The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Ajith Anand - One of the best experts on this subject based on the ideXlab platform.
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Effect of Agrobacterium strain and plasmid copy number on transformation Frequency, Event quality and usable Event quality in an elite maize cultivar
Plant Cell Reports, 2015Co-Authors: Li Zhi, Susan Teronde, Sandra Meyer, Maren L. Arling, James C. Register Iii, Zuo-yu Zhao, Todd J. Jones, Ajith AnandAbstract:Key message Improving Agrobacterium -mediated transformation Frequency and Event quality by increasing binary plasmid copy number and appropriate strain selection is reported in an elite maize cultivar. Abstract Agrobacterium -mediated maize transformation is a well-established method for gene testing and for introducing useful traits in a commercial biotech product pipeline. To develop a highly efficient maize transformation system, we investigated the effect of two Agrobacterium tumefaciens strains and three different binary plasmid origins of replication (ORI) on transformation Frequency, vector backbone insertion, single copy Event Frequency (percentage of Events which are single copy for all transgenes), quality Event Frequency (percentage of single copy Events with no vector backbone insertions among all Events generated; QE) and usable Event quality Frequency (transformation Frequency times QE Frequency; UE) in an elite maize cultivar PHR03. Agrobacterium strain AGL0 gave a higher transformation Frequency, but a reduced QE Frequency than LBA4404 due to a higher number of vector backbone insertions. Higher binary plasmid copy number positively correlated with transformation Frequency and usable Event recovery. The above findings can be exploited to develop high-throughput transformation protocols, improve the quality of transgenic Events in maize and other plants.
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Effect of Agrobacterium strain and plasmid copy number on transformation Frequency, Event quality and usable Event quality in an elite maize cultivar
Plant cell reports, 2015Co-Authors: Li Zhi, Susan Teronde, Maren L. Arling, Zuo-yu Zhao, Todd J. Jones, Sandra E. Meyer, James C. Register, Ajith AnandAbstract:Key message ImprovingAgrobacterium-mediated transformation Frequency and Event quality by increasing binary plasmid copy number and appropriate strain selection is reported in an elite maize cultivar.
Eric T. Swanson - One of the best experts on this subject based on the ideXlab platform.
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let s twist again a high Frequency Event study analysis of operation twist and its implications for qe2
Brookings Papers on Economic Activity, 2011Co-Authors: Eric T. SwansonAbstract:This paper undertakes a modern Event-study analysis of Operation Twist and compares its effects to those that should be expected for the recent quantitative policy announced by the Federal Reserve, dubbed ``QE2''. We first show that Operation Twist and QE2 are similar in magnitude. We identify six significant, discrete announcements in the course of Operation Twist that potentially could have had a major effect on financial markets, and show that four did have statistically significant effects. The cumulative effect of these six announcements on longer-term Treasury yields is highly statistically significant but moderate, amounting to about 15 basis points. This estimate is consistent both with Modigliani and Sutch's (1966) time series analysis and with the lower end of empirical estimates of Treasury supply effects in the literature.
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Let's Twist Again: A High-Frequency Event-Study Analysis of Operation Twist and Its Implications for QE2
Brookings Papers on Economic Activity, 2011Co-Authors: Eric T. SwansonAbstract:This paper undertakes a modern Event-study analysis of Operation Twist and uses its estimated effects to assess what should be expected for the recent policy of quantitative easing by the Federal Reserve, dubbed “QE2.” The paper first shows that Operation Twist and QE2 are similar in magnitude. It then identifies six significant, discrete announcements in the course of Operation Twist that could have had a major effect on financial markets and shows that four did have statistically significant effects. The cumulative effect of these six announcements on longer-term Treasury yields is highly statistically significant but moderate, amounting to about 15 basis points (bp). This estimate is consistent both with time-series analysis undertaken not long after the Event and with the lower end of empirical estimates of Treasury supply effects in the literature. The effects of Operation Twist on long-term agency and corporate bond yields are also statistically significant but smaller, about 13 bp for agency securities and 2 to 4 bp for corporates. Thus, the effects of Operation Twist seem to diminish substantially as one moves from Treasury securities toward private sector credit instruments.
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Let’s twist again: a high-Frequency Event-study analysis of operation twist and its implications for QE2
Research Papers in Economics, 2011Co-Authors: Eric T. SwansonAbstract:This paper undertakes a modern Event-study analysis of Operation Twist and compares its effects to those that should be expected for the recent quantitative policy announced by the Federal Reserve, dubbed ``QE2''. We first show that Operation Twist and QE2 are similar in magnitude. We identify six significant, discrete announcements in the course of Operation Twist that potentially could have had a major effect on financial markets, and show that four did have statistically significant effects. The cumulative effect of these six announcements on longer-term Treasury yields is highly statistically significant but moderate, amounting to about 15 basis points. This estimate is consistent both with Modigliani and Sutch's (1966) time series analysis and with the lower end of empirical estimates of Treasury supply effects in the literature.
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do actions speak louder than words the response of asset prices to monetary policy actions and statements
International Journal of Central Banking, 2004Co-Authors: Refet S Gurkaynak, Brian P Sack, Eric T. SwansonAbstract:We investigate the effects of U.S. monetary policy on asset prices using a high-Frequency Event-study analysis. We test whether these effects are adequately captured by a single factor-changes in the federal funds rate target - and find that they are not. Instead, we find that two factors are required. These factors have a structural interpretation as a "current federal funds rate target" factor and a "future path of policy" factor, with the latter closely associated with Federal Open Market Committee statements.We measure the effects of these two factors on bond yields and stock prices using a new intraday data set going back to 1990. According to our estimates, both monetary policy actions and statements have important but differing effects on asset prices, with statements having a much greater impact on longer-term Treasury yields.
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do actions speak louder than words the response of asset prices to monetary policy actions and statements
Social Science Research Network, 2004Co-Authors: Refet S Gurkaynak, Brian P Sack, Eric T. SwansonAbstract:We investigate the effects of U.S. monetary policy on asset prices using a high-Frequency Event-study analysis. We test whether these effects are adequately captured by a single factor--changes in the federal funds rate target-and find that they are not. Instead, we find that two factors are required. These factors have a structural interpretation as a "current federal funds rate target" factor and a "future path of policy" factor, with the latter closely associated with FOMC statements. We measure the effects of these two factors on bond yields and stock prices using a new intraday dataset going back to 1990. According to our estimates, both monetary policy actions and statements have important but differing effects on asset prices, with statements having a much greater impact on longer-term Treasury yields.
Rejko Krüger - One of the best experts on this subject based on the ideXlab platform.
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subthalamic stimulation modulates cortical motor network activity and synchronization in parkinson s disease
Brain, 2015Co-Authors: Daniel Weiss, Rosa Klotz, Rathinaswamy B Govindan, Marlieke Scholten, Georgios Naros, Friedemann Bunjes, Christoph Meisner, Christian Plewnia, Ander Ramosmurguialday, Rejko KrügerAbstract:Dynamic modulations of large-scale network activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson’s disease. Here, we set out to address the motor network activity and synchronization in Parkinson’s disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson’s disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-Frequency Event-related spectral perturbations were assessed to determine cortical and muscular activity. Next, cross-spectra in the time-Frequency domain were analysed to explore the cortico-cortical synchronization. The time-Frequency modulations enabled us to select a time-Frequency range relevant for motor processing. On these time-Frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical activity in the upper alpha and beta range was significantly facilitated with ‘stimulation on’ compared to ‘stimulation off’ on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With ‘stimulation on’, interhemispheric cortico-cortical coherence in the beta band was significantly attenuated over the bilateral sensorimotor areas. Similarly, the global cortico-cortical phase synchronization was attenuated, and the topographic differentiation revealed stronger desynchronization over the (ipsilateral) right-hemispheric prefrontal, premotor and sensorimotor areas compared to ‘stimulation off’. We further demonstrated that the cortico-cortical phase synchronization was largely dominated by genuine neuronal coupling. The clinical improvement with ‘stimulation on’ compared to ‘stimulation off’ could be predicted from this cortical decoupling with multiple regressions, and the reduction of synchronization over the right prefrontal area showed a linear univariate correlation with clinical improvement. Our study demonstrates wide-spread activity and synchronization modulations of the cortical motor network, and highlights subthalamic stimulation as a network-modulating therapy. Accordingly, subthalamic stimulation may release bilateral cortical computational resources by facilitating movement-related desynchronization. Moreover, the subthalamic nucleus is critical to balance inhibitory and facilitatory cortical players within the motor program. * Abbreviations : MRD : movement-related desynchronization STN-DBS : subthalamic nucleus–deep brain stimulation UPDRS : Unified Parkinson’s Disease Rating Scale
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Subthalamic stimulation modulates cortical motor network activity and synchronization in Parkinson's disease.
Brain : a journal of neurology, 2015Co-Authors: Daniel Weiss, Rosa Klotz, Rathinaswamy B Govindan, Marlieke Scholten, Georgios Naros, Ander Ramos-murguialday, Friedemann Bunjes, Christoph Meisner, Christian Plewnia, Rejko KrügerAbstract:Dynamic modulations of large-scale network activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson's disease. Here, we set out to address the motor network activity and synchronization in Parkinson's disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson's disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-Frequency Event-related spectral perturbations were assessed to determine cortical and muscular activity. Next, cross-spectra in the time-Frequency domain were analysed to explore the cortico-cortical synchronization. The time-Frequency modulations enabled us to select a time-Frequency range relevant for motor processing. On these time-Frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical activity in the upper alpha and beta range was significantly facilitated with 'stimulation on' compared to 'stimulation off' on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With 'stimulation on', interhemispheric cortico-cortical coherence in the beta band was significantly attenuated over the bilateral sensorimotor areas. Similarly, the global cortico-cortical phase synchronization was attenuated, and the topographic differentiation revealed stronger desynchronization over the (ipsilateral) right-hemispheric prefrontal, premotor and sensorimotor areas compared to 'stimulation off'. We further demonstrated that the cortico-cortical phase synchronization was largely dominated by genuine neuronal coupling. The clinical improvement with 'stimulation on' compared to 'stimulation off' could be predicted from this cortical decoupling with multiple regressions, and the reduction of synchronization over the right prefrontal area showed a linear univariate correlation with clinical improvement. Our study demonstrates wide-spread activity and synchronization modulations of the cortical motor network, and highlights subthalamic stimulation as a network-modulating therapy. Accordingly, subthalamic stimulation may release bilateral cortical computational resources by facilitating movement-related desynchronization. Moreover, the subthalamic nucleus is critical to balance inhibitory and facilitatory cortical players within the motor program.
Li Zhi - One of the best experts on this subject based on the ideXlab platform.
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Effect of Agrobacterium strain and plasmid copy number on transformation Frequency, Event quality and usable Event quality in an elite maize cultivar
Plant Cell Reports, 2015Co-Authors: Li Zhi, Susan Teronde, Sandra Meyer, Maren L. Arling, James C. Register Iii, Zuo-yu Zhao, Todd J. Jones, Ajith AnandAbstract:Key message Improving Agrobacterium -mediated transformation Frequency and Event quality by increasing binary plasmid copy number and appropriate strain selection is reported in an elite maize cultivar. Abstract Agrobacterium -mediated maize transformation is a well-established method for gene testing and for introducing useful traits in a commercial biotech product pipeline. To develop a highly efficient maize transformation system, we investigated the effect of two Agrobacterium tumefaciens strains and three different binary plasmid origins of replication (ORI) on transformation Frequency, vector backbone insertion, single copy Event Frequency (percentage of Events which are single copy for all transgenes), quality Event Frequency (percentage of single copy Events with no vector backbone insertions among all Events generated; QE) and usable Event quality Frequency (transformation Frequency times QE Frequency; UE) in an elite maize cultivar PHR03. Agrobacterium strain AGL0 gave a higher transformation Frequency, but a reduced QE Frequency than LBA4404 due to a higher number of vector backbone insertions. Higher binary plasmid copy number positively correlated with transformation Frequency and usable Event recovery. The above findings can be exploited to develop high-throughput transformation protocols, improve the quality of transgenic Events in maize and other plants.
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Effect of Agrobacterium strain and plasmid copy number on transformation Frequency, Event quality and usable Event quality in an elite maize cultivar
Plant cell reports, 2015Co-Authors: Li Zhi, Susan Teronde, Maren L. Arling, Zuo-yu Zhao, Todd J. Jones, Sandra E. Meyer, James C. Register, Ajith AnandAbstract:Key message ImprovingAgrobacterium-mediated transformation Frequency and Event quality by increasing binary plasmid copy number and appropriate strain selection is reported in an elite maize cultivar.
Daniel Weiss - One of the best experts on this subject based on the ideXlab platform.
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subthalamic stimulation modulates cortical motor network activity and synchronization in parkinson s disease
Brain, 2015Co-Authors: Daniel Weiss, Rosa Klotz, Rathinaswamy B Govindan, Marlieke Scholten, Georgios Naros, Friedemann Bunjes, Christoph Meisner, Christian Plewnia, Ander Ramosmurguialday, Rejko KrügerAbstract:Dynamic modulations of large-scale network activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson’s disease. Here, we set out to address the motor network activity and synchronization in Parkinson’s disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson’s disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-Frequency Event-related spectral perturbations were assessed to determine cortical and muscular activity. Next, cross-spectra in the time-Frequency domain were analysed to explore the cortico-cortical synchronization. The time-Frequency modulations enabled us to select a time-Frequency range relevant for motor processing. On these time-Frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical activity in the upper alpha and beta range was significantly facilitated with ‘stimulation on’ compared to ‘stimulation off’ on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With ‘stimulation on’, interhemispheric cortico-cortical coherence in the beta band was significantly attenuated over the bilateral sensorimotor areas. Similarly, the global cortico-cortical phase synchronization was attenuated, and the topographic differentiation revealed stronger desynchronization over the (ipsilateral) right-hemispheric prefrontal, premotor and sensorimotor areas compared to ‘stimulation off’. We further demonstrated that the cortico-cortical phase synchronization was largely dominated by genuine neuronal coupling. The clinical improvement with ‘stimulation on’ compared to ‘stimulation off’ could be predicted from this cortical decoupling with multiple regressions, and the reduction of synchronization over the right prefrontal area showed a linear univariate correlation with clinical improvement. Our study demonstrates wide-spread activity and synchronization modulations of the cortical motor network, and highlights subthalamic stimulation as a network-modulating therapy. Accordingly, subthalamic stimulation may release bilateral cortical computational resources by facilitating movement-related desynchronization. Moreover, the subthalamic nucleus is critical to balance inhibitory and facilitatory cortical players within the motor program. * Abbreviations : MRD : movement-related desynchronization STN-DBS : subthalamic nucleus–deep brain stimulation UPDRS : Unified Parkinson’s Disease Rating Scale
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Subthalamic stimulation modulates cortical motor network activity and synchronization in Parkinson's disease.
Brain : a journal of neurology, 2015Co-Authors: Daniel Weiss, Rosa Klotz, Rathinaswamy B Govindan, Marlieke Scholten, Georgios Naros, Ander Ramos-murguialday, Friedemann Bunjes, Christoph Meisner, Christian Plewnia, Rejko KrügerAbstract:Dynamic modulations of large-scale network activity and synchronization are inherent to a broad spectrum of cognitive processes and are disturbed in neuropsychiatric conditions including Parkinson's disease. Here, we set out to address the motor network activity and synchronization in Parkinson's disease and its modulation with subthalamic stimulation. To this end, 20 patients with idiopathic Parkinson's disease with subthalamic nucleus stimulation were analysed on externally cued right hand finger movements with 1.5-s interstimulus interval. Simultaneous recordings were obtained from electromyography on antagonistic muscles (right flexor digitorum and extensor digitorum) together with 64-channel electroencephalography. Time-Frequency Event-related spectral perturbations were assessed to determine cortical and muscular activity. Next, cross-spectra in the time-Frequency domain were analysed to explore the cortico-cortical synchronization. The time-Frequency modulations enabled us to select a time-Frequency range relevant for motor processing. On these time-Frequency windows, we developed an extension of the phase synchronization index to quantify the global cortico-cortical synchronization and to obtain topographic differentiations of distinct electrode sites with respect to their contributions to the global phase synchronization index. The spectral measures were used to predict clinical and reaction time outcome using regression analysis. We found that movement-related desynchronization of cortical activity in the upper alpha and beta range was significantly facilitated with 'stimulation on' compared to 'stimulation off' on electrodes over the bilateral parietal, sensorimotor, premotor, supplementary-motor, and prefrontal areas, including the bilateral inferior prefrontal areas. These spectral modulations enabled us to predict both clinical and reaction time improvement from subthalamic stimulation. With 'stimulation on', interhemispheric cortico-cortical coherence in the beta band was significantly attenuated over the bilateral sensorimotor areas. Similarly, the global cortico-cortical phase synchronization was attenuated, and the topographic differentiation revealed stronger desynchronization over the (ipsilateral) right-hemispheric prefrontal, premotor and sensorimotor areas compared to 'stimulation off'. We further demonstrated that the cortico-cortical phase synchronization was largely dominated by genuine neuronal coupling. The clinical improvement with 'stimulation on' compared to 'stimulation off' could be predicted from this cortical decoupling with multiple regressions, and the reduction of synchronization over the right prefrontal area showed a linear univariate correlation with clinical improvement. Our study demonstrates wide-spread activity and synchronization modulations of the cortical motor network, and highlights subthalamic stimulation as a network-modulating therapy. Accordingly, subthalamic stimulation may release bilateral cortical computational resources by facilitating movement-related desynchronization. Moreover, the subthalamic nucleus is critical to balance inhibitory and facilitatory cortical players within the motor program.