El evento “Younger Dryas” en el norte de suramérica

En el norte de Suramérica y el Caribe existen indicios de la presencia de un evento frío y seco, análogo al “Younger Dryas” (YD) del Atlántico Norte. Las evidencias más contundentes se encuentran en los registros geoquímicos y micropaleontológicos marinos de la Cuenca del Cariaco (Venezuela) y del Abanico del Amazonas, junto con registros palinológicos de alta resolución de los Andes del Norte. Durante este periodo, las tierras altas de los Andes del norte y las cordilleras de Centro América experimentaron descensos de temperatura y pluviosidad y las áreas costeras del norte de Suramérica registraron eventos de surgencia más intensos. Las condiciones climáticas y oceanográficas se encuentran aparentemente relacionadas con un desplazamiento hacia el sur de la Zona de Convergencia Intertropical (ITCZ) y un fortalecimiento de los vientos Alisios del noreste.In northern South America and the Caribbean there are evidences for the presence of a cold and dry event analogous to the Younger Dryas (YD) from the North Atlantic. The most compelling evidences are found in the geochemical and palynological marine records of the Cariaco Basin (Venezuela) and the Amazon fan, and the high-resolution palynological records from the northern Andes. During the YD, the highlands of the Andes and the Central America cordilleras experienced drops in temperature and moisture, at the same time that coastal upwelling in northern South America was more intense. Climate and oceanographic conditions for the YD were apparently related to the southern displacement of the Intertropical Converge Zone (ITCZ) and the strengthening of the northeast Trade Winds

El evento “Younger Dryas” en el norte de suramérica

En el norte de Suramérica y el Caribe existen indicios de la presencia de un evento frío y seco, análogo al “Younger Dryas” (YD) del Atlántico Norte. Las evidencias más contundentes se encuentran en los registros geoquímicos y micropaleontológicos marinos de la Cuenca del Cariaco (Venezuela) y del Abanico del Amazonas, junto con registros palinológicos de alta resolución de los Andes del Norte. Durante este periodo, las tierras altas de los Andes del norte y las cordilleras de Centro América experimentaron descensos de temperatura y pluviosidad y las áreas costeras del norte de Suramérica registraron eventos de surgencia más intensos. Las condiciones climáticas y oceanográficas se encuentran aparentemente relacionadas con un desplazamiento hacia el sur de la Zona de Convergencia Intertropical (ITCZ) y un fortalecimiento de los vientos Alisios del noreste.In northern South America and the Caribbean there are evidences for the presence of a cold and dry event analogous to the Younger Dryas (YD) from the North Atlantic. The most compelling evidences are found in the geochemical and palynological marine records of the Cariaco Basin (Venezuela) and the Amazon fan, and the high-resolution palynological records from the northern Andes. During the YD, the highlands of the Andes and the Central America cordilleras experienced drops in temperature and moisture, at the same time that coastal upwelling in northern South America was more intense. Climate and oceanographic conditions for the YD were apparently related to the southern displacement of the Intertropical Converge Zone (ITCZ) and the strengthening of the northeast Trade Winds

Consenso colombiano de atención, diagnóstico y manejo de la infección por SARS-COV-2/COVID-19 en establecimientos de atención de la salud Recomendaciones basadas en consenso de expertos e informadas en la evidencia

The “Asociación Colombiana de Infectología” (ACIN) and the “Instituto de Evaluación de Nuevas Tecnologías de la Salud” (IETS) created a task force to develop recommendations for Covid 19 health care diagnosis, management and treatment informed, and based, on evidence. Theses reccomendations are addressed to the health personnel on the Colombian context of health services. © 2020 Asociacion Colombiana de Infectologia. All rights reserved

One sixth of Amazonian tree diversity is dependent on river floodplains

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.Naturali

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

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

Simulating scenarios for compost and vinasse use to improve the economics and environmental aspects of representative Colombian sugarcane production systems

The Colombian industrial sector is moving toward alternative forms of treatment of industrial waste, considering that the waste can be a source of raw material in the production chain. Thus, aiming at the decrease in mineral fertilizer use, and maintaining or even raising the crop yield, the sugarcane industry has recently advanced in the composting of the industrial waste and application in the field, both of them being potentially sustainable practices. This manuscript reports the economic benefits and the greenhouse gas (GHG) emissions related to the sugarcane production system in Colombia that has been simulated in this study to evaluate the beneficial effects of reusing industrial waste from ethanol production. This study was performed using the Virtual Sugarcane Biorefinery (VSB) modeling software for the simulation of agricultural and industrial parameters on integrated alternatives for the sugarcane industry. Colombian sugarcane sector was modeled using three scenarios representing agricultural systems that do not use composted industrial waste vs a paired scenario for each condition where composted waste is utilized. Regarding compost and vinasse use as fertilizer and soil conditioner, GHG emissions from the biogenic origin are not included as a reported item in the matrix of GHG emissions of the sugarcane sector. Inputs for the economic and environmental assessment models are based on actual operational data from two mill sites, one located in the traditional sugarcane production region of Cauca River Valley and the other one, on the agricultural expansion region of Llanos Orientales. Here, we have found that the reuse of composted industrial waste is beneficial and provides an economic cost savings of 2–6% per year. However, it also results in an annual increase of 10–20% in the GHG emissionsCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2012/00282-