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421.
Molecular,Biochemical, and Organismal Analyses of Tomato Plants Simultaneously Attacked by Herbivores from Two Feeding Guilds 总被引:2,自引:0,他引:2
Cesar R. Rodriguez-Saona Richard O. Musser Heiko Vogel Sue M. Hum-Musser Jennifer S. Thaler 《Journal of chemical ecology》2010,36(10):1043-1057
Previous work identified aphids and caterpillars as having distinct effects on plant responses to herbivory. We sought to
decipher these interactions across different levels of biological organization, i.e., molecular, biochemical, and organismal,
with tomato plants either damaged by one 3rd-instar beet armyworm caterpillar (Spodoptera exigua), damaged by 40 adult potato aphids (Macrosiphum euphorbiae), simultaneous damaged by both herbivores, or left undamaged (controls). After placing insects on plants, plants were transferred
to a growth chamber for 5 d to induce a systemic response. Subsequently, individual leaflets from non-damaged parts of plants
were excised and used for gene expression analysis (microarrays and quantitative real-time PCR), C/N analysis, total protein
analysis, proteinase inhibitor (PI) analysis, and for performance assays. At the molecular level, caterpillars up-regulated
56 and down-regulated 29 genes systemically, while aphids up-regulated 93 and down-regulated 146 genes, compared to controls.
Although aphids induced more genes than caterpillars, the magnitude of caterpillar-induced gene accumulation, particularly
for those associated with plant defenses, was often greater. In dual-damaged plants, aphids suppressed 27% of the genes regulated
by caterpillars, while caterpillars suppressed 66% of the genes regulated by aphids. At the biochemical level, caterpillars
induced three-fold higher PI activity compared to controls, while aphids had no effects on PIs either alone or when paired
with caterpillars. Aphid feeding alone reduced the foliar C/N ratio, but not when caterpillars also fed on the plants. Aphid
and caterpillar feeding alone had no effect on the amount of protein in systemic leaves; however, both herbivores feeding
on the plant reduced the amount of protein compared to aphid-damaged plants. At the organismal level, S. exigua neonate performance was negatively affected by prior caterpillar feeding, regardless of whether aphids were present or absent.
This study highlights areas of concordance and disjunction between molecular, biochemical, and organismal measures of induced
plant resistance when plants are attacked by multiple herbivores. In general, our data produced consistent results when considering
each herbivore separately but not when considering them together. 相似文献
422.
423.
Adi T. Utomo Heiko Poth Phillip T. Robbins Andrzej W. Pacek 《International Journal of Heat and Mass Transfer》2012,55(25-26):7772-7781
Thermal conductivity, viscosity and heat transfer coefficient of water-based alumina and titania nanofluids have been investigated. The thermal conductivity of alumina nanofluids follow the prediction of Maxwell model, whilst that of titania nanofluids is slightly lower than model prediction because of high concentration of stabilisers. None of investigated nanofluids show anomalously high thermal conductivity enhancement frequently reported in literature. The viscosity of alumina and titania nanofluids was higher than the prediction of Einstein–Batchelor model due to aggregation. Heat transfer coefficients measured in nanofluids flowing through the straight pipes are in a very good agreement with heat transfer coefficients predicted from classical correlation developed for simple fluids. Experimental heat transfer coefficients in both nanofluids as well as corresponding wall temperatures agree within ±10% with the values obtained from numerical simulations employing homogeneous flow model with effective thermo-physical properties of nanofluids. These results clearly shows that titania and alumina nano-fluids do not show unusual enhancement of thermal conductivity nor heat transfer coefficients in pipe flow frequently reported in literature. 相似文献
424.
介绍了汽车发动机系滚动轴承润滑脂动态可靠性的测试及评价方法,包括SKF Emcor润滑脂动态抗腐蚀测试,FAG FE8润滑脂动态抗极压和磨损性能测试以及FAG FE9润滑脂动态润滑寿命测试,对正确选用润滑脂以及汽车发动机系滚动轴承可靠度设计等提供参考. 相似文献
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427.
The EU-Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM), which is located inside an equatorial port plug, is attached to the shield by an attachment system. The design of the attachment system has to fulfill two conflicting requirements. On the one hand, it has to transfer the high electromagnetic forces acting on the TBM to the shield and on the other hand, it has to compensate the different thermal expansions between the shield and the back plate of the TBM. The recent design approach of the attachment system consists of a hollow cylinder located at the center of the back plate. This design combines two advantages: a simple geometry and correspondingly low fabrication effort and the central location where the differential strain between back plate and shield is minimal. Static and transient thermal-structural analyses of the most demanding load cases, a fast vertical displacement event type II and the operation state tritium outgassing, have been performed to evaluate the design and confirm the compliance with the relevant design codes. A welded connection of the attachment system to the TBM back plate and a bolted connection in combination with a splined shaft is proposed for the shield side because of the dissimilar materials. 相似文献
428.
429.
Polymer‐Based Spherical Activated Carbon as Easy‐to‐Handle Catalyst Support for Hydrogenation Reactions 下载免费PDF全文
Heiko Klefer Macarena Munoz Antje Modrow Bertram Böhringer Peter Wasserscheid Bastian J. M. Etzold 《化学工程与技术》2016,39(2):276-284
The application of polymer‐based spherical activated carbon (PBSAC) as catalyst support offers unprecedented advantages in the handling of the catalyst in all stages of its application due to its superior fluid dynamic properties and dust‐free character, minimizing post processing times and facilitating catalyst recycling. The preparation of PBSAC‐based Pd catalysts has been addressed using PBSAC of different particle sizes and degrees of activation. Prior to Pd deposition, the support was oxidized in nitric and sulfuric acidic media under different operating conditions in order to introduce surface charges for the ion exchange. This method was successfully applied as, even for the mildest functionalization conditions, full deposition of Pd was achieved. The synthesized Pd‐PBSAC catalysts were successfully employed in the hydrogenation of cinnamic acid achieving its complete conversion at an optimum effective rate constant of 0.122 m3 kgPd?1 s?1. 相似文献
430.
Sales agents depend on mobile support systems for their daily work. Independent sales agencies, however, are not able to facilitate
this kind of mobile support on their own due to their small size and lack of the necessary funds. Since their processes correlate
with confidential information and include the initiation and alteration of legally binding transactions they have a high need
for security. In this contribution we first analyze the target domain using qualitative and quantitative methods and propose
an IT-artifact that supports independent sales agencies. It is build as a service platform that supports multi-vendor sales
processes. Afterwards, we examine use cases of sales representatives of independent sales agencies using this system and derive
their security requirements. Using these, we propose a security extension to the IT-artifact and evaluate this extension by
comparing it to existing solutions. Our results show that the proposed artifact extension provides a more convenient and secure
solution than already existing approaches. 相似文献