We present a single-cell motility assay, which allows the quantification of bacterial swimming in a well-controlled environment, for durations of up to an hour and with a temporal resolution greater than the flagellar rotation rates of ∼100 Hz. The assay is based on an instrument combining optical tweezers, light and fluorescence microscopy, and a microfluidic chamber. Using this device we characterized the long-term statistics of the run-tumble time series in individual Escherichia coli cells. We also quantified higher-order features of bacterial swimming, such as changes in velocity and reversals of swimming direction.

http://absimage.aps.org/image/MAR10/MWS_MAR10-2009-001016.pdf

High-resolution, long-term characterization of bacterial motility using optical tweezers

FUS and TDP-43 Phases in Health and Disease.

Combating deleterious phase transitions in neurodegenerative disease.

Sequence Determinants of the Aggregation of Proteins Within Condensates Generated by Liquid-liquid Phase Separation.

Cellular matter can be spatially and temporally organized into membraneless biomolecular condensates. The current thinking is that these condensates form and dissolve via phase transitions driven by one or more condensate-specific multivalent macromolecules known as scaffolds. Cells likely regulate condensate formation and dissolution by exerting control over the concentrations of regulatory molecules, which we refer to as ligands. Wyman and Gill introduced the framework of polyphasic linkage to explain how ligands can exert thermodynamic control over phase transitions. This review focuses on describing the concepts of polyphasic linkage and the relevance of such a mechanism for controlling condensate formation and dissolution. We describe how ligand-mediated control over scaffold phase behavior can be quantified experimentally. Further, we build on recent studies to highlight features of ligands that make them suppressors vs drivers of phase separation. Finally, we highlight areas where advances are needed to further understand ligand-mediated control of condensates in complex cellular environments. These advances include understanding the effects of networks of ligands on condensate behavior and how ligands modulate phase transitions controlled by different combinations of homotypic and heterotypic interactions among scaffold macromolecules. Insights gained from the application of polyphasic linkage concepts should be useful for designing novel pharmaceutical ligands to regulate condensates.

/pdf/polyphasic-linkage-and-the-impact-of-ligand-binding-on-the-12v9s1qinb.pdf

Polyphasic linkage and the impact of ligand binding on the regulation of biomolecular condensates.

ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS.

Erratum: ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS (Molecular Cell (2020) 80(4) (666–681.e8), (S1097276520307218), (10.1016/j.molcel.2020.10.014))

After decades of sound performance, doubts have been raised on the ability of the equity value factor to continue to deliver a positive performance in the aftermath of the 2008 Global Financial Crisis. Indeed, in a context dominated by low yields, sluggish growth and subdued inflation combined with an accelerating digitalization of the economy, the performance of value strategies struggled over the past decade. In this paper, we investigate potential drivers behind this performance lag, such as macroeconomic and microeconomic determinants, ESG characteristics or credit-borrowed components. Based on European and American data, we find that inflation and tightening credit spread levels are the most supportive factors for value stocks. As far as interest rates are concerned, their sustained low levels prevented the value stock universe from clearing its most distressed issuers, also known as "deep value", and thus dampened value performance. As a matter of fact, we show that value has not been systematically an investment strategy bearing a heightened default risk. Our ESG analysis corroborates the "transatlantic divide", the historical gap between the U.S. and Europe on this front, and shows that value and growth stocks are not necessarily all brown and green stocks. In addition, we demonstrate that the small cap segment has not been the magical cure to value underperformance. Finally, we conclude that value is not dead yet, and might even have bright days ahead considering the current improvements in market sentiment, especially if inflation does materialize. Nevertheless, we also emphasize that the current value risk factor is probably different in nature from the one we observed during the golden age of value investing at the beginning of the 2000s. Indeed, trading facilities, ease of access to fundamental data for a large number of investors, ESG investing and the digitalization of the economy may have changed the rules of the game.

Christian Lopez

Papers

ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS.

Erratum: ALS/FTLD-Linked Mutations in FUS Glycine Residues Cause Accelerated Gelation and Reduced Interactions with Wild-Type FUS (Molecular Cell (2020) 80(4) (666–681.e8), (S1097276520307218), (10.1016/j.molcel.2020.10.014))

Understanding the Performance of the Equity Value Factor