688 research outputs found
Sourcing Non-Native Mammal Remains from Dos Mosquises Island, Venezuela: New Multiple Isotope Evidence.
Archeological excavations of Amerindian sites on Dos Mosquises Island, Los Roques Archipelago, Venezuela, uncovered a wide range of evidence reflecting seasonal exploitation of local resources and multiple ritual depositions of large quantities of ceramic figurines, lithics, and faunal remains. Zooarchaeological analysis revealed the presence of modified and unmodified bones and teeth from numerous imported mammal species. Local geographic and environmental conditions preclude permanent establishment of terrestrial mammal populations and as such, there are no native mammalian taxa on the island itself or the surrounding oceanic archipelago. The presence of these faunal remains on Dos Mosquises can be attributed to the intentional movement of animal resources from the mainland to Los Roques by indigenous groups in the Late Ceramic Age (~AD 1200–1500). Despite attributions to a mainland source region, little else is known about the origins of these unique specimens. Here, we apply strontium (87Sr/86Sr), oxygen (δ18O), and carbon (δ13C) isotope analyses of tooth enamel from various archeologically recovered taxa including deer, peccary, tapir, ocelot, margay, opossum, fox, and weasel to investigate their geographic origins via comparisons with macro-regional models of precipitation δ18O and bioavailable 87Sr/86Sr. The 87Sr/86Sr results are highly variable both for the overall assemblage and between specimens within the same taxa, indicating origins from different geochemical environments of mainland South America. The combined archeological and isotopic evidence are consistent with origins within the late pre-colonial Valencioid Sphere of Interaction which encompassed the Lake Valencia Basin, surrounding regions, and several offshore island groups including Los Roques archipelago.Seventh Framework Programme (FP7
Evaluación Histórica y Bio-Ecológica de la Pesquería del Botuto (Strombus gigas) en el Parque Nacional Archipiélago de Los Roques (Venezuela), a través del Estudio de sus Concheros
Late prehistoric economy and society of The islands off the coast of Venezuela: a contextual interpretation of the non-ceramic evidence
Archaeologists have portrayed north-central Venezuela as the seat of the Valencioid
'chiefdom' (a.d. 900-1500) and assumed socio-cultural continuity between the Valencioid culture
and the historic Caraca Indians. These assumptions have neither been constructed nor tested on
socially meaningful archaeological contexts.
My research formulates and tests the cognitive value of the non-ceramic evidence recovered
from socially meaningful archaeological contexts on the islands of the Central Coast of Venezuela
as sources for understanding the developmental trajectory of the Valencioid polity(ies).
The data come from archaeological surveys and excavations on 55 offshore islands and at 47
sites. Through horizontal excavation, off-site control units and statistical control over sample size
it is established that the economic purpose for the occupation of a large Valencioid campsite at
Dos Mosquises Island (a.d. 1400-1500) was primarily to exploit Conch Shell (Strombus gigas) for
food and raw material. Other local resources, such as fishes, lobsters, turtles and birds, were
complementary. The conceptual polarity food/artefact, often applied to the archaeofaunal
analyses, is replaced by contextual discrimination between food, non-food remains and natural
objects, which leads to inferences on social group composition, labour division, specialisation,
differential access to food and the exportation of shell raw material outside the islands.
The results of the contextual analyses of allochthonous mammal and special purpose
artefacts indicate the presence of prominent members of the society (chief, shaman and/or
warriors) and the ceremonial character of the core locus at the Dos Mosquises site. It is suggested
that the organisation of the insular enterprise is most likely controlled from this core locus.
From a macro-regional perspective, the resulting analyses challenge the notion of a 600 yearlong
unilinear evolution toward social complexity of the Valencioid polity. The previous view of
a straightforward, hegemonic character of this polity is replaced by perspective of recurrent long
and short-term changes in the nature and intensity of regional interactions between several
polities. These interactions were based on a changing multilateral negotiations of power through
trade, co-operativev entures,r esourcee xploitation, intermarriage,c eremonial assistancew, arfare
and peace. The purported continuity between the insular Valencioids and the Caraca Indians is
not supported by the archaeological data
Inhaled glucocorticosteroids decrease hydrogen peroxide level in expired air condensate in asthmatic patients
AbstractH2O2is elevated in the exhaled air condensate in several inflammatory disorders of the lung, including bronchial asthma, and thus may reflect inflammatory processes in the airways. Exhaled H2O2may be used to guide the anti-inflammatory treatment of patients with asthma. Therefore in this study we analysed the effect of inhaled glucocorticosteroid beclomethasone for 4 weeks on H2O2level in the exhaled air condensate.Seventeen asthmatics and 10 healthy subjects were included to the study. Eleven patients were given inhaled beclomethasone and six were given placebo (3M Health Care). In all patients pulmonary function tests were performed. H2O2in the expired air condensate was measured spectrofluorimetically (homovanillic acid method).Inhaled beclomethasone significantly decreased H2O2in the expired air condensate in the active-treatment group, with a fall from baseline on day 1 which remained on day 43 (follow-up) (P<0·05). Exhaled H2O2in the active-treatment group was significantly lower than that in placebo group (P<0·05). A negative correlation between H2O2and forced expiratory volume in 1 sec (FEV1) on day 29 was observed.The decrease in exhaled H2O2in the active-treatment group was accompanied by an improvement in pulmonary function tests results.Inhaled glucocorticoids reduce the level of H2O2in the expired air condensate of asthmatic patients over a 4-week period and this may reflect their anti-inflammatory activity in lung diseases
\u27Tavern\u27 by the Saltpan: New England Seafarers and the Politics of Punch on La Tortuga Island, Venezuela, 1682-1782
Regional initiative for the evaluation of Queen Conch (Strombus gigas) exploitation under an historical perspective
The Satellite Cell Niche Regulates the Balance between Myoblast Differentiation and Self-Renewal via p53
Satellite cells are adult muscle stem cells residing in a specialized niche that regulates their homeostasis. How niche-generated signals integrate to regulate gene expression in satellite cell-derived myoblasts is poorly understood. We undertook an unbiased approach to study the effect of the satellite cell niche on satellite cell-derived myoblast transcriptional regulation and identified the tumor suppressor p53 as a key player in the regulation of myoblast quiescence. After activation and proliferation, a subpopulation of myoblasts cultured in the presence of the niche upregulates p53 and fails to differentiate. When satellite cell self-renewal is modeled ex vivo in a reserve cell assay, myoblasts treated with Nutlin-3, which increases p53 levels in the cell, fail to differentiate and instead become quiescent. Since both these Nutlin-3 effects are rescued by small interfering RNA-mediated p53 knockdown, we conclude that a tight control of p53 levels in myoblasts regulates the balance between differentiation and return to quiescence
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