within individual nerve cells.Using scanning electron microscopy with X-ray spectrometry, we have identified accumulations of aluminum in the neurofibrillary tangle-bearing neurons of cases of Alzheimer's disease. Similar accumulations have been found in the brains of the indigenous natives of Guam who suffer from parkinsonism with dementia and from amyotrophic lateral sclerosis. Recent studies using laser microprobe mass analysis suggest that the predominance of aluminum identified within the parikaryon of neurofibrillary tangle-bearing neurons is located within the neurofibrillary tangle itself. Although this ongoing research still cannot ascribe a causal role for aluminum in the etiology and/or pathogenesis of the neurofibrillary tangle, the data suggest that certain environmental factors related to trace elemental constituents may play an important role in the formation of this type of cellular pathology. 相似文献
214.
Scott?A.?ShafferEmail author Yann?Tremblay Jill?A.?Awkerman R.?William?Henry Steven?L.?H.?Teo David?J.?Anderson Donald?A.?Croll Barbara?A.?Block Daniel?P.?Costa 《Marine Biology》2005,147(4):833-843
Light-based archival tags are increasingly being used on free-ranging marine vertebrates to study their movements using geolocation estimates. These methods use algorithms that incorporate threshold light techniques to determine longitude and latitude. More recently, researchers have begun using sea surface temperature (SST) to determine latitude in temperate regions. The accuracy and application of these algorithms have not been validated on free-ranging birds. Errors in both geolocation methods were quantified by double-tagging Laysan (Phoebastria immutabilis Rothschild) and black-footed (P. nigripes Audubon) albatrosses with both leg-mounted archival tags that measured SST and ambient light, and satellite transmitters. Laysan albatrosses were captured and released from breeding colonies on Tern Island, northwestern Hawaiian Islands (23°52N, 166°17W) and Guadalupe Island, Mexico (28°31N, 118°10W) and black-footed albatrosses from Tern Island. Studies were carried out between December 2002 and March 2003. For all birds combined, the mean ± SD great circle (GC) distance between light-based locations and satellite-derived locations was 400±298 km (n=131). Errors in geolocation positions were reduced to 202±171 km (n=154) when light-based longitude and SST-based latitude (i.e. SST/light) were used to establish locations. The SST/light method produced comparable results for two Laysan albatross populations that traveled within distinctly different oceanic regions (open ocean vs more coastal) whereas light-based methods produced greater errors in the coastal population. Archival tags deployed on black-footed albatrosses returned a significantly higher proportion of lower-quality locations, which was attributed to interference of the light sensor on the tag. Overall, the results demonstrate that combining measures of light-based longitude and SST-based latitude significantly reduces the error in location estimates for albatrosses and can provide valid latitude estimates during the equinoxes, when light-based latitude measurements are indeterminate.Communicated by J.P. Grassle, New Brunswick 相似文献
215.
Market responses to hurricanes 总被引:7,自引:0,他引:7
Daniel G. Hallstrom V. Kerry Smith 《Journal of Environmental Economics and Management》2005,50(3):541-561
This paper uses one of the strongest hurricanes to hit the US, Andrew in 1992, to define a quasi-random experiment that permits estimation of the responses of housing values to information about new hurricanes. Lee County, Florida did not experience damage from Andrew. The storm was a “near-miss.” We hypothesize that Andrew conveyed risk information to homeowners in the county. A difference-in-differences (DND) framework identifies the effect of this information on property values in areas likely to experience significant storm damage. The DND findings indicate at least a 19 percent decline in property values. 相似文献
216.
David T. Bell Daniel J. Carter Robert E. Hetherington 《Environmental geochemistry and health》1986,8(4):99-104
Wind tunnel experiments on rehabilitation surfaces at Eneabba, Western Australia evaluated the techniques used by Associated
Minerals Consolidated Ltd. (AMC) and Allied Eneabba Ltd. (AEL) to stabilize regions being revegetated following heavy mineral
sand mining.
Newly landscaped areas proved to be the most erodible, beginning to erode at 9 m sec−1 and producing a soil flux of 10 kg m−1 min−1 at 18 m sec−1 wind speeds. Sandier, more organically-rich, surfaces in the rehabilitation areas were somewhat less erodible with losses
of only 2 kg m−1 min−1 at wind speeds of 18 m sec−1.
The mining companies use various nurse crops and top dressing mulch for surface stabilization. Rows of oats, sparse plantings
of the grass cultivar “SUDAX” (Dekalb ST6) supplied by Westfarmers Ltd. and applications of Terolas, a cold, bituminous surface
binding material supplied by Shell Co. of Australia Ltd., all proved successful in reducing wind erosion in this semi-arid
region where more than 25% of summer days experience winds greater than 8 m sec−1. 相似文献
217.
Jeffrey Conner Scott Camazine Daniel Aneshansley Thomas Eisner 《Behavioral ecology and sociobiology》1985,16(2):115-118
Summary The tenebrionid beetle Bolitotherus cornutus everts a pair of quinone-producing defensive glands in response to mammalian breath. Experiments with a controlled airstream indicate that the beetle recognizes breath on the basis of temperature, humidity, and airflow dynamics. Under attack by mice the beetle everts the glands immediately upon being mouthed and may secure its release as a result. Against ants the beetle is protected by its tough exoskeleton and usually refrains from everting the glands. Other arthropods also show defensive responses when breathed upon.Paper No. 77 of the series Defense Mechanisms of Arthropods 相似文献
218.
Peter?J.?ChristieEmail author Daniel?J.?Mennill Laurene?M.?Ratcliffe 《Behavioral ecology and sociobiology》2004,55(4):341-348
The fee-bee song of male black-capped chickadees (Poecile atricapillus) is considered a single-type song that singers transpose up and down a continuous frequency range. While the ability to shift song pitch in this species provides a mechanism for song matching as an aversive signal in male-male territorial song contests, the functional significance of this behaviour during the solo performances of males during the dawn chorus is unclear. We analysed the dawn chorus songs and singing behaviour of males whose winter-flock dominance status we determined. We used correlation analysis to show that pitch shifts were accompanied by changes to other fine structural characteristics in song, including temporal and relative amplitude parameters. We also found that songs of socially dominant males and songs of their most subordinate flockmates could be distinguished using these methods by the way they performed a between-note frequency measure accompanying pitch shifts. That is, a ratio measure of the internote frequency interval remained constant for songs of high-ranking birds despite changes in absolute pitch, while low-ranking males sang a smaller ratio as they shifted to higher absolute pitches. These findings identify previously unrecognised variation in the songs of black-capped chickadees. More importantly, they indicate a mechanism by which pitch shifting during the dawn chorus of black-capped chickadees could provide a reliable indicator of relative male quality.Communicated by I. Hartley 相似文献
219.
Summary Whirligig beetles aggregate in the daytime into dense single-and multispecies groups (rafts) of hundreds or thousands of individuals. On the 22km shoreline of Lake Itasca in northern Minnesota, these aggregations were on the average 0.8 km apart, and they were usually found day after day in the same ocations.Most beetles apparently do not home to the aggregation of their origin after dispersing at night because (a) the species composition of some aggregations changed greatly, and (b) paint-marked beetles (Dineutus horni) moved overnight from one aggregation as far as 4km, joining 11 of the 14 large (>300 beetles) D. horni groups on the lake.Throughout the night, the largest concentrations of beetles remained within 100m of the diurnal aggregation sites. Beetles reconvened into the compact rafts before daybreak, in part by following each other in sometimes long single files or trains. Their forward motion stopped after they joined large number of other beetles. We infer that following behavior enables those individuals that have dispersed from their original aggregations (during their nocturnal foraging) to find and join other aggregations before daylight.Naive fish ate the beetles despite their noxious secretions. However, fish living near rafting sites and feeding on insects on the water surface in daylight should soon learn to avoid the beetles. The rafting sites would then become safe places. We observed fish attacking only those beetles that had been either dispersed from their rafts or released into open water away from raft sites in the daytime. We speculate that the evolutionary significance of the aggregation behavior is related to predator (fish) avoidance. 相似文献
220.
Suburban Areas in Developing Countries and Their Relationship to Groundwater Pollution: A Case Study of Mar del Plata, Argentina 总被引:1,自引:0,他引:1
Hector E. Massone Daniel E. Martinez Jose L. Cionchi Emilia Bocanegra 《Environmental management》1998,22(2):245-254
2 were sampled in order to verify the impact of these problems on groundwater. All samples were analyzed for major ions, and
about 30 of them for fecal coliforms and heavy metals. Nineteen samples were selected for pesticide analyses. The average
nitrate content was 80 mg/liter, eight times the regional background value. Fecal coliforms were detected in 60% of the analyzed
samples. Zinc content and a high Cl−/HCO3
− ratio were observed in the surroundings of the solid waste disposal area. Moreover, lindane and heptachlor pesticides were
detected in ten samples. 相似文献