Search results for "Dynamics"
showing 10 items of 9782 documents
Information Transfer in Linear Multivariate Processes Assessed through Penalized Regression Techniques: Validation and Application to Physiological N…
2020
The framework of information dynamics allows the dissection of the information processed in a network of multiple interacting dynamical systems into meaningful elements of computation that quantify the information generated in a target system, stored in it, transferred to it from one or more source systems, and modified in a synergistic or redundant way. The concepts of information transfer and modification have been recently formulated in the context of linear parametric modeling of vector stochastic processes, linking them to the notion of Granger causality and providing efficient tools for their computation based on the state&ndash
Questions and controversies in the study of time-varying functional connectivity in resting fMRI.
2020
The brain is a complex, multiscale dynamical system composed of many interacting regions. Knowledge of the spatiotemporal organization of these interactions is critical for establishing a solid understanding of the brain’s functional architecture and the relationship between neural dynamics and cognition in health and disease. The possibility of studying these dynamics through careful analysis of neuroimaging data has catalyzed substantial interest in methods that estimate time-resolved fluctuations in functional connectivity (often referred to as “dynamic” or time-varying functional connectivity; TVFC). At the same time, debates have emerged regarding the application of TVFC analyses to re…
Methionine in a protein hydrophobic core drives tight interactions required for assembly of spider silk
2019
Web spiders connect silk proteins, so-called spidroins, into fibers of extraordinary toughness. The spidroin N-terminal domain (NTD) plays a pivotal role in this process: it polymerizes spidroins through a complex mechanism of dimerization. Here we analyze sequences of spidroin NTDs and find an unusually high content of the amino acid methionine. We simultaneously mutate all methionines present in the hydrophobic core of a spidroin NTD from a nursery web spider’s dragline silk to leucine. The mutated NTD is strongly stabilized and folds at the theoretical speed limit. The structure of the mutant is preserved, yet its ability to dimerize is substantially impaired. We find that side chains of…
Computational methods and theory for ion channel research
2022
Ion channels are fundamental biological devices that act as gates in order to ensure selective ion transport across cellular membranes; their operation constitutes the molecular mechanism through which basic biological functions, such as nerve signal transmission and muscle contraction, are carried out. Here, we review recent results in the field of computational research on ion channels, covering theoretical advances, state-of-the-art simulation approaches, and frontline modeling techniques. We also report on few selected applications of continuum and atomistic methods to characterize the mechanisms of permeation, selectivity, and gating in biological and model channels.
Towards an efficient meshfree solver
2016
In this paper we focus on the enhancement in accuracy approximating a function and its derivatives via smoothed particle hydrodynamics. We discuss about improvements in the solution by reformulating the original method by means of the Taylor series expansion and by projecting with the kernel function and its derivatives. The accuracy of a function and its derivatives, up to a fixed order, can be simultaneously improved by assuming them as unknowns of a linear system. The improved formulation has been assessed with gridded and scattered data points distribution and the convergence has been analyzed referring to a case study in a 2D domain.
Current Accounts and Coordination of Wage Bargaining
2018
This study provides novel evidence on the impact of labor market institutions on current account dynamics. Our results suggest that a high degree of coordination of wage bargaining has a positive effect on the current account balance over the long run. This result is not driven entirely by wage moderation induced by centralized wage setting. We also provide robust evidence that a high degree of coordination of wage bargaining is associated with a slower current account adjustment toward its long-run equilibrium. This result seems theoretically plausible; the aggregate shocks in the exporting sector are largely driven by idiosyncratic shocks and the presence of idiosyncratic shocks increases…
Essays on current account imbalances
2017
Global current account imbalances and intra-euro area imbalances have been at the forefront of academic and policy debates for the last ten years. This thesis examines the determinants of current account balances and external adjustment. It consists of an introduction and four empirical studies. This thesis highlights the importance of institutional factors such as differences in national cultures and cross-country differences in the coordination of wage bargaining on external balances. The first study investigates the effects of deep determinants on current account balances. The point estimates are economically and statistically significant, suggesting that countries populated by Roman Cat…
Constraining the pass-band of future space-based coronagraphs for observations of solar eruptions in the FeXIV 530.3 nm “green line”
2017
This research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 647214) and from the UK Science and Technology Facilities Council. Observations of the solar corona in the FeXIV 530.3 nm “green line” have been very important in the past, and are planned for future coronagraphs on-board forthcoming space missions such as PROBA-3 and Aditya. For these instruments, a very important parameter to be optimized is the spectral width of the band-pass filter to be centred over the “green line”. Focusing on solar eruptions, motions occurring along the line of sight will Doppler shift the line prof…
The effective cross section for double parton scattering within a holographic AdS/QCD approach
2017
A first attempt to apply the AdS/QCD framework for a bottom-up approach to the evaluation of the effective cross section for double parton scattering in proton-proton collisions is presented. The main goal is the analytic evaluation of the dependence of the effective cross section on the longitudinal momenta of the involved partons, obtained within the holographic Soft-Wall model. If measured in high-energy processes at hadron colliders, this momentum dependence could open a new window on 2-parton correlations in a proton.
A dynamic simulation approach to frame drivers and implications of corruption practices on firm performance
2014
Corruption is a multifaceted socio-economic phenomenon widely spread - although with different intensity - all around the world. Many studies on corruption have been conducted at a country-level, but relatively little effort has been placed in evaluating its implications, in terms of both financial and competitive performance, at a firm-level. Therefore, this paper aims at exploring the causal relationships underlying the effect of corruption on firm performance in order to show the different scenarios that may emerge from the combination between external (i.e., contextual conditions) and internal (i.e., organizational characteristics) forces that drive corruption. To this end, we adopt a D…