676 research outputs found
Is accounting enforcement related to risk-taking in the banking industry?
Using a sample of banks from 36 countries, we document that accounting enforcement is negatively related to bank risk-taking. We also provide evidence that accounting enforcement enhances bank stability during the crisis. In addition, we show that banks assume less risk through more conservative lending decisions and a reduction in complexity in jurisdictions with higher accounting enforcement. Our results show that formal institutions such as accounting enforcement are associated with bank financial decisions and risk-taking behavior
Site-selective enzymatic chemistry for polymer conjugation to protein lysine residues: PEGylation of G-CSF at lysine-41
Microbial transglutaminase (mTGase) is an enzyme that catalyzes site-specific protein derivatization at specific glutamines and lysines
Connections between atmospheric sulphuric acid and new particle formation during QUEST III–IV campaigns in Heidelberg and Hyytiälä
This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg (2004) and Hyytiälä (2005), the first representing a polluted site surrounded by deciduous forest, and the second a rural site in a boreal forest environment. We have studied the role of sulphuric acid in particle formation and growth by determining 1) the power-law dependencies between sulphuric acid ([H2SO4]), and particle concentrations (N3−6) or formation rates at 1 nm and 3 nm (J1 and J3); 2) the time delays between [H2SO4] and N3−6 or J3, and the growth rates for 1–3 nm particles; 3) the empirical nucleation coefficients A and K in relations J1=A[H2SO4] and J1=K[H2SO4]^2, respectively; 4) theoretical predictions for J1 and J3 for the days when no significant particle formation is observed, based on the observed sulphuric acid concentrations and condensation sinks. In both environments, N3−6 or J3 and [H2SO4] were linked via a power-law relation with exponents typically ranging from 1 to 2. The result suggests that the cluster activation theory and kinetic nucleation have the potential to explain the observed particle formation. However, some differences between the sites existed: The nucleation coefficients were about an order of magnitude greater in Heidelberg than in Hyytiälä conditions. The time lags between J3 and [H2SO4] were consistently lower than the corresponding delays between N3−6 and [H2SO4]. The exponents in the J3/[H2SO4]^n_(J3)-connection were consistently higher than or equal to the exponents in the relation N3−6/[H2SO4]^n_(N36). In the J1 values, no significant differences were found between the observed rates on particle formation event days and the predictions on non-event days. The J3 values predicted by the cluster activation or kinetic nucleation hypotheses, on the other hand, were considerably lower on non-event days than the rates observed on particle formation event days. This study provides clear evidence implying that the main process limiting the observable particle formation is the competition between the growth of the freshly formed particles and their loss by scavenging, rather than the initial particle production by nucleation of sulphuric acid. In general, it can be concluded that the simple models based on sulphuric acid concentrations and particle formation by cluster activation or kinetic nucleation can predict the occurence of atmospheric particle formation and growth well, if the particle scavenging is accurately accounted for
On the commutability of homogenization and linearization in finite elasticity
We study non-convex elastic energy functionals associated to (spatially)
periodic, frame indifferent energy densities with a single non-degenerate
energy well at SO(n). Under the assumption that the energy density admits a
quadratic Taylor expansion at identity, we prove that the Gamma-limits
associated to homogenization and linearization commute. Moreover, we show that
the homogenized energy density, which is determined by a multi-cell
homogenization formula, has a quadratic Taylor expansion with a quadratic term
that is given by the homogenization of the quadratic term associated to the
linearization of the initial energy density
Connections between atmospheric sulphuric acid and new particle formation during QUEST III–IV campaigns in Heidelberg and Hyytiälä
This study investigates the connections between atmospheric sulphuric acid and new particle formation during QUEST III and BACCI/QUEST IV campaigns. The campaigns have been conducted in Heidelberg (2004) and Hyytiälä (2005), the first representing a polluted site surrounded by deciduous forest, and the second a rural site in a boreal forest environment. We have studied the role of sulphuric acid in particle formation and growth by determining 1) the power-law dependencies between sulphuric acid ([H<sub>2</sub>SO<sub>4</sub>]), and particle concentrations (<I>N</I><sub>3–6</sub>) or formation rates at 1 nm and 3 nm (<I>J</i><sub>1</sub> and <I>J</I><sub>3</sub>); 2) the time delays between [H<sub>2</sub>SO<sub>4</sub>] and <I>N</I><sub>3–6</sub> or <I>J</I><sub>3</sub>, and the growth rates for 1–3 nm particles; 3) the empirical nucleation coefficients <I>A</I> and <I>K</I> in relations <I>J</I><sub>1</sub>=<I>A</I>[H<sub>2</sub>SO<sub>4</sub>] and <I>J</I><sub>1</sub>=<I>K</I>[H<sub>2</sub>SO<sub>4</sub>]<sup>2</sup>, respectively; 4) theoretical predictions for <I>J</I><sub>1</sub> and <I>J</I><sub>3</sub> for the days when no significant particle formation is observed, based on the observed sulphuric acid concentrations and condensation sinks. In both environments, <I>N</I><sub>3–6</sub> or <I>J</I><sub>3</sub> and [H<sub>2</sub>SO<sub>4</sub>] were linked via a power-law relation with exponents typically ranging from 1 to 2. The result suggests that the cluster activation theory and kinetic nucleation have the potential to explain the observed particle formation. However, some differences between the sites existed: The nucleation coefficients were about an order of magnitude greater in Heidelberg than in Hyytiälä conditions. The time lags between <I>J</I><sub>3</sub> and [H<sub>2</sub>SO<sub>4</sub>] were consistently lower than the corresponding delays between <I>N</I><sub>3–6</sub> and [H<sub>2</sub>SO<sub>4</sub>]. The exponents in the <I>J</I><sub>3</sub>∝[H<sub>2</sub>SO<sub>4</sub> ]<sup>n<sub>J3</sub></sup>-connection were consistently higher than or equal to the exponents in the relation <I>N</I><sub>3–6</sub>∝[H<sub>2</sub>SO<sub>4</sub> ]<sup>n<sub>N36</sub></sup>. In the <I>J</I><sub>1</sub> values, no significant differences were found between the observed rates on particle formation event days and the predictions on non-event days. The <I>J</I><sub>3</sub> values predicted by the cluster activation or kinetic nucleation hypotheses, on the other hand, were considerably lower on non-event days than the rates observed on particle formation event days. This study provides clear evidence implying that the main process limiting the observable particle formation is the competition between the growth of the freshly formed particles and their loss by scavenging, rather than the initial particle production by nucleation of sulphuric acid. In general, it can be concluded that the simple models based on sulphuric acid concentrations and particle formation by cluster activation or kinetic nucleation can predict the occurence of atmospheric particle formation and growth well, if the particle scavenging is accurately accounted for
Local and global behaviour of nonlinear equations with natural growth terms
This paper concerns a study of the pointwise behaviour of positive solutions
to certain quasi-linear elliptic equations with natural growth terms, under
minimal regularity assumptions on the underlying coefficients. Our primary
results consist of optimal pointwise estimates for positive solutions of such
equations in terms of two local Wolff's potentials.Comment: In memory of Professor Nigel Kalto
A combined first and second order variational approach for image reconstruction
In this paper we study a variational problem in the space of functions of
bounded Hessian. Our model constitutes a straightforward higher-order extension
of the well known ROF functional (total variation minimisation) to which we add
a non-smooth second order regulariser. It combines convex functions of the
total variation and the total variation of the first derivatives. In what
follows, we prove existence and uniqueness of minimisers of the combined model
and present the numerical solution of the corresponding discretised problem by
employing the split Bregman method. The paper is furnished with applications of
our model to image denoising, deblurring as well as image inpainting. The
obtained numerical results are compared with results obtained from total
generalised variation (TGV), infimal convolution and Euler's elastica, three
other state of the art higher-order models. The numerical discussion confirms
that the proposed higher-order model competes with models of its kind in
avoiding the creation of undesirable artifacts and blocky-like structures in
the reconstructed images -- a known disadvantage of the ROF model -- while
being simple and efficiently numerically solvable.Comment: 34 pages, 89 figure
Analyzing Ideological Communities in Congressional Voting Networks
We here study the behavior of political party members aiming at identifying
how ideological communities are created and evolve over time in diverse
(fragmented and non-fragmented) party systems. Using public voting data of both
Brazil and the US, we propose a methodology to identify and characterize
ideological communities, their member polarization, and how such communities
evolve over time, covering a 15-year period. Our results reveal very distinct
patterns across the two case studies, in terms of both structural and dynamic
properties
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