A short-period Goodwin growth cycle

Growth Theory

On the role of distribution in different theories of cyclical growth

Investment;econometrics

Knowledge Compensation in the German Automobile Industry

Knowledge is one of the most important determinants in single-industry studies of firm survival over the life cycle. Different kinds of knowledge, namely post-entry experience, pre-entry experience, and knowledge acquired by innovative activity positively influence the survival chances of firms. This paper investigates how the kinds of knowledge are able to compensate for each other. Therefore, a statistical survival analysis is performed for the German automobile industry which applies a new approach that combines the Cox regression with instrumental variable estimation. The results show that innovative activity is able to compensate for lacking post-entry experience, supporting Schumpeterian creative destruction.firm survival, patents, innovation, automobile industry, hazard rates

Performance Accuracy of Real-Time GPS Asset Tracking Systems for Timber Haulage Trucks Travelling on Both Internal Forest Road and Public Road Networks

The GPSTRACK project has arisen as a result of a recommendation in the Forest Industry Transport Group (FITG) Code of Practice for Timber Haulage, which was to “Encourage closer co-operation between consignors and hauliers to plan routes in a manner which optimizes the economic returns within a legal framework.” The project involved the installation of Bluetree global positioning systems (GPS) asset tracking systems onto two timber haulage trucks: an articulated Iveco Stralis 530 6*2 tractor unit with tri-axle road friendly air suspension flatbed trailer with a design gross vehicle weight (dgvw) equal to 44 t and a Scania 124 (400) with a rigid (3 axle) + trailer (3 axle) + crane combination with an equivalent dgvw of 44 t. This paper discusses the background and use of real-time asset tracking devices in the context of timber haulage in Ireland. Real-time location information is a relatively new concept for Irish applications (less than 5 years), but there is an increasing deployment of the technology into the truck transport sector in Ireland. The goal of this study was to test the accuracy of the recorded GPS locations relative to the underlying travelled route network based on the criteria of: 1) a fixed GPS receiver location, 2) a truck travelling on public routes, and 3) comparing accuracy of public routes to the accuracy of the truck travelling in a more demanding environment such as the internal forest road network. The results analysis calculated the horizontal root mean square (HRMS) 63 percent GPS accuracy of both trucks tracklog on both the public road network and the internal forest road network over a period of 4 weeks which totalled approximately 15,000 GPS data points. The HRMS accuracy values ranged from 2.55 to 2.47 m for the public roads, while the forest road accuracy were approximately 27 m and 41 m for Iveco and Scania, respectively

A characterization of quadratic-multiplicative mappings

In the spirit of some earlier studies of Jean Dhombres, Roman Ger and Ludwig Reich we discuss the alienation problem for quadratic and multiplicative mappings

An important step towards completing the rheumatoid arthritis cycle

In the previous issue of Arthritis Research & Therapy data are presented showing that circulating immune complexes containing citrullinated fibrin(ogen) are present in anti-citrullinated protein antibody-positive rheumatoid arthritis patients, and that such immune complexes co-localize with complement factor C3 in the rheumatoid synovium. These results corroborate the idea that citrullination is intimately involved in the pathophysiology of rheumatoid arthritis and complete our model (the rheumatoid arthritis cycle) for the development and chronic nature of this disease

Cultured cortical networks described by conditional firing probabilities

Networks of cortical neurons were grown over multi electrode arrays to enable simultaneous measu-rement of action potentials from 60 electrodes. All possible pairs of electrodes (i,j) were tested for syn-chronized activity. We calculated conditional firing probability (CFPi,j[τ]) as the probability of an action potential at electrode j at t=τ, given that a spike was detected at i at t=0. If a CFPi,j[τ] distribution clearly deviated from flat, electrodes i and j were considered related. A function was fitted to each CFP-curve to obtain parameters for strength and delay. In young cultures the set of identified relationships changed rather quickly. At 16 days in vitro (DIV) 50% of the set changed within one day. Beyond 25 DIV this set stabilized: during a period of a week more than 50% of the set remained intact. Most individual relationships developed rather gradually. Moreover, beyond 25 DIV relational strength appeared quite stable during periods of ≈ 10 hours, with coefficients of variation (100×SD/mean) of ≈ 25% on average. CFP analysis provides a robust method to describe the stable underlying probabilistic structure of highly varying spontaneous activity in cultured cortical networks. It may offer a suitable basis for plasticity studies, in which induced changes should exceed spontaneous fluctuations. CFP analysis is likely to describe the network in sufficient detail to detect subtle changes in individual relationships. Analysis of data continuously recorded for ≈ 6 weeks, showed that highest stability is reached after ≈ 25 DIV, suggesting the 4th and 5th week as a suitable period for plasticity studies.\ud \u