Search results for "central america"

Hydrology Affects Environmental and Spatial Structuring of Microalgal Metacommunities in Tropical Pacific Coast Wetlands

2016

The alternating climate between wet and dry periods has important effects on the hydrology and therefore on niche-based processes of water bodies in tropical areas. Additionally, assemblages of microorganism can show spatial patterns, in the form of a distance decay relationship due to their size or life form. We aimed to test spatial and environmental effects, modulated by a seasonal flooding climatic pattern, on the distribution of microalgae in 30 wetlands of a tropical dry forest region: the Pacific coast of Costa Rica and Nicaragua. Three surveys were conducted corresponding to the beginning, the highest peak, and the end of the hydrological year during the wet season, and species abun…

Reconstructing the deep population history of Central and South America

2018

We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least ∼9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by ∼4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary sou…

Stable isotopes covering 96-7 ka BP from stalagmite CM (Santo Tomas Cave, Cuba)

2020

We present a new speleothem trace element and stable isotope record, which extends previous paleoclimate evidence from Cuban speleothems to the last 96 ka. Stable isotope samples were micromilled at a resolution of 0.10-0.33mm, and measured using an IRMS equipped with a Gasbench. Line scans of Element/Calcium ratios of the speleothem were measured by laser ablation ICPMS and were reduced to the resolution of the stable isotope records.

Transition from mildly-tholeiitic to calc-alkaline suite: the case of Chichontepec volcanic centre, El Salvador, Central America

1998

Abstract The Chichontepec volcano is a Plio-Pleistocene composite volcano that erupted lavas ranging from high-alumina basalts to dacites. It experienced a caldera-forming paroxysmal eruption during the early Pleistocene. Pre-caldera lavas are mildly tholeiitic and they evolved mainly by low pressure crystal fractionation, notwithstanding the fact that most mafic lavas (low-MgO high-alumina basalts) retain traces of polybaric evolution. Conversely, post-caldera lavas, which are mainly pyroxene andesites, are clearly calc-alkaline, having evolved by open-system crystal fractionation. Sr–Nd isotopic data and trace elements characteristics indicate that the same mantle source was involved in t…

New insights of the volcanic gas signature of the Central American Volcanic Arc

Volcanic gas emissions carry crucial information on pre- and syn-eruptive processes, and on behaviour of active volcanic systems. Gas variations arise from replenishment of magma storage zones with mafic magma, from magma ascent and evolution, and from interaction with hydrothermal systems and volcanic lakes. As such, volcanic gases represent “open windows” into genesis and release of volatiles from the Earth’s interior. Volcanic emission measurements allow understanding subsurface magmatic and hydrothermal processes, and contribute to eruption forecasting. Carbon dioxide and sulfur gas represent the most abundant and studied gas species. In particular, CO2, due his fast exsolution during m…

Abundance and Distribution Patterns of Thunnus albacares in Isla del Coco National Park through Predictive Habitat Suitability Models

2016

Information on the distribution and habitat preferences of ecologically and commercially important species is essential for their management and protection. This is especially important as climate change, pollution, and overfishing change the structure and functioning of pelagic ecosystems. In this study, we used Bayesian hierarchical spatial-temporal models to map the Essential Fish Habitats of the Yellowfin tuna (Thunnus albacares) in the waters around Isla del Coco National Park, Pacific Costa Rica, based on independent underwater observations from 1993 to 2013. We assessed if observed changes in the distribution and abundance of this species are related with habitat characteristics, fis…

Tratamiento psicofarmacológico del trastorno bipolar en América Latina

2011

Objective: This study assessed the treatment preferences among Latin-American psychiatrists for their bipolar disorder patients and if these preferences reflect the current guidelines. Methods: We designed a survey comprised of fourteen questions. All the questions were aimed at the treatment of bipolar I patients only. We distributed the survey by hand or e-mail to psychiatrists in eight different countries: Argentina, Brasil, Colombia, Costa Rica, Ecuador, México, Perú and Venezuela. Between May 2008 and June 2009, we were able to gather 1143 surveys. Results: As the initial choice of treatment for a bipolar patient who debuts with mania, 61.3% choose a combination of an atypical antipsyc…

New discoveries in New World Atissini as revealed in revision of Pelignellus Sturtevant & Wheeler (Diptera: Ephydridae)

2019

Pelignellus is resurrected from synonymy with Atissa and is revised. The genus and both included species—P. subnudus Sturtevant & Wheeler from the USA (California) and P. freidbergi n. sp. from Central America (Costa Rica, El Salvador, Panama)—are described with an emphasis on structures of the male terminalia, which are fully illustrated. The species are keyed and their distribution data are provided. For perspective and to facilitate recognition of genera and species, the tribe Atissini is diagnosed and a key to genera is provided.

Reframing Central American Migration From Narrative Journalism

2018

Over the past decade, some journalists and media have addressed Central American migration to the United States from an investigative and narrative reporting perspective, providing a more reliable and accurate portrait of the main characters and their underlying reasons for making the move. This article examines how an ethnographic and analytical approach in combination with narrative techniques can improve the coverage of complex issues such as migration, providing more detailed and complete information than conventional media presents. The qualitative analysis focuses on five projects, including the crossmedia On the Road—with a long-form reportage, a book of photographs, and a documentar…

¿Habrá moros en la costa? La producción cultural centroamericana leída desde España / Would there be Moors on the Coast? Central American Cultural Pr…

2017

Resumen: La literatura centroamericana hizo su aparición en la península española cuando Rubén Darío viajo hacia Madrid en 1892. París y Madrid se convirtieron en las metrópolis culturales de Centroamérica a partir de esa fecha. Sin embargo, su pertenencia a la región no fue reconocida como tal. En España esta producción fue leída desde una perspectiva hispano-céntrica que le fue útil a la península para resolver sus propias contradicciones de legitimación en el seno de Europa. En consecuencia, los escritores centroamericanos que publican con éxito en la península no pueden ser centroamericanos y cosmopolitas a la vez. En España se transforman en “hispanoamericanos.” Lo anterior elide su ce…