The Experts below are selected from a list of 4707 Experts worldwide ranked by ideXlab platform
Wolfgang Baumeister - One of the best experts on this subject based on the ideXlab platform.
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Using the Volta phase plate with defocus for cryo-EM single particle analysis.
eLife, 2017Co-Authors: Radostin Danev, Dimitry Tegunov, Wolfgang BaumeisterAbstract:Previously, we reported an in-focus data acquisition method for cryo-EM single-particle analysis with the Volta phase plate (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also removes the resolution limit inherent to the in-focus method thus allowing 3D reconstructions with resolutions better than 3 A.
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Using the Volta phase plate with defocus for cryo-EM single particle analysis
2016Co-Authors: Radostin Danev, Dimitry Tegunov, Wolfgang BaumeisterAbstract:Previously, we reported an in-focus data acquisition method for cryo-EM single particle analysis with the Volta phase plate (VPP) (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also enables 3D reconstructions with resolutions in the 2 A range, demonstrating that, in practice, there are no resolution limitations imposed by the VPP.
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cryo em single particle analysis with the volta phase plate
eLife, 2016Co-Authors: Radostin Danev, Wolfgang BaumeisterAbstract:One way of investigating how proteins and other biological molecules work is to look at their structure. Light microscopes cannot produce detailed enough images to fully reveal these structures, and so a technique called cryo-electron microscopy is often used instead. In this technique, a biological sample is frozen to the temperature of liquid nitrogen and a beam of electrons is fired at it to create an image. By taking many of these images and then subjecting them to computer processing it is possible to reconstruct the three-dimensional structure of the molecule. Frozen biological samples are essentially transparent to the electron beam used in an electron microscope. To view samples, researchers therefore use a method called phase contrast, which relies on a property of the electron beam (called its phase) changing as the beam passes through the sample. The traditional “defocus” method of producing phase contrast from electron microscopy relies on processing a series of slightly out-of-focus images of the sample. Phase plates are add-on devices that are commonly used in light microscopes to produce phase contrast. For many years now, attempts have been made to produce a working phase plate for electron microscopes. However, an effective plate, called the Volta phase plate, has only recently been developed. Danev and Baumeister have now evaluated how well the Volta phase plate performs during the analysis of a single, relatively large protein. This molecule is considered ‘easy’ to analyze using cryo-electron microscopy as relatively few microscopic images need to be recorded to solve the protein’s structure. Danev and Baumeister found that the Volta phase plate matched or slightly exceeded the performance of the traditional defocus method of producing phase contrast, depending on how many images were used to analyze the protein. This is the first time that a phase plate has matched the performance of the defocus method. A future challenge will be to make the experimental procedures and the software involved in using the Volta phase plate more user-friendly. The phase plate also needs to be tested with more ‘difficult’ samples, such as small proteins and samples whose structure could not be established using the defocus method of producing phase contrast.
Radostin Danev - One of the best experts on this subject based on the ideXlab platform.
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Using the Volta phase plate with defocus for cryo-EM single particle analysis.
eLife, 2017Co-Authors: Radostin Danev, Dimitry Tegunov, Wolfgang BaumeisterAbstract:Previously, we reported an in-focus data acquisition method for cryo-EM single-particle analysis with the Volta phase plate (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also removes the resolution limit inherent to the in-focus method thus allowing 3D reconstructions with resolutions better than 3 A.
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Using the Volta phase plate with defocus for cryo-EM single particle analysis
2016Co-Authors: Radostin Danev, Dimitry Tegunov, Wolfgang BaumeisterAbstract:Previously, we reported an in-focus data acquisition method for cryo-EM single particle analysis with the Volta phase plate (VPP) (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also enables 3D reconstructions with resolutions in the 2 A range, demonstrating that, in practice, there are no resolution limitations imposed by the VPP.
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cryo em single particle analysis with the volta phase plate
eLife, 2016Co-Authors: Radostin Danev, Wolfgang BaumeisterAbstract:One way of investigating how proteins and other biological molecules work is to look at their structure. Light microscopes cannot produce detailed enough images to fully reveal these structures, and so a technique called cryo-electron microscopy is often used instead. In this technique, a biological sample is frozen to the temperature of liquid nitrogen and a beam of electrons is fired at it to create an image. By taking many of these images and then subjecting them to computer processing it is possible to reconstruct the three-dimensional structure of the molecule. Frozen biological samples are essentially transparent to the electron beam used in an electron microscope. To view samples, researchers therefore use a method called phase contrast, which relies on a property of the electron beam (called its phase) changing as the beam passes through the sample. The traditional “defocus” method of producing phase contrast from electron microscopy relies on processing a series of slightly out-of-focus images of the sample. Phase plates are add-on devices that are commonly used in light microscopes to produce phase contrast. For many years now, attempts have been made to produce a working phase plate for electron microscopes. However, an effective plate, called the Volta phase plate, has only recently been developed. Danev and Baumeister have now evaluated how well the Volta phase plate performs during the analysis of a single, relatively large protein. This molecule is considered ‘easy’ to analyze using cryo-electron microscopy as relatively few microscopic images need to be recorded to solve the protein’s structure. Danev and Baumeister found that the Volta phase plate matched or slightly exceeded the performance of the traditional defocus method of producing phase contrast, depending on how many images were used to analyze the protein. This is the first time that a phase plate has matched the performance of the defocus method. A future challenge will be to make the experimental procedures and the software involved in using the Volta phase plate more user-friendly. The phase plate also needs to be tested with more ‘difficult’ samples, such as small proteins and samples whose structure could not be established using the defocus method of producing phase contrast.
Herbert W Marsh - One of the best experts on this subject based on the ideXlab platform.
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reciprocal effects between academic self concept self esteem achievement and attainment over seven adolescent years unidimensional and multidimensional perspectives of self concept
Personality and Social Psychology Bulletin, 2008Co-Authors: Herbert W Marsh, Alison J OmaraAbstract:In their influential review, Baumeister, Campbell, Krueger, and Vohs (2003) concluded that self-esteem— the global component of self-concept—has no effect on subsequent academic performance. In contrast, Marsh and Craven's (2006) review of reciprocal effects models from an explicitly multidimensional perspective demonstrated that academic self-concept and achievement are both a cause and an effect of each other. Ironically, both reviews cited classic Youth in Transition studies in support of their respective claims. In definitive tests of these counter claims, the authors reanalyze these data—including self-esteem (emphasized by Baumeister et al.), academic self-concept (emphasized by Marsh & Craven), and postsecondary educational attainment—using stronger statistical methods based on five waves of data (grade 10 through 5 years after graduation; N = 2,213). Integrating apparently discrepant findings under a common theoretical framework based on a multidimensional perspective, academic self-concept had co...
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reciprocal effects between academic self concept self esteem achievement and attainment over seven adolescent years unidimensional and multidimensional perspectives of self concept
Personality and Social Psychology Bulletin, 2008Co-Authors: Herbert W Marsh, Alison J OmaraAbstract:In their influential review, Baumeister, Campbell, Krueger, and Vohs (2003) concluded that self-esteem--the global component of self-concept--has no effect on subsequent academic performance. In contrast, Marsh and Craven's (2006) review of reciprocal effects models from an explicitly multidimensional perspective demonstrated that academic self-concept and achievement are both a cause and an effect of each other. Ironically, both reviews cited classic Youth in Transition studies in support of their respective claims. In definitive tests of these counter claims, the authors reanalyze these data-including self-esteem (emphasized by Baumeister et al.), academic self-concept (emphasized by Marsh & Craven), and postsecondary educational attainment-using stronger statistical methods based on five waves of data (grade 10 through 5 years after graduation; N=2,213). Integrating apparently discrepant findings under a common theoretical framework based on a multidimensional perspective, academic self-concept had consistent reciprocal effects with both achievement and educational attainment, whereas self-esteem had almost none.
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reciprocal effects of self concept and performance from a multidimensional perspective beyond seductive pleasure and unidimensional perspectives
Perspectives on Psychological Science, 2006Co-Authors: Herbert W Marsh, Rhonda CravenAbstract:We (Marsh & Craven, 1997) have claimed that academic self-concept and achievement are mutually reinforcing, each leading to gains in the other. Baumeister, Campbell, Krueger, and Vohs (2003) have c...
Alison J Omara - One of the best experts on this subject based on the ideXlab platform.
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reciprocal effects between academic self concept self esteem achievement and attainment over seven adolescent years unidimensional and multidimensional perspectives of self concept
Personality and Social Psychology Bulletin, 2008Co-Authors: Herbert W Marsh, Alison J OmaraAbstract:In their influential review, Baumeister, Campbell, Krueger, and Vohs (2003) concluded that self-esteem— the global component of self-concept—has no effect on subsequent academic performance. In contrast, Marsh and Craven's (2006) review of reciprocal effects models from an explicitly multidimensional perspective demonstrated that academic self-concept and achievement are both a cause and an effect of each other. Ironically, both reviews cited classic Youth in Transition studies in support of their respective claims. In definitive tests of these counter claims, the authors reanalyze these data—including self-esteem (emphasized by Baumeister et al.), academic self-concept (emphasized by Marsh & Craven), and postsecondary educational attainment—using stronger statistical methods based on five waves of data (grade 10 through 5 years after graduation; N = 2,213). Integrating apparently discrepant findings under a common theoretical framework based on a multidimensional perspective, academic self-concept had co...
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reciprocal effects between academic self concept self esteem achievement and attainment over seven adolescent years unidimensional and multidimensional perspectives of self concept
Personality and Social Psychology Bulletin, 2008Co-Authors: Herbert W Marsh, Alison J OmaraAbstract:In their influential review, Baumeister, Campbell, Krueger, and Vohs (2003) concluded that self-esteem--the global component of self-concept--has no effect on subsequent academic performance. In contrast, Marsh and Craven's (2006) review of reciprocal effects models from an explicitly multidimensional perspective demonstrated that academic self-concept and achievement are both a cause and an effect of each other. Ironically, both reviews cited classic Youth in Transition studies in support of their respective claims. In definitive tests of these counter claims, the authors reanalyze these data-including self-esteem (emphasized by Baumeister et al.), academic self-concept (emphasized by Marsh & Craven), and postsecondary educational attainment-using stronger statistical methods based on five waves of data (grade 10 through 5 years after graduation; N=2,213). Integrating apparently discrepant findings under a common theoretical framework based on a multidimensional perspective, academic self-concept had consistent reciprocal effects with both achievement and educational attainment, whereas self-esteem had almost none.
Dimitry Tegunov - One of the best experts on this subject based on the ideXlab platform.
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Using the Volta phase plate with defocus for cryo-EM single particle analysis.
eLife, 2017Co-Authors: Radostin Danev, Dimitry Tegunov, Wolfgang BaumeisterAbstract:Previously, we reported an in-focus data acquisition method for cryo-EM single-particle analysis with the Volta phase plate (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also removes the resolution limit inherent to the in-focus method thus allowing 3D reconstructions with resolutions better than 3 A.
-
Using the Volta phase plate with defocus for cryo-EM single particle analysis
2016Co-Authors: Radostin Danev, Dimitry Tegunov, Wolfgang BaumeisterAbstract:Previously, we reported an in-focus data acquisition method for cryo-EM single particle analysis with the Volta phase plate (VPP) (Danev and Baumeister, 2016). Here, we extend the technique to include a small amount of defocus which enables contrast transfer function measurement and correction. This hybrid approach simplifies the experiment and increases the data acquisition speed. It also enables 3D reconstructions with resolutions in the 2 A range, demonstrating that, in practice, there are no resolution limitations imposed by the VPP.
