24 research outputs found
Condensation and partial pressure change as a major cause of airflow: experimental evidence
The dominant model of atmospheric circulation is based on the notion that hot air rises, creating horizontal winds. A second major driver has been proposed in the biotic pump theory (BPT), by which intense condensation is the prime cause of surface winds from ocean to land. Critics of the BPT argue that air movement resulting from condensation is isotropic. This paper explores the physics of water condensation under mild atmospheric conditions, within a purpose-designed square-section 4.8m-tall closed-system structure. The data show a highly significant correlation (R2 >0.96, p value <0.001) between observed airflows and partial pressure changes from condensation. The assumption that condensation of water vapour is always isotropic is therefore incorrect
Further experimental evidence that condensation is a major cause of airflow
This paper further explores the physics of water condensation, using an experimental structure designed for that purpose. The data show a highly significant correlation (R2 >0.94, p value <0.001) between observed airflows and partial pressure changes from condensation, when the results of different experiments are pooled. Changes in air density on cooling provide insufficient energy to account for the airflow. The finding is that the kinetic energy of the chilled air falls short by an order of magnitude, even to move a relatively small proportion of the 20 kg of air contained within the structure. Meanwhile the physics of condensation indicate a surplus of kinetic energy is made available from the air surrounding the locus of condensation. At low rates of condensation a considerable proportion of the available kinetic energy in the enclosed air is absorbed in friction and turbulence. That proportion reduces with higher rates of condensation
Birds of Universidad de los Llanos (Villavicencio, Colombia): a rich community at the andean foothills-savanna transition
Objetivos: Desarrollar el inventario de las aves del campus Barcelona de la Universidad de los Llanos, Villavicencio, Colombia, con el objeto de estimar la riqueza de especies, abundancia y asociaciones de hábitat de la avifauna local. Alcance: Caracterización de la diversidad aviar local y su asociación con diferentes tipos de ecosistemas naturales y transformados. Metodología: Inventariamos la avifauna tomando registros visuales y auditivos semanales entre agosto de 2013 y agosto de 2014, además de observaciones no sistemáticas entre 2013 y 2018. Estimamos la riqueza de especies usando estimadores no paramétricos, y categorizamos las abundancias locales y asociaciones de hábitat con base en la frecuencia de encuentros. Principales resultados: Registramos un total de 189 especies a través de observaciones sistemáticas, además de 21 registradas de manera no sistemática para un total de 210 especies. El listado incluye una especie casi amenazada para Colombia, 20 especies migratorias y cuatro ampliaciones de distribución para la cuenca del Orinoco colombiano. La heterogeneidad de la vegetación mantiene una rica comunidad compuesta principalmente por especies asociadas a zonas urbanas, bosque de galería y lagos artificiales. Muchas especies fueron raras y ocasionales, lo cual sugiere que son visitantes o mantienen pequeñas poblaciones dentro del campus. Conclusiones: Este estudioprovee datos básicos sobre la diversidad de aves en ecosistemas transformados en la cuenca del Orinoco, y resalta la importancia de los mosaicos de sabana, bosque y ecosistemas transformados como refugio y áreas de parada de aves residentes y migratorias.Objectives: To conduct a bird inventory at the Barcelona campus of Universidad de los Llanos Villavicencio, Colombia, with the aim of estimating species richness, abundance and habitat associations of the local avifauna. Scope: Characterization of the local avian diversity and its association with different types of natural and transformed ecosystems. Methodology: We inventoried birds using sight and auditory records made weekly between August 2013 and August 2014, plus opportunistic observations made between 2013 and 2018. We estimated species richness using non-parametric estimates, and categorized local abundances and habitat associations based upon encounter frequencies. Main results: We recorded a total of 210 species (189 species through systematic observations, plus 21 recorded non-systematically). The list includes one Colombian near-endemic, 20 migrant species, and four range extensions for the Orinoco basin. The heterogeneous vegetation sustains a rich community composed mainly by species associated with urban zones, gallery forest and artificial lakes. Most species were rare and occasional, which suggests that they are visitors or maintain small populations within the campus. Conclusions: This study provides basic data on bird diversity of transformed ecosystems in the Orinoco basin, and highlights the importance of mosaics of savanna, forest and transformed ecosystems as refuges and stopover areas of resident and migratory birds
Mitochondrial DNA analysis on pre-Columbian bone remains of the Herrera peri
Introducción. Los restos óseos arcaicos son fuente privilegiada de información biológica y su caracterización genética permite confirmar o descartar filiaciones propuestas por otras aproximaciones científicas. La historia precolombina de los Andes orientales se divide en tres periodos principales: i) un poblamiento temprano por parte de grupos cazadores-recolectores; ¡i) un periodo intermedio (Herrera) de pueblos con agricultura incipiente, y iii) un periodo tardío de pueblos chibchas, agrícolas y alfareros (agroalfarero).
Objetivo. Analizar el ADN mitocondrial de restos óseos del periodo Herrera.
Materiales y métodos. Se analizaron 11 individuos pertenecientes al yacimiento arqueológico Madrid 2-41, con una edad aproximada de 2.000 años. Un fragmento (192 pb) del segmento hipervariable I fue amplificado y secuenciado, siguiendo criterios estrictos de autenticidad de ADN arcaico. Las secuencias se compararon con las existentes en bases de datos de Norteamérica y Europa usando herramientas bioinformáticas.
Resultados. Todas las secuencias resultaron idénticas y fueron clasificadas como haplogrupo B. Esto puede relacionarse con el tipo de entierro ritual practicado en Madrid 2-41, es decir, probablemente los individuos analizados hagan parte de una familia jerárquicamente importante en la antigua sociedad Herrera. La búsqueda de secuencias homologas en las bases de datos estadounidense y europea no arrojó coincidencias exactas, aunque existe el reporte de un individuo amazónico de -4.000 años de antigüedad (Brasil) cuya secuencia coincide con la hallada en Madrid 2-41.
Conclusión. Los individuos del yacimiento arqueológico Madrid 2-41 están estrechamente emparentados entre sí por línea materna y presentan una secuencia aparentemente ausente en poblaciones actuales.Q4Q3Artículo original569-577Introduction. Ancient bone remains constitute an important source of biological information, and their genetic characterization allows the confirmation or rebuttal of human affiliations proposed on the basis of non-molecular approaches. Pre-Columbian history of the Eastern Andes in Colombia has been divided into three main periods: (i) an early colonization by groups of hunter-gatherers, (ii) an intermediate period “Herrera” characterized by primitive agriculture and (iii) a late stage of Chibcha-speaking groups, with agriculture and ceramics (“agroalfarero”).
Objective. The mitochondrial DN A on ancient bone remains of the Herrera period were analyzed for comparison with modern and other ancient DNAs.
Materials and methods. Mitochondrial DNA was extracted from 11 Herrera individuals [-2,000 years before present (YBP)] found in the Madrid 2-41 archaeological site near Bogotá, Colombia. A 192 bp segment of the hypervariable segment I was amplified and sequenced, following stringent archaic DNA authenticity criteria. The sequences were compared with those in American and European databases using bioinformatics tools.
Results. All individuals had identical sequences and were classified as haplogroup B. This identity may be related to the type of ritual burial performed in the site, probably exclusively for members of a hierarchically important family of the ancient Herrera society. The search for homologous sequences in the American and European mtDNA data bases produced no identical coincidences, although a Brazilian Amazonio individual (-4,000 YBP) was recorded with a matching sequence.
Conclusion. Individuals buried in the Madrid 2-41 site were maternally closely related and showed a mtDNA sequence that is apparently absent in contemporary populations
Mitochondrial DNA analysis on pre-Columbian bone remains of the Herrera peri
Introducción. Los restos óseos arcaicos son fuente privilegiada de información biológica y su caracterización genética permite confirmar o descartar filiaciones propuestas por otras aproximaciones científicas. La historia precolombina de los Andes orientales se divide en tres periodos principales: i) un poblamiento temprano por parte de grupos cazadores-recolectores; ¡i) un periodo intermedio (Herrera) de pueblos con agricultura incipiente, y iii) un periodo tardío de pueblos chibchas, agrícolas y alfareros (agroalfarero).
Objetivo. Analizar el ADN mitocondrial de restos óseos del periodo Herrera.
Materiales y métodos. Se analizaron 11 individuos pertenecientes al yacimiento arqueológico Madrid 2-41, con una edad aproximada de 2.000 años. Un fragmento (192 pb) del segmento hipervariable I fue amplificado y secuenciado, siguiendo criterios estrictos de autenticidad de ADN arcaico. Las secuencias se compararon con las existentes en bases de datos de Norteamérica y Europa usando herramientas bioinformáticas.
Resultados. Todas las secuencias resultaron idénticas y fueron clasificadas como haplogrupo B. Esto puede relacionarse con el tipo de entierro ritual practicado en Madrid 2-41, es decir, probablemente los individuos analizados hagan parte de una familia jerárquicamente importante en la antigua sociedad Herrera. La búsqueda de secuencias homologas en las bases de datos estadounidense y europea no arrojó coincidencias exactas, aunque existe el reporte de un individuo amazónico de -4.000 años de antigüedad (Brasil) cuya secuencia coincide con la hallada en Madrid 2-41.
Conclusión. Los individuos del yacimiento arqueológico Madrid 2-41 están estrechamente emparentados entre sí por línea materna y presentan una secuencia aparentemente ausente en poblaciones actuales.Q4Q3Artículo original569-577Introduction. Ancient bone remains constitute an important source of biological information, and their genetic characterization allows the confirmation or rebuttal of human affiliations proposed on the basis of non-molecular approaches. Pre-Columbian history of the Eastern Andes in Colombia has been divided into three main periods: (i) an early colonization by groups of hunter-gatherers, (ii) an intermediate period “Herrera” characterized by primitive agriculture and (iii) a late stage of Chibcha-speaking groups, with agriculture and ceramics (“agroalfarero”).
Objective. The mitochondrial DN A on ancient bone remains of the Herrera period were analyzed for comparison with modern and other ancient DNAs.
Materials and methods. Mitochondrial DNA was extracted from 11 Herrera individuals [-2,000 years before present (YBP)] found in the Madrid 2-41 archaeological site near Bogotá, Colombia. A 192 bp segment of the hypervariable segment I was amplified and sequenced, following stringent archaic DNA authenticity criteria. The sequences were compared with those in American and European databases using bioinformatics tools.
Results. All individuals had identical sequences and were classified as haplogroup B. This identity may be related to the type of ritual burial performed in the site, probably exclusively for members of a hierarchically important family of the ancient Herrera society. The search for homologous sequences in the American and European mtDNA data bases produced no identical coincidences, although a Brazilian Amazonio individual (-4,000 YBP) was recorded with a matching sequence.
Conclusion. Individuals buried in the Madrid 2-41 site were maternally closely related and showed a mtDNA sequence that is apparently absent in contemporary populations
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
The original version of this article unfortunately contained a mistake
A rational strategy to support approved COVID-19 vaccines prioritization
The World Health Organization (WHO) proposed a set of criteria to be considered for the prioritization of COVID-19 candidate vaccines for further development of phase II/III clinical trials, thinking in a target audience that includes vaccine scientists, product developers, manufacturers, regulators, and funding agencies. In this paper, a knowledge-based or rational strategy is employed to perform a prioritization matrix of approved COVID-19 vaccines: BBIBP-CorV, JANSSEN, CORONAVAC, SPUTNIK V, MODERNA, PFIZER, and VAXZEVRIA, based on those proposed criteria by WHO, related to safety, efficacy, stability, implementation, and availability. We found that JANSSEN vaccine is the one with the highest score in the present study, but our analysis suggests that the WHO criteria could be more useful if they are considered separately, taking into account the social, demographic and economic characteristics of each country