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The Ciply Phosphatic Chalk (CPC) has been exploited for its enrichment in phosphorus in the early part of the twentieth century to produce fertilisers. Regained interests stimulated new research to characterise the potential for rare earth elements endowment and propose a genetic model for the formation of this phosphate deposit. This work studied the CPC using scanning electron microscopy, X-ray diffraction, cathodoluminescence and geochemical analyses. New insights into the formation of the deposits have been obtained regarding the mode of formation of the deposit. First, the deposit clearly shows evidence of alternating phase of phosphatisation and reworking giving rise to the formation of phosintraclasts which are the dominant phosphatic grains of the deposit. Weak or moderate upwellings brought nutrients to the Mons Basin during a period of sea-level highstand. Negative Ce-anomaly and the presence of bioturbation strongly argue against the development of an important oxygen-minimum zone indicating a low-productivity system. In these conditions, Fe-oxyhydroxides might have played an important role in scavenging phosphorus from the water column to the sediment. Phosphatisation seems to have occurred in the sediment when supersaturation relative to francolite was reached in the sediment pore water. Reworking processes probably consisted of wave action during storms. The REE are hosted in francolite and possess an average ΣREE of 350 ppm for the Hyon borehole. Their shale-normalised patterns are similar to other Cretaceous phosphate deposits but also to Cambrian deposits of China which typically display negative Ce-anomaly and HREE depletion. Post-depositional processes are only evident for the “phosphatic sands” which are strongly enriched in both phosphorus and REE. Further studies should aim to better constrain the paleoenvironmental conditions of deposition using stable isotopic studies. LA-ICP-MS studies should be able to give interesting insights into the compositional variations of the phosintraclasts thus giving elements to better characterise the genetic model of the CPC.

© 2017 Elsevier B.V. RH421 is a voltage-sensitive fluorescent styrylpyridinium dye which has often been used to probe the kinetics of Na+,K+-ATPase partial reactions. The origin of the dye's response has up to now been unclear. Here we show that RH421 responds to phosphorylation of the Na+,K+-ATPase by inorganic phosphate with a fluorescence increase. Analysis of the kinetics of the fluorescence response indicates that the probe is not detecting phosphorylation itself but rather a shift in the protein's E1/E2 conformational equilibrium induced by preferential phosphate binding to and phosphorylation of enzyme in the E2 conformation. Molecular dynamics simulations of crystal structures in lipid bilayers indicate some change in the protein's hydrophobic thickness during the E1-E2 transition, which may influence the dye response. However, the transition is known to involve significant rearrangement of the protein's highly charged lysine-rich cytoplasmic N-terminal sequence. Using poly-L-lysine as a model of the N-terminus, we show that an analogous response of RH421 to the E1 → E2P conformational change is produced by poly-L-lysine binding to the surface of the Na+,K+-ATPase-containing membrane fragments. Thus, it seems that the prime origin of the RH421 fluorescence response is a change in the interaction of the protein's N-terminus with the surrounding membrane. Quantum mechanical calculations of the dye's visible absorption spectrum give further support to this conclusion. The results obtained indicate that membrane binding and release of the N-terminus of the Na+,K+-ATPase α-subunit are intimately involved in the protein's catalytic cycle and could represent an effective site of regulation.

A questão do desequilíbrio econômico regional foi, nos últimos anos, uma preocupação compartilhada mundialmente. Enquanto algumas regiões se destacam como grandes centros de produção caracterizados pelo aumento da competitividade e da inovação, outras sobrevivem com base em estruturas dependentes de produtos e de capital externo. A fim de identificar os fatores que contribuem para o desenvolvimento de uma determinada região, diversas teorias e esquemas analíticos tem avançado nesse sentido, em particular, a abordagem relacionada com as aglomerações produtivas de empresas. Com esse intuito, vários países têm buscado políticas de desenvolvimento regional para apoiar estas novas realidades produtivas com base nas vantagens inerentes das aglomerações de empresas. Este foi o caso, por exemplo, da França, por meio da sua política de apoio aos Sistemas Produtivos Locais (SPLs) e, mais recentemente, aos Polos de Competitividade (PdCs). O objetivo deste artigo é apresentar cada uma dessas duas fases e propor uma reflexão sobre as causas e condições dessa mudança de ação econômica pública.

Cervical reconstruction after postburn scarring remains a challenge for the plastic surgeon. Several well-known procedures are possible: split or full-thickness skin grafts, local flaps, free skin flaps, expanded skin,... In order to evaluate each technique, three procedures are compared with a long-term follow-up (or = 1 year): skin expansion, free flap surgery and full-thickness skin grafting. Fifteen patients are reviewed, with five patients operated according to each method. In this study, each burn patient was suffering from a severe neck burn contracture, restricting the neck motility to a few degrees. These patients were operated on by different surgeons, according to their personal indications. The full-thickness skin graft is usually harvested from the abdomen (by means of a miniabdominoplasty) and is applied under a tie-over dressing. This simple procedure has few complications and gives satisfactory results. Skin expansion provides a good texture and color matching but has a higher morbidity and necessitates several procedures. Free flap surgery is time-consuming, gives a good functional result but poor cosmetic aspect (different colour, excessive bulk). Comparing the functional and aesthetic result of the three types of reconstruction in terms of morbidity, neck mobility, skin elasticity, skin sensitivity, matching and scar recurrence, full-thickness skin grafting seems to be the most adequate technique.