ABSTRACT Introduction: There is a lack of information about cardiac surgery training and professional practice in Latin American (LATAM) countries. This study is the first comparative analysis of cardiac surgical training and professional practice across LATAM and provides the fundamentals for future academic projects of the Latin American Association of Cardiac and Endovascular Surgery (LACES). Methods: International survey-based comparative analysis of the training and professional practice of cardiac surgeons across LATAM. Trainees (residents/fellows) and staf (graduated) surgeons from LATAM countries were included. Results: A total of 289 respondents (staf surgeons N=221 [76.5%]; residents/fellows N=68 [23.5%]) from 18 different countries participated in the survey. Most surgeons (N=92 [45.3%]) reported being unsatisfied with their salaries. Most respondents (N=181 [62.6%]) stated that it was difficult to obtain a leadership position, and 149 (73.8%) stated that it was difficult to find a job after completing training. Only half of the trainee respondents (N=32 [47.1%]) reported that their program had all resident spots occupied. Only 22.1% (N=15) of residents/fellows were satisfied with their training programs. The majority (N=205 [70.9%]) of respondents would choose cardiac surgery as their specialty again. Most surgeons (N=129 [63.9%]) and residents/fellows (N=52 [76.5%]) indicated that the establishment of a LATAM cardiac surgery board examination would be beneficial. Conclusion: Modernization and standardization of training, as well as greater access to opportunities, may be required in LATAM to increase professional satisfaction of cardiac surgeons and to reduce disparities in the specialty. Such changes may enhance the regional response to the dynamic challenges in the feld.

Resumen La expansión de la agricultura y el aumento de la demanda de carne han incrementado las actividades ganaderas intensivas. Los residuos generados son problema ambiental, pero también son una fuente de nutrientes. La pelletización podría ser una alternativa para el uso masivo de estos materiales. El objetivo de este trabajo fue evaluar la aplicación de biofertilizantes pelletizados y en mezcla con fertilizantes químicos, en cultivos extensivos. Se prepararon macetas con suelo de textura franca y bajo nivel de fertilidad, para sembrar trigo (Triticum aestivum L.) en invernadero. El diseño experimental (n=102) incluyó 16 tratamientos y un testigo sin fertilización. Los fertilizantes se aplicaron en dos momentos diferentes: pre-siembra y siembra. Se cosechó la producción vegetativa, se contabilizaron el numero de macollos por planta y se secó el material en estufa para determinar materia seca. No se encontraron diferencias signifcativas entre fechas de aplicación de fertilizantes. Se encontraron diferencias significativas (p<0.0001) entre los tratamientos para ambas variables estudiadas. Los rendimientos fueron similares entre los tratamientos minerales y los orgánicos-minerales, esto sugiere que podrían economizarse fertilizantes químicos y reciclar grandes cantidades de N y P presentes en los residuos orgánicos, además de incoporar materia orgánica al suelo.

Abstract The expansion of agriculture and increased demand for meat have increased intensive livestock farming activities. The waste generated is an environmental problem, but it is also a source of nutrients. Pelletization could be an alternative for the massive use of these materials. The objective of this work was to evaluate the application of pelletized biofertilizers and in mixture with chemical fertilizers in extensive crops. Pots were prepared with loam-textured soil and low fertility level, to plant wheat (Triticum aestivum L.) in greenhouses. The experimental design (n=102) included 16 treatments and a control without fertilization. Fertilizers were applied at two different times: pre-sowing and sowing. Vegetative production was harvested, the number of tillers per plant was counted and the material was dried in an oven to determine dry matter. No significant differences were found between fertilizer application dates. Significant differences (p<0.0001) were found between treatments for both variables studied. Yields were similar between mineral and organic-mineral treatments, suggesting that chemical fertilizers could be economized and large amounts of N and P present in the organic residues could be recycled, in addition to incorporating organic matter to the soil.

Resumen La intensificación ganadera en la zona Pampeana genera grandes cantidades de residuos orgánicos que deben gestionarse adecuadamente para evitar impactos negativos en el ambiente. El compostaje se considera una forma de reciclar los estiércoles animales para valorar su capacidad como fertilizantes. La densificación del material pelletizado puede ser una alternativa para la aplicación de compost mejorando el transporte, el almacenamiento y la dosificación. El objetivo de este trabajo, consistió en evaluar el uso de fertilizantes órgano-minerales en base a compost, pelletizados como fuente de N y P en el cultivo de cebada (Hordeum vulgare L.) y comparar su comportamiento respecto a fuentes de N y P inorgánicas. Se realizó un ensayo experimental a campo que incluyó 4 tratamientos y un testigo sin fertilización. Los fertilizantes P se aplicaron incorporados a la siembra y los fertilizantes N al macollaje en superficie. Se realizó el seguimiento de variables biofísicas no destructivas en estado vegetativo (Chl, LAI y fCOVER) y el rendimiento en grano (kg ha-1) a cosecha. No se encontraron diferencias significtiva de los tratamientos aplicados, lo que suguiere que podrían reemplazarse de forma parcial los fertilizantes minereales e incorporarse materia orgánico al suelo reciclando y valorizándose residuos ganaderos.

Abstract Livestock intensification in the Pampas area generates large quantities of organic wastes that must be properly managed to avoid negative impacts on the environment. Composting is considered to recycle animal manures to value their capacity as fertilizers. The densification of pelletized material can be an alternative for compost application, improving transportation, storage and dosage. The objective of this work was to evaluate the use of organo-mineral fertilizers based on pelletized compost as a source of N and P in barley (Hordeum vulgare L.) and compare their performance with inorganic sources of N and P. An experimental field trial was carried to evaluate the use of pelletized compost-based organo-mineral fertilizers as a source of N and P in barley (Hordeum vulgare L.). An experimental field trial was carried out including 4 treatments and a control without fertilization. P fertilizers were applied incorporated at sowing and N fertilizers at surface-applied. Non-destructive biophysical variables were monitored at the vegetative stage (Chl, LAI and fCOVER) and grain yield (kg ha-1) at harvest. No significant differences were found in the treatments applied, suggesting that mineral fertilizers could be partially replaced and organic matter could be incorporated into the soil by recycling and valorizing livestock residues.

Resumen Se han publicado ya las nuevas guías 2020 de recomendación clínica de la AHA/ACC para el tratamiento de pacientes con valvulopatía. Luego de un análisis profundo, con base en los más grandes estudios clínicos y en la situación en los países de Latinoamérica, la Latinoamerican Association of Cardiac & Endovascular Surgery (LACES) redactó una declaración en relación con algunas de las nuevas recomendaciones.

Abstract The new clinical guidelines of the AHA/ACC for the treatment of patients with Valvulopathy 2020 have been published. After an in-depth analysis, based on the largest clinical trials and taking into account the situation in our countries in Latin America, the Latinoamerican Association of Cardiac & Endovascular Surgery (LACES) drafting a statement on some of the new recommendations.

In the Andean - Patagonian region, nutrient supply for different crops is frequently made using wood chips mixed with manure. These materials are accumulated in piles of 1.5 - 2 m height. As the piles remain for a period of time outdoors, a partial composting may occur, which would be beneficial. Composting is a biooxidative process, involving an organic substrate, a thermophilic phase that must be reached (55°C) and a maturity stage. If the manure piles remain outdoors, nutrients can also be transported by water and lost from the soil through percolation (particulary during winter months of higher precipitations). With the objective of studying if extractable phosphorus in NaHCO3 0.5M (P-Ol of phosphorus Olsen) and inorganic nitrogen (Nin;ammonium plus nitrates) move beneath the piles of manure, composites soil samples were taken from three blocks at different depths in a farm near the town of El Bolsón. The relationship between P-Ol (agronomic threshold) and extractable P in 0.01 M CaCl2 (environmental threshold) was also studied. Manure temperatures were taken in different seasons. Nin showed a high data dispersion and excessively high mean values up to the 200 cm depth. Average values (of three blocks) found for P exceeded the threshold limit of 60 mg kg-1 P-Ol only on the first sampling date in the 0-20cm depth, although individual data for each block reached 52 mg kg-1 in the 40-60 cm depth. A statistically significant linear regression between P-Ol and P-CaCl2 in soils was obtained, and a threshold near 50/60 mg kg-1, similar to the values reported in the literature. High values for both parameters were found in manures. It is advisable to protect piles of manure from rainfall in winter months.

En la región Andino-patagónica frecuentemente la reposición de nutrientes para diferentes cultivos se lleva a cabo mediante el uso de estiércoles mezclados con viruta, comúnmente denominados abonos. Los mismos son acumulados en pilas de 1,5-2 m de altura. Al permanecer durante un período de tiempo al aire libre puede producirse un compostaje parcial, lo cual sería beneficioso. El compostaje es un proceso biooxidativo que involucra un sustrato orgánico, una etapa termofílica que debe alcanzar los 55 °C y una etapa de maduración. Si los abonos permanecen a la intemperie los nutrientes pueden ser transportados por el agua de percolación (particularmente en los meses de invierno de mayor precipitación), perdiéndose del suelo. Con el objetivo de determinar si ocurre un movimiento de fosforó extractable en NaHCO3 0,5M (P-Ol de fósforo Olsen) y nitrógeno inorgánico (Nin de nitrógeno inorgánico, amonio más nitratos) bajo pilas de abono, se tomaron muestras compuestas de suelos de tres bloques a distintas profundidades en un establecimiento cercano a la localidad del Bolsón. Se estudió también la relación entre P-Ol (índice agronómico) y fósforo extractable en 0,01M de CaCl2 (índice ambiental). Se tomaron las temperaturas de las pilas de abono en distintas estaciones del año. Para Nin se observó una alta dispersión en los datos y valores promedio excesivamente altos hasta 200 cm de profundidad. Los valores promedio (de tres bloques) encontrados para P exceden el umbral límite de 60 mg kg-1 P-Ol solo en la primera fecha de muestreo, aunque valores puntuales por bloque llegaron a 52 mg kg-1 a una profundidad de 40-60 cm. Se encontró una regresión lineal estadísticamente significativa entre P-Ol y P-CaCl2 en suelos y un umbral entre 50/60 mg kg-1 P-Ol similar al observado en la bibliografía. Se encontraron valores muy altos para ambas variables en los abonos. Es recomendable proteger las pilas de abono de las lluvias en los meses de invierno.