STAT3 activation is a critical step in gp130-mediated terminal differentiation and growth arrest of a myeloid cell line.

Myeloid leukemia M1 cells can be induced for growth arrest and terminal differentiation into macrophages in response to interleukin 6 (IL-6) or leukemia inhibitory factor (LIF). Recently, a large number of cytokines and growth factors have been shown to activate the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. In the case of IL-6 and LIF, which share a signal transducing receptor gp130, STAT3 is specifically tyrosine-phosphorylated and activated by stimulation with each cytokine in various cell types. To know the role of JAK-STAT pathway in M1 differentiation, we have constructed dominant negative forms of STAT3 and established M1 cell lines that constitutively express them. These M1 cells that overexpressed dominant negative forms showed no induction of differentiation-associated markers including Fc gamma receptors, ferritin light chain, and lysozyme after treatment with IL-6. Expression of either c-myb or c-myc was not downregulated. Furthermore, IL-6- and LIF-mediated growth arrest and apoptosis were completely blocked. Thus these findings demonstrate that STAT3 activation is the critical step in a cascade of events that leads to terminal differentiation of M1 cells.

On the nucleation and growth of amyloid beta-protein fibrils: detection of nuclei and quantitation of rate constants.

We have studied the fibrillogenesis of synthetic amyloid beta-protein-(1-40) fragment (A beta) in 0.1 M HCl. At low pH, A beta formed fibrils at a rate amenable to detailed monitoring by quasi-elastic light-scattering spectroscopy. Examination of the fibrils with circular dichroism spectroscopy and electron microscopy showed them to be highly similar to those found in amyloid plaques. We determined the hydrodynamic radii of A beta aggregates during the entire process of fibril nucleation and growth. Above an A beta concentration of approximately 0.1 mM, the initial rate of elongation and the final size of fibrils were independent of A beta concentration. Below an A beta concentration of 0.1 mM, the initial elongation rate was proportional to the peptide concentration, and the resulting fibrils were significantly longer than those formed at higher concentration. We also found that the surfactant n-dodecylhexaoxyethylene glycol monoether (C12E6) slowed nucleation and elongation of fibrils in a concentration-dependent manner. Our observations are consistent with a model of A beta fibrillogenesis that includes the following key steps: (i) peptide micelles form above a certain critical A beta concentration, (ii) fibrils nucleate within these micelles or on heterogeneous nuclei (seeds), and (iii) fibrils grow by irreversible binding of monomers to fibril ends. Interpretation of our data enabled us to determine the sizes of fibril nuclei and A beta micelles and the rates of fibril nucleation (from micelles) and fibril elongation. Our approach provides a powerful means for the quantitative assay of A beta fibrillogenesis.

Assessment of CO2 adsorption capacity on activated carbons by a combination of batch and dynamic tests

In this work, batch and dynamic adsorption tests are coupled for an accurate evaluation of CO2 adsorption performance for three different activated carbons obtained from olives stones by chemical activation followed by physical activation with CO2 at varying times, i.e. 20, 40 and 60 h. Kinetic and thermodynamic CO2 adsorption tests from simulated flue-gas at different temperature and CO2 pressure are carried out both in batch (a manometric equipment operating with pure CO2) and dynamic (a lab-scale fixed-bed column operating with CO2/N2 mixture) conditions. The textural characterization of the activated carbon samples shows a direct dependence of both micropore and ultramicropore volume on the activation time, hence AC60 has the higher contribution. The adsorption tests conducted at 273 and 293 K showed that, when CO2 pressure is lower than 0.3 bar, the lower the activation time the higher CO2 adsorption capacity and a ranking ωeq(AC20)>ωeq(AC40)>ωeq(AC60) can be exactly defined when T= 293 K. This result can be likely ascribed to a narrower pore size distribution of the AC20 sample, whose smaller pores are more effective for CO2 capture at higher temperature and lower CO2 pressure, the latter representing operating conditions of major interest for decarbonation of a flue-gas effluent. Moreover, the experimental results obtained from dynamic tests confirm the results derived from the batch tests in terms of CO2 adsorption capacity. It is important to highlight that the adsorption of N2 on the synthesized AC samples can be considered negligible. Finally, the importance of a proper analysis of characterization data and adsorption experimental results is highlighted for a correct assessment of CO2 removal performances of activated carbons at different CO2 pressure and operating temperature.

Ventilated Stone Veneer: Mechanical Behaviour, Calculation Methodologies, Major Pathologies and Existing Tests

The increase of building pathologies related to the use of stone materials and the use of ventilated stone veneers, requires the reformulation of design concepts in building façades and also the reformulation of the architectural project. The aim of this paper is to identify, analyze and evaluate synthetically building pathologies in stone ventilated façades in order to obtain the main technical conditions to be considered in the architectural design, by interpreting its mechanical behavior and capabilities to prevent such pathologies and to ensure the proper features during the building lifetime. The methodology is based on both laboratory stone tests and in situ tests about construction systems, by analyzing physical and mechanical behavior of the outer layer in relation to other building requirements. The results imply the need of proper sizing, specific quality control and practical application of calculation methods, to control high concentration pressures in ventilated façades by reaching appropriate project solutions. In conclusion, the research about different pathologies of stone ventilated façades, the study of their mechanical behavior, their anchorage and their connection with their constructive aspects, will help to improve the construction quality of the stone ventilated façade in buildings and to enhance the use of natural stone in modern architecture.

Flexibility clauses in the Stability and Growth Pact: No need for revision. CEPS Policy Brief No. 319, 24 July 2014

This Policy Brief offers an in-depth review of the Stability and Growth Pact (SGP) and looks at whether the margins of flexibility within existing rules are sufficient in the current climate of low growth, or whether there is a need to broaden them. The issue is especially relevant as the changing economic environment is raising fresh questions about whether the EU’s current common economic policies are able to manage dismal growth and low inflation. The fragile state of confidence in financial markets and the unresolved but inevitable questions of moral hazard linked to lax fiscal policies mean that no large-scale fiscal expansion to support the recovery of economic activity is feasible. The discussion may therefore only concern the scope within the SGP to accommodate an unexpected drop in economic activity and to provide room for the implementation of structural reforms. Here, we analyse the flexibility clauses of the Stability and Growth Pact under three headings; namely “exceptional circumstances”, “structural reforms and other relevant factors”, and the “investment clause”. Recommendation: Our main conclusion is that the SGP contains sufficient flexibility to accommodate an unexpected drop in economic activity and has the margins needed to finance structural reforms during the transition to the new regime. We therefore see no need to change the existing rules of the SGP. We believe that the ongoing debate about a fresh growth strategy for the eurozone and the European Union would greatly benefit from removing from the Council table ill-formulated and unnecessary demands for greater flexibility in the SGP.

The 2005 Reform of the Stability and Growth Pact: Too Little, Too Late? Bruges European Economic Research (BEER) Papers 6/November 2006

This paper analyses the main critiques addressed by the literature and the policymakers to the 1997 Stability and Growth Pact. It further indicates to what extent the 2005 reform of the Pact meets those critics. It finally argues that the 2005 reform may be too little and arrive too late to restore the Pact credibility, ensure its enforceability and correctly set the derogations to the excessive deficit procedure on the nature of the shocks which cause the output gap rather than its size: a 3% of GDP limit on deficit spending may be a too binding constraint in front of a strongly negative demand shock, while it is irrationally large in front of a supply shock. Some empirical evidence is provided to identify in the last years strongly negative demand shocks from other shocks in the 25 EU Member States. Had this identifying method been adopted in November 2003, the European Commission and the Council would have both agreed to stop the excessive deficit procedure against Germany, but they would have both proceeded against France which apparently was not at the time hit by a strongly negative demand shock.

Do Clusters Generate Greater Innovation and Growth? An Analysis of European Regions. Bruges European Economic Research (BEER) Papers 21/October 2011

The analysis of clusters has attracted considerable interest over the last few decades. The articulation of clusters into complex networks and systems of innovation -- generally known as regional innovation systems -- has, in particular, been associated with the delivery of greater innovation and growth. However, despite the growing economic and policy relevance of clusters, little systematic research has been conducted into their association with other factors promoting innovation and economic growth. This article addresses this issue by looking at the relationship between innovation and economic growth in 152 regions of Europe during the period between 1995 and 2006. Using an econometric model with a static and a dynamic dimension, the results of the analysis highlight that: a) regional growth through innovation in Europe is fundamentally connected to the presence of an adequate socioeconomic environment and, in particular, to the existence of a well-trained and educated pool of workers; b) the presence of clusters matters for regional growth, but only in combination with a good ‘social filter’, and this association wanes in time; c) more traditional R&D variables have a weak initial connection to economic development, but this connection increases over time and, is, once again, contingent on the existence of adequate socioeconomic conditions.