The Experts below are selected from a list of 181815 Experts worldwide ranked by ideXlab platform
Abdelhafid Bendahmane - One of the best experts on this subject based on the ideXlab platform.
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the heat shock protein chaperone network and Multiple Stress resistance
Plant Biotechnology Journal, 2017Co-Authors: Pierre Jacob, Heribert Hirt, Abdelhafid BendahmaneAbstract:Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more Stressful conditions. In the context of climate change, Stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with Stress resistance. However, multiStress resistance cannot be obtained from the simple addition of single Stress resistance traits. In the field, Stresses are unpredictable and several may occur at once. Consequently, the use of single Stress resistance traits is often inadequate. Although it has been historically linked with the heat Stress response, the heat-shock protein (HSP)/chaperone network is a major component of Multiple Stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under Stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering Multiple Stress resistance in crops through the HSP/chaperone network.
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The heat-shock protein/chaperone network and Multiple Stress resistance
Plant Biotechnology Journal, 2017Co-Authors: Pierre Jacob, Heribert Hirt, Abdelhafid BendahmaneAbstract:Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more Stressful conditions. In the context of climate change, Stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with Stress resistance. However, multiStress resistance cannot be obtained from the simple addition of single Stress resistance traits. In the field, Stresses are unpredictable and several may occur at once. Consequently, the use of single Stress resistance traits is often inadequate. Although it has been historically linked with the heat Stress response, the heat-shock protein (HSP)/chaperone network is a major component of Multiple Stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under Stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering Multiple Stress resistance in crops through the HSP/chaperone network.
Pierre Jacob - One of the best experts on this subject based on the ideXlab platform.
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the heat shock protein chaperone network and Multiple Stress resistance
Plant Biotechnology Journal, 2017Co-Authors: Pierre Jacob, Heribert Hirt, Abdelhafid BendahmaneAbstract:Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more Stressful conditions. In the context of climate change, Stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with Stress resistance. However, multiStress resistance cannot be obtained from the simple addition of single Stress resistance traits. In the field, Stresses are unpredictable and several may occur at once. Consequently, the use of single Stress resistance traits is often inadequate. Although it has been historically linked with the heat Stress response, the heat-shock protein (HSP)/chaperone network is a major component of Multiple Stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under Stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering Multiple Stress resistance in crops through the HSP/chaperone network.
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The heat-shock protein/chaperone network and Multiple Stress resistance
Plant Biotechnology Journal, 2017Co-Authors: Pierre Jacob, Heribert Hirt, Abdelhafid BendahmaneAbstract:Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more Stressful conditions. In the context of climate change, Stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with Stress resistance. However, multiStress resistance cannot be obtained from the simple addition of single Stress resistance traits. In the field, Stresses are unpredictable and several may occur at once. Consequently, the use of single Stress resistance traits is often inadequate. Although it has been historically linked with the heat Stress response, the heat-shock protein (HSP)/chaperone network is a major component of Multiple Stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under Stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering Multiple Stress resistance in crops through the HSP/chaperone network.
Weidong Huang - One of the best experts on this subject based on the ideXlab platform.
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investigation of the rutting performance of various modified asphalt mixtures using the hamburg wheel tracking device test and Multiple Stress creep recovery test
Construction and Building Materials, 2019Co-Authors: Weidong Huang, Husam Sadek, Feipeng Xiao, Chuanqi YanAbstract:Abstract Asphalt modification technology is diversifying and developing complexity to overcome early permanent deformation and ensure satisfactory performance for asphalt concrete pavements. The Hamburg Wheel Tracking Device (HWTD) test has been reported to be successful in assessing asphalt mixtures’ rutting performance. This study includes a comprehensive investigation of the effects of different additives at various contents upon the HWTD testing results of asphalt mixtures. According to the degree of their improvement of the rutting performance in the HWTD test, additives were classified into three categories: (1) the first grade including linear styrene–butadiene–styrene (SBS), branched SBS and Gilsonite; (2) the second grade including high-density polyethylene, and polyphosphoric acid; and (3) the third grade including crumb rubber. Additionally, it was found that higher dosages of modifiers do not necessarily result in the improvement of Hamburg performance, and an optimal content exists for most additives. After the extensive mix testing, the dynamic shear rheometer (DSR) testing results were correlated to the HWTD test results in two categories: polymer modified asphalt and non-polymer modified asphalt. It was found that the compliance value Jnr3.2 from the Multiple Stress Creep Recovery (MSCR) test did not underestimate the rutting resistance of polymer modified asphalt compared to non-polymer modified asphalt as the current rutting factor G*/sin δ did. Jnr3.2 was more reliable than G*/sin δ in characterizing the anti-rutting performance of asphalt mixtures no matter they were polymer modified or non-polymer modified. However, different criteria for Jnr3.2 should be adopted for the polymer modified asphalt and non-polymer modified asphalt respectively.
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investigation of gilsonite polyphosphoric acid and styrene butadiene styrene modified asphalt binder using the Multiple Stress creep and recovery test
Road Materials and Pavement Design, 2017Co-Authors: Naipeng Tang, Weidong Huang, Mao ZhengAbstract:The Multiple Stress creep and recovery (MSCR) test has been proposed as a replacement for the existing high-temperature binder test (G*/sin δ). However, most studies concerning the MSCR test focused on the polymer-modified asphalt. The primary objective of this study was to investigate rutting resistance of non-polymer (Gilsonite and polyphosphoric acid [PPA])- and styrene–butadiene–styrene (SBS) copolymer-modified asphalt using the MSCR test and compare the results with the dynamic shear oscillatory test. Besides, the Hamburg Wheel Tracking Test (HWTT) was conducted to provide a benchmark to examine the rankings based on parameters G*/sin δ and MSCR compliance value Jnr. The test results indicated that there was a linear relationship between phase angle and MSCR percent recovery for the selected binders, but this relationship was dependent on modifier type. In addition, there was divergence in ranking rutting resistance of Gilsonite-, PPA- and SBS-modified asphalt binders according to G*/sin δ and Jnr. H...
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characterizing sbs modified asphalt with sulfur using Multiple Stress creep recovery test
Construction and Building Materials, 2015Co-Authors: Weidong Huang, Naipeng TangAbstract:Abstract The effect of cross-linking agent and SBS content on SBS modified asphalt were investigated using Multiple Stress creep recovery (MSCR) test. Nonlinear viscoelastic characterization of MSCR curve was also performed to derive nonlinear viscoelastic parameters. Cross-linking agent can prominently improve high temperature properties of SBS modified asphalt, especially at lower polymer content. The effect of increasing SBS content is more prominent for binders at lower SBS content. MSCR test failed to distinguish 5.0% and 5.5% SBS modified asphalt in this limited study. All binders modified from 3.0% to 5.5% SBS with sulfur have sufficient delayed elastic response according to AASHTO TP 70. When cross-linking agent was not used, only high dosage SBS modified binders are considered to be modified with an acceptable elastomeric polymer in this study. In addition, there is strong linear relationship between percent recovery and J nr and such relationship is not dependent on Stress level, but is concerned with test temperature. The nonlinear parameter G 2 derived from MSCR curve can be used to identify the existence of cross-linking agent and characterize the elastic response of SBS modified binder. The parameter PS% shows potentiality in evaluating modified binder’s ability to resist permanent deformation. However, PS% used in this study should be further investigated to confirm the applicability for highly modified asphalt.
Raj Dongre - One of the best experts on this subject based on the ideXlab platform.
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practical use of Multiple Stress creep and recovery test characterization of styrene butadiene styrene dispersion and other additives in polymer modified asphalt binders
Transportation Research Record, 2009Co-Authors: John Dangelo, Raj DongreAbstract:The rheological properties of asphalt binders modified by styrene-butadiene-styrene (SBS) depend on formulation variables. The most sensitive of them may be listed as polymer amount, cross-linking agent amount (percentage), and other additives such as polyphosphoric acid (PPA). The dispersion of SBS in an asphalt binder depends on the time and temperature of blending and the base asphalt binder compatibility. In this study an incompatible binder and a compatible base asphalt binder were selected and modified with various amounts of SBS. Elemental sulfur was used as a cross-linking agent in different proportions. Other additives, such as PPA at 0.5% concentration, were also used. High shear blends of SBS-modified asphalt binders were made in the laboratory by varying blending time until an optimum dispersion of polymer was obtained. The dispersion of the polymer was studied with a fluorescence microscope. A Multiple Stress creep and recovery (MSCR) test was used to study creep and recovery behavior of thes...
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revision of the superpave high temperature binder specification the Multiple Stress creep recovery test with discussion
2007 Journal of the Association of Asphalt Paving Technologists: From the Proceedings of the Technical Sessions, 2007Co-Authors: John Dangelo, Robert Q Kluttz, Raj Dongre, Keith E Stephens, Ludo ZanzottoAbstract:The inadequacy of the Superpave high temperature specification parameter, G*/sin δ, to correctly grade the superior field performance of modified asphalt binders has been demonstrated by several researchers. A new parameter that is blind to modification type and is performance based is now needed. As a replacement for the existing high temperature binder test (G*/sin δ), the FHWA has developed an easy to use Multiple Stress Creep and Recovery Test (MSCR) that measures fundamental characteristics of asphalt binders. In this study, several binder parameters proposed to replace the existing Superpave rutting parameter were validated using hotmix testing. Several different binder tests were evaluated to determine which would provide a replacement for the Superpave high temperature binder criteria. The new test and criteria will have to be performance related and blind to modification. The results from these binder tests were compared against hot-mix rutting results from the Asphalt Pavement Analyzer, the Hamburg Wheel Tracking, the ALF test sections and actual roadway sites. The results from the mixture rut testing showed that different rut testers will provide completely different ranking of binders. This difference is related to the Stress level applied by the different testers. This hot-mix testing indicates that the different binders, specifically the polymer modified binders, have different Stress dependencies. The binder criteria currently used to specify the high temperature properties are specifically intended to be run in the linear viscoelastic range and therefore can not determine the Stress dependency on binder materials. The multi step creep and recovery test can be run at Multiple Stress levels and can characterize the Stress dependency of polymer modified binders. The MSCR test was developed as a result of these findings and other results from various internal studies conducted by FHWA. A separate sub-study was also conducted in this research to understand the effect of Stress and strain on the microstructure of polymer modified binders. It was found that in MSCR data there is a clear relationship between %recovery and %strain in the creep portion of the test. In some cases, at least, this is the dominant relationship. Very high strain causes yield behavior in polymer modified asphalt binders (PMA). After high strain, PMAs still exhibit recovery but the rate of recovery is reduced. At high strain, binder morphology, tensile and shear properties change. A test procedure was developed to run creep and recovery testing on one sample at Multiple Stress levels (MSCR). This test procedure makes it easy to evaluate how the binder response will change under different Stress conditions. A property called non-recoverable compliance Jnr was developed based on the non-recovered strain at the end of the recovery portion of the test divided by the initial Stress applied during the creep portion of the test. The Jnr value normalizes the strain response of the binder to Stress which clearly shows the differences between different polymer-modified binders.
Hassan A Tabatabaee - One of the best experts on this subject based on the ideXlab platform.
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Multiple Stress creep and recovery and time sweep fatigue tests
Transportation Research Record, 2010Co-Authors: Nader Tabatabaee, Hassan A TabatabaeeAbstract:Crumb rubber modification (CRM) is an effective means of improving neat asphalt performance. Numerous studies have investigated the effects of CRM using the current Superpave® laboratory tests. Recent studies have shown that the assumption of linear viscoelastic behavior or employing insufficient Stress or strain levels makes current tests inadequate for properly assessing the performance of binders, especially when modified. This problem has resulted in the development of improved test methods such as the time sweep binder fatigue test and the Multiple Stress creep and recovery (MSCR) test for permanent deformation. The present study assesses the performance of binders modified with a wide range of crumb rubber content using these newly developed test methods. Additional binder and mixture performance tests were used to compare and validate the results. The results showed that the new tests performed well in predicting performance. Current Superpave criteria also showed good conformance with mixture test...
