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Monte JV  De Nova PJ  Soler C 《Hereditas》2001,135(2-3):233-238
Amplified fragment length polymorphism (AFLP) DNA markers were used to characterize the genetic diversity and relationships in wild species of the genus Aegilops. Fifty populations, which included the species Aegilops biuncialis (UUMM), Ae. neglecta (UUMMNN), Ae. ovata (UUMM), Ae. ventricosa (DDNN) and Ae. triuncialis (UUCC) were selected. These populations are distributed in the Iberian peninsula and Balearic islands. Five AFLP selective primer combinations generated a total of 527 amplification products of which 517 (98.10%) detected polymorphisms. Aegilops neglecta showed the least variation in contrast with Ae. biuncialis that presented the highest degree of polymorphism. Genetic relationships within the populations were evaluated by generating a similarity matrix based on the Jaccard index. In the resulting phenogram Ae. ventricosa appears segregated from the other species, probably owing to the influence of the D genome. The species sharing the U genome are located in the main cluster. The branching pattern of the U genome group reflects the proximity of the species sharing the M genome. Ae. biuncialis and Ae. ovata are clearly separated suggesting that the super index system should be used to differentiate the M genomes of both species. The variation among populations within species in relation to their geographical origin and results previously obtained by the authors using biochemical and molecular markers are discussed.  相似文献   
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Biogenic reefs are important for habitat provision and coastal protection. Long‐term datasets on the distribution and abundance of Sabellaria alveolata (L.) are available from Britain. The aim of this study was to combine historical records and contemporary data to (1) describe spatiotemporal variation in winter temperatures, (2) document short‐term and long‐term changes in the distribution and abundance of S. alveolata and discuss these changes in relation to extreme weather events and recent warming, and (3) assess the potential for artificial coastal defense structures to function as habitat for S. alveolata. A semi‐quantitative abundance scale (ACFOR) was used to compare broadscale, long‐term and interannual abundance of S. alveolata near its range edge in NW Britain. S. alveolata disappeared from the North Wales and Wirral coastlines where it had been abundant prior to the cold winter of 1962/1963. Population declines were also observed following the recent cold winters of 2009/2010 and 2010/2011. Extensive surveys in 2004 and 2012 revealed that S. alveolata had recolonized locations from which it had previously disappeared. Furthermore, it had increased in abundance at many locations, possibly in response to recent warming. S. alveolata was recorded on the majority of artificial coastal defense structures surveyed, suggesting that the proliferation of artificial coastal defense structures along this stretch of coastline may have enabled S. alveolata to spread across stretches of unsuitable natural habitat. Long‐term and broadscale contextual monitoring is essential for monitoring responses of organisms to climate change. Historical data and gray literature can be invaluable sources of information. Our results support the theory that Lusitanian species are responding positively to climate warming but also that short‐term extreme weather events can have potentially devastating widespread and lasting effects on organisms. Furthermore, the proliferation of coastal defense structures has implications for phylogeography, population genetics, and connectivity of coastal populations.  相似文献   
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Relationships of diversity, distribution and abundance of benthic decapods in intertidal and shallow subtidal waters to 10 m depth are explored based on data obtained using a standardized protocol of globally-distributed samples. Results indicate that decapod species richness overall is low within the nearshore, typically ranging from one to six taxa per site (mean = 4.5). Regionally the Gulf of Alaska decapod crustacean community structure was distinguishable by depth, multivariate analysis indicating increasing change with depth, where assemblages of the high and mid tide, low tide and 1 m, and 5 and 10 m strata formed three distinct groups. Univariate analysis showed species richness increasing from the high intertidal zone to 1 m subtidally, with distinct depth preferences among the 23 species. A similar depth trend but with peak richness at 5 m was observed when all global data were combined. Analysis of latitudinal trends, confined by data limitations, was equivocal on a global scale. While significant latitudinal differences existed in community structure among ecoregions, a semi-linear trend in changing community structure from the Arctic to lower latitudes did not hold when including tropical results. Among boreal regions the Canadian Atlantic was relatively species poor compared to the Gulf of Alaska, whereas the Caribbean and Sea of Japan appeared to be species hot spots. While species poor, samples from the Canadian Atlantic were the most diverse at the higher infraordinal level. Linking 11 environmental variables available for all sites to the best fit family-based biotic pattern showed a significant relationship, with the single best explanatory variable being the level of organic pollution and the best combination overall being organic pollution and primary productivity. While data limitations restrict conclusions in a global context, results are seen as a first-cut contribution useful in generating discussion and more in-depth work in the still poorly understood field of biodiversity distribution.  相似文献   
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Overabundant white-tailed deer (Odocoileus virginianus) populations have been reported in many urban and suburban communities across the United States. Large populations of deer can potentially increase the risk of human-wildlife conflicts, such as deer-vehicle collisions, transmission of disease to humans, and vegetation damage. In 2003, efforts to control white-tailed deer numbers were initiated at the National Aeronautical and Space Agency's (NASA) Lyndon B. Johnson Space Center (JSC) in Houston, Texas, using the long-lasting, single-dose contraceptive SpayVac. Our objectives were to evaluate the effectiveness of SpayVac for reducing white-tailed deer fertility and determine the partial cost for treatment. Between 2003 and 2004, we monitored 45 adult female deer (34 treated with SpayVac, 11 controls treated with a placebo). Fawning rate over 2 yr for deer treated with SpayVac >30 days prior to the rut was 0% (n=31), whereas the fawning rate for control deer was 78% (n=11). Inoculation 1 mo prior to the breeding season was sufficient time to achieve fertility control. We conclude that SpayVac can effectively reduce the fertility of urban white-tailed deer.  相似文献   
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NsPEF ablation induces apoptosis markers, but specific cell death pathways have not been fully defined. To identify nsPEF-activated cell death pathways, wildtype human Jurkat cells and clones with deficiencies in extrinsic and intrinsic apoptosis pathways were investigated. NsPEFs activated caspase isozymes and induced identical electric field-dependent cell death in clones deficient in FADD or caspase-8, indicating that extrinsic apoptosis pathways were not activated. This was confirmed when cytochrome c release was shown to be unaffected by the pan caspase inhibitor, z-VAD-fmk. NsPEF-treated APAF-1-silenced cells did not exhibit caspase-3/7 and -9 activities and corresponding electric field-dependent cell death in this clone was attenuated compared to its vector control at low, but not at high electric fields. These data demonstrate that nsPEFs induce intrinsic apoptosis activate by cytochrome c release from mitochondria through an APAF-1- and caspase-dependent pathway as well as through caspase-independent mechanisms that remain to be defined. Furthermore, the results establish that nsPEFs can overcome natural and oncogenic mechanisms that promote cell survival through inhibition of apoptosis and other cell death mechanisms.  相似文献   
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A post-release study was performed to assess the impact of Torymus sinensis (Hymenoptera: Torymidae), the biological control agent of Dryocosmus kuriphilus (Hymenoptera: Cynipidae), on native cynipid gall inducers in Italy. In total, 14,512 non-target galls were collected, corresponding to seven genera: Andricus, Aphelonyx, Biorhiza, Cynips, Diplolepis, Neuroterus, and Synophrus, and 8708 chalcid parasitoids were recorded. The Torymidae family accounted for about 30%, and Bootanomyia (=Megastigmus) dorsalis, Torymus affinis and T. flavipes were the most represented species. A total of 116 T. sinensis emerged from 15 different oak galls, mainly Andricus curvator and A. inflator. In controlled conditions, oviposition was recorded on A. cydoniae, A. grossulariae and A. lucidus, while no mating with native congeneric species occurred. This paper confirms the realised host-range expansion by T. sinensis. Even if it were extremely difficult to evaluate its magnitude, the impact appears minimal, and an occasional feeding with no changes in the distribution or abundance of non-target hosts is expected.  相似文献   
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The excretion of a diffusible factor was detected in sporulating, avermectin-producing strain ofStreptomyces avermitilis. The factor induced the formation of aerial mycelium and spores by a nonsporulating mutant.  相似文献   
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