6 research outputs found

    Trace-elemental and multi-isotopic (Sr-Nd-Pb) discrimination of jade in the circum-Caribbean: Implications for pre-colonial inter-island exchange networks

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    Dense and strong, hydrothermal-metasomatic jadeitite and jadeite-omphacite rocks were used as tools and adornments throughout the wider Caribbean since initial inhabitation. Regionally, rich sources of jadeitite and jadeite-omphacite jade are known only in Guatemala (north and south of the Motagua Fault Zone), eastern Cuba and the northern Dominican Republic, establishing that humans transported jadeitic material over vast distances. This study validates that geochemical fingerprinting is a viable provenance method for Caribbean pre-colonial jadeitic lithologies. An assemblage of 101 source rocks has been characterised for trace element and combined Sr-Nd-Pb isotope compositions. Four statistical approaches (Principal Component Analysis, t-Distributed Stochastic Neighbour Embedding, Decision Tree, and Multiclass Regression) were assessed, employing source-distinct trace element ratios. A multiclass regression technique based on trace element ratios of immobile high field strength, light to medium rare earth and fluid-mobile, large-ion-lithophile elements is shown to be most effective in discriminating the four source regions. Ninety-one % of the Guatemalan samples can be discriminated from the Dominican and Cuban sources using La/Th, Zr/Hf and Y/Th ratios. Jadeitic rocks cropping out in the Dominican Republic can be distinguished from Cuban jades employing Er/Yb, Nb/Ta and Ba/Rb ratios with 71% certainty. Furthermore, the two Guatemala sources, north and south of the Motagua Fault Zone, can be discriminated by using (among others) Zr/Hf, Ta/Th, La/Sm and Dy/Y ratios with an 89% success rate. This raises the possibility of determining, in detail, former trading and mobility networks between different islands and the Meso- and Central American mainland within the Greater Caribbean. The provenance technique was applied to 19 pre-colonial jade celts excavated from the Late Ceramic Age Playa Grande archaeological site in the northern Dominican Republic. Three artefacts are discriminated as derived from the Guatemalan source, indicating that, despite a source of jade within 25 km, material was traded from Guatemala. The presence of Guatemalan jade in the Playa Grande lithic assemblage provides further evidence of large scale (>3000 km), regional trading and indigenous knowledge transfer networks.This research received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement No 319209 (ERC-Synergy NEXUS 1492) and the European Union’s Horizon 2020 research and innovation programme under grant agreement No 654208 (Europlanet 2020 RI). We are grateful to the Museo del Hombre Dominicano for providing the Playa Grande samples. Thanks to Richard Smeets, Bas van der Wagt, Kirsten van Zuilen, Bouke Lacet, Eva Kelderman and Quinty Boosten for analytical assistance

    Metabolic and Functional Profile of Premenopausal Women With Metabolic Syndrome After Training With Elastics as Compared to Free Weights

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    The aim of this study was to compare the effects of a strength training program (STP) using free weights (FW) versus elastic tubing (ET) in 62 premenopausal, sedentary women diagnosed with metabolic syndrome (MS). Participants were randomly assigned to the FW or ET experimental group (EG) or a control group whose members remained sedentary. Members of each EG followed their assigned STP for 12 weeks, and biomarkers (BMs) related to MS and motor function (MF) parameters were evaluated. Both EGs showed a significant reduction in C-reactive protein level and a positive trend in the other BMs. Almost all MF parameters increased significantly in both EGs. No positive changes were found in the CG. These results indicate that the implementation of an STP, with either FW or ET, improves both metabolic health and MF and should be considered part of the basic approach to health care in women

    Endoscopic ultrasound-assisted endoscopic resection of carcinoid tumors of the gastrointestinal tract Resección endoscópica asistida por ecoendoscopia de tumores carcinoides del aparato digestivo

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    Introduction: usually found in the gastrointestinal tract, carcinoids are the most frequent neuroendocrine tumors. Most of these lesions are located in areas that are difficult to access using conventional endoscopy (small intestine and appendix); carcinoid tumors found in the gastroduodenal tract and in the large intestine can be studied endoscopically; in these cases, if localized disease is confirmed, local treatment by endoscopic resection may be the treatment of choice. Since endoscopic ultrasonography has been shown to be the technique of choice for the study of tumors exhibiting submucosal growth, the selection of patients who are candidates for a safe and effective local resection should be based on this technique. Patients and method: we selected patients with gastrointestinal carcinoid tumors who were endoscopically treated between 1997 and 2002. Those patients with tumors measuring less than 10 mm, which had not penetrated the muscularis propria, and those with localized disease were considered candidates for endoscopic resection. The endpoints of this study were to assess the effectiveness (complete resection) and safety (complications) of the technique. Follow-up consisted of eschar biopsies performed one month and twelve months after the resection. Results: during the aforementioned period, we resected endoscopically 24 tumors in 21 patients (mean age: 51.7 years; 71.5% males). Most lesions were incidental discoveries made during examinations indicated for other reasons. Resection was indicated in most cases as a result of the suspected presence of a carcinoid tumor after endoscopic ultrasonography. Endoscopic ultrasonography also enabled us to clearly identify the layer where the lesion had originated, as well as the size of the lesion. The carcinoid tumor was removed in 13 cases (54.2%) by using the conventional snare polypectomy technique, in 9 cases (37.5%) assisted by a submucosal injection of saline solution and/or adrenaline, and in 2 cases (8.3%) after ligating the lesion with elastic bands. In all cases the resection was complete, with no recurrence during the follow-up period, and no major complications, except for a single case in which a post-polypectomy hemorrhage occurred that was endoscopically solved. Conclusions: in properly selected patients, the endoscopic resection of carcinoid tumors is a safe and effective technique that permits a complete resection in all cases with few complications. Endoscopic ultrasonography is the technique of choice for selecting the patients who are candidates for endoscopic resection.<br>Introducción: los carcinoides son los tumores neuroendocrinos más frecuentes, representado el tracto digestivo una de sus localizaciones más habituales. La mayoría de las lesiones se localizan en áreas poco accesibles para la endoscopia convencional (intestino delgado y apéndice); los carcinoides localizados en el tracto gastroduodenal y en el intestino grueso pueden ser estudiados endoscópicamente; en estos casos, si se confirma una enfermedad localizada, el tratamiento local mediante resección endoscópica puede ser el tratamiento de elección. Dado que la ecoendoscopia se ha mostrado como la técnica de elección en el estudio de los tumores de crecimiento submucoso, la selección de los pacientes candidatos a una resección local segura y efectiva ha de basarse en esta técnica. Pacientes y método: se han seleccionado los pacientes con tumores carcinoides digestivos tratados endoscópicamente entre 1997 y 2002. Se consideraron subsidiarios de resección endoscópica aquellos pacientes con tumores menores de 10 mm, que respetan la muscular propia y con un estudio de extensión negativo. Los objetivos finales del estudio fueron la evaluación de la eficacia (resección completa) y seguridad (complicaciones) de la técnica. El seguimiento consistió en biopsias de la escara al mes y los 12 meses de la resección. Resultados: en el periodo referido hemos resecado endoscópicamente 24 tumores en 21 pacientes (edad media de 51,7 años; 71,5% varones). Las lesiones eran en su mayoría hallazgos incidentales en exploraciones indicadas por otros motivos. La resección se indicó en la mayoría de los casos por sospecha ecoendoscópica de tumor carcinoide. La ecoendoscopia además permitió establecer con claridad la capa de origen de la lesión y el tamaño de la misma. La extirpación se llevó a cabo en 13 casos (54,2%) mediante la técnica convencional de polipectomía con asa, en 9 casos (37,5%) asistida con inyección submucosa de suero salino y/o adrenalina y en 2 casos (8,3%) tras ligar la lesión con bandas elásticas. En todos los casos la resección fue completa, sin recidivas durante el seguimiento. En un único caso se produjo una complicación mayor: una hemorragia postpolipectomía que se controló endoscópicamente. Conclusiones: la resección endoscópica de los tumores carcinoides, en pacientes bien seleccionados, es una técnica segura y eficaz permitiendo una resección completa en todos los casos con escasas complicaciones. La ecoendoscopia es la técnica de elección para seleccionar los pacientes candidatos a resección endoscópica
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