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11.
Ocean acidification (OA) and the biological consequences of altered seawater chemistry have emerged as a significant environmental
threat to healthy marine ecosystems. Because a more acidic ocean interferes with fixation of calcium carbonate to form shells
or calcified skeletons, future ocean chemistry may significantly alter the physiology of calcifying marine organisms. These
alterations may manifest themselves directly in the calcification process, or have synergistic effects with other environmental
factors such as elevated temperatures. New tools permit us to explore subtle changes in gene expression patterns in response
to environmental conditions. We raised sea urchins (Strongylocentrotus franciscanus) under conditions simulating future atmospheric CO2 levels of 540 and 970 ppm. When larvae raised under elevated CO2 conditions were subjected to 1-h acute temperature stress, their ability to mount a physiological response (as measured by
expression of the molecular chaperone hsp70) was reduced relative to those raised under ambient CO2 conditions. These results represent the first use of gene expression assays to study the effects of OA on sea urchin development.
They highlight the importance of looking at multiple environmental factors simultaneously as this approach may reveal previously
unsuspected biological impacts of atmospheric changes. 相似文献
12.
13.
Gretchen Spreitzer 《组织行为杂志》2007,28(8):1077-1095
This paper provides an exploratory look at how the leadership practices of business organizations may foster more peaceful societies. I develop the logic for positive relationships between participative organizational leadership, employee empowerment, and peace. I offer several mechanisms to explain why these different manifestations of voice are likely to contribute to peaceful societies. I then draw on several cross‐national databases to provide a preliminary examination of the hypotheses. I find support for the hypotheses regarding the positive effects of participative leadership and employee empowerment in work organizations on peace. The paper concludes by discussing contributions of this research to the organizational studies literature and offers directions for future research. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
14.
Clément Feger Laurent Mermet Bhaskar Vira Prue F.E. Addison Richard Barker Frank Birkin John Burns Stuart Cooper Denis Couvet Thomas Cuckston Gretchen C. Daily Colin Dey Louise Gallagher Rosemary Hails Stephen Jollands Georgina Mace Emily Mckenzie Markus Milne Paolo Quattrone Alexandre Rambaud Shona Russell Marta Santamaria William J. Sutherland 《Conservation biology》2019,33(4):972-975
Article impact statement: New collaborations with accounting research can improve conservation impact of ecosystem-based information systems. 相似文献
15.
Ozone biomonitoring is a detection and monitoring techniquethat involves documenting ozone-induced visible injury toknown ozone-sensitive species under conditions of ambientexposure. The USDA Forest Service administers a long-term,nationwide ozone biomonitoring program to address public andscientific concerns about ozone impacts on forest health. Asystematic grid is used as the basis for biomonitoring sitelocations. At each site, trained field crews evaluate amaximum of thirty plants of up to six species and record the amount and severity of leaf-injury on individualplants. Injury from ozone was found more often on biomonitoring sites in the eastern Unites States than in theinterior or west-coast areas. Further results from thenortheast reveal that in any year, there is a higherpercentage of ozone-injured plants with more severe symptomsin areas with relatively high ozone concentrations than inareas with relatively low ozone. In very dry years (e.g.,1999) the percentage of injured plants and injury severityestimates are both sharply reduced even though ambient ozoneexposures are high. These findings demonstrate thatbiomonitoring data provide meaningful evidence of when highozone concentrations during the growing season have biologicalsignificance. Any assessment of ozone stress in the forestenvironment must include both biomonitoring (i.e., plantresponse) and air quality data to be complete. 相似文献
16.
This research examines how the effectiveness of transformational leadership may vary depending on the cultural values of an individual. We develop the logic for why the individual value of traditionality (emphasizing respect for hierarchy in relationships) moderates the relationship between six dimensions of transformational leadership and leadership effectiveness. The hypotheses are examined on leaders from Asia and North America. The results indicate support for the moderating effect of traditional values on the relationship between four dimensions of transformational leadership (appropriate role model, intellectual stimulation, high performance expectations, and articulating a vision) on leadership effectiveness. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
17.
Countryside Biogeography of Moths in a Fragmented Landscape: Biodiversity in Native and Agricultural Habitats 总被引:15,自引:0,他引:15
Taylor H. Ricketts Gretchen C. Daily Paul R. Ehrlich John P. Fay 《Conservation biology》2001,15(2):378-388
Abstract: Studies of fragmented landscapes, especially in the tropics, have traditionally focused on the native fragments themselves, ignoring species distributions in surrounding agricultural or other human-dominated areas. We sampled moth species richness within a 227-ha forest fragment and in four surrounding agricultural habitats (coffee, shade coffee, pasture, and mixed farms) in southern Costa Rica. We found no significant difference in moth species richness or abundance among agricultural habitats, but agricultural sites within 1 km of the forest fragment had significantly higher richness and abundance than sites farther than 3.5 km from the fragment. In addition, species composition differed significantly between distance classes ( but not among agricultural habitats), with near sites more similar to forest than far sites. These results suggest that (1) different agricultural production regimes in this region may offer similar habitat elements and thus may not differ substantially in their capacities to support native moth populations and (2) that the majority of moths may utilize both native and agricultural habitats and move frequently between them, forming "halos" of relatively high species richness and abundance around forest fragments. Correlations between species richness and the amount of nearby forest cover, measured over circles of various radii around the sites, suggest that halos extend approximately 1.0–1.4 km from the forest edge. The extent of these halos likely differs among taxa and may influence their ability to survive in fragmented landscapes. 相似文献
18.
Bielmyer GK Arnold WR Tomasso JR Isely JJ Klaine SJ 《Environmental monitoring and assessment》2012,184(5):2797-2804
Copper sheeting is a common roofing material used in many parts of the world. However, copper dissolved from roof sheeting
represents a source of copper ions to watersheds. Researchers have studied and recently developed a simple and efficient model
to predict copper runoff rates. Important input parameters include precipitation amount, rain pH, and roof angle. We hypothesized
that the length of a roof also positively correlates with copper concentration (thus, runoff rates) on the basis that runoff
concentrations should positively correlate with contact time between acidic rain and the copper sheet. In this study, a novel
system was designed to test and model the effects of roof length (length of roof from crown to the drip edge) on runoff copper
concentrations relative to rain pH and roof angle. The system consisted of a flat-bottom copper trough mounted on an apparatus
that allowed run length and slope to be varied. Water of known chemistry was trickled down the trough at a constant rate and
sampled at the bottom. Consistent with other studies, as pH of the synthetic rainwater decreased, runoff copper concentrations
increased. At all pH values tested, these results indicated that run length was more important in explaining variability in
copper concentrations than was the roof slope. The regression equation with log-transformed data (R
2 = 0.873) accounted for slightly more variability than the equation with untransformed data (R
2 = 0.834). In log-transformed data, roof angle was not significant in predicting copper concentrations. 相似文献
19.
We investigated physiological traits responsible for determining the tide-height and latitudinal distributions of Northeastern Pacific Nucella congeners. First, we determined the thermotolerances of two species of intertidal dogwhelks, N. ostrina and N. canaliculata, which co-occur on the Oregon coast. We found that N. ostrina, which are distributed higher on the shore, and thus experience higher habitat temperatures, than N. canaliculata, had correspondingly higher heat-coma temperatures. Second, we acclimated individuals of all five Northeastern Pacific Nucella congeners to a common temperature and determined their thermotolerances, measured as recovery from thermal exposure, after a 5-day, 3-week, and 7-week acclimation period. The south-latitude (N. emarginata) and mid-latitude (N. ostrina) high-intertidal species were more thermotolerant than the mid-latitude low-intertidal (N. canaliculata and N. lamellosa) and north-latitude high-intertidal (N. lima) species. The results of these two experiments suggest that temperature plays a role in determining the tide-height and latitudinal distributions of these Nucella species. Finally, we measured total and inducible levels of an evolutionarily conserved and ecologically relevant protein, the 70-kDa heat-shock protein (Hsp70), which has been found to confer thermotolerance in model laboratory organisms. The results showed that the level of total, not stress inducible, Hsp70 was a better predictor of thermotolerance and that there were species-specific differences in the relationship between Hsp70 expression and thermotolerance. We suggest that Hsp70 expression may be important in conferring thermotolerance in Nucella species in nature and that higher levels of molecular chaperones may underlie increased thermotolerance between conspecifics.Communicated by P.W. Sammarco, Chauvin 相似文献
20.
Henry?M.?SpliethoffEmail authorView authors OrcID profile
return OK on get Rebecca?G.?Mitchell Hannah?Shayler Lydia?G.?Marquez-Bravo Jonathan?Russell-Anelli Gretchen?Ferenz Murray?McBride 《Environmental geochemistry and health》2016,38(4):955-971
Urban community gardens provide affordable, locally grown, healthy foods and many other benefits. However, urban garden soils can contain lead (Pb) that may pose risks to human health. To help evaluate these risks, we measured Pb concentrations in soil, vegetables, and chicken eggs from New York City community gardens, and we asked gardeners about vegetable consumption and time spent in the garden. We then estimated Pb intakes deterministically and probabilistically for adult gardeners, children who spend time in the garden, and adult (non-gardener) household members. Most central tendency Pb intakes were below provisional total tolerable intake (PTTI) levels. High contact intakes generally exceeded PTTIs. Probabilistic estimates showed approximately 40 % of children and 10 % of gardeners exceeding PTTIs. Children’s exposure came primarily from dust ingestion and exposure to higher Pb soil between beds. Gardeners’ Pb intakes were comparable to children’s (in µg/day) but were dominated by vegetable consumption. Adult household members ate less garden-grown produce than gardeners and had the lowest Pb intakes. Our results suggest that healthy gardening practices to reduce Pb exposure in urban community gardens should focus on encouraging cultivation of lower Pb vegetables (i.e., fruits) for adult gardeners and on covering higher Pb non-bed soils accessible to young children. However, the common practice of replacement of root-zone bed soil with clean soil (e.g., in raised beds) has many benefits and should also continue to be encouraged. 相似文献