8 research outputs found

    A study of the dry forest communities in the Dominican Republic

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    This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevés in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani (thorny dry forest on coastal dunes), Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest), Consoleo moniliformis-Camerarietum linearifoliae (dry forest on hard limestones), Lemaireocereo hystricis-Prosopidetum juliflorae (northern Dominican disturbed dry forest), Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils) and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi). This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.Este trabalho apresenta um estudo florístico e fitossociológico das comunidades de florestas secas da República Dominicana. Um total de 69 amostras foram obtidas pelo método relevé em biótopos florestais secos. As amostras foram posteriormente submetidas à análise de correspondência destendenciada para a determinação e estudo de possíveis agrupamentos. O estudo não abrange formações arbóreas desenvolvidas sobre serpentinitos, nem as chamadas florestas semideciduais, peculiares às áreas de maior pluviosidade. Foram identificados nove fitocenoses. Os resultados mais significativos levaram à descrição de seis novas associações fitossociológicas: Simaroubetum berteroani (floresta espinhosa seca em dunas costeiras), Phyllostylo rhamnoidis-Prosopidetum juliflorae (floresta seca perturbada do sul da República Dominicana), Consoleo moniliformis-Camerarietum linearifoliae (floresta seca sobre calcários compactos), Lemaireocereo hystricis-Prosopidetum juliflorae (floresta seca perturbada do norte da República Dominicana), Lycio americani-Prosopidetum juliflorae (floresta seca perturbada desenvolvida em solos salinos) Guettardo ellipticae-Guapiretum discoloris (floresta seca em colinas de topo achatado em Montecristi). O trabalho realizado representa um importante avanço nos estudos fitossociológicos e florísticos dos territórios do Caribe.This research paper was possible thanks to the sponsorship of the Agencia Española de Cooperación Internacional para el Desarrollo (AECID), under the auspices of the Ministerio de Asuntos Exteriores y de Cooperación de España, which funded the project (cod. A/3499/05)

    Compósitos en estado hidrogel con aplicación en la adsorción de metales pesados presentes en aguas residuales

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    Heavy metal pollution is a problem, that to date has not been mitigated. For this reason, it is necessary to constantly innovate among traditional techniques in order to be able to apply efficient processes in such a way that contaminants can be removed or even recovered to be reincorporated into productive processes. In this context, adsorption is such a versatile technique that its application with materials of different characteristics is viable. Among the materials that have been characterized as efficient adsorbents, are inorganic particles and polymers/biopolymers. These components by themselves have acceptable adsorbent capacities, but in recent years the generation of polymeric matrices in the hydrogel state reinforced with inorganic materials or mixtures of polymeric networks generating composites has been explored to improve or increase the adsorption capacity. Composite hydrogels combine effective adsorption, high specific surface area and easy applicability, so they represent a great alternative for the elimination of heavy metal ions present in aquatic ecosystems. For this reason, the review of the state of the art of materials with adsorbent properties is carried out, as well as the strategies to generate composites in a hydrogel state with properties adapted for the adsorption of heavy metal ions, also contemplating the challenges and areas of opportunity related to generation of this type of innovative materials.La contaminación por metales pesados es un problema, que hoy en día no se ha logrado disminuir. Por esta razón, es necesario innovar constantemente las técnicas tradicionales con el fin de aplicar procesos eficientes que ayuden a remover los contaminantes e incluso recuperarlos para ser reincorporados a procesos productivos. En este contexto, la adsorción es una técnica tan versátil, que es viable su aplicación con materiales de diferentes características. Entre los materiales que han resultado adsorbentes eficientes, se encuentran las partículas inorgánicas y los polímeros/biopolímeros. Estos componentes por si solos presentan capacidades adsorbentes aceptables, pero en los últimos años se ha explorado la generación de matrices poliméricas en estado hidrogel reforzadas con materiales inorgánicos o mezclas de redes poliméricas generando compósitos, para mejorar o incrementar la capacidad de adsorción. Los hidrogeles compósitos conjugan una adsorción eficaz, buena área superficial específica y de fácil aplicabilidad, por lo que representan una gran alternativa para la disminución de los iones de metales pesados presentes en los ecosistemas acuáticos. Por este motivo, es la presente revisión de los materiales con propiedades adsorbentes, las estrategias para generar compósitos en estado hidrogel y sus propiedades adaptadas para la adsorción de iones de metales pesados, así como los retos y las áreas de oportunidad implícitos en esta generación de materiales innovadores.

    Biodiversidad 2016. Estado y Tendencias de la Biodiversidad Continental de Colombia

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    Esta tercera entrega del reporte anual de la biodiversidad en Colombia profundiza en la línea editorial iniciada el año 2014 mediante nuevas propuestas analíticas y gráficas, con la intención de garantizar que la información llegue a todos los públicos y pueda ser discutida de manera amena sin sacrificio de calidad. La apuesta comunicativa sigue siendo central en el proyecto institucional y los nuevos lenguajes con los que estamos aprendiendo a conversar con la sociedad y las instituciones son un experimento que esperamos sea cada vez más satisfactorio: ya estamos construyendo la versión 2017 con el apoyo de las nuevas tecnologías digitales de manera que la potencia de la conexión vital colombiana se exprese en toda su capacidad. Por los contenidos es evidente que aún distamos mucho de tener una capacidad de seguimiento sistemático para la mayoría de temas relativos a la gestión de la biodiversidad y los servicios ecosistémicos, la única manera de evaluar si las medidas de política y las inversiones que realiza la sociedad están teniendo los efectos deseados. De hecho, parte de las limitaciones reconocidas por robustamente los cambios positivos o negativos que afectan los diferentes niveles de organización de la vida planetaria, por lo cual las mismas metas de Aichi, nuestra carta de navegación global, están pendientes de verificación. Un propósito adicional de este proceso es la invitación a todos los colombianos para contribuir con la construcción y alimentación de los indicadores básicos de seguimiento a la gestión, ya que es imposible identificar las tendencias de largo plazo en que están inmersas la flora y fauna colombianas sin el apoyo de las instituciones, los investigadores y los ciudadanos: en el país de la megadiversidad, el reto es inmenso. Por este motivo, este reporte irá abriendo sus páginas a expertos, incluso indígenas o de comunidades locales, para que presenten de manera sistemática y documentada sus perspectivas del cambio ambiental y sus efectos en la biodiversidad, con el ánimo de promover el compromiso de todos en su gestión. La única manera de superar el riesgo de extinción es mediante un activo proceso de aprendizajes sociales que haga que todos los sectores asuman una parte de la compleja responsabilidad que significa proteger todas las formas de vida del país, una décima parte mal contada de las planetarias. Agradezco a las decenas de personas que contribuyeron con este reporte, a quienes nos han apoyado en todas las etapas de producción y a sus lectores y usuarios, quienes son en último término los jueces de su utilidad.Bogotá, D. C

    Correction to : The evolution of the ventilatory ratio is a prognostic factor in mechanically ventilated COVID-19 ARDS patients (Critical Care, (2021), 25, 1, (331), 10.1186/s13054-021-03727-x)

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    Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

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    © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit

    Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

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    © 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research
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