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Mechanics and Single-Molecule Interrogation of DNA Recombination: Supplemental Video 8
A supplemental video from the 2016 review by Jason C. Bell and Stephen C. Kowalczykowski "Mechanics and Single-Molecule Interrogation of DNA Recombination" from the Annual Review of Biochemistry.
Supplemental Video 8 Optical trapping and manipulation of single molecules of gapped λ DNA for direct imaging of RecA filament assembly.
This video first shows 1-μm streptavidin-coated polystyrene beads flowing through Channel 1 of a multichannel microfluidic flow chamber and the subsequent isolation of two beads by a split-beam dual optical trap (Step 1). Solution flow is left to right. The beads are then transferred to Channel 2 which contains gapped λ DNA molecules comprising 8155 nucleotides of SSB-coated ssDNA flanked by 21.08 and 24.59 kbp of YOYO-1 stained dsDNA; the gapped DNA is biotinylated at each of the molecule and is captured in situ by binding to the streptavidin-coated beads (Step 2). The molecule is then transferred to a DNA-free Channel 3 where the distal end of the flow-extended molecule is captured by the other bead which is micromanipulated using a steerable mirror in line with one of the infrared laser beams (Step 3). The molecule is then rotated perpendicular to flow and imaged in buffer optimized for visualizing YOYO-1 stained dsDNA in Channel 4 (Step 4). The molecule is then transferred to Channel 5 containing Mg2+:ATPγS which accelerates YOYO-1 dissociation (Step 6). The molecule was then successively incubated in reaction buffer containing fluorescein labeled RecA Mg2+:ATPγS and either RecOR or RecFOR and imaged in Channel 5 to measure the rates of nucleation and growth (Step 7). Published with permission from Reference 110.
Mechanics and Single-Molecule Interrogation of DNA Recombination: Supplemental Video 9
A supplemental video from the 2016 review by Jason C. Bell and Stephen C. Kowalczykowski "Mechanics and Single-Molecule Interrogation of DNA Recombination" from the Annual Review of Biochemistry.
Supplemental Video 9 Composite video depicting the experimental procedure used to visualize DNA pairing on single λ DNA-dumbbell molecules by optical trapping.
A DNA pairing reaction (2 min) was performed with the 430 nt substrate at a 2 μm bead distance. Text and illustrations were inserted at appropriate places to facilitate description. A four-channel flow cell with a flow-free reservoir was used. Solution flow is top to bottom. First two 1-μm streptavidin-coated polystyrene beads are captured in dual optical traps. Next a single DNA molecule is captured on one bead. The DNA-dumbbell is made by sliding the DNA along the other bead until the biotinylated end attaches. The DNA end-to-end distance is set and the YOYO-1 dye is removed. The DNA-dumbbell is incubated with fluorescent RecA nucleoprotein filaments in the flow-free reservoir for 2 min. Afterward the DNA-dumbbell is moved to the observation channel and is extended to near contour length to image the pairing products. Published with permission from Reference 152.
Mechanics and Single-Molecule Interrogation of DNA Recombination: Supplemental Video 10
A supplemental video from the 2016 review by Jason C. Bell and Stephen C. Kowalczykowski "Mechanics and Single-Molecule Interrogation of DNA Recombination" from the Annual Review of Biochemistry.
Supplemental Video 10 Dissociation of heterologously paired RecA nucleoprotein filaments during a DNA pairing experiment.
Video performed as in Supplemental Video 9 showing RecA nucleoprotein filaments both heterologously bound and homologously bound (left and right red spots respectively) during the extension step of a pairing assay performed using the 1762 nt homologous ssDNA. As the beads are separated several loop-release events are observed involving the heterologously bound filament (left) before its dissociation from λ DNA whereas the homologously bound RecA nucleoprotein filament (right) remains stably bound. Published with permission from Reference 152.
Leading Leadership Research: A Framework for Research and Practice
David Day of The University of Western Australia Business School discusses his article "Leadership Development: An Outcome-Oriented Review Based on Time and Levels of Analyses." In this video he outlines a framework for leader development over time. Dr. Day explains that focusing research and intervention on proximal indicators like competencies and self-views helps determine longer-term outcomes such as hierarchical complexity and sophisticated sense-making matching these to the leaders’ environments.
Developing Your Leaders: Linking Short-Term Change to Long-Term Success
David Day of The University of Western Australia Business School discusses his article "Leadership Development: An Outcome-Oriented Review Based on Time and Levels of Analyses." In this video he outlines a framework for leader development over time. Dr. Day explains that focusing research and intervention on proximal indicators like competencies and self-views helps determine longer-term outcomes such as hierarchical complexity and sophisticated sense-making matching these to the leaders’ environments.
Lessons for Leadership Scholars: Where Can You Take Your Research?
What Can Leadership Development Do for Your Organization?
Lisa Dragoni of Wake Forest University discusses her article "Leadership Development: An Outcome-Oriented Review Based on Time and Levels of Analyses” which she co-wrote with David Day of the University of Western Australia Business School. In this video she reviews the research on leadership development. Dr. Dragoni outlines the conditions that support leadership development at an organizational level. These include interpersonal comfort among team members their expertise and shared mindset.
The Growing Impact of Citizen Astronomers
Marshall et al. "Ideas for Citizen Science in Astronomy"
Insect Flight: From Newton's Law to Neurons: Video 1
A video from the 2016 review by Z. Jane Wang "Insect Flight: From Newton's Law to Neurons" from the Annual Review of Condensed Matter Physics.
Shown: A model fly hovers briefly and succumbs to pitching instability. This is an example of flight instability with feedback control (1; also see Section 2).
Insect Flight: From Newton's Law to Neurons: Video 2
A video from the 2016 review by Z. Jane Wang "Insect Flight: From Newton's Law to Neurons" from the Annual Review of Condensed Matter Physics.
Shown: With a time-delayed discrete feedback control scheme the model fly can hover stably (1; also see Section 3.4).
The Role of Craving in Substance Use Disorders: Theoretical and Methodological Issues: Supplemental Video 1
A supplemental video from the 2016 review by Michael A. Sayette "The Role of Craving in Substance Use Disorders: Theoretical and Methodological Issues" from the Annual Review of Clinical Psychology.
Shear Banding of Complex Fluids: Supplemental Video 1
A video from the 2016 review by Thibaut Divoux Marc A. Fardin Sebastien Manneville and Sandra Lerouge "Shear Banding of Complex Fluids" from the Annual Review of Fluid Mechanics.
Shown: The temporal evolution of the global shear stress (left) during a shear startup experiments at a shear rate of 0.5 s−1 together with the velocity profiles (right) recorded simultaneously to the rheological data across the 1-mm gap a Taylor-Couette cell. The moving wall is located at r = 0 and the experiment is performed on a 1% w.t. Carbopol microgel.
Drop Impact on a Solid Surface: Supplemental Video 1
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: The impact of a mercury drop onto glass for similar impact conditions as Wortington’s sketch in Figure 1b. Courtesy of Erqiang Li.
Drop Impact on a Solid Surface: Supplemental Video 2
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Prompt splash during the impact of a mercury drop onto a superhydrophobized glass surface. Courtesy of Erqiang Li.
Drop Impact on a Solid Surface: Supplemental Video 3
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Corona splash of an ethanol drop impacting onto a dry glass plate. Courtesy of Erqiang Li.
Drop Impact on a Solid Surface: Supplemental Video 4
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Time-resolved interference imaging of the dimple formation and entrapment of an air disc under a water drop impacting a glass plate at low impact velocity. The view is through the bottom plate. The debt variation between a dark and bright fringe is 160 nm. Frame rate is 5 Mfps. From Li & Thoroddsen (2015).
Drop Impact on a Solid Surface: Supplemental Video 5
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Time-resolved interference imaging of the dimple formation and entrapment of an air disc under a water drop impacting a glass plate at high impact velocity. The compression of the air inside the disc is evident from the rapid expansion following the first contact. Frame rate is 5 Mfps. From Li & Thoroddsen (2015).
Drop Impact on a Solid Surface: Supplemental Video 6
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Entrapment of an air disc under a water drop impacting a glass plate. The view is through the bottom plate. The air disc contracts producing capillary waves on the free surface. These waves touch the glass at the center thereby entrapping a small microdrop inside the bubble inside the drop. Frame rate is 50 kfps. From Thoroddsen et al. (2003).
Drop Impact on a Solid Surface: Supplemental Video 7
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Prompt splash and entrapment of central air disc for impacting water drop at high velocity. Azimuthal instability is visible in the base of the ejecta. Frame rate is 500 kfps. From Thoroddsen et al. (2012).
Drop Impact on a Solid Surface: Supplemental Video 8
A supplemental video from the 2016 review by C. Josserand and S.T. Thoroddsen "Drop Impact on a Solid Surface" from the Annual Review of Fluid Mechanics.
Shown: Ejected microdroplets. The smallest and fastest droplets emerge first with progressively larger and slower droplets detaching from the front of the lamella. Frame rate is 1 Mfps. From Thoroddsen et al. (2012).