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991.
Connectivity is central to ecology and evolution as it focuses on the movement of individuals or genes across landscapes. Genetic connectivity approaches aim to understand gene flow but often estimate it indirectly based on metrics of genetic differentiation, which can also be affected by other evolutionary forces such as genetic drift. Gene flow and genetic drift are driven by separate ecological mechanisms with potentially differing effects on genetic differentiation and interpretations of genetic connectivity. The ecological mechanisms contributing to gene flow and genetic drift are primarily effective dispersal, or movement followed by successful reproduction, and the number of breeders in a local population, Nb, respectively. Yet, rarely are these ecological mechanisms and genetic connectivity measured simultaneously across landscapes. We examine the roles of effective dispersal and Nb on genetic connectivity across the entire range of the endangered snail kite (Rostrhamus sociabilis plumbeus), between 2006–2015. We find that both Nb and effective dispersal are important predictors of genetic connectivity across this landscape, but that Nb has a 3 × stronger effect on genetic connectivity. Furthermore, Nb is positively correlated with heterozygosity and allelic richness within patches, suggesting a potentially important role of genetic drift, in addition to gene flow, on genetic connectivity. These results emphasize that conservation efforts should focus on not only between‐patch processes of movement but also within‐patch processes regarding habitat quality and local population size for increasing genetic connectivity. 相似文献
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993.
Faergestad EM Rye M Walczak B Gidskehaug L Wold JP Grove H Jia X Hollung K Indahl UG Westad F van den Berg F Martens H 《Proteomics》2007,7(19):3450-3461
A novel approach for revealing patterns of proteome variation among series of 2-DE gel images is presented. The approach utilises image alignment to ensure that each pixel represents the same information across all gels. Gel images are normalised, and background corrected, followed by unfolding of the images to 1-D pixel vectors and analysing pixel vectors by multivariate data modelling. Information resulting from the data analysis is refolded back to the image domain for visualisation and interpretation. The method is rapid and suitable for automatic routines applied after the gel alignment. The approach is compared with spot volume analysis to illustrate how this approach can solve persistent problems like mismatch of protein spots, erroneous missing values and failure to detect variation in overlapping proteins. The method may also detect variation in the border area of saturated proteins. The approach is given the name pixel-based analysis of multiple images for the identification of changes (PMC). The method can be used for multiple images in general. Effects of pretreatment of the images are discussed. 相似文献
994.
Background
The status of α-tocopherol (vit E) and selenium (Se) has been shown to influence disease resistance in pigs, and may be important for the health of weanling pigs. 相似文献995.
Robert F H Dekker Aneli M Barbosa Ellen C Giese Saulo D S Godoy Luiz G Covizzi 《International microbiology》2007,10(3):177-185
The physiological requirements needed to enhance the production of laccases by the ascomycete Botryosphaeria rhodina MAMB-05 in submerged cultivation were examined under non-induced and induced (veratryl alcohol, VA) conditions. Under non-induced conditions (-VA), the initial pH, C:N ratio, and inorganic N source did not influence laccase production, in contrast to Tween 80, soybean oil, and copper, which significantly increased laccase production, and proline and urea, which suppressed laccase formation. In addition, Tween 60 could serve as the sole carbon source for the production of these enzymes. Under VA-induced conditions of fungal growth, factors such as inoculum type, time-point of addition of inducer, initial pH, C:N ratio, and type of N source, influenced the production of laccases; however, unlike the non-induced conditions, proline and urea did not act as suppressors. Each of these physiological conditions exerted different effects on biomass production. The nutritional conditions examined for B. rhodina MAMB-05 are discussed in relation to their influence on fungal growth and laccase production. 相似文献
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997.
998.
Early trajectories of forest understory development on reclamation sites: influence of forest floor placement and a cover crop 下载免费PDF全文
S. Ellen Macdonald Alia E. K. Snively Jordana M. Fair Simon M. Landhäusser 《Restoration Ecology》2015,23(5):698-706
We tested whether direct placement of forest floor material (FFM: litter, fibric, humus layers and surface mineral horizons) and sowing of a cover crop (Melilotus officinalis) could facilitate the establishment of native forest understory species at a reclaimed coal mine in Alberta, Canada. FFM was salvaged at two depths (15 and 40 cm) from a recently harvested native aspen forest and immediately placed at the same depths on the reclamation site. Total richness (approximately 61 species in 96 subplots) was similar in each of 3 years post‐placement; total richness for all 3 years combined was 87 including 34 typical boreal forest understory species plus 30 other natives. The deeper treatment reduced cover of all species, native and non‐native species in year 1. In year 3, the deeper treatment still had lower cover of non‐native species but had higher cover of forest understory species in years 2 and 3. The deeper treatment also resulted in lower species richness per plot, but only in year 1. In year 2 (when the biennial clover was at its tall stage), the cover crop treatment was associated with lower cover of non‐native species but did not affect the cover of native forest understory species. Direct placement of FFM can help facilitate establishment of a diverse native boreal forest understory in a reclaimed landscape. Although richness and cover may be initially higher with shallower salvage and placement, deeper salvage may ultimately be better for encouraging establishment of native forest understory species. 相似文献
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1000.
Austin Miller Jessica Schafer Cameron Upchurch Ellen Spooner Julie Huynh Sebastian Hernandez Brooke McLaughlin Liam Oden Hanna Fares 《Traffic (Copenhagen, Denmark)》2015,16(3):284-297
Lysosomes are dynamic organelles that undergo cycles of fusion and fission with themselves and with other organelles. Following fusion with late endosomes to form hybrid organelles, lysosomes are reformed as discrete organelles. This lysosome reformation or formation is a poorly understood process that has not been systematically analyzed and that lacks known regulators. In this study, we quantitatively define the multiple steps of lysosome formation and identify the first regulator of this process. 相似文献