A Baseline Model of Industry Evolution

The paper analyses some general dynamic properties of industries characterized by heterogeneous firms and continuing stochastic entry. After a brief critical assessment of some significant drawbacks of recent contributions to modeling of stochastic industrial dynamics, we propose a novel analytical apparatus able to derive some generic properties of the underlying competition process combining persistent technological heterogeneity, differential growth of individual firms and turnover. The basic model, we suggest, is indeed applicable with proper modifications to a large class of evolutionary processes, well beyond industrial dynamics.Evolution, Competition, Stochastic entry, Industrial dynamics, Evolutionary games

Cycles of construing in radicalization and deradicalization: a study of Salafist Muslims.

© Taylor & Francis Group, LLC.This article explores radicalization and deradicalization by considering the experiences of six young Tunisian people who had become Salafist Muslims. Their responses to narrative interviews and repertory grid technique are considered from a personal construct perspective, revealing processes of construing and reconstruing, as well as relevant aspects of the structure and content of their construct systems. In two cases, their journeys involved not only radicalization but self-deradicalization, and their experiences are drawn on to consider implications for deradicalization.Peer reviewedFinal Accepted Versio

Technology requirements for advanced earth-orbital transportation systems, dual-mode propulsion

The application of dual-mode propulsion concepts to fully reusable single-stage-to-orbit (SSTO) vehicles is discussed. Dual-mode propulsion uses main rocket engines that consume hydrocarbon fuels as well as liquid hydrogen fuel. Liquid oxygen is used as the oxidizer. These engine concepts were integrated into transportation vehicle designs capable of vertical takeoff, delivering a payload to earth orbit, and return to earth with a horizontal landing. Benefits of these vehicles were assessed and compared with vehicles using single-mode propulsion (liquid hydrogen and oxygen engines). Technology requirements for such advanced transportation systems were identified. Figures of merit, including life-cycle cost savings and research costs, were derived for dual-mode technology programs, and were used for assessments of potential benefits of proposed technology activities. Dual-mode propulsion concepts display potential for significant cost and performance benefits when applied to SSTO vehicles

Technology requirements for advanced earth-orbital transportation systems: Summary report

Areas of advanced technology that are either critical or offer significant benefits to the development of future Earth-orbit transportation systems were identified. Technology assessment was based on the application of these technologies to fully reusable, single-state-to-orbit (SSTO) vehicle concepts with horizontal landing capability. Study guidelines included mission requirements similar to space shuttle, an operational capability beginning in 1995, and main propulsion to be advanced hydrogen-fueled rocket engines. The technical and economic feasibility of this class of SSTO concepts were evaluated as well as the comparative features of three operational take-off modes, which were vertical boost, horizontal sled launch, and horizontal take-off with subsequent inflight fueling. Projections of both normal and accelerated technology growth were made. Figures of merit were derived to provide relative rankings of technology areas. The influence of selected accelerated areas on vehicle design and program costs was analyzed by developing near-optimum point designs

From vertex detectors to inner trackers with CMOS pixel sensors

The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order of magnitude improvement on readout speed and improved radiation tolerance. This triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz 180 nm, for the design of a CPS well adapted for the new ALICE-ITS running conditions. This paper reports the R&D results for the conception of a CPS well adapted for the ALICE-ITS.Comment: 4 pages, 4 figures, VCI 2016 conference proceeding

A Salmonella virulence factor activates the NOD1/NOD2 signaling pathway.

The invasion-associated type III secretion system (T3SS-1) of Salmonella enterica serotype Typhimurium (S. Typhimurium) activates the transcription factor NF-κB in tissue culture cells and induces inflammatory responses in animal models through unknown mechanisms. Here we show that bacterial delivery or ectopic expression of SipA, a T3SS-1-translocated protein, led to the activation of the NOD1/NOD2 signaling pathway and consequent RIP2-mediated induction of NF-κB-dependent inflammatory responses. SipA-mediated activation of NOD1/NOD2 signaling was independent of bacterial invasion in vitro but required an intact T3SS-1. In the mouse colitis model, SipA triggered mucosal inflammation in wild-type mice but not in NOD1/NOD2-deficient mice. These findings implicate SipA-driven activation of the NOD1/NOD2 signaling pathway as a mechanism by which the T3SS-1 induces inflammatory responses in vitro and in vivo

Islets of Langerhans Are Protected from Inflammatory Cell Recruitment during Reperfusion of Rat Pancreas Grafts

Background: Ischemia/reperfusion (I/R) injury plays a pivotal role in the development of graft pancreatitis, with ischemia time representing one of its crucial factors. However, it is unclear, whether exocrine and endocrine tissue experience similar inflammatory responses during pancreas transplantation (PTx). This study evaluated inflammatory susceptibilities of islets of Langerhans (ILH) and exocrine tissue after different preservation periods during early reperfusion. Methods: PTx was performed in rats following 2 h (2h-I) or 18 h (18h-I) preservation. Leukocyte-endothelial cell interactions (LEI) were analyzed in venules of acinar tissue and ILH in vivo over 2 h reperfusion. Nontransplanted animals served as controls. Tissue samples were analyzed by histomorphometry. Results: In exocrine venules leukocyte rolling predominated in the 2h-I group. In the 18h-I group, additionally, high numbers of adherent leukocytes were found. Histology revealed significant edema formation and leukocyte extravasation in the 18h-I group. Notably, LEI in postcapillary venules of ILH were significantly lower. Leukocyte rolling was only moderately enhanced and few leukocytes were found adherent. Histology revealed minor leukocyte extravasation. Conclusion: Ischemia time contributes decisively to the extent of the I/R-injury in PTx. However, ILH have a significantly lower susceptibility towards I/R, even when inflammatory reactions in adjacent exocrine tissue are evident. Copyright (C) 2010 S. Karger AG, Base

L'utilisation et l'application de deux matériaux non traditionnels contrastés en remblais et en fondations de chaussées

The increased use of non-traditional materials is driven from multiple perspectives. These include societies’ desire for a more sustainable future, reinforced by legislation, regulation and policy mechanisms to encourage the greater use of such materials. This paper discusses two contrasting materials. Tyre bales are free-draining and lightweight and have been used in road foundations and embankments over soft ground as well as in slope failure repair or slope stabilisation. Electric arc furnace steel slag has been used as a direct replacement for a road embankment and a base course layer, as well as in a rail track. Experience demonstrates that such uses become widespread only when a given environmentally friendly material has a cost advantage and/or a performance benefit, and the material and its use is included in an appropriate standard or specification. It is concluded that the lack of a Quality Protocol is likely to further impede their use.Les progrès vers une utilisation accrue de matériaux non traditionnels sont motivés par un certain nombre de points de vue différents. Le premier d’entre eux est un enjeu de plus en plus important des sociétés pour un avenir plus durable; cela est souvent renforcé par des mécanismes législatifs, réglementaires et politiques de haut niveau visant à encourager une utilisation accrue de ces matériaux. Cet article traite de deux matériaux contrastés. Les balles de pneus sont drainantes et légères et ont été utilisées dans des fondations routières et dans des remblais sur les sols mous ainsi que lors des réparations et stabilisation de talus. Les scories d'aciérie de four à arc électrique ont été utilisées pour remplacer directement un remblai routier et une couche de base, ainsi que sur une voie ferrée. L'expérience montre que ces utilisations ne se généralisent que lorsqu'un matériau respectueux de l'environnement présente un avantage en termes de coûts et / ou un avantage en termes de performances, et que le matériau et son usage sont inclus dans une norme ou une spécification appropriée. Il est conclu que l’absence de protocole de qualité risque d’entraver leur utilisation.The work on tyre bales was variously supported by Veolia Environmental Trust, the Waste Resource Action Programme (WRAP), Inverness & Nairn Enterprise and Transport Scotland. The steel slag studies were financially supported by FCT vy the POCI 2010 program (Project PPCDT/ECM/56952/2004), by the cohesion found FEDER and the company doctoral grant SFRH/BDE/15661/2007