Exact present solution with consistent future approximation: a gridless algorithm to solve stochastic dynamic models

This paper proposes an algorithm that finds model solutions at a particular point in the state space by solving a simple system of equations. The key step is to characterize future behavior with a Taylor series expansion of the current period’s behavior around the contemporaneous values for the state variables. Since current decisions are solved from the original model equations, the solution incorporates nonlinearities and uncertainty. The algorithm is used to solve the model considered in Coeurdacier, Rey, and Winant (2011), which is a challenging model because it has no steady state and uncertainty is necessary to keep the model well behaved. We show that our algorithm can generate accurate solutions even when the model series are quite volatile. The solutions generated by the risky-steady-state algorithm proposed in Coeurdacier, Rey, and Winant (2011), in contrast, is shown to be not accurat

How does opportunistic behavior influence firm size?

This paper relates firm size and opportunism by showing that, given certain behavioral dispositions of humans, the size of a profit-maximizing firm can be determined by cognitive aspects underlying firm-internal cultural transmission processes. We argue that what firms do better than markets - besides economizing on transaction costs - is to establish a cooperative regime among its employees that keeps in check opportunism. A model depicts the outstanding role of the entrepreneur or business leader in firm-internal socialization processes and the evolution of corporate cultures. We show that high opportunism-related costs are a reason for keeping firms' size small

Volatile hiring: uncertainty in search and matching models

In search-and-matching models, the nonlinear nature of search frictions increases average unemployment rates during periods with higher volatility. These frictions are not, however, by themselves sufficient to raise unemployment following an increase in perceived uncertainty; though they may do so in conjunction with the common assumption of wages being determined by Nash bargaining. Importantly, option-value considerations play no role in the standard model with free entry. In contrast, when the mass of entrepreneurs is finite and there is heterogeneity in firm-specific productivity, a rise in perceived uncertainty robustly increases the option value of waiting and reduces job creation

Infection and the microbiome in bronchiectasis

Bronchiectasis is marked by bronchial dilatation, recurrent infections and significant morbidity, underpinned by a complex interplay between microbial dysbiosis and immune dysregulation. The identification of distinct endophenotypes have refined our understanding of its pathogenesis, including its heterogeneous disease mechanisms that influence treatment and prognosis responses. Next-generation sequencing (NGS) has revolutionised the way we view airway microbiology, allowing insights into the "unculturable". Understanding the bronchiectasis microbiome through targeted amplicon sequencing and/or shotgun metagenomics has provided key information on the interplay of the microbiome and host immunity, a central feature of disease progression. The rapid increase in translational and clinical studies in bronchiectasis now provides scope for the application of precision medicine and a better understanding of the efficacy of interventions aimed at restoring microbial balance and/or modulating immune responses. Holistic integration of these insights is driving an evolving paradigm shift in our understanding of bronchiectasis, which includes the critical role of the microbiome and its unique interplay with clinical, inflammatory, immunological and metabolic factors. Here, we review the current state of infection and the microbiome in bronchiectasis and provide views on the future directions in this field.</p

Nonlocal effects in high energy charged particle beams

Within the framework of the thermal wave model, an investigation is made of the longitudinal dynamics of high energy charged particle beams. The model includes the self-consistent interaction between the beam and its surroundings in terms of a nonlinear coupling impedance, and when resistive as well as reactive parts are included, the evolution equation becomes a generalised nonlinear Schroedinger equation including a nonlocal nonlinear term. The consequences of the resistive part on the propagation of particle bunches are examined using analytical as well as numerical methods.Comment: 6 pages, 6 figures, uses RevTeX

Temperature and concentration dependence of the electrochemical PtHg4 alloy formation for mercury decontamination

New and improved methods to remove toxic mercury from contaminated waters and waste streams are highly sought after. Recently, it was shown that electrochemical alloy formation of PtHg4 on a platinum surface with mercury ions from solution can be utilized for decontamination, with several advantages over conventional techniques. Herein, we examine the alloy formation process in more detail by mercury concentration measurements using inductively coupled plasma mass spectrometry in batch measurements as well as electrochemical quartz crystal microbalance analysis both in batch and in flowing water with initial mercury concentrations ranging from 0.25 to 75000 \ub5g L−1 Hg2+. Results show that mercury is effectively removed from all solutions and the rate of alloy formation is constant over time, as well as for very thick layers of PtHg4. The apparent activation energy for the electrochemical alloy formation was determined to be 0.29 eV, with a reaction order in mercury ion concentration around 0.8. The obtained results give new insights that are vital in the assessment and further development of electrochemical alloy formation as a method for large scale mercury decontamination

The paradox of public acceptance of bike sharing in Gothenburg

Bike sharing is one of the most promising urban planning interventions to facilitate an all-necessary transition towards a more sustainable transport paradigm. Regardless of the fact that hundreds of schemes run in more than 50 countries worldwide, bike sharing is still moderately investigated by research. This paper reports on a primarily quantitative study of 558 responses that was set to frame attitudes reflecting public acceptance towards the rapidly expanding bike-sharing scheme in Gothenburg (Styr & Ställ), in an attempt to identify the ‘formula for success’. The respondents generally believed that Styr & Ställ is a pro-environmental, inexpensive and healthy transport mode, which complements the city’s public transport services and promotes a more human-friendly identity for Gothenburg. Even the respondents that self-reported a small (or no) likelihood to use bike sharing were positive towards the scheme. This means that they recognise that bike sharing has a significant pro-social potential and is not a system favouring a particular road-user segment over others that might not be interested or able to use it. The fact that the majority of the respondents do not Bike sharing is one of the most promising urban planning interventions to facilitate an all-necessary transition towards a more sustainable transport paradigm. Regardless of the fact that hundreds of schemes run in more than 50 countries worldwide, bike sharing is still moderately investigated by research. This paper reports on a primarily quantitative study of 558 responses that was set to frame attitudes reflecting public acceptance towards the rapidly expanding bike-sharing scheme in Gothenburg (Styr & Ställ), in an attempt to identify the ‘formula for success’. The respondents generally believed that Styr & Ställ is a pro-environmental, inexpensive and healthy transport mode, which complements the city’s public transport services and promotes a more human-friendly identity for Gothenburg. Even the respondents that self-reported a small (or no) likelihood to use bike sharing were positive towards the scheme. This means that they recognise that bike sharing has a significant pro-social potential and is not a system favouring a particular road-user segment over others that might not be interested or able to use it. The fact that the majority of the respondents do not use the scheme and yet its popularity is still vast indicates that there is much potential for more use in real terms

Quantifying and controlling entanglement in the quantum magnet Cs2_2CoCl4_4

The lack of methods to experimentally detect and quantify entanglement in quantum matter impedes our ability to identify materials hosting highly entangled phases, such as quantum spin liquids. We thus investigate the feasibility of using inelastic neutron scattering (INS) to implement a model-independent measurement protocol for entanglement based on three entanglement witnesses: one-tangle, two-tangle, and quantum Fisher information (QFI). We perform high-resolution INS measurements on Cs$_2$CoCl$_4$, a close realization of the $S=1/2$ transverse-field XXZ spin chain, where we can control entanglement using the magnetic field, and compare with density-matrix renormalization group calculations for validation. The three witnesses allow us to infer entanglement properties and make deductions about the quantum state in the material. We find QFI to be a particularly robust experimental probe of entanglement, whereas the one- and two-tangles require more careful analysis. Our results lay the foundation for a general entanglement detection protocol for quantum spin systems.Comment: Main text: 7 pages, 4 figures. Supplementary Information: 15 pages, 15 figure

Streptolysin O Induces the Ubiquitination and Degradation of Pro-IL-1beta

Group A Streptococcus (GAS) is a common and versatile human pathogen causing a variety of diseases. One of the many virulence factors of GAS is the secreted pore-forming cytotoxin streptolysin O (SLO), which has been ascribed multiple properties, including inflammasome activation leading to release of the potent inflammatory cytokine IL-1beta from infected macrophages. IL-1beta is synthesized as an inactive pro-form, which is activated intracellularly through proteolytic cleavage. Here, we use a macrophage infection model to show that SLO specifically induces ubiquitination and degradation of pro-IL-1beta. Ubiquitination was dependent on SLO being released from the infecting bacterium, and pore formation by SLO was required but not sufficient for the induction of ubiquitination. Our data provide evidence for a novel SLO-mediated mechanism of immune regulation, emphasizing the importance of this pore-forming toxin in bacterial virulence and pathogenesis