A novel molybdenum iron-sulfur-containing aldehyde oxidoreductase (AOR) belonging to the xanthine oxidase family was isolated and characterized from the sulfate-reducing bacterium Desulfovibrio alaskensis NCIMB 13491, a strain isolated from a soured oil reservoir in Purdu Bay, Alaska. D. alaskensis AOR is closely related to other AORs isolated from the Desulfovibrio genus. The protein is a 97-kDa homodimer, with 0.6 +/- 0.1 Mo, 3.6 +/- 0.1 Fe and 0.9 +/- 0.1 pterin cytosine dinucleotides per monomer. The enzyme catalyses the oxidation of aldehydes to their carboxylic acid form, following simple Michaelis-Menten kinetics, with the following parameters (for benzaldehyde): K(app/m)= 6.65 microM; V app = 13.12 microM.min(-1); k(app/cat) = 0.96 s(-1). Three different EPR signals were recorded upon long reduction of the protein with excess dithionite: an almost axial signal split by hyperfine interaction with one proton associated with Mo(V) species and two rhombic signals with EPR parameters and relaxation behavior typical of [2Fe-2S] clusters termed Fe/S I and Fe/S II, respectively. EPR results reveal the existence of magnetic interactions between Mo(V) and one of the Fe/S clusters, as well as between the two Fe/S clusters. Redox titration monitored by EPR yielded midpoint redox potentials of -275 and -325 mV for the Fe/S I and Fe/S II, respectively. The redox potential gap between the two clusters is large enough to obtain differentiated populations of these paramagnetic centers. This fact, together with the observed interactions among paramagnetic centers, was used to assign the EPR-distinguishable Fe/S I and Fe/S II to those seen in the reported crystal structures of homologous enzymes.

This paper summarises the methodological approach and main results of the MARHE project (Employment and Human Resources in the Fisheries Socio-Economic System). This project had as its main aim the search for alternative futures for the fisheries sector in Portugal, with particular attention being paid to the human resources situation and the working and living conditions of the fisheries-dependent populations in the coastal areas. This is a particularly interesting case, since fisheries were once an important activity and they are now in deep recession, even though it is generally recognised that the future utilisation of maritime resources offer an immense potential. As part of the research, a Delphi exercise was implemented involving in two successive stages some of the leading actors and experts dealing with the sector in Portugal. Other initiatives were held in the context of the MARHE project providing direct and indirect inputs to the scenarios and recommendations that were put forward in the sequence of the Delphi exercise. Overall the activities described in the paper contributed to the mobilisation of major actors and to discussions that may have practical implication for the future of the sector, if certain conditions are now met in the follow up to the project.

Nitrous oxide (N(2)O) is a greenhouse gas, the third most significant contributor to global warming. As a key process for N(2)O elimination from the biosphere, N(2)O reductases catalyze the two-electron reduction of N(2)O to N(2). These 2 x 65 kDa copper enzymes are thought to contain a CuA electron entry site, similar to that of cytochrome c oxidase, and a CuZ catalytic center. The copper anomalous signal was used to solve the crystal structure of N(2)O reductase from Pseudomonas nautica by multiwavelength anomalous dispersion, to a resolution of 2.4 Angstrom. The structure reveals that the CuZ center belongs to a new type of metal cluster, in which four copper ions are liganded by seven histidine residues. N(2)O binds to this center via a single copper ion. The remaining copper ions might act as an electron reservoir, assuring a fast electron transfer and avoiding the formation of dead-end products.

This paper summarises the methodological approach and main results of the MARHE project (Employment and Human Resources in the Fisheries Socio-Economic System). This project had as its main aim the search for alternative futures for the fisheries sector in Portugal, with particular attention being paid to the human resources situation and the working and living conditions of the fisheries-dependent populations in the coastal areas. This is a particularly interesting case, since fisheries were once an important activity and they are now in deep recession, even though it is generally recognised that the future utilisation of maritime resources offer an immense potential. As part of the research, a Delphi exercise was implemented involving in two successive stages some of the leading actors and experts dealing with the sector in Portugal. Other initiatives were held in the context of the MARHE project providing direct and indirect inputs to the scenarios and recommendations that were put forward in the sequence of the Delphi exercise. Overall the activities described in the paper contributed to the mobilisation of major actors and to discussions that may have practical implication for the future of the sector, if certain conditions are now met in the follow up to the project.

Coordination/detachment of a pendent functionality in the Zn(ii) complex with a macrocyclic ligand L gives rise to on/off switching of exciplex emission, defining an elementary molecular machine whose movements are driven by both pH and light.

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One can assist to significant changes in the organisation of manufacturing systems during the last years. Lean production, network enterprise or the virtual enterprises are reference concepts of the re-organisation of manufacturing systems. Some authors mention a new enterprise paradigm, of generalisation of intelligent manufacture, organised in networks and assisted by information and communication technologies. The first part of the paper develops a critical approach to the illusion connected to these concepts, calling the attention to the diversity of the type of relationships among firms. If virtual enterprises (VE) are networks of firms with intensive usage of ICT, one can verify a predominance of a technicist perspective. This one considers that the development of VEs is a technological problem, of development and management of information systems, and of entrepreneurial share of different databases. Sociology can be useful, even fundamental in an anthropocentric approach. The last part of the paper is on the Portuguese situation in the automobile sector, approaching the types of entrepreneurial organisation.

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