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排序方式： 共有268条查询结果，搜索用时 32 毫秒
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Mariëlle L. van Toor Bart Kranstauber Scott H. Newman Diann J. Prosser John Y. Takekawa Georgios Technitis Robert Weibel Martin Wikelski Kamran Safi 《Landscape Ecology》2018,33(6):879-893
Context
High-resolution animal movement data are becoming increasingly available, yet having a multitude of empirical trajectories alone does not allow us to easily predict animal movement. To answer ecological and evolutionary questions at a population level, quantitative estimates of a species’ potential to link patches or populations are of importance.Objectives
We introduce an approach that combines movement-informed simulated trajectories with an environment-informed estimate of the trajectories’ plausibility to derive connectivity. Using the example of bar-headed geese we estimated migratory connectivity at a landscape level throughout the annual cycle in their native range.Methods
We used tracking data of bar-headed geese to develop a multi-state movement model and to estimate temporally explicit habitat suitability within the species’ range. We simulated migratory movements between range fragments, and calculated a measure we called route viability. The results are compared to expectations derived from published literature.Results
Simulated migrations matched empirical trajectories in key characteristics such as stopover duration. The viability of the simulated trajectories was similar to that of the empirical trajectories. We found that, overall, the migratory connectivity was higher within the breeding than in wintering areas, corroborating previous findings for this species.Conclusions
We show how empirical tracking data and environmental information can be fused for meaningful predictions of animal movements throughout the year and even outside the spatial range of the available data. Beyond predicting migratory connectivity, our framework will prove useful for modelling ecological processes facilitated by animal movement, such as seed dispersal or disease ecology.34.
35.
Maarten Soetaert Annemie Decostere Hans Polet Bart Verschueren Koen Chiers 《Fish and Fisheries》2015,16(1):104-124
In trawl fisheries, beam trawls with tickler chains, chain mats or bobbin ropes are used to target flatfish or shrimp. High fuel consumption, seabed disturbance and high discard rates are well‐known disadvantages of this fishing technique. These shortcomings are increasingly gaining international public and political attention, especially with the upcoming discard ban in Europe. The most promising alternative fishing technique meeting both the fisherman's aspirations, and the need for ecological progress is pulse fishing with electrotrawls. Here, the mechanical stimulation by tickler chains or bobbins is replaced by electrical stimulation resulting in reduced bottom contact, fuel costs and discards. Although a significant amount of research has been done on electrotrawls and their impact on marine organisms, most data were published in very diverse sources ranging from local non‐peer‐reviewed reports with a limited distribution to highly consulted international peer‐reviewed journals. Therefore, there is a clear need for a comprehensive yet concise and critical overview, covering and summarizing all these data and making these available for the scientific community. This article aims to meet the above goals by discussing the working principle of electric fields, the history of electrotrawls and their current application in the North Sea and impact on marine organisms. It is concluded by elaborating on the opportunities and challenges for the further implementation of this alternative fishing technique. 相似文献
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The Xinjiang plateau of western China has been shown to have a high prevalence for human cystic echinococcosis (CE) caused by Echinococcus granulosus, and human alveolar echinococcosis (AE) caused by Echinococcus multilocularis. The domestic dog is suspected to be the primary definitive host for the transmission of both E. granulosus and E. multilocularis to humans in this locality. Seventeen of 30 stray dogs from Hejing County of Xinjiang were found positive for E. granulosus post mortem, and one double infection was suspected. Worm samples were collected, dyed by carmine, and observed microscopically. Carmine staining examination clearly revealed the differences in number of proglottids and appearance of uterine branches and lateral genital pore for those two species of Echinococcus. Furthermore, gene target DNA fragments were amplified for formal identification of the two parasite species, based on 12s rRNA mitochondrial gene. The PCR products were purified and sequenced. Compared with NCBI GenBank, the DNA sequences demonstrated 100% identity with E. granulosus (sheep strain, G1 genotype) and E. multilocularis. 相似文献
38.
Inge M. Hanssen Anneleen Paeleman Lieve Wittemans Kris Goen Bart Lievens Claude Bragard Alfons C. R. C. Vanachter Bart P. H. J. Thomma 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(2):131-146
Over a period of a few years, Pepino mosaic virus (PepMV) has become one of the most important viral diseases in tomato production worldwide. Infection by PepMV can cause
a broad range of symptoms on tomato plants, often leading to significant financial losses. At present, five PepMV genotypes
(EU, LP, CH2, US1 and US2) have been described, three of which (EU, LP and US2) have been reported in Europe. Thus far, no
correlation has been found between different PepMV genotypes and the symptoms expressed in infected plants. In this paper,
the genetic diversity of the PepMV population in Belgian greenhouses is studied and related to symptom development in tomato
crops. A novel assay based on restriction fragment length polymorphism (RFLP) was developed to discriminate between the different
PepMV genotypes. Both RFLP and sequence analysis revealed the occurrence of two genotypes, the EU genotype and the CH2 genotype,
within tomato production in Belgium. Whereas no differences were observed in symptom expression between plants infected by
one of the two genotypes, co-infection with both genotypes resulted in more severe PepMV symptoms. Furthermore, our study
revealed that PepMV recombinants frequently occur in mixed infections under natural conditions. This may possibly result in
the generation of viral variants with increased aggressiveness. 相似文献
39.
Colaprete A Schultz P Heldmann J Wooden D Shirley M Ennico K Hermalyn B Marshall W Ricco A Elphic RC Goldstein D Summy D Bart GD Asphaug E Korycansky D Landis D Sollitt L 《Science (New York, N.Y.)》2010,330(6003):463-468
Several remote observations have indicated that water ice may be presented in permanently shadowed craters of the Moon. The Lunar Crater Observation and Sensing Satellite (LCROSS) mission was designed to provide direct evidence. On 9 October 2009, a spent Centaur rocket struck the persistently shadowed region within the lunar south pole crater Cabeus, ejecting debris, dust, and vapor. This material was observed by a second "shepherding" spacecraft, which carried nine instruments, including cameras, spectrometers, and a radiometer. Near-infrared absorbance attributed to water vapor and ice and ultraviolet emissions attributable to hydroxyl radicals support the presence of water in the debris. The maximum total water vapor and water ice within the instrument field of view was 155 ± 12 kilograms. Given the estimated total excavated mass of regolith that reached sunlight, and hence was observable, the concentration of water ice in the regolith at the LCROSS impact site is estimated to be 5.6 ± 2.9% by mass. In addition to water, spectral bands of a number of other volatile compounds were observed, including light hydrocarbons, sulfur-bearing species, and carbon dioxide. 相似文献