Constraint Release for Reptating Filaments in Semiflexible Networks Depends on Background Fluctuations.

Entangled semiflexible polymer networks are usually described by the tube model, although this concept has not been able to explain all experimental observations. One of its major shortcomings is neglecting the thermal fluctuations of the polymers surrounding the examined test filament, such that disentanglement effects are not captured. In this study, we present experimental evidence that correlated constraint release which has been predicted theoretically occurs in entangled, but not in crosslinked semiflexible polymer networks.

Measuring structural parameters of crosslinked and entangled semiflexible polymer networks with single-filament tracing.

Single-filament tracing has been a valuable tool to directly determine geometrical and mechanical properties of entangled polymer networks. However, systematically verifying how the stiffness of the tracer filament or its molecular interactions with the surrounding network impacts the measurement of these parameters has not been possible with the established experimental systems. Here we use mechanically programmable DNA nanotubes embedded in crosslinked and entangled F-actin networks, as well as in synthetic DNA networks, in order to measure fundamental, structural network properties like tube width and mesh size with respect to the stiffness of the tracers.

Predicted Earnings Losses from Graduating during COVID-19.

Poor labour market conditions at the start of a worker's career can result in earnings losses for many years. The 2021 cohort of Canadian high school and post-secondary students have seen employment prospects diminish amid economic lockdowns to contain the spread of coronavirus disease 2019 (COVID-19). The goal of this article is to predict earnings losses for this cohort.

Trends in Referrals to a Pediatric Transgender Clinic.

Objectives: We characterized referral trends over time at a transgender clinic within an integrated health system in Northern California. We identified the transition-related requests of pediatric transgender and gender-nonconforming patients and evaluated differences in referrals by age group.

Methods: Medical records were analyzed for all patients <18 years of age in the Kaiser Permanente Northern California health system who were referred to a specialty transgender clinic between February 2015 and June 2018.

Glassy dynamics in composite biopolymer networks.

The cytoskeleton is a highly interconnected meshwork of strongly coupled subsystems providing mechanical stability as well as dynamic functions to cells. To elucidate the underlying biophysical principles, it is central to investigate not only one distinct functional subsystem but rather their interplay as composite biopolymeric structures. Two of the key cytoskeletal elements are actin and vimentin filaments.