The biological relevance of molybdenum was demonstrated in the early 1950s-1960s, by Bray, Beinert, Lowe, Massey, Palmer, Ehrenberg, Pettersson, Vänngård, Hanson and others, with ground-breaking studies performed, precisely, by electron paramagnetic resonance (EPR) spectroscopy. Those earlier studies, aimed to investigate the mammalian xanthine oxidase and avian sulfite oxidase enzymes, demonstrated the surprising biological reduction of molybdenum to the paramagnetic Mo⁵⁺. Since then, EPR spectroscopy, alongside with other spectroscopic methods and X-ray crystallography, has contributed to our present detailed knowledge about the active site structures, catalytic mechanisms and structure/activity relationships of the molybdenum-containing enzymes.
This Chapter will provide a perspective on the contribution that EPR spectroscopy has made to some selected systems. After a brief overview on molybdoenzymes, the Chapter will be focused on the EPR studies of mammalian xanthine oxidase, with a brief account on the prokaryotic aldehyde oxidoreductase, nicotinate dehydrogenase and carbon monoxide dehydrogenase, vertebrate sulfite oxidase, and prokaryotic formate dehydrogenases and nitrate reductases.

http://docentes.fct.unl.pt/lblm/files/epr_book-chap_4.pdf

Apesar da escrita ter, habitualmente, uma maior expressão no ensino da Matemática que a própria oralidade, os alunos não estão habituados a explicitar raciocínios e a utilizar linguagem matemática apropriada. A comunicação matemática escrita tem algumas particularidades que podem ser diretamente trabalhadas com os alunos. Por exemplo, a escrita ajuda os alunos a dar sentido à Matemática e a melhorar o próprio discurso. As produções dos alunos transportam informações para o professor contribuindo para a planificação e concretização da sua prática profissional. Assim, e apesar de frequentemente ser descurada, a escrita matemática pode ser trabalhada na sala de aula, em particular, com futuros professores. Este artigo reporta parte de uma experiência realizada com uma turma da Licenciatura em Educação Básica, tendo por base a resolução em grupo de um problema de Geometria e o registo escrito do processo de resolução elaborado pelos alunos. Pretendeu-se desta forma caraterizar a comunicação escrita dos alunos e identificar contributos desta para a compreensão por parte do professor dos conhecimentos dos alunos. A análise da escrita matemática dos alunos, tendo por base um conjunto de critérios previamente definidos, permitiu identificar a preferência destes pelo recurso à representação verbal, dificuldades em fundamentar adequadamente as respostas apresentadas e uma forte tendência para desvalorizar as abordagens prévias que não conduziram à resposta ao problema. Permitiu ainda identificar uma tendência para não explicitar o entendimento das questões que lhes eram colocadas. A forma como os conceitos matemáticos surgem nas repostas escritas permite identificar aspetos relevantes do conhecimento dos alunos.

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The last decades have shown an increasing amount of research into expectations of science and technology. Especially for emerging technologies, expectations held by different stakeholder are guiding the direction of research and development. In this article the results of an investigation into the expectations of specific actors regarding the development of emerging battery technology for applications in the power grid are presented. It is set up as an explorative study within the framework of Constructive Technology Assessment (CTA). A number of studies since the 1990s have indicated a growing need for energy storage options in the power grid, where batteries appear to be capable of providing a range of valuable services to the grid. Cost-effectiveness on a large scale will however require considerable technical improvements. The configuration of energy storage may differ in the specific location and exploitation of the storage assets, as well as in the investments in new storage capacity. In this study the visions and expectations of several relevant actors are analysed using interviews and surveys in terms of expectations of technological development, expectations concerning stakeholder roles, and channels of interaction between the relevant actors. The results indicate a divide in expectations between the user side of the technology (the electric power industry) and the development side (academic researchers). Opinions differ with respect to the obstacles to technological development, the actors relevant in early technological development, and the most suitable channels for interaction between these actors. It follows from the theoretical background that conflicts in expectations provide the opportunity for the acceleration of technological development and adoption through stakeholder participation. Small interactive workshops, where conflicts identified in this paper are discussed, were identified as a suitable channel in order to reach consensus in visions and expectations for battery technology.

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http://docentes.fct.unl.pt/lblm/files/jiengchem-2017-54-341.pdf

Die Ausweitung von Robotertechnologien nicht nur in der Industrie, sondern zunehmend auch in Dienstleistungsbereiche, stellt große Herausforderungen an die Mensch-Roboter-Kollaboration. Der Artikel beleuchtet psychologische, soziologische, arbeitswissenschaftliche und berufspädagogische Gesichtspunkte bei der Gestaltung und dem Einsatz von Robotern in Produktion und Service. Zu diesem Zweck werden zunächst spezifische Merkmale der Mensch-Roboter-Interaktion dargestellt, um anschließend Prinzipien der Funktionsteilung zwischen Menschen und Robotern in Arbeitssystemen des Produktions- und Servicebereichs zu diskutieren. Zu berücksichtigen sind hier die Organisation gesellschaftlicher Arbeit, die spezifischen Arbeitsaufgaben sowie die Möglichkeiten und Grenzen der informationstechnischen Realisierung solcher Aufgaben. Der Artikel endet mit dem Plädoyer, bei der Entwicklung und Anwendung von Robotern arbeitswissenschaftliche Kriterien mit Ansätzen partizipativer Technikgestaltung zu kombinieren.

http://docentes.fct.unl.pt/lblm/files/inorgchem-2017-56-8900.pdf

In this paper an interoperability solution is proposed, aiming to go from (building) construction models to energy simulation. Moreover, the energy simulation results will feed the KPI’s analysis of a designed building. The proposed solution will be used to translate different data formats allowing the communication between different systems in an automated environment. The solution presented in this paper exploits the concept of Plug’n’Interoperate (PnI), that is supported by the principle of self-configuration as to automate, as much as possible, the configuration and participation of systems into a shared interoperability environment. In order to validate this approach two different scenarios were taken into account, translating from a CAD (Computer- Aided Design) model data format to an energy simulation data format.

The nitric oxide radical ˙NO (NO) is a signalling molecule involved in several physiological processes in humans, including vasodilation, immune response, neurotransmission, platelet aggregation, apoptosis and gene expression. Undue normal conditions, NO synthases catalyse the formation of NO from l-arginine and dioxygen. Yet, upon a hypoxic event, when the decreased dioxygen concentration compromises NO synthase activity, cells can generate NO from another source: nitrite. Since the late 1990s, it has become clear that nitrite can be reduced back to NO under hypoxic/anoxic conditions. Simultaneously, it was realised that nitrite can exert a significant cytoprotective action in vivo during ischaemia and other pathological conditions. Presently, blood and tissue nitrite are recognised as NO “storage forms” that can be made available in order to maintain NO formation and ensure cell signalling and survival under challenging conditions. To reduce nitrite to NO, human cells can use different metalloproteins that are present in cells for carrying out other functions, including several haemic proteins and molybdoenzymes, forming what we refer to as “non-dedicated nitrite reductases”. In this chapter, two non-dedicated nitrite reductases—xanthine oxidase and myoglobin—will be described, and the human nitrate/nitrite/NO signalling pathway will be discussed within the cellular context and the nitrogen cycle scenario.

http://docentes.fct.unl.pt/lblm/files/rsc_book-denitrification-2017-chap_17.pdf

Molybdenum is essential to most organisms, being found in the active site of enzymes that catalyze redox reactions involving carbon, nitrogen and sulfur atoms of key metabolites. Some of the molybdenum-dependent reactions constitute key steps in the global biogeochemical cycles of carbon, nitrogen and sulfur, with particular emphasis on the atmospheric dinitrogen fixation into ammonium. Presently, more than 50 molybdoenzymes are known. The great majority are prokaryotic, with eukaryotes holding only a restricted number of molybdoenzymes. Tungsten, probably because of its limited bioavailability, is less used, being found most often in anaerobic thermophilic prokaryotes.

This chapter provides an overview on the molybdo- and tungstoenzymes.
Their physiological context and significance will be described in Section 1.2,where the recent hypothesis that the lack of molybdenum could have been the limiting factor for the life evolution and expansion on early Earth will receive special attention (Section 1.2.1). A brief introduction to the chemical properties that shape the catalytically competent molybdenum/tungsten centres will be made in Section 1.3. In Section 1.4, the enzymes will be grouped in five main families (Sections 1.4.1 to 1.4.5), according to their metal/cofactor structure, and a general view on the structural (section (a)) and mechanistic (section (b)) versatility of each family will be presented. A brief account of novel heteronuclear centres containing molybdenum, whose physiological function is not yet fully understood, will be made in Section 1.4.6. A final outlook on our present knowledge about these enzymes will conclude this chapter.

http://docentes.fct.unl.pt/lblm/files/mo_w_enzymes-rsc_book-chap_1.pdf

http://docentes.fct.unl.pt/lblm/files/ica-2017-455-350.pdf

A new stem cheloniid turtle, Cabindachelys landanensis, gen. et sp. nov., is represented by a nearly complete skull and partial hyoid collected in lower Paleocene shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda, Angola. A partial chelonioid carapace previously reported from this locality is referred here to C. landanensis. Cabindachelys landanensis possesses clear synapomorphies of Pan-Cheloniidae, including a rod-like rostrum basisphenoidale, V-shaped basisphenoid crest, and secondary palate, but also retains a reduced foramen palatinum posterius, unlike most other pan-cheloniids. Phylogenetic analysis suggests that C. landanensis forms a weakly-supported clade with Erquelinnesia gosseleti, Euclastes acutirostris, Euclastes wielandi and Terlinguachelys fischbecki, although a close relationship between the protostegid T. fischbecki and these durophagous pan-cheloniids is unlikely. The Paleocene–Eocene strata near Landana have produced a number of turtle fossils, including the holotype specimen of the pleurodire Taphrosphys congolensis. A turtle humerus collected c. 1 m above the holotype skull of C. landanensis differs from humeri of chelonioids and Taphrosphys, indicating that a third turtle taxon is present at Landana. Cheloniid fossil material is rare in the Landana assemblage, in comparison with the abundant remains of Taphrosphys congolensis found throughout the stratigraphic section. This disparity implies that C. landanensis preferred open marine habitats, whereas Taphrosphys congolensis spent more time in nearshore environments. The appearance of new durophagous species such as C. landanensis in the early Paleocene reflects the rapid radiation of pan-cheloniids as they diversified into open niches following the K–Pg extinction.

This paper uses the combinatorics of Young tableaux to prove the plactic monoid of infinite rank does not satisfy a non-trivial identity, by showing that the plactic monoid of rank n cannot satisfy a non-trivial identity of length less than or equal to n. A new identity is then proven to hold for the monoid of n×n upper-triangular tropical matrices. Finally, a straightforward embedding is exhibited of the plactic monoid of rank 3 into the direct product of two copies of the monoid of 3×3 upper-triangular tropical matrices, giving a new proof that the plactic monoid of rank 3 satisfies a non-trivial identity.

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