1,087 research outputs found
Understanding the dependence on the pulling speed of the unfolding pathway of proteins
The dependence of the unfolding pathway of proteins on the pulling speed is
investigated. This is done by introducing a simple one-dimensional chain
comprising units, with different characteristic bistable free energies.
These units represent either each of the modules in a modular protein or each
of the intermediate "unfoldons" in a protein domain, which can be either folded
or unfolded. The system is pulled by applying a force to the last unit of the
chain, and the units unravel following a preferred sequence. We show that the
unfolding sequence strongly depends on the pulling velocity . In the
simplest situation, there appears a critical pulling speed : for pulling
speeds
it is the pulled unit that unfolds first. By means of a perturbative expansion,
we find quite an accurate expression for this critical velocity.Comment: accepted for publication in JSTA
Feynman diagrams with the effective action
A derivation is given of the Feynman rules to be used in the perturbative
computation of the Green's functions of a generic quantum many-body theory when
the action which is being perturbed is not necessarily quadratic. Some
applications are discussed.Comment: Extended revised version. RevTex, 19 pages, 10 figure
Conspiracy beliefs, regulatory self-efficacy and compliance with COVID-19 health-related behaviors: The mediating role of moral disengagement
Although recent studies on the 2019 coronavirus disease (COVID-19) have highlighted the negative effects of moral disengagement on intentions to comply with COVID-19 containment measures, little is known about the mediating role of moral disengagement in the relationship between regulatory self-efficacy in complying with the containment measures, beliefs in conspiracy theories and compliance with COVID-19 health-related behaviors. Data were collected from 1164 young adults (women, N = 796; 68.4%; mean age 25.60 ± 4.40 years) who completed an online survey from 15th May to 22nd June 2021. Results of the multi-group path analyses indicated that higher beliefs in conspiracy theories were associated with lower compliance with COVID-19 health-related behaviors, whereas higher self-efficacy beliefs in complying with the containment measures were associated with higher compliance with COVID-19 health-related behaviors. Moral disengagement significantly mediated the associations between beliefs in conspiracy theories, regulatory self-efficacy, and compliance with COVID-19 health-related behaviors. Finally, the tested model was gender-invariant. Findings suggest that public health authorities and social care professionals should promote interventions aimed at improving regulatory self-efficacy, emphasizing the moral significance of respecting or ignoring the recommended COVID-19 measures (e.g., physical distance in public), and enhancing people's concern for the potential harms of their immoral actions
Sex pheromone signal and stability covary with fitness
If sexual signals are costly, covariance between signal expression and fitness is expected. Signal–fitness covariance is important, because it can contribute to the maintenance of genetic variation in signals that are under natural or sexual selection. Chemical signals, such as female sex pheromones in moths, have traditionally been assumed to be species-recognition signals, but their relationship with fitness is unclear. Here, we test whether chemical, conspecific mate finding signals covary with fitness in the moth Heliothis subflexa. Additionally, as moth signals are synthesized de novo every night, the maintenance of the signal can be costly. Therefore, we also hypothesized that fitness covaries with signal stability (i.e. lack of temporal intra-individual variation). We measured among- and within-individual variation in pheromone characteristics as well as fecundity, fertility and lifespan in two independent groups that differed in the time in between two pheromone samples. In both groups, we found fitness to be correlated with pheromone amount, composition and stability, supporting both our hypotheses. This study is, to our knowledge, the first to report a correlation between fitness and sex pheromone composition in moths, supporting evidence of condition-dependence and highlighting how signal–fitness covariance may contribute to heritable variation in chemical signals both among and within individuals
Carbon nanodots as nanocarrier for Squaraines: an in vitro evaluation of their Photodynamic activity
Modelling the unfolding pathway of biomolecules: theoretical approach and experimental prospect
We analyse the unfolding pathway of biomolecules comprising several
independent modules in pulling experiments. In a recently proposed model, a
critical velocity has been predicted, such that for pulling speeds
it is the module at the pulled end that opens first, whereas for
it is the weakest. Here, we introduce a variant of the model that is
closer to the experimental setup, and discuss the robustness of the emergence
of the critical velocity and of its dependence on the model parameters. We also
propose a possible experiment to test the theoretical predictions of the model,
which seems feasible with state-of-art molecular engineering techniques.Comment: Accepted contribution for the Springer Book "Coupled Mathematical
Models for Physical and Biological Nanoscale Systems and Their Applications"
(proceedings of the BIRS CMM16 Workshop held in Banff, Canada, August 2016),
16 pages, 6 figure
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