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391.
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Satellite telemetry reveals behavioural plasticity in a green turtle population nesting in Sri Lanka
Peter Bradley Richardson Annette C. Broderick Michael S. Coyne Lalith Ekanayake Thushan Kapurusinghe Chandralal Premakumara Susan Ranger M. M. Saman Matthew J. Witt Brendan J. Godley 《Marine Biology》2013,160(6):1415-1426
Satellite transmitters were deployed on ten green turtles (Chelonia mydas) nesting in Rekawa Sanctuary (RS-80.851°E 6.045°N), Sri Lanka, during 2006 and 2007 to determine inter-nesting and migratory behaviours and foraging habitats. Nine turtles subsequently nested at RS and demonstrated two inter-nesting strategies linked to the location of their residence sites. Three turtles used local shallow coastal sites within 60 km of RS during some or all of their inter-nesting periods and then returned to and settled at these sites on completion of their breeding seasons. In contrast, five individuals spent inter-nesting periods proximate to RS and then migrated to and settled at distant (>350 km) shallow coastal residence sites. Another turtle also spent inter-nesting periods proximate to RS and then migrated to a distant oceanic atoll and made forays into oceanic waters for 42 days before transmissions ceased. This behavioural plasticity informs conservation management beyond protection at the nesting beach. 相似文献
394.
Matthew R. Gilg M. Camila Restrepo Ronald Walton Pamela M. Brannock Thomas J. Hilbish Emmanuel Rodriguez 《Marine Biology》2013,160(7):1737-1750
Divergence at gamete recognition loci is hypothesized to result in speciation in broadcast spawning invertebrates. Many gamete recognition loci evolve quickly and show patterns of positive selection, yet the advantage of divergence is rarely known. M7 lysin is a sperm protein in the Mytilus edulis species complex that shows evidence of adaptive evolution. This locus is polymorphic with two distinct clades within Mytilus galloprovincialis, one of which, the D clade, shows the strongest signal of positive selection. We tested whether the geographic patterns in allele frequency were consistent with the hypothesis that positive selection on D clade alleles (G D ) was due to reinforcement. Populations of M. edulis showed little evidence of introgression of G D alleles, but there was no consistent evidence of reproductive character displacement. The lack of consistent patterns expected of reinforcement suggests that another mechanism is likely responsible for the adaptive divergence of M7 lysin. 相似文献
395.
Ünal Akkemik Hulya Caner Grace A. Conyers Matthew J. Dillon Nurgül Karlioğlu 《国际发展与全球生态学杂志》2013,20(5):395-405
The Rough Cilicia Archaeological Survey Project investigates landscape transformation as a component to its regional survey of ancient Rough Cilicia (south coastal Turkey opposite Cyprus). Rough Cilicia was celebrated during antiquity for pristine cedar forests that stood between 1500 and 1800 m in altitude along the slopes of the Taurus Mountains. Today along the front range of the Taurus Mountains this forest is completely denuded or otherwise replanted with recent growth in the past 80 years. We employ paleoenvironmental analysis of relic cedar forests in the Taurus Mountains to construct a timeline of anthropogenic disturbances associated with population growth over time and thereby assess the sustainability of ancient forestry practices. To obtain these data, the team recovers pollen and carbon samples from geomorphologic trenches excavated in the cedar zone, tree ring data from dendrochronological survey of the existing forest, and archaeological data from remains of ancient highland settlements. Preliminary results indicate that current perspectives about the timing of deforestation in this region are flawed and that the initial deforestation coincided with regional site abandonment and population decline at the end of antiquity. 相似文献
396.
Duling MG Stefaniak AB Lawrence RB Chipera SJ Virji MA 《Environmental geochemistry and health》2012,34(3):313-322
Exposure to some manufactured beryllium compounds via skin contact or inhalation can cause sensitization. A portion of sensitized
persons who inhale beryllium may develop chronic beryllium disease (CBD). Little is understood about exposures to naturally
occurring beryllium minerals. The purpose of this study was to assess the bioaccessibility of beryllium from bertrandite ore.
Dissolution of bertrandite from two mine pits (Monitor and Blue Chalk) was evaluated for both the dermal and inhalation exposure
pathways by determining bioaccessibility in artificial sweat (pH 5.3 and pH 6.5), airway lining fluid (SUF, pH 7.3), and alveolar
macrophage phagolysosomal fluid (PSF, pH 4.5). Significantly more beryllium was released from Monitor pit ore than Blue Chalk
pit ore in artificial sweat buffered to pH 5.3 (0.88 ± 0.01% vs. 0.36 ± 0.00%) and pH 6.5 (0.09 ± 0.00% vs. 0.03 ± 0.01%).
Rates of beryllium released from the ores in artificial sweat were faster than previously measured for manufactured forms
of beryllium (e.g., beryllium oxide), known to induce sensitization in mice. In SUF, levels of beryllium were below the analytical
limit of detection. In PSF, beryllium dissolution was biphasic (initial rapid diffusion followed by latter slower surface
reactions). During the latter phase, dissolution half-times were 1,400 to 2,000 days, and rate constants were ~7 × 10−10 g/(cm2·day), indicating that bertrandite is persistent in the lung. These data indicate that it is prudent to control skin and inhalation
exposures to bertrandite dusts. 相似文献
397.
Carbon stocks across a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands 总被引:1,自引:0,他引:1
Powers MD Kolka RK Bradford JB Palik BJ Fraver S Jurgensen MF 《Ecological applications》2012,22(4):1297-1307
Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands ranging from 9 to 306 years old. Live tree C stocks increased with age to a maximum near the middle of the chronosequence in unmanaged stands, and increased across the entire chronosequence in thinned stands. C in live understory vegetation and C in the mineral soil each declined rapidly with age in young stands but changed relatively little in middle-aged to older stands regardless of management. Forest floor C stocks increased with age in unmanaged stands, but forest floor C decreased with age after the onset of thinning around age 40 in thinned stands. Deadwood C was highly variable, but decreased with age in thinned stands. Total ecosystem C increased with stand age until approaching an asymptote around age 150. The increase in total ecosystem C was paralleled by an age-related increase in total aboveground C, but relatively little change in total belowground C. Thinning had surprisingly little impact on total ecosystem C stocks, but it did modestly alter age-related trends in total ecosystem C allocation between aboveground and belowground pools. In addition to characterizing the subtle differences in C dynamics between thinned and unmanaged stands, these results suggest that C accrual in red pine stands continues well beyond the 60-100 year management rotations typical for this system. Management plans that incorporate longer rotations and thinning in some stands could play an important role in maximizing C stocks in red pine forests while meeting other objectives including timber extraction, biodiversity conservation, restoration, and fuel reduction goals. 相似文献
398.
399.
Matthew P. Davis Nancy I. Holcroft Edward O. Wiley John S. Sparks W. Leo Smith 《Marine Biology》2014,161(5):1139-1148
The vast darkness of the deep sea is an environment with few obvious genetic isolating barriers, and little is known regarding the macroevolutionary processes that have shaped present-day biodiversity in this habitat. Bioluminescence, the production and emission of light from a living organism through a chemical reaction, is thought to occur in approximately 80 % of the eukaryotic life that inhabits the deep sea (water depth greater than 200 m). In this study, we show, for the first time, that deep-sea fishes that possess species-specific bioluminescent structures (e.g., lanternfishes, dragonfishes) are diversifying into new species at a more rapid rate than deep-sea fishes that utilize bioluminescence in ways that would not promote isolation of populations (e.g., camouflage, predation). This work adds to our understanding of how life thrives and evolution shaped present-day biodiversity in the deep sea, the largest and arguably least explored habitat on earth. 相似文献
400.
Hebert GN Odom MA Craig PS Dick DL Strauss SH 《Journal of environmental monitoring : JEM》2002,4(1):90-95
The determination of sub-ppm concentrations of aqueous perfluoroalkylsulfonate (PFSt) anions, including perfluorooctylsulfonate (PFOS), has been accomplished with a relatively simple mass spectrometric procedure that does not require extraction of the analytes into an organic solvent or a chromatographic separation prior to injection into the negative-ion electrospray ionization mass spectrometer. Sample pretreatment was minimized and consisted of dilution of the aqueous samples of groundwater, surface water, tap water, and distilled water with acetonitrile, addition of dodecylsulfate (DDS) as an internal standard, and, in some cases, addition of known amounts of perfluorobutylsulfonate (PFBS) or PFOS for standard-addition experiments. The linear-response range for PFOS is 25.0 microg L(-1) to 2.5 mg L(-1). The lower limit of this range is three orders of magnitude lower than an equally straightforward chromatographic method. The relative errors for standard aqueous solutions containing only 25.0 microg L(-1) and 2.5 mg L(-1) PFOS are +/- 14% and +/- 7%, respectively, with 133 microg L(-1) DDS as the internal standard. The detection limit and quantification limit for PFOS in these standards are 5.0 microg L(-1) and 25.0 microg L(-1), respectively. Six different PFS anions, containing three to eight carbon atoms, were identified and quantified in an aqueous film-forming foam (AFFF) formulation using the method of standard additions. Two alkylsulfate anions and two perfluoroalkylcarboxylate anions were also identified in the AFFF formulation. 相似文献