PAHO/WHO proposes to implement the role of Advanced Practice Nurse (APN) in Latin America, to reduce gaps in coverage and access to health care. For this purpose, it is necessary to train nursing professionals with an expanded role, which allows them to collaborate in the diagnosis, treatment, and monitoring of people with specific diseases, under established protocols and clinical guidelines and within consolidated interdisciplinary health teams in a cost-effective way. One of the areas with the greatest coverage deficit in Latin America is adult oncology, with inequality in care opportunities for these patients. Part of the premature deaths attributable to this disease are due to the lack of access to timely diagnosis and treatment. As a contribution to the reduction of this gap, a training program of Advanced Nursing Practice was developed, addressing the most urgent needs in the field of oncology. The necessary competencies were defined to develop a professional-level master’s degree program, considering prevention, early detection, diagnosis, treatment, and monitoring of people with oncological diseases at different levels of care. A program of this kind is an opportunity to reduce the access gap and coverage of health care for people with cancer, improving their quality of life and their survival.

Objective: To determine the frequency of extended spectrum β-lactamases (ESBL) in clinical infections caused by Escherichia coli y Klebsiella pneumoniae and the frequency of CTX-M among them at the Instituto Nacional de Salud del Niño-Breña, Lima, Peru. Methods: ESBL producing strains of E. coli and K. pneumoniae collected from August 2012 and January 2013 were analyzed; a total of 724 E. coli and 181 K. pneumoniae consecutive, non- repeated isolates from community and hospital acquired infections were included. Identification was performed by conventional biochemistry, ESBL phenotype was detected following the Jarlier´s method and PCR was used to detect CTX-M. Results: overall prevalence of ESBL was 31% (281 strains); 207/724 (28.6%) E. coli and 74/181 (40.9%) K. pneumoniae. The bla gene was detected in 256 of ESBL producing strains (91.1%). Conclusions: The CTX-M phenotype of ESBL producing strains is present in our institution. Despite of showing information of a single institution, these data bring a glance of what the antimicrobial resistance pattern may be at a national level and underscores the utility of molecular biology in designing preventing measures.

Objetivo: Determinar la frecuencia de β-lactamasas de espectro extendido (BLEE) en Escherichia coli y Klebsiella pneumoniae y la frecuencia de CTX-M en las productoras de BLEE en el Instituto Nacional de Salud del Niño - Breña (INSN-B). Material y métodos: Se analizaron enterobacterias productoras de BLEE del INSN-B entre los meses de agosto de 2012 y enero del 2013. Se incluyeron 724 aislamientos de Escherichia coli y 181 aislamientos de Klebsiella pneumoniae, consecutivos no repetidos, de pacientes hospitalizados y de la comunidad. La identificación se realizó por bioquímica convencional. la detección fenotípica de BLEE se hizo por el método de Jarlier y la detección genotÃpica de CTX-M mediante reacción en cadena de la polimerasa (PCR). Resultados: 281 (31%) de los aislamientos de ambas enterobacterias fueron productoras de BLEE; 207/724 (28,6%) E. coli y 74/181 (40,9%) K. pneumoniae. Se detectó el gen bla en 256 de los aislamientos productores de BLEE (91,1%). Conclusiones: Las BLEE de tipo CTX-M están presentes en nuestra institución, a pesar que nuestros datos representan una sola institución, brinda parte del panorama nacional sobre la resistencia a los antimicrobianos; por lo tanto, el enfoque de epidemiológico molecular es importante para desarrollar más y mejores estrategias de control y manejo de estos patógenos en nuestro país.

Resumo A relevância do câncer de mama para as mulheres tem impulsionado pesquisas sobre a mortalidade desta doença. Todavia, estes estudos estão sujeitos aos problemas gerados pelos óbitos oriundos de causas mal definidas (CMD). A fim de evidenciar as possíveis distorções causadas pelas CMD em estudos que avaliam a mortalidade, foram calculadas taxas de mortalidade, padronizadas por faixa etária, com e sem correção para CMD, para os anos de 1990, 2000 e 2010. Feito isso, foram estimados modelos de regressão com dados em painel, que permitiram identificar que a correção para CMD: a taxa de mortalidade por câncer de mama dos municípios brasileiros elevou-se em cerca de 9% no período considerado; as taxas de mortalidade das regiões Sul, Sudeste, Nordeste e Norte se aproximaram; foi reduzida a tendência de crescimento da mortalidade em quase 60%, principalmente nas regiões Sudeste e Sul; aumentou, de forma mais acentuada, a mortalidade das cidades com menos de 5 mil habitantes; diminuiu a significância de grande parte dos fatores associados ao câncer de mama; revelou que o efeito da longevidade e dos gastos públicos em saúde estariam superestimados. Tais resultados ressaltam a importância da correção para CMD na geração de indicadores fidedignos de mortalidade.

Abstract The relevance of breast cancer for women has driven research about mortality of this disease. However, these studies are affected by problems generated by deaths due to ill-defined causes (IDC). To highlight distortions caused by IDC in studies that evaluate mortality, we calculated the age-standardized mortality rates of breast cancer, with and without adjustment for IDC for the years 1990, 2000, and 2010. Then, panel data regression models were estimated and enabled us to identify that the adjustment for IDC: has elevated breast cancer mortality rate of Brazilian municipalities by 9% in the period considered; has drawn mortality rates of the South, Southeast, Northeast and North regions closer; has reduced the increasing trend of mortality by almost 60%, mainly in the Southeast and South regions; has increased, more sharply, the mortality in cities with less than 5 thousand inhabitants; has curbed the significance of most factors associated with breast cancer; has revealed that the effect of longevity and the public health expenditure may be overestimated. These results highlight the importance of adjustment for IDC in producing reliable mortality indicators.

Resumo A relevância do câncer de mama para as mulheres tem impulsionado pesquisas sobre a mortalidade desta doença. Todavia, estes estudos estão sujeitos aos problemas gerados pelos óbitos oriundos de causas mal definidas (CMD). A fim de evidenciar as possíveis distorções causadas pelas CMD em estudos que avaliam a mortalidade, foram calculadas taxas de mortalidade, padronizadas por faixa etária, com e sem correção para CMD, para os anos de 1990, 2000 e 2010. Feito isso, foram estimados modelos de regressão com dados em painel, que permitiram identificar que a correção para CMD: a taxa de mortalidade por câncer de mama dos municípios brasileiros elevou-se em cerca de 9% no período considerado; as taxas de mortalidade das regiões Sul, Sudeste, Nordeste e Norte se aproximaram; foi reduzida a tendência de crescimento da mortalidade em quase 60%, principalmente nas regiões Sudeste e Sul; aumentou, de forma mais acentuada, a mortalidade das cidades com menos de 5 mil habitantes; diminuiu a significância de grande parte dos fatores associados ao câncer de mama; revelou que o efeito da longevidade e dos gastos públicos em saúde estariam superestimados. Tais resultados ressaltam a importância da correção para CMD na geração de indicadores fidedignos de mortalidade.

Abstract The relevance of breast cancer for women has driven research about mortality of this disease. However, these studies are affected by problems generated by deaths due to ill-defined causes (IDC). To highlight distortions caused by IDC in studies that evaluate mortality, we calculated the age-standardized mortality rates of breast cancer, with and without adjustment for IDC for the years 1990, 2000, and 2010. Then, panel data regression models were estimated and enabled us to identify that the adjustment for IDC: has elevated breast cancer mortality rate of Brazilian municipalities by 9% in the period considered; has drawn mortality rates of the South, Southeast, Northeast and North regions closer; has reduced the increasing trend of mortality by almost 60%, mainly in the Southeast and South regions; has increased, more sharply, the mortality in cities with less than 5 thousand inhabitants; has curbed the significance of most factors associated with breast cancer; has revealed that the effect of longevity and the public health expenditure may be overestimated. These results highlight the importance of adjustment for IDC in producing reliable mortality indicators.

ABSTRACT The Early Entrepreneurial Activity of business in Ecuador reflected a high growth in the economy during the last two decades. The objective of this workis to study the behavior of the innovative capacity of entrepreneurial businesses with respect to internationalization. This study has a non-experimental design of descriptive type under a quantitative paradigm. The data collected shows that the price behavior of the manufactured product in Ecuador is higher than the international one in the study context. In addition, the internationalization capacity is affected by the high costs of raw material that must be covered by entrepreneurial businesses.

RESUMEN La Actividad Emprendedora Temprana de los negocios en el Ecuador refleja un alto crecimiento en la economía durante las dos últimas décadas. El presente trabajo tiene como objetivo estudiar el comportamiento de la capacidad innovadora de los negocios emprendedores con respecto a la internacionalización.Este estudio tiene un diseño no experimental de tipo descriptivo bajo un paradigma cuantitativo. Los datos recolectados demuestran que el comportamiento de precios del producto manufacturado en Ecuador es mayor al internacional en el contexto de este estudio. Además, la capacidad de internacionalización se ve afectada por altos costos de materia prima que deben cubrir los negocios emprendedores.

From the Complex Thought perspective, this research aims to analyze the students' life experience during the early college years. Three fundamental principles proposed by Edgar Morin (dialogic, holographic and organizational recursion) were a theoretical framework. From the qualitative methodology, the in-depth interview technique was applied to students with different educational paths. The findings were organized around three categories: autonomy/dependency, study/work and continuity/discontinuity.

Esta investigación se propone analizar desde el punto de vista del pensamiento complejo, las experiencias vitales de estudiantes durante los primeros años en la universidad. Se han tomado como referencia teórica, algunas de las más destacadas ideas de Edgar Morin, específicamente los tres principios de la complejidad: dialógico, recursivo y hologramático. La metodología utilizada es cualitativa, se analizan entrevistas en profundidad a estudiantes con diferentes trayectorias académicas. Los principales resultados obtenidos se organizan alrededor de las categorías autonomía/dependencia, estudio/trabajo y continuidad/discontinuidad.

RESUMO Objetivo Analisar o comportamento da mortalidade por câncer de mama nos municípios brasileiros e avaliar a influência de fatores socioeconômicos e demográficos sobre as taxas e mortalidade. Métodos Foram calculadas taxas de mortalidade, padronizadas por faixa etária e corrigidas por causas mal definidas, centradas em 1990, 2000 e 2010. Posteriormente, foram estimados modelos de regressão, com dados em painel, que permitiram verificar o grau de associação entre os fatores de interesse e a taxa de mortalidade pela doença. Resultados Verificou-se uma tendência de crescimento da mortalidade no país. Contudo, os modelos indicaram que a mortalidade poderia ter diminuído (tendência negativa), principalmente no Sudeste e Sul, caso alguns fatores associados à doença (por exemplo, nível de renda, educação, longevidade, taxa de fecundidade, gastos em saúde, infraestrutura, entre outros) tivessem permanecido constantes durante o período considerado. Observou-se que a mortalidade por câncer de mama apresentou associação positiva/significativa com a longevidade e negativa/significativa com o nível de gastos públicos em saúde. A mortalidade foi maior nas regiões Sul e Sudeste, nos municípios com mais de 500 000 habitantes e naqueles onde a população é inferior a 5 000. Conclusões O crescimento da renda per capita, a elevação da expectativa de vida e a diminuição da taxa de fecundidade podem estar associados a elevadas taxas de mortalidade por câncer de mama e a uma tendência de crescimento na mortalidade por esse câncer nos municípios brasileiros.

ABSTRACT Objective To analyze breast cancer mortality trends in Brazilian municipalities and assess the influence of socioeconomic and demographic factors on mortality rates. Methods Age-adjusted mortality rates were calculated for the periods centered in 1990, 2000, and 2010 and corrected for ill-defined causes of death. After that, panel data regression models were developed for analysis of the association between the factors of interest and the mortality rate from breast cancer in Brazilian municipalities. Results A growing trend was detected in breast cancer mortality in Brazil. However, the models showed that the mortality could have decreased (negative trend), especially in the Southeast and South regions, if some associated factors (such as income, education, longevity, fertility rate, health spending, and infrastructure, among others) had remained constant during the study period. Breast cancer mortality was positively/significantly associated with longevity and negatively/significantly associated with public health spending. Mortality was higher in the South and Southeast, in municipalities with more than 500 000 inhabitants and in those with population below 5 000. Conclusions The growth in per capita income, the increase in life expectancy, and the decrease in fertility rates may be associated with high breast cancer mortality and a trend towards increased mortality from this cancer in Brazilian municipalities.

RESUMEN Objetivo Analizar las tendencias de la mortalidad por cáncer de mama en municipios brasileños y evaluar la influencia de factores socioeconómicos y demográficos sobre las tasas de mortalidad. Métodos Se calcularon las tasas de mortalidad, ajustadas por grupo etario y corregidas por causas mal definidas, para los años 1990, 2000 y 2010. Posteriormente, se calcularon modelos de regresión, a partir de datos de panel, que permitieron verificar el grado de asociación entre distintos factores de interés y la tasa de mortalidad por esta enfermedad. Resultados Se verificó que había una tendencia al aumento de la mortalidad en el país. Sin embargo, los modelos indicaron que la mortalidad podría haber disminuido (tendencia negativa), principalmente en el sudeste y el sur, si algunos factores asociados (por ejemplo, nivel de ingresos, educación, longevidad, tasa de fecundidad, gastos en salud, infraestructura, entre otros) hubieran permanecido constantes durante el período en estudio. Se observó que la mortalidad por cáncer de mama presentó una asociación positiva y significativa con la longevidad, y negativa y significativa con el nivel del gasto público en salud. La mortalidad fue mayor en las zonas sur y sudeste, en los municipios con más de 500 000 habitantes y en aquellos cuya población es inferior a 5000. Conclusiones El aumento de los ingresos per cápita, el incremento de la esperanza de vida y la disminución de la tasa de fecundidad pueden estar asociados a tasas altas de mortalidad por cáncer de mama y a una tendencia al aumento de dicha mortalidad en los municipios brasileños.

La antracnosis en ñame, causada por el hongo Colletotrichum gloeosporioides, es una enfermedad relevante que posee el potencial de destruir el 100% de la cosecha, convirtiéndose en la principal limitante fitosanitaria para el rendimiento del cultivo en el país. Esta es una situación preocupante considerando que aproximadamente 35.000 familias de pequeños y medianos agricultores de la Costa Atlántica Colombiana subsisten de este cultivo; es por esto que el objetivo de este trabajo fue caracterizar molecularmente 42 aislamientos del hongo procedentes de plantas de ñame con síntomas de la enfermedad, utilizando la técnica molecular "DNA Amplification Fingerprinting (DAF)", caracterizada por su resolución en la determinación de la variabilidad genética de diferentes organismos. Para la determinación de polimorfismos, se amplificaron 16 marcadores DAF implementando iniciadores tipo decámero, los cuales fueron visualizados por electroforesis en microchip con el equipo MCE-202 MultiNA. Se evaluó la reproducibilidad de la técnica DAF. La amplificación arrojó 391 bandas inequívocamente polimórficas en todas las muestras, el coeficiente de Dice identificó cinco grupos con 0.30% de similaridad y el índice de diversidad genética fue de 0.28; datos que reflejan un alto grado de variabilidad en la colección estudiada de C. gloeosporioides. Ésta puede deberse, al intercambio de germoplasma, a su condición heterotálica, a las mutaciones y al alto potencial de dispersión de las conidias que le permiten mantener la viabilidad bajo condiciones adversas. Por último, se encontró que DAF es una técnica reproducible, confirmando que es una metodología fiable para la caracterización molecular de hongos.

Yam anthracnose, caused by the fungus Colletotrichum gloeosporioides, is a significant disease that has the potential to destroy harvests in 100%, causing the decrease in crop yields nationally. Consequently, its situation affects approximately 35.000 families of small farmers the Atlantic Coast for whom it is the livelihoods. Due to above, the objective of this work was to perform the molecular characterize of 42 C. gloeosporioides isolates from yam plants with symptoms of the disease, using the molecular technique "DNA Amplification Fingerprinting (DAF)" useful for its resolution in determining the genetic variability of different organisms. For polymorphisms determination, were amplified 16 DAF markers by using primers decamers type, the banding patron was visualized by electrophoresis in microchip 202 MCE-MultiNA equipment also, we assessed of DAF technique reproducibility. The amplification process yielded 391 unequivocally polymorphic bands in all samples, Through Dice coefficient we identified five groups with 0.30% of similarity and a genetic diversity index of 0.28. Our data show a high degree of variability in the collection of C. gloeosporioides studied. The high variability could be due to several reasons like germplasm exchanges, the heterothallic condition of fungal isolates, a presence of mutations and the high potential for conidia dispersal that allow it to maintain its viability under adverse conditions. Finally, we found that DAF technique is reproducible, confirming that it is a reliable methodology for the fungi molecular characterization.

Introduction: during the first days of life the mother is the main source of nutrients for the newborn. However, breastfeeding difficulties are common and may generate excessive neonatal weight loss. Objective: estimate the magnitude and association between breastfeeding problems and excessive neonatal weight loss beyond the physiological norm in the neonatology ward in a social security hospital in Lima, Peru. Methods: we conducted a cross sectional analysis of the recorded neonatal weight in a routine evaluation (between 24 and 72 hours of life) and compared it against birth weight. Excessive weight loss was defined as a difference greater than or equal to 7 %. Breastfeeding problems (defined as problems with breastfeeding initiation, mouth position, breastfeeding duration, breastfeeding frequency, too much clothing, nipple pain and C form) were investigated using a survey and visual verification. The association between excessive weight loss and breastfeeding problems, adjusted by other factors, was quantified using a multiple generalized linear model. Results: excessive weight loss was present in 18.8% (74/393) of the newborns. Improper positioning of the mouth on the nipple was present in 53.7% (211/393) of neonates while nipple pain was reported by 44.0% (173/393) of mothers. In the adjusted analysis, nipple pain [PR = 1.50 (95% CI: 1.02 to 2.22)] and improper positioning of the mouth [PR = 1.67 (95% CI: 1.09- 2.57)] were associated with an increased occurrence of excessive neonatal weight loss. Conclusions: breastfeeding problems are common. These difficulties are significantly associated with an increased occurrence of excessive neonatal weight loss. Improvements in breastfeeding practices, for example through educational programs, may decrease the occurrence of excessive neonatal weight loss.

Introducción: durante los primeros días de vida la madre es la principal fuente de alimento para el recién nacido. Sin embargo, es común que la madre presente trastornos de la lactancia y se genere una pérdida de peso neonatal superior a la fisiológica. Objetivo: estimar la magnitud y asociación entre los trastornos de la lactancia y la pérdida de peso neonatal superior a la fisiológica en neonatos en el área de alojamiento conjunto de un servicio de neonatología en un hospital de la Seguridad Social en Lima, Perú. Métodos: estudio de tipo transversal analítico. Registramos el peso neonatal en una evaluación de rutina (entre las 24 y 72 horas de vida) y lo comparamos con el peso al nacer. La pérdida de peso excesiva fue definida como una diferencia igual o mayor al 7%. Mediante una encuesta y una verificación visual investigamos los trastornos de la lactancia materna (retraso en el inicio, posición de la boca, duración de la lactancia, frecuencia de la lactancia, sobreabrigo, dolor en el pezón y forma de la C). La asociación entre la pérdida de peso excesiva y los trastornos, ajustada por otros factores, fue cuantificada mediante un modelo lineal generalizado múltiple. Resultados: en 18,8% (74/393) de los neonatos, la pérdida de peso excesiva fue igual o superior al 7% del peso al nacer. La posición inadecuada de la boca en el pezón estuvo presente en el 53,7% (211/393) de los neonatos, mientras que el dolor en el pezón fue reportado en el 44,0% (173/393) de las madres. En el análisis ajustado, el dolor en el pezón [RP = 1,50 (IC95%:1,02-2,22)] y la posición inadecuada de la boca [RP = 1,67 (IC95%:1,09-2,57)] estuvieron asociados a una mayor pérdida de peso excesiva. Conclusiones: los trastornos de la lactancia son comunes. Estos factores están directa y positivamente asociados a una mayor pérdida de peso excesiva. La introducción de mejoras en las prácticas de lactancia, por ejemplo mediante programas educativos, podría disminuir la pérdida de peso neonatal excesiva.

Background: Gastrointestinal polyp refers to a localized tumor or growth that protrudes through the lumen of the gastrointestinal tract. The most common clinical presentation is recurrent rectal bleeding; as well it could be associated with abdominal pain, prolapsed polyp, pruritus, pain after defecation or constipation. Colonoscopy is the procedure of choice for diagnosis and treatment. Objective: Describe clinical manifestations colonoscopy and histological characteristics in pediatric population with colonic polyps, studied at the Department of Gastroenterology and Nutrition of our institution. Methods: A retrospective observational, descriptive, cross-sectional study was conducted. We reviewed the case records of all the patients that were submitted to endoscopic procedures between June 4, 2010 to December 31, 2013. Results: We reviewed 56 clinical records, 49 met the inclusion criteria. Male patients (59.2%); the main symptom was lower intestinal hemorrhage (83.7%); the most common site was rectal in 51%. Conclusions: In pre-school and school-age patients with non anemic lower intestine hemorrhage, the main diagnose is an intestinal polyp, which should be treated and followed as long as necessary.

Antecedentes: el pólipo gastrointestinal es un tumor o crecimiento localizado que protruye desde la pared hacia la luz intestinal. Su manifestación clínica más común es la rectorragia recurrente; también puede causar dolor abdominal, prolapso del pólipo por el recto, prurito, dolor después de la defecación, diarrea mucosa o constipación de vientre. La colonoscopia es el procedimiento de elección para diagnosticar y tratar los pólipos. Objetivo: describir las características clínicas, colonoscópicas e histológicas de los pacientes pediátricos con poliposis colónica, atendidos en el Servicio de Gastroenterología y Nutrición del Instituto Nacional de Pediatría, México. Materiales y métodos: estudio observacional, transversal, retrospectivo, descriptivo. Se revisaron todos los expedientes de los pacientes a quienes se realizó estudio endoscópico del 4 de junio del 2010 al 31 de diciembre del 2013. Resultados: se revisaron 56 expedientes; 49 cumplían los criterios de inclusión con predominio del sexo masculino (59.2%). El síntoma principal de estos pacientes fue el sangrado moderado del tubo digestivo bajo no anemizante en 41 casos (83.7%); la localización más frecuente fue rectal (51%). Conclusiones: en pacientes preescolares y escolares con hemorragia de tubo digestivo bajo "no anemizante", la primera posibilidad diagnóstica es un pólipo que debe ser diagnosticado, tratado y, en su caso, seguido por el tiempo necesario.

Resumen Tubérculos del género Dioscorea comercializados con fines medicinales, fueron recolectados con el propósito de lograr su establecimiento a condiciones in vitro. Previamente se lograron identificar taxonómicamente las especies y por medio de análisis fitoquímicos demostrar su potencial farmacéutico. El material recolectado fue identificado como Dioscorea coriacea, D. lehmannii, D. meridensis, D. polygonoides y una especie comestible D. trífida. Tubérculos recolectados de centros de acopio y traídos de campo fueron lavados, desinfectados, asperjados con Ácido Giberélico (AG3) y sembrados en sustrato BM-2®, en invernadero a 18°C día y 10°C noche. Los tubérculos completos o por secciones fueron almacenados en bolsas herméticas a temperatura ambiente. Posteriormente se desinfectó material vegetal de las especies D. coriacea, D. lehmannii, D. meridensis y D polygonoides, seleccionando explantes de brotes sanos (D. coriacea / laboratorio) para su establecimiento. Se evaluaron tres medios de cultivo para establecimiento, el que presentó los mejores resultados fue Medio Murashige & Skoog (1962) suplementado con BAP 1 mL/L, AG3 1 mL/L y Putrescina 2 mL/L. Para la extracción y análisis de metabolitos secundarios se utilizaron tubérculos de D. coriacea, D. lehmannii y D. polygonoides, empleando como solvente de extracción metanol. Se encontró mayor concentración de extracto vegetal en D. coriacea (54%), y mediante cromatografía en capa delgada (CCD), se confirmó la presencia de saponinas, que resultó mayor en comparación con D. polygonoides especie reconocida por su alto contenido de saponinas. Estos resultados permitirán realizar análisis más avanzados de los compuestos presentes y plantear su propagación masiva en condiciones in vitro.

Abstract Wild tubers of the genus Dioscorea sold for medicinal use were collected for the purpose of achieving its establishment under in vitro conditions. First we taxonomically identified the species and through phytochemical analysis demonstrated pharmaceutical potential. The material collected was identified as Dioscorea coriacea, D. lehmannii, D. meridensis, D. polygonoides and the edible species D. trifida. Tubers collected from wholesale distributors and from the field were washed, disinfected, sprayed with Gibberellic Acid (GA3) and planted in substrate BM-2®, in a greenhouse at 18 ° C during the day and 10 ° C overnight. Whole tubers or sections thereof were stored in sealed bags at room temperature. Subsequently plant material of the species D. coriacea, D. lehmannii, D. meridensis and D. polygonoides was disinfected and healthy buds (D. coriacea / laboratory) were selected for in vitro establishment. Three different culture media were evaluated for establishment; that which presented the best results was the Murashige & Skoog (1962) medium, supplemented with BAP 1 mL / L, GA3 1 mL / L and Putrescin 2 mL / L. For the collection and analysis of secondary metabolites, tubers of D. coriacea, D. lehmannii and D. polygonoides were used, using methanol as the extraction solvent. The highest concentration of plant extract, 54%, was found in D. coriacea, a higher value than that of D. polygonoides, which had been reported previously; the presence of saponins was confirmed by thin layer chromatography (TLC). These results will enable more advanced analysis of the present compounds and enhance their mass propagation under in vitro conditions.

Three types of Cretaceous/Paleogene (K/Pg) boundary deposits are widely distributed in western and central Cuba. Most deposits belong to type 1, with an original volume of circa 4000 km3 (Peñalver, Cacarajícara and Amaro formations), and contain in its lower part thick gravity flow deposits. Above the coarse clastics rests a monotonous, mainly massive calcarenite to calcilutite section (homogenite), settled from a hyperdense suspension. The Cacarajícara and Amaro formations accumulated in the southern border of the North American Mesozoic paleomargin, whereas the Peñalver Formation deposited in a southern basin, developed on the extinct Cuban Cretaceous volcanic arc. Type 1 deposits are similar to the "clastic carbonate unit" of Yucatán. Type 2 deposits (Deep Sea Drilling Project, DSDP, leg 77 sites 536, 540 and the "chaotic clastic complex" interbedded in the middle part of the Santa Clara Formation), are local, have thinner basal gravity flow accumulations, and, instead of homogenite, contain ejecta rich deposits. Type 3 deposits (Moncada Formation) are mainly built by reworked ejecta, accumulated during the pass of megatsunami waves, which also affected the upper levels of Type 1 and 2 deposits. We carefully searched for data on the sedimentology and geological setting of each deposit, in order to obtain a detailed picture of its paleogeographic framework. Our research shows that, in an area proximal to Chicxulub crater, the regional relief was a main factor controlling sediment features and distribution of the Mesozoic-Cenozoic boundary sections.

Tres tipos de capas del límite Cretácico-Paleógeno (K/Pg) están ampliamente distribuidas en Cuba occidental y central. El grueso pertenece a los depósitos del tipo 1 (originalmente unos 4000 km3; formaciones Peñalver, Cacarajícara y Amaro), que contienen en su porción inferior potentes depósitos de flujos gravitacionales. Encima descansa una sección mayormente masiva, calcarenítica a calcilutítica (homogenita), depositada a partir de suspensiones hiperdensas. Las formaciones Cacarajícara y Amaro se acumularon en el borde meridional del margen continental mesozoico norteamericano, mientras que la Formación Peñalver se depositó en una cuenca meridional, desarrollada sobre el extinto arco volcánico cretácico cubano. Los depósitos del tipo 1 son muy similares a la "unidad clástica carbonatada" de Yucatán. Los depósitos del tipo 2 (DSDP 536, 540 y el "complejo clástico caótico" intercalado en la Formación Santa Clara) son locales, con flujos gravitacionales basales menos potentes y, en lugar de la homogenita, sedimentos ricos en eyecta. Los depósitos del tipo 3 (Formación Moncada) están en gran parte constituidos de eyecta redepositada por olas de megatsunamis, las cuales afectaron también los niveles superiores de los tipos 1 y 2. Los autores revisamos cuidadosamente la información sedimentológica y el entorno geológico de cada depósito para lograr una imagen detallada de la paleogeografía regional. Nuestra investigación muestra que, en un área no lejana al cráter de Chicxulub, el relieve fue un factor fundamental en el control de los rasgos y distribución de los depósitos de la catástrofe en el tránsito Mesozoico/Cenozoico.

The present work is aimed to investigate the corrosion resistance of rare earth (RE) protective coatings deposited by spontaneous deposition on AA6061 aluminum alloy substrates. Coatings were deposited from water-based Ce(NO3)3 and La(NO3)3 solutions by varying parameters such as rare earth solution concentration, bath temperature and immersion time. The values of the Tafel slopes indicate that the cathodic process is favored by concentration polarization rather than activation polarization.

Este trabajo tiene como objetivo la investigación de la resistencia a la corrosión de recubrimientos de tierras raras mediante el proceso de inmersión, depositadas en aleaciones comerciales de aluminio AA6061. Para ello, se utilizaron diferentes soluciones de Ce(NO3)3 y La(NO3)3 evaluando parámetros tales como: la concentración de la solución, temperatura y tiempo de inmersión. Los valores de las pendientes de Tafel y su comportamiento indican que el proceso catódico está favorecido por una polarización por concentración más que la polarización por activación.