Crecimiento y rendimiento de Cupressus lusitanica Mill. en Antioqu?a, Colombia, utilizando parcelas permanentes

Tesis (M. Sc) -- CATIE; UCR, (Costa Rica), 1975Datos sobre distribuci?n diam?trica, rendimiento y crecimiento de bosques de C. lusitancia fueron obtenidos por estudios basados en cuatro mediciones de 42 parcelas permanentes, localizadas en el departamento de Antioquia, Colombia. La funci?n gamma se adapt? bien a la distribuci?n diam?trica obteni?ndose nueve ecuaciones con coeficientes de determinaci?n entre 0.96 y 0.98. Las ecuaciones fueron obtenidas por las combinaciones de 3 clases de edad: 5.1-10 a?os, 10.1-15 a?os y 15.1-20 a?os, y con 3 clases de ?ndice de sitio a saber IS 16. Las distribuciones diam?tricas encontradas, caracterizadas por el dominio de clases diam?tricas inferiores, demuestran que el sistema de manejo de estos bosques o es muy conservador o no existe

DIVERSIDAD Y COMPOSICIÓN FLORÍSTICA EN BOSQUES SUCESIONALES ANDINOS DE LA REGIÓN DEL RÍO PORCE, COLOMBIA DIVERSITY AND FLORISTIC COMPOSITION OF SUCCESSIONAL ANDEAN FORESTS OF THE PORCE REGION, COLOMBIA

La sucesión secundaria en las regiones tropicales tiende a variar de una localidad a otra debido, entre muchos factores, al tipo e intensidad de la perturbación, la distancia al bosque original, la fauna existente, la topografía y el clima local, los cuales determinan la composición florística y la velocidad con la que la sucesión avanza. En esta investigación se estudió la dinámica del proceso sucesional en suelos dedicados previamente a la ganadería en el cañón del río Porce (Antioquia), Colombia. Se muestrearon en total 25 parcelas, incluyendo 9 (20 x 50 m) en bosques primarios y 16 (20 x 25 m) en bosques secundarios; para éstos últimos la edad fue estimada en estudios previos usando datación por radiocarbono (C14), fotografías aéreas y una imagen de satélite de alta resolución. Se calculó la diversidad y la composición florística en los bosques secundarios, y los resultados se compararon con los obtenidos en bosques primarios cercanos. Se registraron 220 y 197 especies en los bosques primarios y secundarios, respectivamente. Las dos coberturas presentaron composición florística diferente sugiriendo alta diversidad beta. Análisis multivariados mostraron un gradiente sucesional definido y una alta correlación entre la composición florística y las variables ambientales. No obstante, en el área de estudio se presenta un proceso sucesional degradado como consecuencia del uso previo de la tierra. El índice de valor de importancia indica que en los bosques primarios la especie más importante fue Anacardium excelsum (Anacardiaceae) y en los secundarios Vismia baccifera (Hyperiaceae). Además, este índice y la presencia y ausencia de las especies en cada fase de desarrollo, sugieren la existencia de un gradiente sucesional que se ajusta tanto a la teoría clásica clementsiana de relevo florístico, como a la de composición florística original. El ajuste de ciertas especies a dos de las teorías sucesionales existentes, sugieren que el proceso sucesional es diferente y de complejidad variable según las características ecofisiológicas de las especies involucradas y las del ecosistema que se está regenerando.<br>Some studies indicate that tropical secondary succession is to be affected by factors such as disturbances, distance from original forests, surface configuration, and local climate, determining not only the composition of species but also the time trend of the succession itself. This study seeks to understand the dynamics of successional processes in soils devoted to cattle ranching over various decades in the Porce region of Colombia. A set of 25 permanent plots was measured, including 9 plots (20 x 50 m) in primary forests and 16 (20 x 25m) in secondary forests. The age of secondary forests was estimated in previous studies, using radiocarbondating, aerial photographs and a high-resolution satellite image. Both diversity and composition of species in secondary forests were calculated, and the results were compared against those obtained from natural forests located in the same study area. In total, 220 and 197 species were identified in primary and secondary forests, respectively. The floristic composition for both vegetation types was significantly different, indicating a high Beta diversity. Multivariate analyses suggest the existence of a well-defined successional gradient, and a high correlation between composition of species and some environmental variables as well. However, the study area is characterized by a successional process highly degraded, which seems to be the obvious consequence of the previous land use. The importance value index indicates that Anacardium excelsum (Anacardiaceae) and Vismia baccifera (Hypericaceae) tend to be the dominant species in primary and secondary forests, respectively. The importance value index and the presence or absence of species show that the ecological behavior of various species of the successional gradient may be explained by both the relay and original floristic composition. This finding might be the result of ecophysiological strategies of the species and environmental attributes of the ecosystems, which are experiencing slow but natural recovery

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

© 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

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

© 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