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91.
92.
Kerstin Jantke Christine Schleupner Uwe Andreas Schneider 《Biodiversity and Conservation》2011,20(3):581-605
Protected areas in the European Union under the Natura 2000 reserve system cover about 17 percent of the total land area.
Systematic evaluations of the effectiveness of the current reserve system have been scarce and restricted to regional assessments.
One reason for that may be the poor availability of comprehensive fine scale biodiversity data for the highly fragmented and
densely human-populated European continent. We apply recently developed modeling tools for systematic conservation planning
to conduct a detailed gap analysis using coarse scale species occurrence data. The employed mathematical model uses mixed
integer programming to determine the cost-minimizing distribution of habitat locations subject to biophysical, economic, and
policy restrictions. We include fine scale wetland habitat data as well as species-specific proxies for population density
and viable population threshold. First, we evaluate the performance of the current Natura 2000 system in covering endangered
wetland vertebrate species. Results show that five area-demanding vertebrates are not covered by the current reserve system.
Second, we identify potentials for expanding the network to move toward complete coverage for the considered species mostly
in countries of North-Eastern Europe. About 3 million hectares of additional reserve area at a cost of 107 million Euro per
year would be required to achieve coverage of all considered species. Third, we present spatially explicit priority regions
for a cost-effective expansion of the current reserve network. 相似文献
93.
Auxins or Sugars: What Makes the Difference in the Adventitious Rooting of Stored Carnation Cuttings? 总被引:1,自引:0,他引:1
Mar��a ��ngeles Agull��-Ant��n Jos�� S��nchez-Bravo Manuel Acosta Uwe Druege 《Journal of Plant Growth Regulation》2011,30(1):100-113
Cold storage of cuttings is frequently applied in the vegetative propagation of ornamental plants. Dianthus caryophyllus was used to study the limiting influences of auxin and sugars on adventitious root formation (ARF) in cuttings stored at
5°C. Carbohydrate levels during storage were modulated by exposing cuttings to low light or darkness. The resulting cuttings
were treated (or not) with auxin and planted, and then ARF was evaluated. Carbohydrate levels in the cuttings were monitored
and the influence of light treatment on indole-3-acetic acid (IAA) and zeatin (Z) in the basal stem was investigated. Dark
storage for up to 4 weeks increased the percentage of early rooted cuttings and the final number and length of adventitious
roots, despite decreased sugar levels in the stem base. Light during cold storage greatly enhanced sugar levels, particularly
in the stem base where the Z/IAA ratio was higher and ARF was lower than observed in the corresponding dark-stored cuttings.
Sugar levels in nonstored and dark-stored cuttings increased during the rooting period, and auxin application enhanced the
accumulation of sugars in the stem base of nonstored cuttings. Auxin stimulated ARF most strongly in nonstored, less so in
light-stored, and only marginally in dark-stored cuttings. A model of auxin-sugar interactions in ARF in carnation is proposed:
cold storage brings forward root induction and sink establishment, both of which are promoted by the accumulation of auxin
but not of sugars, whereas high levels of sugars and probably also of cytokinins act as inhibitors. Subsequent root differentiation
and growth depend on current photosynthesis. 相似文献
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95.
Priming of defence genes for amplified response to secondary stress can be induced by application of the plant hormone salicylic acid or its synthetic analogue acibenzolar S‐methyl. In this study, we show that treatment with acibenzolar S‐methyl or pathogen infection of distal leaves induce chromatin modifications on defence gene promoters that are normally found on active genes, although the genes remain inactive. This is associated with an amplified gene response on challenge exposure to stress. Mutant analyses reveal a tight correlation between histone modification patterns and gene priming. The data suggest a histone memory for information storage in the plant stress response. 相似文献
96.
“Missing perikymata”—fact or fiction? A study on chimpanzee (Pan troglodytes verus) canines 下载免费PDF全文
Horst Kierdorf Carsten Witzel Uwe Kierdorf Matthew M. Skinner Mark F. Skinner 《American journal of physical anthropology》2015,157(2):276-283
Recently, a lower than expected number of perikymata between repetitive furrow‐type hypoplastic defects has been reported in chimpanzee canines from the Fongoli site, Senegal (Skinner and Pruetz: Am J Phys Anthropol 149 (2012) 468–482). Based on an observation in a localized enamel fracture surface of a canine of a chimpanzee from the Taï Forest (Ivory Coast), these authors inferred that a nonemergence of striae of Retzius could be the cause for the “missing perikymata” phenomenon in the Fongoli chimpanzees. To check this inference, we analyzed the structure of outer enamel in three chimpanzee canines. The teeth were studied using light‐microscopic and scanning‐electron microscopic techniques. Our analysis of the specimen upon which Skinner and Pruetz (Am J Phys Anthropol 149 (2012) 468–482) had made their original observation does not support their hypothesis. We demonstrate that the enamel morphology described by them is not caused by a nonemergence of striae of Retzius but can be attributed to structural variations in outer enamel that result in a differential fracture behavior. Although rejecting the presumed existence of nonemergent striae of Retzius, our study provided evidence that, in furrow‐type hypoplastic defects, a pronounced tapering of Retzius increments can occur, with the striae of Retzius forming acute angles with the outer enamel surface. We suggest that in such cases the outcrop of some striae of Retzius is essentially unobservable at the enamel surface, causing too low perikymata counts. The pronounced tapering of Retzius increments in outer enamel presumably reflects a mild to moderate disturbance of the function of late secretory ameloblasts. Am J Phys Anthropol 157:276–283, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
97.
Marcia L. Moss Garrit Koller Jörg W. Bartsch Sinja Rakow Uwe Schlomann Fred H. Rasmussen 《Analytical biochemistry》2015
We have developed a new amplification system for proteinases that is sensitive, simple, and inexpensive to run, exemplified by a horseradish peroxidase (HRP)-conjugated, dual MMP2 (matrix metalloproteinase 2) and ADAM8 (a disintegrin and metalloproteinase 8) peptide substrate assay presented herein. The HRP-conjugated substrate is attached to beads through a 6× histidine tag and then incubated with the target enzyme, cleaving the HRP reporter. This product is subsequently removed from the unreacted bound portions of the substrate by magnetic deposition of the beads. The amount of product is then quantified using a standard HRP color development assay employing 3,3′,5,5′-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2). This HRP amplification system represents a new approach to proteinase assays and could be applied to other enzymes, such as lipases, esterases, and kinases, as long as the unreacted substrate can be physically separated from the product and catalysis by the enzyme to be quantified is not impaired dramatically by steric hindrance from the HRP entity. 相似文献
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100.
Christopher Lößner Uwe Warnken Armin Pscherer Martina Schnölzer 《Analytical biochemistry》2011,(1):41530
Quantitative proteomics has increasingly gained impact in life science research as a tool to describe changes in protein expression between different cellular states. Stable isotope labeling by amino acids in cell culture (SILAC) is a powerful technique for relative quantification of proteins. However, the accuracy of quantification is impaired by the metabolic conversion of arginine to proline resulting in additional heavy labeled proline peptide satellites. Here we reinvestigated the addition of unlabeled proline during cell cultivation under SILAC conditions considering several thousand peptides and demonstrated that the arginine-to-proline conversion is prevented independent of the cell line used. 相似文献