Producción de pitahaya en Costa Rica

Informe final de proyecto de investigación "Producción de pitahaya en Costa Rica"Universidad de Costa Rica/[736-B7-035]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM

Curvas de absorción de nutrientes bajo dos métodos de fertilización en sandia, en Guanacaste, Costa Rica

En la Finca Experimental de Santa Cruz, Guanacaste, en el año 2005, se evalúo el efecto de dos modalidades de fertilización en el cultivo de la sandía (Citrullus lanatus(Thunb) Matsum & Nakai cv. Mickeylee): fertilización líquida aplicada en el agua de riego y el abonamiento granular y foliar aplicado por el método convencional. Se prepararon dos lotes de 300 m2 y se realizaron muestreos al azar de plantas y se analizó el contenido de nutrimentos en su parte vegetativa, productiva y sistema radical en las etapas de 15, 21, 27,33, 40, 45, 51, 57 y 63 dds., para ambas modalidades de fertilización. En los primeros 33 días del ciclo del cultivo, la absorción de nutrimentos fue muy lenta, luego la planta incrementó fuertemente la producción de materia seca y acumulación de elementos nutritivos hasta el final de su ciclo (63 dds). Los picos de máxima absorción ocurrieron entre los 51 y 57 dds en ambos sistemas de abonamiento, coincidiendo con la etapa de mayor producción y desarrollo de frutos. La acumulación de nutrimentos en orden decreciente, para los dos sistemas de fertilización, fue similar y se denotan: K>N>Ca>Mg>P>Fe>S>Mn>Zn>Cu. La absorción total de nutrimentos en el sistema de fertirriego fue de un 30% y en el convencional de un 20%, desde la siembra hasta la etapa de prefloración (1-33 dds), el 70 % restante de absorción en el fertirriego y el 80 % en el convencional, se dio desde la etapa de floración hasta el llenado de frutos (40-57 dds). El sistema de fertilización (fertirriego) es el más recomendable, por ser más eficaz (mayor fraccionamiento de los fertilizantes), mejor utilizado por la planta, menor uso de mano de obra

Allometric correlation in Hylocereus costaricensis y H. monocanthus (pitahaya): A tool to quantify growth

Introducción. La pitahaya es una planta que pertenece a la familia de las cactáceas, esta crece naturalmente en árboles o tutores muertos en zonas estacionalmente secas y posee una arquitectura variable en su crecimiento por ser una planta epífita y hemiepífita, sus tallos verdes son estructuras que cumplen un papel de tallo-hoja. Actualmente en Costa Rica existe poca información sobre el crecimiento y la cuantificación de la morfometría de la pitahaya. Objetivo. El objetivo de este trabajo fue relacionar variables no destructivas con variables destructivas para construir una herramienta para el uso de proyecciones de crecimiento en pitahaya en Costa Rica. Materiales y métodos. El trabajo se efectuó entre los años 2016-2017. Se muestrearon al azar tallos provenientes de plantas sembradas en suelo y sustratos. Se evaluó: largo, grosor basal, medio y alto (A), área fotosintética (método indirecto) y biomasa (peso fresco, seco y porcentaje de humedad) para cada tallo. Se construyó una base de datos y se calcularon regresiones lineales, asimismo, se comparó con la prueba de Kruskal Wallis (α=0,05) la variabilidad entre sitios (suelo arcilloso, franco y viveros) de siembra. Resultados. Las regresiones lineales mostraron que el largo por el ancho presentó una correlación significativa (r2=0,85) con la variable peso seco y una correlación altamente significativa (r2=0,97) con la variable área fotosintética. Se determinaron dos criterios matemáticos para generar ecuaciones de mejor ajuste con el fin de lograr una mayor precisión en las proyecciones de las variables. El peso mostró diferencias significativas (α=0,01) según los sitios de crecimiento del tallo. Conclusión. Las regresiones lineales mostraron alta precisión (r2>0,85) en algunas variables de crecimiento en los tallos de pitahaya, lo cual podría ser una herramienta eficaz para generar cuantificaciones de crecimiento en el cultivo a partir de un parámetro alométrico.Introduction. Dragon fruit plant (Pitahaya) is a cactacea family plant, it grows naturally in dead trees or stakes in seasonally dry areas, and it has an out-of-order architecture in the growth for being and epiphyte and hemiepiphyte plant, its green steams are structures that play the role of steam-leaf. Currently, in Costa Rica, there is little information on the growth and quantification of dragon fruit morphometry. Objective. The objective of this work was to relate non-destructive variables with destructive variables to develop a useful tool for the use growth projections in dragon fruit in Costa Rica. Materials and methods. The study was carried from 2016 to 2017. Stems from plants sown in soil and substrates were randomly sampled. The following were evaluated: longitude, basal, medium and apical thickness (A), leaf area (indirect method) and biomass (fresh weight, dry weight and moisture percentaje) for each stem. A database was built and it’s linear regressions were calculated, and the site variability (clay soil, loam soil and nurseries) was compared with Kruskal Wallis (α=0.05) test. Results. Linear regressions showed highly significant correlation (r2= 0.97) with the significative correlation (r2=0.85) with dry weight and that the longitude by width presented a foliar area. Two mathematical criteria were determined, to generate better fit equation for more accurate projections of variables. The weight showed significative differences (α=0.01) according to stem growth sites. Conclusion. Linear regression showed high precision (r2= 0.85) in some growth variables in dragon fruit steams, wich could be an effective tool to generate crop growth quantification.Universidad de Costa Rica/[520-B7-004]/UCR/Costa RicaUniversidad de Costa Rica/[520-B6-022]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigaciones Agronómicas (CIA)UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de AgronomíaUCR::Sedes Regionales::Sede de Guanacaste::Recinto de Santa Cruz::Finca Experimental de Santa Cruz (FESC

Size and shape of experimental unit for Brachiaria hybrid CIAT 36087 grass yield trials

Objetivo: Determinar el tamaño y la forma de unidad experimental para ensayos de rendimiento de Brachiaria híbrido CIAT 3608, mediante el método de regresión múltiple, en el cantón de Santa Cruz, Guanacaste, Costa Rica. Materiales y Métodos: Para esto, se sembró un ensayo de uniformidad y los datos obtenidos fueron empleados para aplicar el método regresión múltiple. En este método, la variabilidad residual, medida como coeficiente de variación, correspondiente a los diferentes tamaños y formas de unidad experimental que se simularon se modeló en función del largo y ancho mediante una regresión múltiple. Se ajustaron dos modelos de regresión múltiple, uno que incluyó el término de interacción entre las regresoras y otro que no. Resultados: El modelo sin el término de interacción fue el que mejor ajustó, tuvo mayor R2 y todos los coeficientes estimados fueron significativos (p < 0,05). Después, se calcularon las derivadas parciales con respecto al largo y al ancho de la ecuación de regresión estimada por el modelo sin interacción y se igualaron a -1. Se resolvió el sistema de ecuaciones resultante y se obtuvo la combinación de ancho y largo de unidad experimental que minimiza el coeficiente de variación. Para este trabajo esa combinación resultó ser de 4,95 m de largo y el ancho es de 6,03 m. Conclusiones: En el marco de las condiciones en que se realizó este trabajo, es suficiente para obtener resultados precisos con la especie Brachiaria híbrido CIAT 3608, una unidad experimental de 5 X 6 m de largo y ancho, respectivamente. Esto es, una unidad experimental de 30 m2.Universidad de Costa Rica/[520-B8-009]/UCR/Costa RicaUCR::Sedes Regionales::Sede de Guanacast

Nitrogen and potassium fertilization in corn in an Alfisol of Guanacaste, Costa Rica

Introducción. En Guanacaste, Costa Rica, el maíz (Zea mays) es un cultivo de consumo cultural desde épocas precolombinas, muchos agricultores destinan zonas para su siembra en asocio con otros cultivos. Sin embargo, las variedades utilizadas requieren estudios de fertilización y nutrición para mejorar la calidad de las mazorcas y vida postcosecha. Objetivo. Evaluar en la variedad de maíz J-Sáenz, el efecto de dosis crecientes de nitrógeno y potasio, en combinación con tres densidades de siembra. Materiales y métodos. El estudio se realizó en la Finca Experimental de Santa Cruz, Universidad de Costa Rica, en 2018. Se evaluaron tres dosis de N (100, 200, 300 kg ha-1 con una base de 160 kg ha-1 de K2O) y K2O (100, 160 y 200 kg ha-1 con una base de 300 kg N ha-1) con tres densidades de siembra (50 000, 57 143 y 66 667 plantas ha-1) con la variedad J-Sáenz. Se evaluó el rendimiento del cultivo, el porcentaje de mazorca expuesta y la acumulación de nutrimentos en estado fenológico R5. Los datos se sometieron a análisis de varianza con estructura factorial y modelos lineales generalizados con pruebas de separación de medias DGC. Resultados. Hubo incremento significativo en la producción de grano al aumentar la densidad de siembra de 50 000 a 66 667 plantas ha-1. La mayor eficiencia en el uso de N y K se logró con la aplicación de 100 kg de cada elemento a la densidad de 57 000 plantas ha-1. La variable mazorca expuesta no se relacionó con las dosis de nutrimentos. El maíz aumentó la absorción con el incremento de las dosis de N pero no de K. Conclusión. La densidad de siembra de 57 143 plantas ha-1 mostró el mejor rendimiento a dosis de 100 kg de N ha-1 y 100 kg de K2O ha-1.Introduction. In Guanacaste, Costa Rica, corn (Zea mays) has been a cultural crop for consumption since pre-Colombian times. Many farmers have set aside areas for its planting in association with other crops. However, the varieties used require fertilization and plant nutrition studies to improve ear quality and postharvest life. Objective. To evaluate the effect of increasing doses of nitrogen and potassium in the J-Saenz maize variety, in combination with three sowing densities. Materials and methods. The study was conducted at the Santa Cruz Experimental Farm, Universidad de Costa Rica, in 2018. Three doses of N (100, 200, 300 kg ha-1 with a base of 160 kg ha-1 of K2O) and K2O (100, 160 and 200 kg ha-1 with a base of 300 kg N ha-1) were evaluated with three sowing densities (50 000, 57 143, and 66 667 plants ha-1) with the J-Sáenz variety. The crop yield, the percentage of exposed ear, and the accumulation of nutrients in the phenological R5 stage were evaluated. The data were subjected to analysis of variance with a factorial structure and generalized linear models with DGS tests of means separation. Results. There was a significant increase in grain production by increasing the sowing density from 50 000 to 66 667 plants ha-1. The highest efficiency in the N and K use was achieved with the application of 100 kg ha-1 of each element at a density of 57 000 plants ha-1. The exposed ear variable was not related to nutrient doses. Corn increased absorption with increasing doses of N but not K. Conclusion. The planting density of 57 143 plants ha-1 showed the best yield at doses of 100 kg of N ha-1 and 100 kg of K2O ha-1.Universidad de Costa Rica/[733-B7-290]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigaciones Agronómicas (CIA)UCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de AgronomíaUCR::Sedes Regionales::Sede de Guanacaste::Recinto de Santa Cruz::Finca Experimental de Santa Cruz (FESC

Global Survey of Outcomes of Neurocritical Care Patients: Analysis of the PRINCE Study Part 2

BACKGROUND: Neurocritical care is devoted to the care of critically ill patients with acute neurological or neurosurgical emergencies. There is limited information regarding epidemiological data, disease characteristics, variability of clinical care, and in-hospital mortality of neurocritically ill patients worldwide. We addressed these issues in the Point PRevalence In Neurocritical CarE (PRINCE) study, a prospective, cross-sectional, observational study. METHODS: We recruited patients from various intensive care units (ICUs) admitted on a pre-specified date, and the investigators recorded specific clinical care activities they performed on the subjects during their first 7 days of admission or discharge (whichever came first) from their ICUs and at hospital discharge. In this manuscript, we analyzed the final data set of the study that included patient admission characteristics, disease type and severity, ICU resources, ICU and hospital length of stay, and in-hospital mortality. We present descriptive statistics to summarize data from the case report form. We tested differences between geographically grouped data using parametric and nonparametric testing as appropriate. We used a multivariable logistic regression model to evaluate factors associated with in-hospital mortality. RESULTS: We analyzed data from 1545 patients admitted to 147 participating sites from 31 countries of which most were from North America (69%, N = 1063). Globally, there was variability in patient characteristics, admission diagnosis, ICU treatment team and resource allocation, and in-hospital mortality. Seventy-three percent of the participating centers were academic, and the most common admitting diagnosis was subarachnoid hemorrhage (13%). The majority of patients were male (59%), a half of whom had at least two comorbidities, and median Glasgow Coma Scale (GCS) of 13. Factors associated with in-hospital mortality included age (OR 1.03; 95% CI, 1.02 to 1.04); lower GCS (OR 1.20; 95% CI, 1.14 to 1.16 for every point reduction in GCS); pupillary reactivity (OR 1.8; 95% CI, 1.09 to 3.23 for bilateral unreactive pupils); admission source (emergency room versus direct admission [OR 2.2; 95% CI, 1.3 to 3.75]; admission from a general ward versus direct admission [OR 5.85; 95% CI, 2.75 to 12.45; and admission from another ICU versus direct admission [OR 3.34; 95% CI, 1.27 to 8.8]); and the absence of a dedicated neurocritical care unit (NCCU) (OR 1.7; 95% CI, 1.04 to 2.47). CONCLUSION: PRINCE is the first study to evaluate care patterns of neurocritical patients worldwide. The data suggest that there is a wide variability in clinical care resources and patient characteristics. Neurological severity of illness and the absence of a dedicated NCCU are independent predictors of in-patient mortality.status: publishe

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

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