Subduction Zones of the Caribbean : the sedimentary, magmatic, metamorphic and ore-deposit records UNESCO/iugs igcp Project 546 Subduction Zones of the Caribbean

The International Union of Geosciences (IUGS) and UNESCO IGCP project 546 Subduction Zones of the Caribbean (http://www.ugr.es/~agcasco/igcp546/) was launched in 2007 and scheduled to be completed by the end of the current year 2011. It was set up with the aim of gathering researchers interested in the geological evolution of the Caribbean realm. The development of this region is largely controlled by a number of subduction zones that formed along its margins from the break-up of Pangea during the Jurassic until Present. The current setting is characterized by a very complex plate-tectonic configuration dominated by subduction zones, large-scale strike-slip faults, volcanic arcs and collision belts (Figure 1). The project was built upon previous developments of IGCP project 433 Caribbean Plate Tectonics (2000-2005), of which the Special Volume 4 (Issue 1-2) of Geologica Acta Caribbean Plate Tectonics. Stratigraphic, Magmatic, Metamorphic and Tectonic Events (Iturralde Vinent and Lidiak, 2006) deserves mentioning

Tectonic implications of paleontologic dating of Cretaceous-Danian sections of Eastern Cuba

The sedimentary rocks intercalated in volcanic and metavolcanic sections of Mayarí-Baracoa and Sierra del Purial Mountains (Eastern Cuba), yielded Cretaceous through Danian microfossils. In the Mayarí Mountains the Téneme Fm consists of basalts and hyaloclastites with minor intercalations of well-bedded foliated limestone and shaly limestone that in the type area contain a Turonian or early Coniacian planktonic foraminifera assemblage. In the Morel area (Moa-Baracoa massif), back-arc pillow basalts with ribbon cherts include a late Turonian or Coniacian limestone bed intercalated with interbedded organic-rich calcareous shales near the top. The upper part of the Coniacian (?)-Campanian Santo Domingo Fm crops out west of Moa and it consists of finegrained well-bedded volcaniclastic rocks with two intercalated lenses of coarse-grained impure biocalcirudites to biocalcarenites. These rocks yielded a mixed penecontemporaneous planktonic and benthonic microfossil assemblage attributed to the lower part of the late Campanian (Globotruncanita calcarata Zone). At Sierra del Purial, crystalline limestones embedded within the metavulcano-sedimentary Río Baracoa section (Purial metamorphic complex) yielded Campanian microfossils. The Maastrichtian Yaguaneque (=Cañas) limestones crop out extensively in both Mayarí-Baracoa and Purial Mountains. All the formations previously mentioned unconformably overlie and tectonically intermingle with the late Maastrichtian-early Danian clastic rocks of the Mícara and La Picota Fms. Our new dates demonstrate that in the Greater Antilles the PIA (Primitive Island Arc-tholeiite) recorded by the Téneme Fm would be Late Cretaceous in age in opposition to the Lower Cretaceous age proposed for the PIA basalts. The protolith of the Purial metamorphic complex is probably Maastrichtian-early Danian, but certainly Campanian and older in age. This fact suggests that the metamorphism that affected the Purial rocks took place probably in the late Maastrichtian and was coeval with the detachment, exhumation and emplacement of mafic-ultramafic thrust-sheet bodies. This event recorded in Eastern Cuba/Western Hispaniola and Guatemala might have been related to the insertion of thick oceanic ridges into the subduction zone

High pressure metamorphism of ophiolites in Cuba

High-pressure metamorphic complexes of ophiolitic material in Cuba trace the evolution of the northern margin of the Caribbean Plate during the Mesozoic. In the northern ophiolite belt of western and central Cuba, these complexes document cold (i.e., mature) subduction of oceanic lithosphere. Age data indicate subduction during pre-Aptian times followed by mélange formation and uplift during the Aptian-Albian. The P-T evolution is clockwise with relatively hot geothermal gradient during exhumation (i.e., "Alpine-type"), suggesting that exhumation may have been triggered by unroofing processes ensuing arrest of subduction. It is hypothesized that tectonic processes related to termination of subduction led to formation of characteristic oscillatory zoning of garnet recorded in blocks separated by ca. 800 km along strike of the belt. In eastern Cuba, the complexes document hot subduction with peak conditions at ca. 750 ºC, 15-18 kbar followed by near-isobaric cooling (i.e., counterclockwise P-T path). The contrasting petrologic evolution in the two regions indicates that the correlation of eastern and western-central Cuban mélanges is doubtful. The age and tectonic context of formation of these hot-subduction complexes is uncertain, but available data are consistent with formation during the Aptian-Albian due to a) the birth of a new subduction zone and/or b) subduction of young oceanic lithosphere or a ridge. Furthermore, tectonic juxtaposition of high-pressure ophiolitic material and subducted platform metasediments in the Escambray complex (central Cuba) that were decompressed under relatively cold geothermal gradients ("Franciscan-type" P-T paths) indicates syn-subduction exhumation during the uppermost Cretaceous (ca. 70 Ma). The diversity of P-T paths, ages and tectonic settings of formation of the high-pressure complexes of ophiolitic material in Cuba document a protracted history of subduction at the northern margin of the Caribbean Plate during the Mesozoic

Comparative proteomics of exosomes secreted by tumoral jurkat t cells and normal human t cell blasts unravels a potential tumorigenic role for valosin-containing protein

We have previously characterized that FasL and Apo2L/TRAIL are stored in their bioactive form inside human T cell blasts in intraluminal vesicles present in multivesicular bodies. These vesicles are rapidly released to the supernatant in the form of exosomes upon re-activation of T cells. In this study we have compared for the first time proteomics of exosomes produced by normal human T cell blasts with those produced by tumoral Jurkat cells, with the objective of identify proteins associated with tumoral exosomes that could have a previously unrecognized role in malignancy. We have identified 359 and 418 proteins in exosomes from T cell blasts and Jurkat cells, respectively. Interestingly, only 145 (around a 40%) are common. The major proteins in both cases are actin and tubulin isoforms and the common interaction nodes correspond to these cytoskeleton and related proteins, as well as to ribosomal and mRNA granule proteins. We detected 14 membrane proteins that were especially enriched in exosomes from Jurkat cells as compared with T cell blasts. The most abundant of these proteins was valosin-containing protein (VCP), a membrane ATPase involved in ER homeostasis and ubiquitination. In this work, we also show that leukemic cells are more sensitive to cell death induced by the VCP inhibitor DBeQ than normal T cells. Furthermore, VCP inhibition prevents functional exosome secretion only in Jurkat cells, but not in T cell blasts. These results suggest VCP targeting as a new selective pathway to exploit in cancer treatment to prevent tumoral exosome secretion

Cichlid biogeography: comment and review

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72313/1/j.1467-2979.2004.00148.x.pd

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Sinopsis de la Constitución Geológica de Cuba

A synthesis of the historical geology and constitution of Cuba is here presented. In this context, Cuba can be differentiated into the foldbelt and the neoautochthonous. In the foldbelt, Early-Middle Jurassic to Late Eocene rocks, as well as some minor Neoproterozoic elements, are distinctly deformed and metamorphosed. They represent fragments of structures detached from the western Caribbean and Pacific realms. These are passive margin-foreland sections detached from the Maya block (Yucatan peninsula), parts of the Strait of Florida block (Bahamas); fragments of antique oceanic crusts and island arc segments, both of Cretaceous and Paleocene-Middle Eocene age. The neoautochthonous represent a set of several sedimentary basins of latest Eocene to Recent, that like a carpet, rest unconformably above the foldbelt. These rocks are slightly deformed and represent the latest evolution of Cuban archipelago. The main differences between the foldbelt and the neoautochthonous lies in the fact that the foldbeld encompasses elements detached from several old tectonic plates (North American, Caribbean and, probably, Pacific), while the neoautochthonous evo l ved entirely on a passive segment of the North American plate margin, after the acretionary process that lead to the formation of the foldbelt. Two possible interpretations of the structure of the foldbelt are discussed, and according one of those models, it is presented a set of evolutionary maps and cross sections of the Caribbean