Redes Eléctricas Digitais Power Line Communication :- Desafios e Oportunidades para Cabo Verde

Para distribuir e socializar a informação, nos mais diversos locais e das formas mais rápidas possíveis, proliferam as redes de comunicação de dados, cada vez mais presentes em nosso quotidiano, especialmente através do uso das novas tecnologias. Dentre elas, destaca-se a tecnologia Power Line Communication (PLC) Linha de força de comunicação, em que os dados são transmitidos através da corrente eléctrica. Hoje, um pouco por todo o mundo, estuda-se a alternativa viável, desafios e oportunidades de se utilizar a rede de energia eléctrica como um canal efectivo para transmissão de dados, voz e imagem, tornando-se assim, também uma rede de comunicação de dados. Ainda sem uma oferta comercial a funcionar em Cabo Verde, apesar de já terem sido feito algumas tentativas de testes de equipamentos, a Power Line Communication é já utilizada com sucesso em vários países, ligando em banda larga casas e empresas. Assim, este trabalho pretende fazer o enquadramento da tecnologia em si, bem como analisar os desafios e oportunidades da implementação do PLC no mercado Cabo-verdiano.

Effects of adrenergic and cholinergic blockade on insulin-induced stimulation of calf blood flow in humans.

Euglycemic hyperinsulinemia stimulates both sympathetic nerve activity and blood flow to skeletal muscle, but the mechanism is unknown. Possible mechanisms that may stimulate muscle blood flow include neural, humoral, or metabolic effects of insulin. To determine whether such insulin-induced vasodilation is modulated by stimulation of adrenergic or cholinergic mechanisms, we obtained, in eight healthy lean subjects, plethysmographic measurements of calf blood flow during 3 h of hyperinsulinemic (1 mU.kg-1.min-1) euglycemic clamp performed alone or during concomitant beta-adrenergic (propranolol infusion), cholinergic (atropine infusion), or alpha-adrenergic (prazosin administration) blockade. Euglycemic hyperinsulinemia alone increased calf blood flow by 38 +/- 10% (means +/- SE) and decreased vascular resistance by 27 +/- 4% (P < 0.01). The principal new observation is that these insulin-induced vasodilatory responses were not attenuated by concomitant propranolol or atropine infusion, nor were they potentiated by prazosin administration. In conclusion, these findings provide evidence that during euglycemic hyperinsulinemia in lean healthy humans stimulation of muscle blood flow is not mediated primarily by beta-adrenergic or cholinergic mechanisms. Furthermore, alpha-adrenergic mechanisms do not markedly limit insulin-induced stimulation of muscle blood flow.

El Advergaming en el digital signage: actores que determinan la obtención del "flow experience" de acuerdo a la ubicación de un dispositivo de emisión de contenido digital, dinámico e interactivo con videojuegos de marca

En la recerca d’eines que suposen la interactivitat com a punt clau en el model de comunicació, la present investi- gació aborda l’ús de videojocs amb contingut publicitari o “advergaming” com a punt central d’estudi i pretén es- tablir els factors que determinen una experiència de joc òptima a través de l’ús de pantalles digitals com a mitjà difusor d’aquest tipus de contingut. Parlarem de “flow experience” o teoria de la psicologia po- sitiva segons el seu creador i precursor Mihály Csíkszent- mihályi, i serà la perspectiva des de la qual pretenem desenvolupar aquest estudi, entenent el “flow experience” com l’estat òptim o nivell més alt d’experiència d’usuari que es pot assolir durant una activitat

Continuous arterial spin labeling of mouse cerebral blood flow using an actively-detuned two-coil system at 9.4T.

Among numerous magnetic resonance imaging (MRI) techniques, perfusion MRI provides insight into the passage of blood through the brain's vascular network non-invasively. Studying disease models and transgenic mice would intrinsically help understanding the underlying brain functions, cerebrovascular disease and brain disorders. This study evaluates the feasibility of performing continuous arterial spin labeling (CASL) on all cranial arteries for mapping murine cerebral blood flow at 9.4 T. We showed that with an active-detuned two-coil system, a labeling efficiency of 0.82 ± 0.03 was achieved with minimal magnetization transfer residuals in brain. The resulting cerebral blood flow of healthy mouse was 99 ± 26 mL/100g/min, in excellent agreement with other techniques. In conclusion, high magnetic fields deliver high sensitivity and allowing not only CASL but also other MR techniques, i.e. (1)H MRS and diffusion MRI etc, in studying murine brains.

Combination of fluorescent reporters for simultaneous monitoring of root colonization and antifungal gene expression by a biocontrol pseudomonad on cereals with flow cytometry.

Some root-associated pseudomonads sustain plant growth by suppressing root diseases caused by pathogenic fungi. We investigated to which extent select cereal cultivars influence expression of relevant biocontrol traits (i.e., root colonization efficacy and antifungal activity) in Pseudomonas fluorescens CHA0. In this representative plant-beneficial bacterium, the antifungal metabolites 2,4-diacetylphloroglucinol (DAPG), pyrrolnitrin (PRN), pyoluteorin (PLT), and hydrogen cyanide (HCN) are required for biocontrol. To monitor host plant effects on the expression of biosynthetic genes for these compounds on roots, we developed fluorescent dual-color reporters suited for flow cytometric analysis using fluorescence-activated cell sorting (FACS). In the dual-label strains, the constitutively expressed red fluorescent protein mCherry served as a cell tag and marker for root colonization, whereas reporter fusions based on the green fluorescent protein allowed simultaneous recording of antifungal gene expression within the same cell. FACS analysis revealed that expression of DAPG and PRN biosynthetic genes was promoted in a cereal rhizosphere, whereas expression of PLT and HCN biosynthetic genes was markedly less sustained. When analyzing the response of the bacterial reporters on roots of a selection of wheat, spelt, and triticale cultivars, we were able to detect subtle species- and cultivar-dependent differences in colonization and DAPG and HCN gene expression levels. The expression of these biocontrol traits was particularly favored on roots of one spelt cultivar, suggesting that a careful choice of pseudomonad-cereal combinations might be beneficial to biocontrol. Our approach may be useful for selective single-cell level analysis of plant effects in other bacteria-root interactions.

Perception et communication du risque: du diabète à la maladie cardiovasculaire [Risk perception and communication: from diabetes to cardiovascular diseases].

Evidence-based medicine has enabled to approach disease in a more rational and scientific way. Clinical research has identified behaviours and risk factors that could cause disease often "silent" at the beginning, such as diabetes. Despite the clear impact of these evidences on public health, it seems that the individual risk perception level remains weak. To mention as well, the health professionals very often have a different views, which makes it difficult to communicate the risk with patients. In this article we describe the principles of risk perception, the diabetes related risk perception concerning cardiovascular complications, and suggest some practical strategies and tools which could improve risk communication in the everyday practice.

Mutant HbpR transcription activator isolation for 2-chlorobiphenyl via green fluorescent protein-based flow cytometry and cell sorting.

Mutants were produced in the A-domain of HbpR, a protein belonging to the XylR family of σ(54)-dependent transcription activators, with the purpose of changing its effector recognition specificity from 2-hydroxybiphenyl (2-HBP, the cognate effector) to 2-chlorobiphenyl (2-CBP). Mutations were introduced in the hbpR gene part for the A-domain via error-prone polymerase chain reaction, and assembled on a gene circuitry plasmid in Escherichia coli, permitting HbpR-dependent induction of the enhanced green fluorescent protein (egfp). Cells with mutant HbpR proteins responsive to 2-CBP were enriched and separated in a flow cytometry-assisted cell-sorting procedure. Some 70 mutants were isolated and the A-domain mutations mapped. One of these had acquired true 2-CBP recognition but reacted hypersensitively to 2-HBP (20-fold more than the wild type), whereas others had reduced sensitivity to 2-HBP but a gain of 2-CBP recognition. Sequencing showed that most mutants carried double or triple mutations in the A-domain gene part, and were not located in previously recognized conserved residues within the XylR family members. Further selection from a new mutant pool prepared of the hypersensitive mutant did not result in increased 2-CBP or reduced 2-HBP recognition. Our data thus demonstrate that a one-step in vitro 'evolutionary' adaptation of the HbpR protein can result in both enhancement and reduction of the native effector recognition.

Characterization of Human Late Outgrowth Endothelial Progenitor-Derived Cells under Various Flow Conditions.

Background: Endothelial progenitor-derived cells (EPC) are a cell therapy tool in peripheral arterial disease and for re-endothelialization of bypasses and stents. Objective: To assess EPC behavior under flow conditions normally found in vivo. Results: EPC were isolated from human cord blood, cultured on compliant tubes and exposed in an in vitro flow system mimicking hemodynamic environments normally found in medium and large arteries. EPC exposed for 24 h to unidirectional (0.3 ± 0.1 or 6 ± 3 dynes/cm(2)) shear stress oriented along flow direction, while those exposed to bidirectional shear stress (0.3 ± 3 dynes/cm(2)) or static conditions had random orientation. Under bidirectional flow, tissue factor (TF) activity and mRNA expression were significantly increased (2.5- and 7.0-fold) compared to static conditions. Under low shear unidirectional flow TF mRNA increased 4.9 ± 0.5-fold. Similar flow-induced increases were observed for TF in mature umbilical vein-derived endothelial cells. Expression of tissue-type plasminogen activator (t-PA), urokinase (u-PA) and monocyte chemotactic protein 1 (MCP1) were reduced by 40-60% in late outgrowth endothelial progenitor-derived cells (LO-EPC) exposed to any flow environment, while MCP1, but not t-PA or u-PA, was decreased in HUVEC. Conclusions: Flow, in particular bidirectional, modifies the hemostatic balance in LO-EPC with increased TF and decreased plasminogen activator expression.

En route to a more democratic European Union – An analysis of the communication strategies of European Citizens’ Initiatives (ECIs)

L’èxit de l’iniciativa ciutadana europea (ICE) com a instrument de democràcia directa a nivell europeu està directament relacionat amb la seva promulgació. Els ciutadans d’arreu Europa han d’estar informats sobre aquest nou mecanisme per tal que es dugui a terme, la qual cosa suposa una dificultat. Aquest estudi qualitatiu ens mostra els recursos i problemes en la divulgació de les ICE. Una anàlisi basat en entrevistes amb diferents organitzadors d’aquestes ICE que ens dona algunes idees sobre les seves estratègies de comunicació, així com l’ús d’eines de comunicació i relacions amb els mitjans de comunicació. A banda de les dificultats lingüístiques i financeres hi ha altres obstacles més específics relacionats amb l’ICE.

Développement de la communication intentionnelle gestuelle à partir des usages culturels des objets dans l'interaction triadique enfant-objet-adulte

Pour que deux protagonistes parviennent à communiquer, ils doivent non seulement partager les signes verbaux et/ou non verbaux qu'ils utilisent, mais ils doivent également parvenir à accéder à l'intention communicative de chacun. Ce dernier aspect de la communication a été intimement lié aux significations et aux connaissances que les protagonistes partagent (angl. common ground). Malgré le fait que l'importance des significations partagées ait été soulignée dans la littérature concernant la communication entre adultes, cet aspect n'a pas été étudié en ce qui concerne le développement précoce de la communication. Dans le présent travail, nous suggérons d'investiguer le lien entre les significations partagées entre le jeune enfant et l'adulte et la capacité de l'enfant à communiquer de manière intentionnelle via des gestes. En nous appuyant sur l'approche de la Pragmatique de l'Objet (Moro & Rodríguez, 2005), nous suggérons que les connaissances concernant l'usage culturel de l'objet que construit progressivement l'enfant représentent un type de significations que l'enfant partage avec autrui. 12 dyades mère-enfant ont été enregistrées à l'aide d'une caméra lors d'interactions avec quatre objets. Les observations ont eu lieu au domicile des familles et ont été conduites chaque deuxième mois lorsque les enfants ont été âgés de 8 à 16 mois (groupe 1) et de 16 à 24 mois (groupe 2). Les observations ont été codées pour le niveau de maîtrise de l'usage culturel par l'enfant ainsi que pour la production de gestes par l'enfant et par l'adulte. Nous avons trouvé que plus l'enfant maîtrise les usages culturels des objets, plus il produit de gestes, et plus ces gestes remplissent une fonction communicative explicite. Concernant les gestes de l'adulte, les résultats dévoilent que plus l'enfant maîtrise les usages conventionnels des objets, plus l'adulte adresse des gestes communicatifs à l'enfant, plus ses gestes sont produits de manière complexe et plus l'intention des gestes communicatifs de l'adulte est complexe. Pris ensemble, ces résultats suggèrent que le partage de significations sur l'usage culturel des objets représente un type de connaissances communes qui permettent au bébé et à ses protagonistes de communiquer.

"Pas vraiment, votre honneur...": vadémécum de la communication entre experts forensiques et magistrats

La présente communication a pour objet la communication entre experts forensiques et magistrats. En confrontant les notions juridiques d'expertise (notamment en regard du nouveau Code de procédure pénale), d'expert judiciaire aux pratiques habituellement admises dans le milieu forensique, elle met en lumière les décalages existant entre les attentes des juristes et les réponses que peuvent apporter les experts aux questions d'expertise qui leur sont posées. La contribution se conclura par quelques brèves recommandations pouvant constituer les prémisses d'un vadémécum de la communication destiné tant aux experts qu'aux magistrats.