The Experts below are selected from a list of 72582 Experts worldwide ranked by ideXlab platform
Allan Stensballe - One of the best experts on this subject based on the ideXlab platform.
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induction of a regulatory phenotype in cd3 cd4 hla dr t cells after allogeneic mixed lymphocyte culture indications of both contact dependent and independent activation
International Journal of Molecular Sciences, 2017Co-Authors: Anne Louise Revenfeld, Rikke Baek, Malene Jorgensen, Kim Varming, Allan StensballeAbstract:Although the observation of major histocompatibility complex II (MHCII) receptors on T cells is longstanding, the explanation for this occurrence remains enigmatic. Reports of an inducible, endogenous expression exist, as do studies demonstrating a protein acquisition from other cells by mechanisms including vesicle transfer. Irrespective of origin, the presence of the human MHCII isotype, human leukocyte antigen DR (HLA-DR), potentially identifies a regulatory T cell population. Using an allogeneic mixed lymphocyte culture (MLC) to induce an antigen-specific immune response, the role of antigen-presenting cells (APCs) for the presence of HLA-DR on cluster of differentiation 3(CD3)+ CD4+ T cells was evaluated. Moreover, a Functional phenotype was established for these T cells. It was demonstrated that APCs were essential for HLA-DR on CD3+ CD4+ T cells. Additionally, a regulatory T cell phenotype was induced in CD3+ CD4+ HLA-DR+ responder T cells with an expression of CD25, CTLA-4, CD62L, PD-1, and TNFRII. This phenotype was induced both with and without physical T cell:APC contact, which could reveal novel indications about its Functionality. To further investigate contact-independent communication, a phenotype of the small cell-derived vesicles from the MLCs was determined. Yet heterogeneous, this vesicle phenotype displayed contact-dependent differences, providing clues about their Intended Function in cellular communication.
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Induction of a Regulatory Phenotype in CD3+ CD4+ HLA-DR+ T Cells after Allogeneic Mixed Lymphocyte Culture; Indications of Both Contact-Dependent and -Independent Activation
MDPI AG, 2017Co-Authors: Anne Louise Revenfeld, Rikke Baek, Kim Varming, Malene Møller Jørgensen, Allan StensballeAbstract:Although the observation of major histocompatibility complex II (MHCII) receptors on T cells is longstanding, the explanation for this occurrence remains enigmatic. Reports of an inducible, endogenous expression exist, as do studies demonstrating a protein acquisition from other cells by mechanisms including vesicle transfer. Irrespective of origin, the presence of the human MHCII isotype, human leukocyte antigen DR (HLA-DR), potentially identifies a regulatory T cell population. Using an allogeneic mixed lymphocyte culture (MLC) to induce an antigen-specific immune response, the role of antigen-presenting cells (APCs) for the presence of HLA-DR on cluster of differentiation 3(CD3)+ CD4+ T cells was evaluated. Moreover, a Functional phenotype was established for these T cells. It was demonstrated that APCs were essential for HLA-DR on CD3+ CD4+ T cells. Additionally, a regulatory T cell phenotype was induced in CD3+ CD4+ HLA-DR+ responder T cells with an expression of CD25, CTLA-4, CD62L, PD-1, and TNFRII. This phenotype was induced both with and without physical T cell:APC contact, which could reveal novel indications about its Functionality. To further investigate contact-independent communication, a phenotype of the small cell-derived vesicles from the MLCs was determined. Yet heterogeneous, this vesicle phenotype displayed contact-dependent differences, providing clues about their Intended Function in cellular communication
R J Mahon - One of the best experts on this subject based on the ideXlab platform.
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incipient resistance of helicoverpa punctigera to the cry2ab bt toxin in bollgard ii cotton
PLOS ONE, 2010Co-Authors: Sharon Downes, Tracey Parker, R J MahonAbstract:Combinations of dissimilar insecticidal proteins (“pyramids”) within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt) transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the Intended Function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not ‘bullet proof’ and that rapid evolution to Bt toxins in the Cry2 class is possible.
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adaptive management of pest resistance by helicoverpa species noctuidae in australia to the cry2ab bt toxin in bollgard ii cotton
Evolutionary Applications, 2010Co-Authors: Sharon Downes, R J Mahon, Louise Rossiter, Greg Kauter, Tracey Leven, Gary P Fitt, G H BakerAbstract:In Australia, monitoring Helicoverpa species for resistance to the Cry2Ab toxin in second generation Bacillus thuringiensis (Bt) cotton has precisely fulfilled its Intended Function: to warn of increases in resistance frequencies that may lead to field failures of the technology. Prior to the widespread adoption of two-gene Bt cotton, the frequency of Cry2Ab resistance alleles was at least 0.001 in H. armigera and H. punctigera. In the 5 years hence, there has been a significant and apparently exponential increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. Herein we review the history of deploying and managing resistance to Bt cotton in Australia, outline the characteristics of the isolated resistance that likely impact on resistance evolution, and use a simple model to predict likely imminent resistance frequencies. We then discuss potential strategies to mitigate further increases in resistance frequencies, until the release of a third generation product. These include mandating larger structured refuges, applying insecticide to crops late in the season, and restricting the area of Bollgard II® cotton. The area planted to Bt-crops is anticipated to continue to rise worldwide; therefore the strategies being considered in Australia are likely to relate to other situations.
Jing Li - One of the best experts on this subject based on the ideXlab platform.
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design for lifecycle cost and preventive maintenance using time dependent reliability
Advanced Materials Research, 2010Co-Authors: Amandeep Singh, Zissimos P Mourelatos, Jing LiAbstract:Reliability is an important engineering requirement for consistently delivering acceptable product performance through time. As time progresses, the product may fail due to time phenomena such as time-dependent operating conditions, component degradation, etc. The degradation of reliability with time may increase the lifecycle cost due to potential warranty costs, repairs and loss of market share. In design for lifecycle cost and preventive maintenance, we must account for product quality, and time-dependent reliability. Quality is a measure of our confidence that the product conforms to specifications as it leaves the factory. Reliability depends on 1) the probability that the system will perform its Intended Function successfully for a specified interval of time, and 2) on the probability that the system response will not exceed an objectionable by the customer or operator, threshold for a certain time period. Quality is time-independent, and reliability is time-dependent. This paper presents a methodology to determine the optimal design and preventive maintenance of time-dependent, multi-response systems, by minimizing the cost during the life of the product. The lifecycle cost includes a production, an inspection, and an expected variable cost. All costs depend on quality and/or reliability. A roller clutch example highlights the design methodology for lifecycle cost.
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design for lifecycle cost using time dependent reliability
Design Automation Conference, 2009Co-Authors: Amandeep Singh, Zissimos P Mourelatos, Jing LiAbstract:Reliability is an important engineering requirement for consistently delivering acceptable product performance through time. As time progresses, the product may fail due to time phenomena such as time-dependent operating conditions, component degradation, etc. The degradation of reliability with time may increase the lifecycle cost due to potential warranty costs, repairs and loss of market share. In design for lifecycle cost, we must account for product quality, and time-dependent reliability. Quality is a measure of our confidence that the product conforms to specifications as it leaves the factory. Reliability depends on 1) the probability that the system will perform its Intended Function successfully for a specified interval of time (no hard failure), and 2) on the probability that the system response will not exceed an objectionable by the customer or operator, threshold for a certain time period (no soft failure). Quality is time-independent, and reliability is time-dependent. This article presents a design methodology to determine the optimal design of time-dependent, multi-response systems, by minimizing the cost during the life of the product. The conformance of multiple responses is treated in a series-system fashion. The lifecycle cost includes a production, an inspection, and an expected variable cost. All costs depend on quality and/or reliability. The key to our approach is the calculation of the so-called system cumulative distribution Function (time-dependent probability of failure). For that we use an equivalent time-invariant “composite” limit state which is accurate for monotonic or non-monotonic in time, systems. Examples highlight the calculation of the cumulative distribution Function and the design methodology for lifecycle cost.Copyright © 2009 by ASME
Sharon Downes - One of the best experts on this subject based on the ideXlab platform.
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incipient resistance of helicoverpa punctigera to the cry2ab bt toxin in bollgard ii cotton
PLOS ONE, 2010Co-Authors: Sharon Downes, Tracey Parker, R J MahonAbstract:Combinations of dissimilar insecticidal proteins (“pyramids”) within transgenic plants are predicted to delay the evolution of pest resistance for significantly longer than crops expressing a single transgene. Field-evolved resistance to Bacillus thuringiensis (Bt) transgenic crops has been reported for first generation, single-toxin varieties and the Cry1 class of proteins. Our five year data set shows a significant exponential increase in the frequency of alleles conferring Cry2Ab resistance in Australian field populations of Helicoverpa punctigera since the adoption of a second generation, two-toxin Bt cotton expressing this insecticidal protein. Furthermore, the frequency of cry2Ab resistance alleles in populations from cropping areas is 8-fold higher than that found for populations from non-cropping regions. This report of field evolved resistance to a protein in a dual-toxin Bt-crop has precisely fulfilled the Intended Function of monitoring for resistance; namely, to provide an early warning of increases in frequencies that may lead to potential failures of the transgenic technology. Furthermore, it demonstrates that pyramids are not ‘bullet proof’ and that rapid evolution to Bt toxins in the Cry2 class is possible.
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adaptive management of pest resistance by helicoverpa species noctuidae in australia to the cry2ab bt toxin in bollgard ii cotton
Evolutionary Applications, 2010Co-Authors: Sharon Downes, R J Mahon, Louise Rossiter, Greg Kauter, Tracey Leven, Gary P Fitt, G H BakerAbstract:In Australia, monitoring Helicoverpa species for resistance to the Cry2Ab toxin in second generation Bacillus thuringiensis (Bt) cotton has precisely fulfilled its Intended Function: to warn of increases in resistance frequencies that may lead to field failures of the technology. Prior to the widespread adoption of two-gene Bt cotton, the frequency of Cry2Ab resistance alleles was at least 0.001 in H. armigera and H. punctigera. In the 5 years hence, there has been a significant and apparently exponential increase in the frequency of alleles conferring Cry2Ab resistance in field populations of H. punctigera. Herein we review the history of deploying and managing resistance to Bt cotton in Australia, outline the characteristics of the isolated resistance that likely impact on resistance evolution, and use a simple model to predict likely imminent resistance frequencies. We then discuss potential strategies to mitigate further increases in resistance frequencies, until the release of a third generation product. These include mandating larger structured refuges, applying insecticide to crops late in the season, and restricting the area of Bollgard II® cotton. The area planted to Bt-crops is anticipated to continue to rise worldwide; therefore the strategies being considered in Australia are likely to relate to other situations.
Anne Louise Revenfeld - One of the best experts on this subject based on the ideXlab platform.
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induction of a regulatory phenotype in cd3 cd4 hla dr t cells after allogeneic mixed lymphocyte culture indications of both contact dependent and independent activation
International Journal of Molecular Sciences, 2017Co-Authors: Anne Louise Revenfeld, Rikke Baek, Malene Jorgensen, Kim Varming, Allan StensballeAbstract:Although the observation of major histocompatibility complex II (MHCII) receptors on T cells is longstanding, the explanation for this occurrence remains enigmatic. Reports of an inducible, endogenous expression exist, as do studies demonstrating a protein acquisition from other cells by mechanisms including vesicle transfer. Irrespective of origin, the presence of the human MHCII isotype, human leukocyte antigen DR (HLA-DR), potentially identifies a regulatory T cell population. Using an allogeneic mixed lymphocyte culture (MLC) to induce an antigen-specific immune response, the role of antigen-presenting cells (APCs) for the presence of HLA-DR on cluster of differentiation 3(CD3)+ CD4+ T cells was evaluated. Moreover, a Functional phenotype was established for these T cells. It was demonstrated that APCs were essential for HLA-DR on CD3+ CD4+ T cells. Additionally, a regulatory T cell phenotype was induced in CD3+ CD4+ HLA-DR+ responder T cells with an expression of CD25, CTLA-4, CD62L, PD-1, and TNFRII. This phenotype was induced both with and without physical T cell:APC contact, which could reveal novel indications about its Functionality. To further investigate contact-independent communication, a phenotype of the small cell-derived vesicles from the MLCs was determined. Yet heterogeneous, this vesicle phenotype displayed contact-dependent differences, providing clues about their Intended Function in cellular communication.
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Induction of a Regulatory Phenotype in CD3+ CD4+ HLA-DR+ T Cells after Allogeneic Mixed Lymphocyte Culture; Indications of Both Contact-Dependent and -Independent Activation
MDPI AG, 2017Co-Authors: Anne Louise Revenfeld, Rikke Baek, Kim Varming, Malene Møller Jørgensen, Allan StensballeAbstract:Although the observation of major histocompatibility complex II (MHCII) receptors on T cells is longstanding, the explanation for this occurrence remains enigmatic. Reports of an inducible, endogenous expression exist, as do studies demonstrating a protein acquisition from other cells by mechanisms including vesicle transfer. Irrespective of origin, the presence of the human MHCII isotype, human leukocyte antigen DR (HLA-DR), potentially identifies a regulatory T cell population. Using an allogeneic mixed lymphocyte culture (MLC) to induce an antigen-specific immune response, the role of antigen-presenting cells (APCs) for the presence of HLA-DR on cluster of differentiation 3(CD3)+ CD4+ T cells was evaluated. Moreover, a Functional phenotype was established for these T cells. It was demonstrated that APCs were essential for HLA-DR on CD3+ CD4+ T cells. Additionally, a regulatory T cell phenotype was induced in CD3+ CD4+ HLA-DR+ responder T cells with an expression of CD25, CTLA-4, CD62L, PD-1, and TNFRII. This phenotype was induced both with and without physical T cell:APC contact, which could reveal novel indications about its Functionality. To further investigate contact-independent communication, a phenotype of the small cell-derived vesicles from the MLCs was determined. Yet heterogeneous, this vesicle phenotype displayed contact-dependent differences, providing clues about their Intended Function in cellular communication