The Impact of Parenthood on Labour Market Outcomes of Women and Men in Poland

Poland records one of the lowest gender wage gaps in Europe. At the same time, it is a socially conservative country where women's rights have been on the decline. We argue that, in the Polish context, the gender gap in income is a more appropriate measure of gendered labour market outcomes than the gap in the hourly wage. We analyse the gender gap in income in Poland in relation to the parenthood status, using the placebo event history method, adjusted to low resolution data, and the two waves of the Polish Generations and Gender Survey (2010, 2014). Contrary to similar studies conducted in Western Europe, our analysis uncovers a large degree of anticipatory behaviour in both women and men who expect to become parents. We show that mothers' income decreases by about 20% after birth, but converges to the income trajectory of non-mothers after 15 years. In contrast, the income of eventual fathers is higher than that of non-fathers both before and after birth, suggesting that the fatherhood child premium might be driven primarily by selection. We also demonstrate a permanent increase in hours worked for fathers, as opposed to non-fathers and a decrease in hours worked for mothers who converge to the trajectory of non-mothers after 15 years from the birth. Finally, we compare the gender gaps in income and wages of women and men in the sample with those of individuals in a counterfactual scenario where the entire population is childless. We find no statistically significant gender gaps in the counterfactual scenario, thereby concluding that the gender gaps in income and wages in Poland are driven by parenthood and most likely, by differences in labour market participation and hours worked

Stability of sedimenting flexible loops

We study the behaviour of circular flexible loops sedimenting in a viscous fluid by numerical simulations and linear stability analysis. The numerical model involves a local slender-body theory approximation for the flow coupled to the Euler-Bernoulli elastic forces for an inextensible fibre. Starting from an inclined circle, we simulate the dynamics using truncated Fourier modes to observe three distinct regimes of motion: absolute stability, two-, and three-dimensional dynamics, depending on therelative importance of elastic and gravitational forces. We identify the governing parameter and develop a simple semi-analytic stability criterion, which we verify numerically. In all cases, sedimenting loops converge to stable, planar shape equilibria with one free parameter related to the initial conditions and material properties of the fibre

DNA Supercoiling-Induced Shapes Alter Minicircle Hydrodynamic Properties

DNA in cells is organized in negatively supercoiled loops. The resulting torsional and bending strain allows DNA to adopt a surprisingly wide variety of 3-D shapes. This interplay between negative supercoiling, looping, and shape influences how DNA is stored, replicated, transcribed, repaired, and likely every other aspect of DNA activity. To understand the consequences of negative supercoiling and curvature on the hydrodynamic properties of DNA, we submitted 336 bp and 672 bp DNA minicircles to analytical ultracentrifugation (AUC). We found that the diffusion coefficient, sedimentation coefficient, and the DNA hydrodynamic radius strongly depended on circularity, loop length, and degree of negative supercoiling. Because AUC cannot ascertain shape beyond degree of non-globularity, we applied linear elasticity theory to predict DNA shapes, and combined these with hydrodynamic calculations to interpret the AUC data, with reasonable agreement between theory and experiment. These complementary approaches, together with earlier electron cryotomography data, provide a framework for understanding and predicting the effects of supercoiling on the shape and hydrodynamic properties of DNA

Narzędzia hydrodynamiki w badaniach elastycznych makromolekuł

final_authorLisicki, MaciejMaciołek, AnnaMatyka, MaciejRóżycki, Bartos

Hydrodynamic effects in the capture of rod-like molecules by a nanopore

3310Publikacja bezkosztow

Hydrodynamic effects in the capture of rod-like molecules by a nanopore

Abstract In the approach of biomolecules to a nanopore, it is essential to capture the effects of hydrodynamic anisotropy of the molecules and the near-wall hydrodynamic interactions which hinder their diffusion. We present a detailed theoretical analysis of the behaviour of a rod-like molecule attracted electrostatically by a charged nanopore. We first estimate the time scales corresponding to Brownian and electrostatic translations and reorientation. We find that Brownian motion becomes negligible at distances within the pore capture radius, and numerically determine the trajectories of the nano-rod in this region to explore the effects of anisotropic mobility. This allows us to determine the range of directions from the pore in which hydrodynamic interactions with the boundary shape the approach dynamics and need to be accounted for in detailed modelling.</jats:p

Stability of sedimenting flexible loops

Abstract </jats:p

Pychastic: Precise Brownian dynamics using Taylor-Itō integrators in Python

11Publikacja bezkosztow

Electrostatic Collapse of Intrinsically Disordered Acid-Rich Protein Is Sensitive to Counterion Valency

This dataset accompanies publication of the same title.Intrinsically disordered proteins (IDPs) respond sensitively to their ionic environment, yet the mechanisms driving ion-induced conformational changes remain incompletely understood. Here, we investigate how counterion valency modulates the dimensions of an extremely charged model IDP, the aspartic and glutamic acid-rich protein AGARP. Fluorescence correlation spectroscopy and size exclusion chromatography reveal a pronounced, valency-dependent reduction in its hydrodynamic radius, with divalent cations (Ca2&#43;, Mg2&#43;) inducing collapse at much lower activities than monovalent cations (Na&#43;, K&#43;). Molecular dynamics simulations, direct sampling, and polyampholyte theory quantitatively capture the Debye–Hückel screening by monovalent ions but not the enhanced compaction driven by divalent ion binding. Circular dichroism spectroscopy shows that compaction occurs without secondary structure formation. Our results demonstrate a structure-free electrostatic collapse and suggest that specific chelation of divalent ions by disordered polyanionic protein chains is a key mechanism regulating IDP compaction, with implications for understanding their behavior in biologically relevant ionic environments.</p