Innovation and Firm Growth: Is R&D Worth It?

The paper contributes to an emerging literature that critically questions the degree to which R&D, at the centre of national and transnational innovation policies, results in firm growth. The differences in how innovation affects firm growth is explored for small and large publicly quoted US pharmaceutical firms between 1950 and 2008. We observe that the positive impact of R&D on firm growth is highly conditional upon a combination of firm-specific characteristics such as firm size, patenting and persistence in patenting. For small firms, R&D boosts growth for only a subset of firms: namely, those that patent persistently for a minimum of five years. For large pharmaceutical firms, on the other hand, R&D may have a negative impact on growth; potentially resulting from the low R&D productivity these firms have suffered from since the mid-1990s. These results raise important issues around the R&D and firm growth relationship for small and large firms as well the role of persistence in innovation for boosting firm performance.     

Oxidation of 1-Phenyl-3-Pyrazolidones. Decay Kinetics of the Intermediate Free Radical

The decay kinetics of the free radical produced electrochemically by monoelectronic oxidation of Phenidone has been studied by polarography, spectrophotometry and ESR spectrometry at different pH's, temperatures and reagent concentrations. The results obtained with the three techniques, together with the information of flash photolytic experiments, prove that the red-orange decaying species responsible for the cathodic polarographic wave is a primary free radical product of oxidation. The kinetic data indicate that a dismutation of the radical is the rate determining step. The preliminary results on some derivatives of Phenidone are also reported.     

Fe(lll)-enhanced sonochemical degradation of methylene blue in aqueous solution

The sonochemical degradation rate of Methylene Blue (MB) is markedly increased in the presence of Fe(Ill), a rather inexpensive reagent for the application of sonochemistry to wastewater treatment. The effect of Fe(lll) is due to a sonochemically induced Fenton reaction, where both reactants (Fe(ll) and H2O2) are sonochemically synthesized. Hydroperoxide/superoxide, generated upon sonochemical processes in aerated solution, is a key species involved in both Fe(lll) reduction to Fe(ll) and in the production of H2O2. The Fenton reaction between Fe(ll) and H2O2 then produces hydroxyl radicals, enhancing the degradation of MB. A further enhancement of the degradation of the substrate in the presence of Fe(lll) takes place upon addition of H2O2, which is likely to favor the Fenton process. Interestingly, H2O2 alone, in the absence of Fe(lll), has a very limited effect on the sonochemical degradation rate.     

Identification of domains responsible for von Willebrand factor type VI collagen interaction mediating platelet adhesion under high flow

We have identified type VI collagen (Col VI) as a primary subendothelial extracellular matrix component responsible for von Willebrand factor (vWF)-dependent platelet adhesion and aggregation under high tensile strength. Intact tetrameric Col VI was the form of the collagen found to be capable of promoting vWF-mediated platelet adhesion/aggregation under this shear condition, whereas removal of the predominant portion of the terminal globules by pepsin treatment abrogated its activity. The inability of the pepsin-digested Col VI to support any platelet interaction at high flow was because of the failure of the A3(vWF) domain to bind to this form of collagen, suggesting a stringent requirement of a tridimensional conformation or of intactness of its macromolecular structure. In contrast, the A1(vWF) domain bound to both intact and pepsin-digested Col VI tetramers but, in accordance with the cooperating function of the two vWF domains, failed to support platelet adhesion/aggregation under high shear onto Col VI by itself. The putative A1(vWF) binding site resided within the A7(VI) module (residues 413-613) of the globular amino-terminal portion of the alpha3(VI) chain. Soluble recombinant A7(VI) polypeptide strongly perturbed the vWF-mediated platelet adhesion to Col VI under high shear rates, without affecting the binding of the vWF platelet receptor glycoprotein Ibalpha to its cognate ligand A1(vWF). The findings provide evidence for a concerted action of the A1(vWF) and A3(vWF) domains in inducing platelet arrest on Col VI. This is accomplished via an interaction of the A1(vWF) domain with a site contained in the alpha3 chain A7(VI) domain and via a conformation-dependent interaction of the A3(vWF) domain with the intact tetrameric collagen. The data further emphasize that Col VI microfilaments linking the subendothelial basement membrane to the interstitial collagenous network may play a pivotal role in the hemostatic process triggered upon damage of the blood vessel wall.     

Molecular beam epitaxy and properties of GaAsBi/GaAs quantum wells grown by molecular beam epitaxy: effect of thermal annealing

We have grown GaAsBi quantum wells by molecular beam epitaxy. We have studied the properties of a 7% Bi GaAsBi quantum well and their variation with thermal annealing. High-resolution X-ray diffraction, secondary ion mass spectrometry, and transmission electron microscopy have been employed to get some insight into its structural properties. Stationary and time-resolved photoluminescence shows that the quantum well emission, peaking at 1.23 μm at room temperature, can be improved by a rapid annealing at 650°C, while the use of a higher annealing temperature leads to emission degradation and blue-shifting due to the activation of non-radiative centers and bismuth diffusion from the quantum well.     

The DataGrid Workload Management System: Challenges and Results

The workload management task of the DataGrid project was mandated to define and implement a suitable architecture for distributed scheduling and resource management in a Grid environment. The result was the design and implementation of a Grid Workload Management System, a super-scheduler with the distinguishing property of being able to take data access requirements into account when scheduling jobs to the available Grid resources. Many novel issues in various fields were faced such as resource management, resource reservation and co-allocation, Grid accounting. In this paper, the architecture and the functionality provided by the DataGrid Workload Management System are presented.     

Adaptive-randomised self-calibration of electro-mechanical shutters for space imaging

This work describes the self-calibration of a high-precision open-loop mechanism. The self-calibration method is applied to a mechanical shutter for space applications, which was launched onboard the ESA-ROSETTA mission (launch: 2 March 2004). It is based on an adaptive ‘model reference’ and a ‘randomised’ search method which may be generalised to applications in which high performance and functionality are strongly interconnected. The method makes use of an adaptive ‘model-reference’ control approach [K.J. Astrom, B. Wittenmark, On self-tuning regulators Automatica 9 (1973) 185–199 [16]; K.J. Astrom, Theory and application of adaptive control, in: Proceedings of the Eighth IFAC World Conference, Kyoto, Japan, 1981 [17]; D.E. Seborg, S.L. Shah, T.F. Edgar, Adaptive control strategies for process control, AIChE Journal 6(32) (1986) 881–895 [18]] to guarantee mechanism performance. The proposed control system comprises both a deterministic adaptive part and a random-search one [K.L. Clarkson, Applications of random sampling in computational geometry, II, in: Proceedings of the Fourth Annual ACM Symposium on Computational Geometry, 1998, pp. 1–11 [19]; P.K. Agarwal, M. Sharir, Efficient randomised algorithms for some geometric optimisation problems, Discrete Computational Geometry 16 (1996) 317–337 [15]] to guarantee shutter mechanism functionality and performance over testing lifetime (5×10⁴ cycles).     

Interval-valued soft constraint problems

Constraints and quantitative preferences, or costs, are very useful for modelling many real-life problems. However, in many settings, it is difficult to specify precise preference values, and it is much more reasonable to allow for preference intervals. We define several notions of optimal solutions for such problems, providing algorithms to find optimal solutions and also to test whether a solution is optimal. Most of the time these algorithms just require the solution of soft constraint problems, which suggests that it may be possible to handle this form of uncertainty in soft constraints without significantly increasing the computational effort needed to reason with such problems. This is supported also by experimental results. We also identify classes of problems where the same results hold if users are allowed to use multiple disjoint intervals rather than a single one.